Final Report - Team 16-4

Final Design
Report
A Sensing Stroller
Prepared for:
1. Our client: Ms. Nancy Cowles,
Kids In Danger,
Chicago, Illinois
2. DTC Professors:
Kathleen Carmichael and Allison Bedell
Date of final presentation:
12/03/2016
Submitted by:
Jaelon Woodard
Jacob Hechter
Annick Nshuti
Bharat Rao
Section 16, Team number 04
Engineering Design and Communication Program
McCormick School of Engineering and Applied
Science Northwestern University

i
Table Of Contents
Executive Summary 1
Introduction 2
Users and Major Project Requirements 4
Our Approach 5
Formative Research Findings 6
Design Concept and Rationale 8
Limitations and Directions for future development 12
Conclusion 14
Appendices
Appendix A: Project Definition Version 3 15
Appendix B: Background Research 17
Appendix C: Client Interview Guide Summary 20
Appendix D: User Observation Summary 1 24
Appendix E: User Observation Summary 2 26
Appendix F: Mockup Documentation 28
Appendix G: User Testing Summary 1 31
Appendix H: User Testing Summary 2 34
Appendix I: Design Review Summary 37
Appendix J: Project Freeze Documentation 39
Appendix K: Prototype Construction 45
Appendix L: Individual Research | Bharat Rao 49
Appendix M: Individual Research | Jaelon Woodard 57
Appendix N: Individual Research | Annick Nshuti 61
Appendix O: Individual Research | Jacob Hechter 66

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List of Figures
Figure 1: Our Approach 5
Figure 2: The Design Concept 7
Figure 3: Child Checking Circuit 8
Figure 4: Restrain Checking Circuit 9
Figure 5: Tipping Warning Circuit 10
Figure 6: Drawing of Shifting Hand Positions 25
Figure 7: Front View of Mockup Frame 28
Figure 8: Side View of Mockup Frame 28
Figure 9: Top view of the Mockup 28
Figure 10: View of proposed dash board handle 28
Figure 11: View of Steering Reigns 29
Figure 12: View of Back Axle and Wheels 29
Figure 13: View of Back Wheel 29
Figure 14: Front axle and wheels 29
Figure 15: Front and Inside View of Seat 30
Figure 16: Side and outside view of Seat 30
Figure 17: Orthographic View of Overall Structure 41
Figure 18: Isometric Drawing of the overall structure 42
Figure 19: Vibrating Stroller Handle 43
Figure 20: Seat Belt Sensor 43
Figure 21: Toy Steering Wheel 44
Figure 22: Back Wheel 46
Figure 23: Aluminum Rod Attachment 46
Figure 24: Fully Assembled Frame Extension 47
Figure 25: Assembled Toy Steering Wheel 47
Figure 26: Electronics 48

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**Figure 27: Geographical segmentation of market share by percent revenue for
baby stroller market
51
Figure 28: Basic lightweight umbrella stroller 53
Figure 29: Bugaboo Cameleon 3 Stroller 53
Figure 30 58

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List of Tables
Table 1: Requirements and Specifications 15
Table 2: Major User Observations 1 25
Table 3: Major User Observations 2 27
Table 4: User Testing Results 1 32
Table 5: Design Review Feedback 37
Table 6: Changes Based On Design Review 38
Table 7: Bill of Materials 40
Table 8: Materials for Prototype Construction 45
Table 9: Safety, Ease of Use, Maneuverability Benchmarks of Top Ranked Strollers 52

1
Executive Summary
Stroller injuries are well documented, yet they still happen despite the increasing safety
measures taken by manufacturers. Children who fall out of strollers are more susceptible to head
trauma and bodily bruising than they would be as an adult. Nancy Cowles, our client, came to
our DTC team in hopes of finding a solution for this problem. Our team consists of Annick
Nshuti, Jacob Hechter, Bharat Rao and Jaelon Woodard and we are team 16-4.
Within the restraint of ten weeks, our team’s design focuses on further decreasing the
possibility for injury by implementing electronic warnings, a distracting toy for the child, and a
modified skeletal structure for the stroller to prevent tipping.
Electronic Feedback
Our design utilizes an electronic circuit to provide another layer of feedback for the
parent when they’re using the stroller. Our stroller causes the handles to vibrate when the seatbelt
is not engaged for the child. Additionally, the stroller will emit a warning sound when it is about
to tip over. This will not only call the parent into action, but should the stroller be out of
eyesight, it will alert a bystander to the danger that’s about to happen to the child and allow them
to react before the child is harmed.
Skeletal Structure Alteration
The Sensing Stroller has a widened wheelbase compared to traditional strollers to address
the issue of tipping. The modified wheelbase provides greater stability to the stroller by
distributing the weight it’s holding over a larger area, making it less likely for the stroller to tip
over.
Removable Toy Wheel
There’s a removable toy wheel in front of the child. The wheel provides something to
distract the baby, as a bored child is much more likely to accidentally harm themselves than an
unoccupied one. Without distraction, the baby is more likely to try to climb out of the stroller
when they see something that attracts their attention, thus tipping the stroller over and potentially
injuring themselves.
Recount
With these key elements, the stroller fulfills the goal of being safer than a commercial
alternative. Our stroller is not the “perfect” design, however, due to our constraints such as
money, time, and manufacturing capability. Therefore, our stroller is just one possible solution to
this safety issue. We recommend future teams to test and research what structure of a stroller
would be the safest to prevent tipping, as well as how best to rectify human error that causes
accidents. At some point, the design itself can’t be better, but the way it’s used will make the
difference.

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Introduction
From 1990 to 2010, almost 370,000 children five years or younger were diagnosed or
treated for some stroller and/or carrier related injury (Fowler, Kobe, Roberts, Collins, &
McKenzie, 2016). 370,000 computes to about 17,000 stroller or carrier related injuries per year.
Despite of the high maintenance and production standards that are in place by the American
Society for Testing and Materials (ASTM) and United States Consumer Product Safety
Commission (US CPSC), stroller and carrier related injuries have prevailed, evidenced by the
statistics above. Today, strollers and carriers are commonly used products in the United States
due to their functionality and efficiency transporting infants from one location to the other. Over
the 20 years that stroller and carrier related injuries were studied, from 1990 to 2010, there was a
decline proving that the standards are getting stricter and the strollers are being manufactured
with the goal of safety as the number one priority. However, there is still a need to address this
issue to come closer to eradicating the injuries present due to strollers and carriers.
Hence, Team 16-4 undertook the problem working with Nancy Cowles of Kids in Danger
(KID) to design and develop a safer stroller. Ms. Cowles did not have a specific path that she
wanted us to take to build a safer stroller; however, she encouraged considerations of different
paths and left it up to the team to make the decision regarding the specific age group to target
and the type/specifications of the stroller. Over nine weeks in the Fall Quarter of 2016, from
September to December, at Northwestern University, Team 16-4 went through the design
process to build a stroller to address the safety issue.
Actions have been taken to target the problem. Various manufactured strollers and
carriers have integrated safety features. The changes made in the products have been mostly
structural, however. The modifications to build safer strollers have all met the standards in place
by the ASTM and US CPSC, but unfortunately most products offer multipurpose features that
address safety and some other concern instead of focusing solely on safety. For example,
Bugaboo designed and produced a stroller with bigger wheels, wider and sturdier base, and
overall heavier chassis. The design features Bugaboo chose to integrate highlight an attempt to
create a stroller that is less responsive to jittery movements that could injure the baby. There is
another motive to Bugaboo’s choice to design a sturdier and bulkier chassis, however. The
company, while manufacturing a safer chassis, also went through efforts to make a more
aesthetically pleasing stroller. What are now being called “urban assault” strollers, Bugaboo’s
bulkier and more rigid product diverges from a typical standard stroller design to appeal to a new
brand of consumers. Though Bugaboo aimed at producing a safer stroller, they had ulterior
motives for their design choices providing one instance of firms manufacturing strollers that
offer multipurpose features not solely focused on safety. Moreover, carelessness on the part of
the guardian as well as an adverse environment are reasons for “stroller-related” injuries. Stroller
manufacturers have not attempted at designing a stroller that is not only structurally safer, but
also targets and mitigates the risk of negligence on the part of the guardian. This is such an
important factor in stroller safety, but no company has seemed to notice it. If they have, they
have not done anything about it thus far. Alternative solutions were needed to solve this problem.
As stated above, in our research we found that parent negligence was a direct cause of
stroller related injuries. We used this research finding to inspire the key modifications and

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features for our redesigned stroller. From this finding, we began the process to come up with
possible solutions to solving this negligence problem. Ultimately, of all solutions considered, we
found that incorporating sensors would be the safest and most viable. Along with the addition of
sensors to our design, we wanted to direct our focus to the structure of the stroller as well. We
designed different mockups to represent the changes to our stroller and underwent user testing;
user testing provided us with benefits and drawbacks that we had not considered for the
modifications we were trying to make. We synthesized all the information we received from user
testing, and we combined some features we thought we could integrate into our prototype by
addressing the constraints, what each feature offered in terms of solving the safety issue, and the
effectiveness of each feature. What emerged was a stroller that consisted of a modified wheel
base for stability, sensors to alarm and warn guardians, and a toy steering wheel to keep the
infant distracted preventing jostling.
We feel our design addresses the major areas of concern regarding injury in the case
study done from 1990 to 2010 because it addresses the problem of parent negligence, and
focuses only on the issue of safety. The following report documents the progress our team made
in developing the stroller, from the early stages of brainstorming to mock-up testing to design
concepts and prototype building. Additionally, highlighted in this report are the niche users we
observed and plan to target with our product. Finally, this report concludes with the exact needs
that this product meets but also with specific limitations that the stroller has including
propositions for future design.

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Users and Major Requirements - JW
Users
Our users consist of guardians, children, stroller manufacturers, standards regulators, and
KID. KID’s (Kids in Danger) mission is to promote the development of safer products, advocate
for children and educate the public, especially parents and caregivers, about dangerous children’s
products. KID
Reaches out to parents, caregivers, service providers and others through workshops on dangerous
children’s products, media coverage, speaking engagements, social media and web presence and
printed materials; Serves as a watchdog on regulatory agencies and manufacturers to assure safe
children’s products and advocates for stronger protections for our most vulnerable consumers;
Encourages designers and engineers to build safety into each product and promotes the
development of the safest products possible for our children.
Because KID is an advocacy group, they don’t have the means to engineer a stroller
themselves as a manufacturing company would. Thus, they can only ask and urge companies to
think about the safety of children who will be using their products. In order for our design to be
considered successful, our requirements are that the stroller must have latching mechanisms that
resist unintentional forces of up to 45 pounds, have no hazardous points or edges, paint and
surface coatings, small parts, wood smooth and free of splinters, a parking brake, able to hold a
static weight of 100 pounds, not tip over on a 12 degree incline with 40 pounds, and no slippage
of restraining straps greater than 1 inch. There are currently voluntary regulations and a proposed
bill that would add new regulations to the voluntary standards (ASTM F833).

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Our Approach
Figure 1: Our Approach

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Formative researchfindings
Observations from the user observations that were conducted at the different user sites, the
findings from our research, and our client’s desires are the main things that influenced the way
we structured our initial mockups. In fact, our alternative matrices were thought of as a result
of three main problems we identified in current strollers.
In addition, expert interviews and mock review helped us gain some more insightful
knowledge about the kind of design we wanted to integrated, and this led to the team making
new decisions or alternating the approach to solve a particular safety problem in a current
stroller.
1.Most accidents happen when parents are away from the strollers
This triggered us to think of introducing a vocal and vision systems that could signal both
a parent that is away or a parent who is using a stroller that chances for an accident happen are
too high. (an example of an accident is when is about to tip on either axis, or in front).
Our design is made to solve the problems of parents who are away, in that even if a
parent is too away to save the kid, any other person who is near would hear the sounding alarm
and be able to save the child. Also, even if the part of saving the accident from happening is
completely impossible, at least the baby is immediately followed up right after the accident,
hence less chances of perilous accident aftermath.
Since our user and expert interviews thought our design would, to some extent, be solving the
safety standards, our team decided to integrate an alerting system for a standard stroller.
2. Tipping over problems in strollers
How can we reduce the chances for a stroller to tip over? Most stroller tipping is a result
of unequal weight distribution in a stroller and the relative position of center of gravity of the
stroller system. As a method to approach this, we thought of lowering the center of mass and
integrating a larger wheel base for the stroller by using bigger wheels in the back and enlarging
the base of the stole.
Overall, this will improve on the stability of a current stroller and it will be addressed by
integrating a larger wheel base for equal distribution of the weight
3.Lack of easy maneuverability in strollers
Since clearly most parents would not agree that most strollers have easy maneuverability
systems, our group’s starting question was “how can we ensure easy maneuverability in a
stroller?” In other words, what design can help the use of a stroller that requires the least
amount of attention ie, improve on the maneuverability. One way to solve that was integrating
a 360- degree freedom front wheel, and putting a rotatable bar.

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DesignConceptand Rationale
Overview
The “Sensing Stroller” design that this team has decided contains three major aspects:
Electronic Feedback, a removable toy steering wheel for the child to interact with, and
modifications to the wheelbase to make it more stable. The feedback serves to warn the parents
of two major dangers facing their child, if the seatbelt has become undone and if the stroller is
tipping. The removable toy steering wheel is an in place to distract a child to distract it from its
surroundings and discourage reaching behavior that may cause the child to fall from the stroller.
The wheelbase modifications are to increase its length and width, to provide a longer lever and
make it more difficult to tip over.
The following sections describe design of each of the above aspects, and the reasoning
for their addition
Figure 2: The Design Concept
Electronic Feedback System
The electronic feedback assembly consists of 6 major parts (See Appendix J):
 An Arduino or similar small computational device, mounted on the back of the stroller
 A Reed Sensor with a magnet, mounted on both portions of the stroller restraint clip
 One or more vibrating motors, mounted on the handle of the stroller
 A limit switch mounted on the stroller seat
 A speaker, mounted next to the Arduino
 An at least 2 axis gyroscope and accelerometer. In this case, it is already integrated into
the Arduino

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There are three main functions of the assembly:
 To check if there is a child in the stroller
 To warn the user if the stroller harness isn’t engaged
 To warn the user if it is tipping
The assembly to check if a child is in the stroller consists of the Arduino and the limit
switch. The limit switch is placed inside the seat, so that the weight of the child presses down on
it and completes a circuit to give signal. The purpose of this assembly is to conserve resources,
as we don’t want to be consuming battery power or processing power when the child is in the
seat. Both other functions are conditional upon the child being in the seat.
Figure 3: Child Checking Circuit
Stroller Harness Assembly
The assembly to warn the user if the stroller harness isn’t engaged consists of a reed
sensor, a vibrating motor, and the Arduino. A reed sensor is basically a magnetic sensor, and
when a magnet is brought near, it completes the circuit. In this case, the reed sensor would be
attached to one side of the harness buckle, and the magnet is attached to the other. If the harness
is engaged, the circuit is complete, and the Arduino receives a signal. However, if the harness is
not engaged, the circuit is not complete, and the Arduino gets no signal. If the Arduino doesn’t
get the signal, then the Arduino sends power to the vibrating motor in the handle, and the parents
receives a relatively quiet but very noticeable signal the harness is not in use.
Falls from strollers make up 66.8% of stroller injuries (Appendix B). A significant
portion of that can be attributed to the seat belt not being fastened by the parent or being defeated
by the child in the stroller (Appendix O). The rationale behind this assembly is that by letting
users know that the harness is not in use will remind them to engage the restraints, thusly
reducing the rates of restrain non-use, as well as to notice when their child has defeated the
restraints.

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Figure 4: Restrain Checking Circuit
Tipping Alarm
The assembly to warn the user if the stroller is tipping. It consists of a gyroscope, a
speaker, and the Arduino. Using the gyroscope, the Arduino keeps track of its orientation
compared to its starting position, storing it as the initial pitch, yaw, and roll values. Should the
difference between the original yaw or roll values and the current yaw or roll values become too
high, it will be the indication that the stroller is in the process of tipping. When this occurs, the
Arduino will send a signal to the speaker, which will generate a loud alarm, to grab the attention
of the user and other nearby people.
The rationale for this assembly is that any sort of attention grabbing warning for a stroller
tipping would give a user a better chance to respond to intervene and stop the stroller from
tipping. Stroller tipping accounts for 15.5% percent of total stroller injuries, and this assembly
gives the opportunity to intervene and stop some of these incidents. Even if the parents are
usable to prevent tipping, they still are more aware of the situation, and able to respond to any
injury in a timelier manner than without the alarm.

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Figure 5: Tipping Warning Circuit
Toy Removable Steering Wheel
The removable steering wheel is a free spinning steering wheel within arm’s reach of the
child occupying the stroller. It is attached to a bent rod, which is attached further down the
stroller seat. This rod can be easily detached from the stroller by the parent to prevent
obstruction due to the steering wheel (figure 12 and 13). The steering wheel itself is a “Baby
And Toddler Car Driver With Driving Tunes - Take Along Toy” (Table 7).
The rational for this design is how children behave when they are in the stroller.
Oftentimes, when they see something particularly interesting, they attempt to interact with it by
reaching out and attempting to grasp it. This can cause causing them to fall out when they
unbalance themselves. This is especially common when the stroller is stopped, so the purpose of
the steering wheel is to provide entertainment while in the stroller and reduce dangerous
behaviors (Appendix O).
Widened Wheel Base
For the purposes of widening the wheel base, the back wheels of the stroller will be
moved backwards 12 inches and, the distance between the wheels will be increased an additional
3 inches, 1.5 on each side. This, along with the removal of any existing back axel in the base
will provide a widened back wheel base and an area where it remains comfortable to move and
the user won’t accidentally kick the stroller.
The reason for this modification is to increase the stability of the stroller and prevent
tipping. As stated earlier, stroller tipping accounts for 15.5% percent of total stroller injuries,
and that number can be decreased if the strollers wheel base is widened, increasing the amount of
torque and force required to cause the stroller to tip. The reasoning for the specific numbers
above is that in our prototype, those length and width increases move the wheels to just under the

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outside edges of the stroller handle. This is the limit of the wheel base size where it still remains
comfortable to push and steer.
Rationale Summary
The major purpose of all three modifications is to prevent or mitigate two major sources
of injury, falls from stroller because the seat belt was not fastened and the stroller tipping over.
Falls from strollers make up 66.8% of stroller injuries (Appendix B). A significant portion of
that can be attributed to the seat belt not being fastened by the parent or being defeated by the
child in the stroller. Another reason for these falls is reaching behavior that children engage in
when attempting to interacting with their environment, causing them to fall out when they
unbalance themselves. This is especially common when the stroller is stopped, so the purpose of
the steering wheel is to provide entertainment while in the stroller and reduce dangerous
behaviors (Appendix O). Strollers tipping also makes up 15.5% of the remaining total injuries,
so widening the stroller base to increase stability and adding a warning for stroller tipping exist
to reduce incidence and severity of these incidences.

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Directions for Future Development
Introduction
Team 16-4, under the specific constraints of time interval and location, designed a stroller
that targeted the problem of stroller related injuries with a concentration on guardian negligence
and carelessness. Additionally, we decided to devise a solution for distracting the baby so that
they would not jostle around too much in the stroller causing tipping. Some of the designs we
chose to implement could be taken further granted more time, so below are the propositions for
future development to build upon the current designs that are in place in our stroller.
Structure:
● The expansion and extension of the wheel base provided great stability to the
stroller and did its job in preventing tipping. However, we found that the hinges
connecting the large back wheels to the main chassis of the stroller were quite
loose. The weight of the back wheels put immense tension on the hinges, which is
what caused them to loosen over time. Under our time constraints, we were forced
to settle with a large, stabilizing, and loose wheel base in place behind the chassis.
An idea for development for future teams could possibly be to devise a way to
maintain the stability of the stroller given the large extended wheel base while
also keeping the hinges tightly in place.
● We think the toy steering wheel was a great addition to the stroller as it indirectly
prevented stroller injury while keeping the baby occupied and happy. Given more
time though, we would have liked to rubberize the aluminum parts that connect
the steering wheel to the chassis of the stroller. The aluminum sticks out like a
sore thumb in terms of the unity of the design giving the stroller a very cold look.
Because the rest of the stroller’s chassis is coated with black foam, we would
have liked to coat the aluminum apparatus of the toy steering wheel with black
foam as well. A proposition for future teams would be to incorporate a more
aesthetically pleasing apparatus for the toy steering wheel – one that hides the
aluminum and maintains design unity.
● When the time came to decide the features we wanted to implement into the
stroller, we chose sensors, a widened wheel base, and a toy steering wheel. These
three features were all chosen over modified steering, specifically using a handle
or wheel. We wished we could have incorporated one handed steering into our
design. Though it may incline guardians to multitask while pushing the stroller,
we thought it would enhance the maneuverability of the stroller. After all, pushing
a stroller that is meant to be pushed with one hand is safer and more efficient than
pushing a stroller that is not meant to be pushed with one hand. Unfortunately, we
decided to leave this feature out given the complexity of the concept and the time
constraints we were under; however, undertaking and implementing this concept
would be extremely beneficial in the long run for designing a stroller that satisfies
multiple use cases.
Seat:
● Early in the design process, our team had the intention of modifying the seat to
increase the comfortability for the infant. We did not end up going this route, but

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we think it is imperative that the seat be considered to increase comfort and
safety. We chose to retrofit a stroller that had a seat with a small area for the
infant’s buttocks. Due to our time constraints, though, we decided to only focus
on the sensors, toy steering wheel, and expanded wheel base using a previously
designed stroller. If given more time, we would have liked to consider the right-
sized seat as well as material to make the baby more comfortable, discouraging
them from moving around too much, which in turn would prevent safety hazards.
Future design teams could consider a modified seat as an extended solution to
solving the safety issue. Moreover, consideration of building a completely new
chassis from scratch would be a solution to expanding the area of the seat for the
infant’s buttocks.
● Memory foam seating is one design feature we were thinking about
implementing. Because of its design and properties, we decided not to go this
route and scrap building a new seat all together. Research into materials like that
of memory foam but with different energy properties could further the
development of a safer and more comfortable seat.

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Conclusion - JW
As a team, we feel as if we’ve accomplished our goals of minimizing tipping risk, and helping to
minimize accidental user error. The sensing stroller is sturdy due to the wheelbase modification,
it helps keep the child from getting themselves into danger with the steering wheel, and provides
extra layers of warning for impending danger with the electronic sensors. With the limitations of
time and money, there are a few areas we’d like to improve upon if the circumstances were
different. The stroller is safe, but it’s maneuverability is limited and makes the stroller feel bulky.
We’d also like more time to tinker with the electronic capabilities of the stroller, as it’s an area
that could provide the stroller with even more safety capabilities. These are the two main areas
we would suggest future teams to focus on with more resources and manufacturing capabilities.

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Appendix A: Project Definition Version 3
Project Name: Safer Stroller Project
Client: Nancy Cowles/Kids in Danger (KID)
Team Members: Annick Nshuti, Jaelon Woodard, Jacob Hechter, Bharat Rao
Date: 11/14/2016
MissionStatement: To design stroller add-ons which reduce the commonality of children
falling from strollers, and reduce the commonality of strollers tipping while children are in the
strollers.
Project Deliverables: A conceptual model of the above stroller modifications prototype stroller
containing these modifications. The conceptual model may take the form of sketches or other
visual media to demonstrate the function.
Constraints:
● Time limit within the quarter - approximately 11-12 weeks total
● 100-dollar budget - materials/mock-ups
● Not enough time to find or meet experts
Users/Stakeholders:
● Parents, relatives, or other guardians who will be using the stroller
● Experts and Users around campus
● Children who will be transported in the stroller
● Kids In Danger, who will advocate for the adoption of greater stroller safety.
● Stroller companies, who would be theoretically manufacturing and selling the strollers
Table 1: Requirements and Specifications
Requirements Specifications
Reduce Likelihood of Tipping ● Larger overall wheel base
● Lower center of
● Incorporate an electronic Auditory feedback in
potential tipping situations
Reduce likelihood of Falling from
stroller ● Entertainment Device to prevent dangerous child
behaviors like reaching outside of the stroller
● Incorporate electronic feedback to warn of seat
belt being disengaged.
Consumer Benefits
● Storage space ● Area for parents to store other things they carried
with them
● Easy to access Arduino to change batteries
Cost
● Minimize consumer cost ● Use lowest cost sensors and electronics that can be

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used, or items available in the shop
● Construction of stroller done in inexpensive
locations (The Shop)

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Appendix B: Background Research1
Date(s): 9/21/2016 - 9/23/2016
Time(s): 5:00 - 5:30 PM
Location(s): Lisa’s Cafe, Ford Design Building G211
Key People In Attendance: Jacob Hechter, Annick Nshuti, Jaelon Woodard, Bharat Rao
Methods:
Currently, our research methods consists solely of research from academic sources and other
online resources, as well as information gained from a client interview.
Findings:
● Injuries
○ Contact of injury
■ Overwhelmingly the result of contact with the ground (78.7%)
■ Second largest cause was the result of contact with the stroller itself
(14.2%)
○ Cause of injury
■ Large portions of injuries occurred as a result of a fall from a stroller
(66.8%)
■ Second largest portion of injuries occurred because the stroller tipped over
(15.5%)
○ Demographics of Injury
■ 43.0% younger than 1 year
■ 34.7% between 1 and 2 years of age
● Reason for this high amount in a 0 to 5-year-old age range is the
increased usage of strollers for children under the age of two
compared to those older than 2
■ Slight Male Bias - 53%-47%
● This kind of bias appears with most/all child related products (Mrs.
Cowles)
○ Nature of the Injury
■ The head (43.0%) and face (31.0%) were most commonly injured the most
injured part of the child
■ The most common diagnoses were soft tissue injuries (39.4%) and
traumatic brain injuries/concussions (24.6%)
■ Note: the reporting methodology recorded the most severe injury under
injury type, and those labeled under head and face could have had other
serious injuries on other parts of their bodies
■ On average, one child dies each year from stroller-related injuries
according to data from 2007-2009. Many of these deaths occur when
babies are left to sleep with the stroller’s back rest in the reclined position.
They may slip feet-first through a leg opening until their head is trapped
and they are strangled — at least 5 deaths are associated with this hazard.
(“Product Hazards - Strollers | Kids In Danger,” n.d.)
○ (Fowler, Kobe, Roberts, Collins, & McKenzie, 2016)
○ When do these injuries occur?

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■ Research says the stroller usually is tipped over or the baby slides down
and out of their restraints in the stroller.
■ Not locking the wheels on the stroller is a common cause for why strollers
tip over when supporting weight or a child. (“Falls From Strollers And
Baby Carriers Can Cause Serious Injuries,” n.d.)
■ (Rettner, 17, & ET, n.d.)
● Stroller Design and Specifications
○ Height: ~40”
○ Width: 20”-25”
○ Depth/Length: 18” - 27”
○ Usually foldable
○ 3 or 4 wheeled
■ 4 wheels are more stable
○ Plastic, Steel, or Aluminum frames
○ Cloth or canvas seating
○ Some have detachable car seats
○ Ranges derived from (“Featured Products - Graco,” n.d.)
● Standards for Strollers
○ Strollers must adhere to ASTM F833, which is a set of tests and specifications in
order to be deemed safe for public use.
○ Standards range from physical tests to design specifications such as having no
sharp edges. (“Federal Register Notices | CPSC.gov,” n.d.)
● Types of Strollers
○ Standard size: decent amount of storage, 16-37 pounds, most come with a car seat
adapter, almost flat fully reclined seat
○ Car seat frame stroller: Less expensive, weighs less than standard size (6-11
pounds), and also clicks right into the stroller or car.
○ Lightweight: Usually made of canvas. The canvas provides the ease of allowing
the stroller to fold up and fit almost wherever (compact). No car seat adapter →
used for babies >6 months. Smaller wheels which is more dangerous, less
maneuverable, and hard to push on rough surfaces.
○ Jogging: Large, air filled wheels. Can be rolled smoothly and straight while on a
jog or walk. No car seat adapter. Not compact. 23-31 pounds. Shock absorbers.
○ Double: Stroller designed for two babies. Usually for twins. Weighs between 21-
36 pounds. Bassinet included with most.
Implications:
● Should we actually build a stroller, the 4 wheeled, more stable design would be preferred.
● A large portion of the injuries occur because of falls from the stroller, and subsequent
contact with the ground, making the secure fastening of the child in the stroller a high
priority target for improvement
● The head and face seem to be the most commonly injured, which would indicate another
high priority focus area, to attempt to protect the head.
● The most common cause of death seems to be resulting from strangulation in the harness,
which would be another highly important focus area
References

19
Falls From Strollers And Baby Carriers Can Cause Serious Injuries. (n.d.). Retrieved October 5,
2016, from http://www.npr.org/sections/health-shots/2016/08/18/490468692/falls-
from-strollers-and-baby-carriers-can-cause-serious-injuries
Featured Products - Graco. (n.d.). Retrieved November 15, 2016, from
http://www.gracobaby.com/products/pages/featuredproducts.aspx
Federal Register Notices | CPSC.gov. (n.d.). Retrieved November 15, 2016, from
https://www.cpsc.gov/Regulations-Laws--Standards/Federal-Register-
Notices/2013/Safety-Standard-for-Carriages-and-Strollers/#h-20
Product Hazards - Strollers | Kids In Danger. (n.d.). Retrieved from
http://www.kidsindanger.org/product-hazards/strollers/
Rettner, R., 17, S. W. | A., & ET, 2016 12:01am. (n.d.). Serious Head Injuries from Baby
Strollers on the Rise. Retrieved November 15, 2016, from
http://www.livescience.com/55785-stroller-injuries-children.html

20
Appendix C: Client Interview Guide and Summary
Date: 9/26/2016
Time: 5:00 - 5:30 PM
Location: Ford Design Building G211
Key People In Attendance: Prof. Carmichael, Prof. Bedell, Jacob Hechter, Annick Nshuti,
Jaelon Woodard, Bharat Rao, other DTC teams, Nancy Cowles (Telepresence)
Conditions of Environment: Interview through Skype
Missionof Kids In Danger
The primary mission of KID is as an advocacy and awareness group centered around
infants and consumer products commonly used by infants, or by parents of infants. They provide
awareness about recalls and provide advocacy for those hurt by faulty strollers, as well as work
with lawmakers and manufacturers on stroller standards. Their mission is to reduce injury to
young children.
Information/Notes
● Biggest threat to kids in strollers?
○ Threat to children is commonly due to falls, in any product
○ Some of these injuries occur because of inadequate securing of the latch the
parent wasn’t aware of
○ Finger pinching, amputation
○ Wheels
○ Brakes
○ Openings can be dangerous - the child becoming entrapped and getting strangled
■ Getting fingers caught in small opening
● Want something that is easy to use, that parents don’t have to think about
○ A harness seems to be what she’s looking for
● Common inconvenience? Don’t look at all the warnings (information overload)
○ Use intuitively, and the warnings should be either visual or audio
● Sometimes just leave the child at home because “it's at home and it's safe”
● Think the mandatory standard is pretty strong
● Second hand strollers? Not as “sharp” or possibly recalled and people don’t always know
what’s recalled
○ As long as it’s safe and not recalled
○ Old products don’t meet current standards
○ More beat up, wear and tear
● One stroller for the baby’s early years?
○ Parents often don’t know that infants and older children need different types of
strollers, leading to more likely restraint related injuries.
● Variety is good but it’s mostly up to our discretion as long as the problem is solved
● What would you consider success?
○ A prototype that addresses the hazards and could pass safety testing in its final
phase
○ Is it marketable?
● Foreign made strollers?
○ Most brands made in foreign countries?

21
○ The manufacturer's responsibility to know the safety standards and abide by them.
○ As long as it’s the same quality, most parents don’t know whether or not brands
are American made
● Parents often blame themselves for their children’s injuries, even with faulty products
● Injuries are underreported as not everyone goes straight to the emergency room rather
than urgent care
● Common for babies to wear safety gear like a helmet?
○ Most don’t but there are helmets available for special needs children
○ Most parents don’t want to try to get their parents to wear helmets as it’s a hassle.
● Complaints about strollers that aren’t injury related?
○ Easy to fold
○ Get children in and out
○ Weight of the stroller
○ Does the car seat fit well?
● Specific model that’s best for safety and ease of use?
○ No, as cost doesn’t always guarantee top of the line safety
○ Being hard to use means less likely to be bought
● Males generally more likely to be injured?
○ Across all infant product injury patterns, not just stroller
● Parents aren’t going to buy it because it's safe, that's just an assumption they make
○ Parents think about comfort a lot, but they don’t really know what is comfortable
for babies other than from how they behave
○ Appearance: It looks cool/it looks safe
● Going to get a list of child care centers who are willing to help
● Previous problems engineering groups have had
○ User input is important
○ Parents with young children, individual meetings are going to take some time
○ Big groups are other things you could look at (go to toys are us or to the park and
watch or ask)
● Good idea to focus on a single stroller OR good idea to make it so it forces the user to
buy a new stroller
● Safety.gov “yelp page”
● Time to set up latch is a big factor
Perspective
Users: It is important to note a clear distinction between injury due to a faulty stroller and
injury due to the misinformed or unaware parents/guardians. The overall opinion of the
team after the interview with Ms. Cowles is that there is a gray area in how some of the
babies/infants actually get injured. Further research will allow us to enhance our
understanding of this distinction, which right now is not very clear to us. Certain statistics
have been made available that give us information about the injuries solely caused by a
faulty stroller; however, there are scenarios in which the injury could be caused by a
combination of both a faulty stroller and an unaware parent or guardian. These scenarios
could be categorized under one specific cause when the injury and situation is really not
that simple.
Competition/Market: Ms. Cowles was informative about the feature details of general
strollers. However, the perspective of the group is that there is still much to be researched

22
and discussed about the overall stroller market. The competitive nature of the market,
especially today, is one reason certain companies tend to cut corners: companies want to
rush a product to market in order to compete with a rival product, or they have a
misunderstanding of specifications that the product must meet. Additional information
about specific stroller brands and their histories detailing manufacturing and marketing
could be useful in determining how and why certain faulty strollers end up penetrating
the market.
Conditions of Use: Under various circumstances, babies and even parents/guardians will
choose to operate the stroller in different ways. Our group would like to search for these
varying conditions of uses, which could vary for a number of reasons: a different stroller
brand, lax parenting, or a generally uncomfortable baby. Comfort is also subjective. A
stroller that enters the market could be found comfortable by one infant but not by
another. The question is if this is the fault of the manufacturer or the user’s problem.
These questions we hope will be answered in the user scenarios.
Client Preferences:
Ease of use: our client makes it clear that the product she prefers is the one that easy to
use and preferably does not require the parents to think about the procedures of use. The
steps and the time it takes to set up the latch are crucial.
She is also interested in a product that not only passes the safety test but also involves
additional safety features. In this case our client seems to be interested in features like a
harness
Getting rid of unsafe or faulty features like open holes and making sure that the product
has an adequately secure latch is another preference mentioned by our client.
Last but not least, our client is interest in a product that is marketable, that is a fit for
good demand and the one that addresses the hazards.
Unanswered/New Questions:
● What is the statistical commonality of secondhand stroller purchase?
○ How many times will a stroller get resold, on average?
● What are specific behaviors of parents that commonly lead to injury of children, or that
are riskier in general?
○ Are there injuries that could be avoided by making parts of the strollers less
complex or time consuming to work with?
● What is the commonality of children unbuckling their harnesses because they were
uncomfortable?
○ If common, how can harnesses be made more comfortable?
● How do the mechanical functions of various components of the stroller specifically
operate, like clips or latching mechanisms?
● What are the specific characteristics of each of the materials that strollers are made out
of, and what characteristics would be most important to safe stroller design?
● How many injuries are the result of faulty wheel locking?
● Parent preference of strollers vs harnesses
Action Items:

23
● Additional Interviews/Observations: Now that we have a clearer vision of what Mrs.
Cowles wants from us, and the additional information she provided, we should be able to
begin interviewing various other individuals about the problems of stroller use and safety.
We will be receiving a list of places which have both experts on infants and strollers we
can interview, as well as many users (parents) who we can interview and observe to
obtain other insights into the problem. User interviews are especially important to
schedule, since our users are parents with infants, and are going to require some. We also
should follow up with Mrs. Cowles for the purpose of answering more question that arise.
● Further Research: As stated under the perspectives section, there are several area of
research that can be pursued independently by members of this design group in order to
answer questions remaining from the interview, and new questions that have arisen from
the interview.
● Brainstorm: With the information from this interview and our secondary research, we can
now begin to generate ideas for potential improvements to stroller design.

24
Appendix D: User Observation Summary 1
Date: 10/09/2016
Time: 12:00 to 1:00 PM
Location: Northwestern University Lake fill
Key People In Attendance: Jacob Hechter
Conditions of Environment: Sunny, Chilly, which a breeze
Introduction
On 10/09/2016, Jacob Hechter went to the Northwestern University Lakefill to observe parents
pushing using strollers. The purpose of this session was to gain some basic insight into the
behaviors of parents as they use strollers. The observation lasted and hour total, but only three
strollers were observed during that time. This summary explains the methodology and results of
this observation. The weather was sunny, chilly, and with a breeze.
Methodology
This took place on the various paths around the Lakefill. Users were observed as they walked
around the Lakefill with the strollers in use, and specific points of interest and deviations from
expected stroller uses were noted.
Information About Users
There were three user groups observed. Group 1 was a father, mother, and child group. They
were using a standard, 4 wheeled stroller. The strollers manipulating mechanism had two
vertical bars on the ends, which the father grasped while pushing. The stroller was being pushed
by the father. Group 2 was a large group, most likely two families with 4 young children total.
They possessed a stroller, but no child was in the stroller. The stroller itself was being pushed by
one of the older children. Group 3 was a father, mother, and child group. They were using a
standard, 4 wheeled stroller. The stroller was being pushed by the father.
User Interactions and Deviations from Expected Behavior
The father in group 1 was pushing the stroller forward, generally leaning forward slightly as he
pushed. The point of interest here is how he turned the stroller. The run in question was a very
gentle right turn, along a gently right curving path. See Figure 6 for visualization.
1. Released both hands from the stroller push bars
2. Moved both hands to the right side of the stroller
3. Griped the right vertical bar with both hands
4. Seemed to pull the right side towards himself, as method of turning the stroller
5. Released with both hands
6. Moved hands back to original position
Group 2’s stroller was, as indicated above, being pushed by one of the kids. The kid had the
stroller tilted, so it rested on its back wheels, and was moving it around like described. The father
in group 3 did not display any deviation in usage with the stroller. The only piece of information
to add was that he was carrying a camera over his shoulder, which might possibly interfere with
stroller use.

25
User Observation Table:
Table 2: Major User Observations 1
Observations Opportunities Follow-ups
One user let go of the stroller for a
moment to reposition his hands in an
attempt to gain better leverage to
make a gentle turn.
Alter the design of the
stroller to make it more
maneuverable.
Look into other 4-wheeled
products for ideas into
maneuverability.
Strollers are sometimes wheeled
while they are actually not in use,
with the theoretical occupant walking
Compact down into an
easy to carry, wear, or
store format.
Ways of reducing weight
and making easier to store.
Figure 6: Drawing of Shifting Hand Positions
A visualization of the process by which the father
shifted his grip on the stroller handle.

26
Appendix E: User Observation Summary (10/10/16)
Introduction
Jaelon Woodard observed a user of a stroller at her apartment complex’s greeting room on
October 10, 2016 at 2025 Sherman Avenue Evanston, Illinois. Jaelon Also spoke with the user,
professor Cole, as well as her daughter, Evelyn, in order to learn how they felt about the strollers
they have and their experiences. The purpose of the observation was to learn exactly what they
use the stroller for, why they got the specific kind, what they like about them, and their
grievances with the ones they have. The observation lasted for fifty minutes, from 5:10 PM to
6:00 PM.
Methodology
The observation took place in the greeting room of an apartment complex. The user and her
daughter had two strollers with them, which were different in design and practical use. The user
was asked how she felt about her strollers, what she would change, and how she would make a
stroller better fit her needs. The user was then asked to condense and expand both strollers.
Finally, Evelyn was asked what she liked about the strollers.
Information about the users and their strollers
Professor Cole is a former DTC teacher and her daughter, Evelyn, is about two and a half years
old. They obtained one stroller for free from a friend and another one for free from a baby store.
They use the hand me down, which is much larger and heavier, for long distance walks and when
they need the extra storage. They use the other stroller, which is much lighter and doesn’t have
storage space, for shorter walks.
These were the main characteristics that she wanted in a stroller:
● Lightweight
● Intuitive to fold/unfold
● Storage space
● Easy to get over cracks in sidewalk
● Better maneuverability to turn tight corners
● A tray for the child to put snacks
● Easily removable seat cover for washing
User’s interactions and difficulties with their strollers
Heavy Stroller:
● One difficulty is that there’s no way to know whether the stroller is locked/unlocked to
fold and unfold. Also, the process is difficult and requires two hands and a foot, meaning
the child can wander away.
● Another difficulty is that the seat cover gets dirty and isn’t easily removable for washing.
● Another difficulty is that the stroller is heavy, so it’s harder to push and maneuver in tight
spaces.
● One benefit is the roof that goes all the way down to shield the child from bad weather.
● Another benefit is the storage space.
● Another benefit is the tray for the child’s snacks.
Light Stroller:
● One difficulty is that the stroller has no roof.

27
● Another difficulty is that the stroller is very flimsy, so going over cracks in the road can
sometimes almost cause the child to fall out.
● Another difficulty is that there’s no storage space.
● Another difficulty is that there’s no tray, so if the child wants to eat there’s a great chance
they’ll get dirty.
● One benefit is that because it’s lightweight, it’s easier to push around.
● Another benefit is that it’s much easier to fold and has a visible cue to know whether it’s
locked or unlocked to fold up or unfold.
User Observation Table
Table 3: Major User Observations 2
Observations Opportunities Follow-up
User had difficulty
folding and unfolding.
A more user friendly and less
intensive folding mechanism with
feedback.
Make a more intuitive to
use locking system
User has two strollers to
cover all the functions
necessary
Take best aspects of both to make one
stroller, less money than 2
Make storage space on a
lightweight stroller
User has trouble turning
the strollers in tight
spaces
Make wheels with a better turning
radius
Replace wheels or
revamp the structure of
leg/wheel connection
Excessive features that
aren’t intuitive to use
Strip down the superfluous functions
that aren’t key to safety and basic
comfort. This helps the weight
K.I.S.S. approach to
making the stroller. Make
it safe but simple.

28
Appendix F: Mockup Documentation
Introduction:
The stroller mockup (Figures 7, 8, 9) was constructed from the frame of a (Insert brand here)
umbrella stroller. The stroller had its seating removed, to make space for working with and
altering the stroller. Various points on the stroller were cut, for the purposes of making the
stroller base adjustable beyond what was allowed by the stroller initially, to test different base
configurations for stability. The back wheels were sawed off and replaced by two large wheels
on an axle (Figures 11 and 12), to test if the stroller stability was improved by increasing the size
of the back wheels. The front wheels were taped in place to construct a front axle (Figure 13)
which can be steered by pulling upon the reigns (Figure 14) to approximate some method of
front wheel steering, be it a bar like in the mockup or a steering wheel. The stroller also
possesses a dashboard with lights which alert the user to one of five potential dangerous
situations (Figure 9). These dangerous situations are: the stroller tipping, the stroller’s restraints
being undone, the being structurally unsound because it was not unfolded all the way, the wheel
lock not being engaged, and the stroller having unbalanced weight which may cause tipping.
Figure 7: Front View of Mockup Frame Figure 8: Side View of Mockup Frame
Figure 9: Top view of the Mockup Figure 10: View of proposed dash board handle

29
Figure 11: View of Steering Reigns Figure 12: View of Back Axle and Wheels
Figure 13: View of Back Wheel Figure 14: Front axle and wheels
The Seat Mockup was constructed for the purposes of testing improved stroller comfort for the
child. It consists of a hard foam core shell (Figure 15), with strips of hard foam on the inside of
the seat, covered by felt (Figure 16). The mockup was specifically created to test if the child was
more comfortable with a seat with a great deal of rigidity and structure, which would support
their body better than a softer material.

30
Figure 15: Front and Inside View of Seat Figure 16: Side and outside view of Seat

31
Appendix G: User Testing Summary 1
Date: 10/28/16
Time: 7:15 pm - 8:15 pm
Location: The user/expert’s office, Ford Building
Key People in Attendance: Annick Nshuti (Author); and the Users/expert Prof J Alex Birdwell
Conditions of environments: In the user's office, specifically outside the office itself(lobby),
(the stroller was not going to fit in the space in the office)
Condition of users: Comfortable, Unstressed, Timed because he had other people to talk to
after
Purpose:
The purpose of the user testing was to get user feedback on our design concepts, and to
therefore determine if our design ideas were feasible and appropriate from a consumer
perspective.
The specific concepts that were shown to the user/expert for the purpose of the testing were:
(1) The integrating of a larger wheel base as a way to improve the weight distribution over the
stroller and increasing its overall stability,
(2) The use of electronic visual and sound feedback to warn the user of dangerous situations,
and
(3) The integrating of 360-degree freedom front wheel and larger wheels in the back for
improved stroller maneuverability.
(4) The use of hard foam and sturdy backing for the seating
Testing Methodology:
This design review was performed by Annick Nshuti, who had brought the mock-up to perform
user testing with Prof J. Alex Birdwell at his office on the 2nd
floor of Ford building. Because of
the incompleteness of our mock-up, the explanations went further to drawings, verbal
descriptions, and storyboards. After thoroughly explaining the features that our final design
would integrate we set forth questions we had for our user/expert. Notes were taken based on
user feedback.
Questions:
1. To what extent do you think our design addresses the safety issues that are common in
current strollers?
2. Is the idea of integrating of the auditory and visual feedback worth the effort?
3. After hearing and observing our design ideas, what do you think can be improved on it?
4. Is there something missing that you expected?
5. If you could change a thing on our design what would it be?
6. Any comments or questions or further thoughts on our design?

32
Results/User Feedback:
Table 4: User Testing Results 1
The problem we are
solving
Description The user’s feedback Other Suggestions
Stability problems Integrating a larger
wheelbase, and
bigger back wheels
The back wheel can
easily cause the
tipping over if they
are large and heavy.
Bring the back-
wheels backwards,
in a way that doesn’t
make the person’s
feet hit the stroller.
Decrease the seat
elevation
Maneuverability of a
stroller
1.360-degree
freedom for the front
wheels
2. A steering bar to
turn the stroller
The user thinks
these two will solve
the maneuverability
problems in a daily
use of a stroller
despite the fact that
our mock-up didn’t
have them
integrated yet.
Electronic system The auditory
feedback
The light feedback
The auditory
feedback would be
much more efficient
and the best way to
alarm urgent
hazards like a tip-
over
This will require
mechanical skills
that we are not
equipped with yet.
The user suggests
we start using the
mechatronics lab.
Referred us to Prof.
Nick Manchuk,
FordB.100
Comfortable seat Foam straps under
the seat
Seat of any
made stroller
is generally
comfortable.
The user suggests
we focus on solving
the above problems
and may be get a
seat from another
stroller or just buy a
more comfortable
car seat.

33
Questions that emerged from our user-testing with Prof Birdwell:
Will our design integrate any storages?
Does opening the hinges interfere with the entire safety of the stroller?
What will power our the electronic system?
Can sensors replace the light warning system?
Conclusion:
The suggestions and feedback from the user/expert testing will help our group as we work
toward making our final mock-up specifically making use of sound for a tipping warning and
making use of vibration for a disengaged or failed seat belt as well as integrating a larger wheel
base and bigger back wheel that run towards the sides of the stroller.
Limitations:
One of the major limitations was that due to the time-frame our mock-up was unfinished and this
made some features hard to understand for our user during the user testing. Secondly, this
prevented the users from interacting with the mockup, and providing feedback because of their
interactions, and as a result their feedback may not reflect the actual user-interaction with the
stroller. Time was also relatively not really enough and definitely more topics could have been
discussed about.

34
Appendix H: User Testing Summary 2
Date: 11/01/16
Time: 7:15 pm - 8:15 pm
Location: The user's home,
Key People in Attendance: Jacob Hechter (Author); Representatives of the other three teams;
and the Users, Jamie and Lauren Zuercher
Conditions of environments: In the user's home, specifically the living room
Condition of users: Comfortable and Unstressed
Purpose:
The purpose of the user testing was to get user feedback on our design concepts, and to see if
they were viable and desirable from a consumer perspective. The specific concepts that were
shown to the users for the purpose of the testing was: (1) The use of hard foam and sturdy
backing for the seating (2) The use of electronic feedback to warn the user of dangerous
situations and (3) The use of a front wheel steering system.
Testing Methodology:
This design review was performed by Jacob Hechter along with representatives of several other
teams who also traveled to perform user testing with the Zuechers. Because of the difficulty of
transporting the mockup due to its size, testing was done through the use of drawings, verbal
descriptions, and storyboards. Notes were taken based on user feedback. Notes were also taken
on the feedback given to other teams
Results/UserFeedback:
Other User Testing
● Multiple Pocket action is nice, but bigger pocket action is best
● Side by side double stroller
● Magnet to keep the straps out of the way – huge thing!!!
● Son will always favor one side of the stroller, and lean on that size when sleeping
● 2-3 year olds are crazy, trying to get everywhere
● Hard metal thing around a child’s neck would cause them to go “ape”
● Charging for parents
○ Parents are going to forget a ton of stuff, including charging
● They love the roller coaster design, because of simplicity
○ “Throw them in and shut it down”
● For a thing that stops the stroller when you let go of it, making it stop immediately would
be disastrous

35
○ Cause people to fall and trip and all kinds of awful things
● Multiple places to charge the battery
● Parents purchases are about pragmatism and multiuse – want the stroller to be simple
● Parents Want children to sleep as much as possible if focusing at 0-6 months
● For the first year, parents are terrified the baby is going to die
● A good consumer goal would be to Maximize sleep-ability for maximum
Our User Testing
● Light would be tough
○ Tough to see in bright light
○ Audio can startle the baby and wake them
● Child will sink into the stroller
● Always leaning one side
● Sensor to check to make sure they aren’t leaning on the straps
● Vibration sensor
○ So you get feedback but the babies don’t
● Suburban parent vs city parent
● Preventing a stroller from being stolen – Bluetooth connection
● Age dependent comfort
○ Don’t want things that can jostle and transfer lots of energy
○ Kids aren’t active until like 6 months
○ More important to ensure something to entertain them – more fidgety when not in
motion
● Push car – 1 handle
● Babies take up 80% of your brain – needs to be idiot proof
● Plan for a baby that’s fighting the parent
Analysis:
Electronic Feedback: The use of a light to warn parents of a danger in the stroller is likely to be
ineffective, as a result of any light being generated being difficult to see in bright conditions.
The use of a sound for warning of non-immediate is also problematic, because of the potential to
wake up the child, an outcome that users desire very little. The use of feedback that is easy for
the parents to detect but hard for the child to detect is the goal, and vibration is one such method.
The users also recommend a Bluetooth application to let parents know that the stroller is moving
if they are not using it, to warn of danger and to warn of people trying to steal the stroller.
The Seat: The use of a solid structure and hard foam appears to be a possibly damaging idea, as
the increase in energy being transferred into the child in the stroller due to increased rigidity may
be a serious health concern. They mentioned that they would prefer some method of entertaining
the child to be added to the stroller, such as a toy steering wheel. This is in line with research

36
that suggests that children are most likely to fall out of strollers when the stroller is stopped and
they are no longer distracted by the motion and changing scenery.
Front Wheel Steering: Mentioned the idea that, instead of a steering bar or wheel, the design
should incorporate a handle similar to a push car.
Other: The design needs to be prepared for a non-compliant infant, and needs to be designed so
that an exhausted parent with 80% of their thought process taken up by their child can make use
of the stroller. Making strollers easier to use and designing it to remove common inconveniences
would significantly increase user value and appeal.
Conclusion:
The refinements described in the analysis will be made to the design, specifically making use of
sound for a tipping warning and making use of vibration for a disengaged or failed seat belt.
These general improvements to reduce user effort when making use of the stroller is also a good
direction to take design.
Limitations:
One of the major limitations was the inability to actually transport the mockup for the purposes
of user testing. This prevented the users from interacting with the mockup, and providing
feedback because of their interactions, and as a result their feedback may not reflect the actual
interaction with the stroller.

37
Appendix I: Design ReviewSummary
Date: 11/09/16
Time: 4:00 - 4:40
Location: Ford DTC Classroom
Key People in Attendance: Jacob Hechter, Annick Nshuti, Jaelon Woodard, Bharat Rao,
remainder of DTC Section 16, Professor Carmichael, Professor Bedell
Table 5: Design Review Feedback
Categories Positive
Comments
Negative
Comments
Features to
Add
Features to
Remove
Other
Comments
Wheel
Base/Structur
e
Possibly
increase
folding
compatibility
Need to
consider air
filled wheels
vs solid
rubber
wheels.
Front wheel
Steering
The method
may
generally
reduce
maneuverabil
ity
Can put large
amount of
weight on the
front wheels,
which when
fully turned,
may
May just
remove this
feature
altogether
We’re doing
a lot with this
mock-up, and
we may wish
to back off
and focus on
fewer things,
and cut out
something
high
effort/low
reward like
this
Could
possibly
encourage
one-handed
steering
Toy Steering
Wheel/Entert
ainment
Current
method of
creation is
very
complex, and
could
Folding
mechanism,
just make it
so it can be
detached and
reattached

38
possibly
cause harm to
child
easily
Warning
Sensors
Existence of
sensors can
warn parents
and others to
dangers
which may
have
otherwise
gone
unnoticed,
and save
lives.
Without some
method of
turning it off,
could become
an annoyance
to the parents
Nearby wires
may be
dangerous to
child
Some method
of disabling
the sensors
when the
stroller is not
in use, so as
to not annoy
or frustrate
the user
(Pressure
sensor or off
switch)
Make use of a
2-axis
gyroscope
instead of a
3-axis, since
we only care
about two
axes.
Needs to
account for
things like
sudden stops
and the parent
popping a
wheelie
Table 6: Changes Based On Design Review
Concern Change
Need to prevent false alarms for sensors to
reduce irritation and frustration due to those
false alarms
Pressure Sensor, which senses when the
stroller is occupied. Or add an off switch, to
allow the parents to turn the warnings on and
off.
Pressure sensor to detect the variation in
pressure on the wheels. (tipping)
Need to ensure the safety of the child due to
possible electrical danger
Insulate wiring well and keep as far out of the
child's reach as possible
Front wheel steering may reduce
maneuverability
Will likely remove from final design, to free
up time, money, and other resources.
Steering wheel may pose a hazard to the child Reduce complexity, and make it very easy for
parents to remove.
Keep all possible pinch points far out of
child’s reach.

39
Appendix J: Project Freeze Documentation
Date: 11/10/16
Time: 9:00 - 11:00 PM
Location: Ford Breakout Room
Key People in Attendance: Jacob Hechter, Annick Nshuti, Jaelon Woodard, Bharat Rao
DesignFreeze Documentation: Safer Stroller
Design Description:
Our team envisions our design as being more stable and maneuverable than the common stroller.
Our design also addresses the need for the child to be distracted, in order to minimize the self-
inflicted risk of falling out of the stroller.
Our design will look like a typical middle-high end stroller but with several modifications to its
structure. The wheelbase will be wider so as to provide a more even spread of the weight from
the child. The structure of the stroller itself will be made from aluminum piping, as it’s
lightweight and easy to manipulate but strong and supportive.
We will also use wheels that are larger in the rear with smaller wheels in the front in order to
offset the possible extra weight from the child either leaning back far in their seat, or from the
parent resting extra weight on the steering handle.
Another feature our design will have is electronic sensors to emit a sound when the stroller is
about to tip, or vibration if the seatbelt is unlocked. This will provide extra safety as the parent
will know whether their child has managed to unbuckle themselves or provide an increase in
reaction time to potentially stop the stroller from tipping over.
Additionally, we will place a removable toy steering wheel in front of the child’s seat. The aim is
to provide something that can distract the child and keep them occupied. When a child isn’t
occupied, that’s usually when they can get themselves into safety issues or get distracted by
something they can’t reach, so they try to get out of their stroller which leads to them tipping it
or falling out.

40
Table 7: Bill of Materials
Item Description Quantity Vendor Part
Number
Unit Cost Total Cost
Arduino Board module that
will power the
sensors in the
stroller
1 Arduino N/A $30.00 $30.00
ALEKO® BS-
MC12S 1 Set
Magnetic Contact
Reed Switch
Magnet and reed
sensor that will
transmit and sense
when seat belt is
clicked and
fastened
1 Amazon BS-MC12S $4.79 $4.79
Aluminum piping Unpolished
General Purpose
Aluminum Tubing:
• 0.065‘” wall
thickness
•1" outer diameter
•3' length
1 McMaster-
Carr
89965K681 $19.41 $19.41
Toy Steering Wheel Baby And Toddler
Car Driver With
Driving Tunes -
Take Along Toy
1 Amazon N/A $9.99 $9.99
Vibrating Motors DIY Mini
Vibrating Motors
1 Amazon N/A $7.99 $7.99
uxcell 20 x Micro
Limit Switch Long
Hinge Roller Arm
Set micro limit
switches which
will be used to
determine if a child
is in a seat.
1 Amazon s14031900
am1446
$8.32 $8.32

41
Figure 17: Orthographic View of Overall Structure

42
Figure 18: Isometric Drawing of the overall structure

43
Figure 19: Vibrating Stroller Handle
Figure 20: Seat Belt Sensor

44
Figure 21: Toy Steering Wheel

45
Appendix K: Prototype Construction
The following is a table of the materials needed for altering an already made stroller.
Table 8: Materials for Prototype Construction
Material Quantity
Arduino 1
Toy Steering Wheel 1
Vibrating Motors 1
uxcell 20 x Micro Limit Switch Long Hinge Roller Arm 1
ALEKO® BS-MC12S 1 Set Magnetic Contact Reed Switch 1
Note: The bill of materials has more specific information for each part used and the cost of
individual parts.
Tools used for construction:
 Lathe
 Vertical band saw
 Phillips screwdriver
 Power drill
 Taps
 Screws
 Hand saw
 Hot glue
 Meter stick
 Wire cutters
 Drill press

46
Extending the Wheel Base
1. Cut off the back wheels of the stroller using a vertical band saw
Figure 22: Back Wheel
2. Sand the cut aluminum frame.
3. Drill through the aluminum rods in order to place a screw of your desired size
4. Acquire another aluminum rod and drill through it at the same size
5. Screw the rods together orthogonal from each other
6. Drill through the other end of the new wheel base at a predetermined size
7. With your chosen set of wheels(preferably larger), attach them to the wheelbase with
screws and use a nut to secure them in place.
Figure 23: Aluminum Rod
Attachment

47
Implementing the Toy Steering Wheel
1. Take an aluminum scrap metal rod
2. Place it in the drill press and drill a hole in the exact center of the rod
3. Make the hole the same size as the screw you wish to use
4. Tap the rod so it has ridges for the screw
5. Remove the steel rod and place it in a lathe
6. Drill a hole on each end of the rod at your predetermined size
7. Tap the ends so screws can be inserted
8. Drill two holes on the sides of the stroller where you will place the bar
9. Screw the bar into place
10. Take another steel rod and thread the end of it so it can be screwed into the other rod
11. Hot glue the steering wheel onto the end of the inserted aluminum rod so it’s in front of
and facing the infant
Implementation of Electronics
 Set up a circuit that contains two limit switches
 One switch needs to detect whether or not the seatbelt is engaged
 The other switch needs to detect the child sitting in the seat
 Both switches must be engaged, or else the vibrating motors will be engaged within the
steering handle
Figure 24: Fully Assembled Frame
Extension
Figure 25: Assembled Toy
Steering Wheel

49
Appendix L: Individual Research| Bharat Rao
Introduction
The nature of the stroller market may help determine how our design can become more
competitive, nonconformist, and powerful. By understanding how the macroscale market and
microscale stroller industry function, the design team can make inferences about the specific
parts of the stroller that firms manufacture to gain a competitive edge in the market. The process
to gain this edge can enlighten us as to what we need to do to be competitive in this market while
building a safer stroller.
Methods
The gathering of sources began in the first week of October and ended in the second week of
November. Literature and sources were reviewed based on their relevance to various topics.
These topics include specific competitors in the stroller market, market share of strollers that
cater to a specific need, parts of the stroller, stroller benchmarks, the best stroller brands, and the
growth of the stroller market. Consumer and ranking reports provided insight into the stroller
benchmarks and top stroller brands in the market. Strollers, like many other products, are
subjective, meaning using the word “best” to describe a stroller is not particularly correct.
Different users with different needs will prefer a different stroller than some other user.
However, comparing the consumer and ranking reports with one another and highlighting
similarities between the strollers that are consistently ranked in the top provides evidence of
specific features and benchmarks that consumers prefer. Additionally, stroller brands that are
consistently at the top of the consumer and ranking reports are the brands that create these
benchmarks, or barriers to entry. The competitive nature of the market is dependent upon how
other companies can mimic or exceed the benchmarks that the top stroller brands are setting.
Company websites such as Britax’s, Bugaboo’s, and Thule’s, proved to be the most helpful in
revealing the key features of the brands’ specific models. The websites were accessed early in
the research process to highlight the key features that made-up standards and benchmarks.
Highlighting only the brand and not their specific models was unhelpful in drawing a conclusion
about the dominance of one or two specific firm(s). The features fall under the following three
categories:
● Maneuverability
● Ease of use
● Safety
The above features and their relevance to designing a stroller that meets certain benchmarks can
be addressed by analyzing the websites and brands’ strollers through pictures and feature
descriptions. Again, multiple stroller brands have different strollers that they design to cater to
multiple types and groups of consumers; however, determining the features that are common to
all models helps establish the benchmark for strollers among firms in the market. Market share of
specific firms, growth of the stroller market, and specific competitors in the market are topics
that were covered in business databases such as IBISWorld and in finance related publications
such as Bloomberg and Businesswire. Finance publications and business databases were
accessed for a short period, one to two days, due to the type of information they offered. Most of
the information could be easily parsed because it was all quantitative. Simply putting these
numbers in the context of the stroller market was all that was necessary to understand what they
meant. Unfortunately, there was no accessible data online or in text that told of a specific firm’s

50
market share. The stroller market is quite specific, and a lot of stroller companies are subsidiary
companies of bigger vendors that participate in producing and selling a variety of items.
Although this data was not available, the data that was offered a different perspective from the
company websites. Where the company websites provided a more design oriented perspective
qualitatively, the databases and financial literature provided a more business oriented
quantitative approach to solving the problem. The following information details the results of the
research in three categories: competitors, benchmarks, and changing standards via design
choices.
Results
The following data and results help in narrowing the goal of building a safer stroller. To build a
safer stroller that consumers are willing to buy, the product must first meet the standards and
benchmarks that other firms have established. Products that do not meet standards set by other
firms rarely survive for long in the hypercompetitive nature of markets. In other words, for the
product to reach the user, it must be competitive. The competitiveness of the stroller is dependent
on the features that it provides, and whether these features compare to the features of strollers
already on the market now. Getting familiar with the benchmarks, standards, and firms is a step
in designing a competitive, safe, and powerful stroller. For the sake of simplicity, the three
categories above (maneuverability, ease of use, safety) will be the measures of stroller quality.
These three categories were not randomly chosen but were the common ways of ranking strollers
among consumerreports.org, babygearlab.com, and ranker.com, and therefore they will be the
ways of defining stroller quality in this appendix. Determining the benchmarks and how firms
are redefining them as well as identifying the firms and the emergence of new competition will
help Team 16-4 design a safer more competitive stroller.
Competitors
There are tons of vendors in the stroller market. The lack of data regarding specific firm’s market
share demonstrates that not one specific company dominates the market. However, there are
other measures that reveal important pieces of information in designing a competitive stroller.
Geographically, there is a dense market share in Europe compared to that of any other country.
According to Technavio, a market research firm, the geographical segment of global baby
stroller market share in 2015 via percent of revenue was in Europe, at 42.33% (Technavio,
2015). PR Newswire writes that the reason for the dense market share in Europe compared to
other countries like the United States is because of “the improvements in product quality along
with rising demand for multifunctional and convenient baby travel gear and decreasing price
amongst the population” (PR Newswire, 2015). This data also highlights an important
misconception among consumers in the United States that strollers are mostly American made,
when in fact, two key vendors in the stroller market, Bugaboo and Thule, are currently
headquartered in Europe (Bugaboo International, 2016; Thule, 2016). Despite of the differences
in market share segmentation geographically, overall growth in the stroller market is expected to
rise. IBISWorld predicts that there will be 3.1% annualized growth until 2020 for the stroller
industry highlighting that strollers are becoming a lifestyle for not only families in Europe but all
around the world, as well (IBISWorld, 2016). The specific models and features that are
associated with the strollers families are buying are representative of the type of lifestyle that the
families are living. In 2015, 37% of the market share was comfort strollers highlighting a need
that consumers have for multipurpose products (PR Newswire, 2015). Comfort strollers are ones

51
Figure 27: Geographical segmentation
of market share by percent revenue for
baby stroller market
Source: Businesswire
(http://www.businesswire.com/news/ho
me/20160218005039/en/Improved-
Functionality-Performance-Drive-
Global-Baby-Stroller)
that can be used for a variety of purposes. This will be highlighted in the next section.
Essentially, what this quantitative data reveals, especially the geographical segmentation of
market share, is that not only are stroller sales expected to increase, but that specific models and
features of brands are catered to specific lifestyles. The lifestyle that families live in Europe may
call for a drastically different stroller than the lifestyle that families live in the United States.
Since our product is being considered among American consumers, this data tells us that we
must consider the American lifestyle. Again, Technavio states that “baby strollers and prams
such as joggers are especially very popular in the US” revealing that the nature of lifestyle in the
United States may be one where users enjoy participating in some activity, hence a jogging
stroller is more fitting, whereas compared to Europe, the lifestyle is more relaxed and calls for a
comfort stroller instead (Technavio, 2015).
Benchmarks
Companies and their manufacturers design strollers that meet a consumer’s specifics needs. In
this way, some stroller companies have a niche market; however, this niche market is the result
of a specific model of stroller that the brand has built. Stroller brands themselves diversify as
much as they can to target as many different consumers as possible. The goal of this section is to
analyze and highlight the features that are common among various models and brands of strollers
to create a benchmark for production. Among the strollers ranked on consumerreports.org, the
Britax B-Agile 4 stroller is one of the highest ranked strollers
with a score of 83 out of 100 because it is “Compact and
sturdy, with excellent maneuverability. Car seat compatible as
sold. Generous canopy with mesh for ventilation, and a large
storage pocket, too. Very easy to fold/unfold.”
(ConsumerReports, 2016). On babylist.com, a model like the
B-Agile 4 by Britax makes the “Best Strollers of 2016” list for
its ease of use. One parent saying “I love this stroller because
it is basically idiot-proof. It has one-button press and a handle
you lift on to collapse. It comes with a collapsible sunshade,
newborn headrest and converter clips that allow you to pop the
infant car seat into the stroller for easy transition from the car.
I couldn’t be more satisfied!” (Babylist, 2016). On ranker.com,
Britax ranks number one for best stroller brand of 2016 and
has 47 up-votes (Ranker, 2016). The similarities between these
two models of stroller are quite clear. It is extremely easy to
use, which is clearly a facet of strollers that parents care about
a lot. Britax, being consistently ranked in the top five among
different ranking sites, proves that it is producing strollers that
do not require much assembly or time to get used to.
Established benchmarks among the ease of use category could
be compactness, large storage, and easy folding. Additionally, on the safety front there are
similarities among strollers on different reports and rankings sites. For example, the Chicco
Activ3 Stroller, rated 81 out of 100 by ConsumerReports “performs well on all types of terrain…
and contains the hand-operated brake” (ConsumerReports, 2016). The Bugaboo Buffalo Stroller
and BOB Motion Stroller, ranked fifth and sixth respectively, for “Top 10 Standard-sized
Strollers” on diapers.com exhibit the ability to ride on all terrains because of their multifaceted
suspension system. (Diapers, 2016). Safety and maneuverability standards can be discussed with

52
these reviews. A strong suspension system is a benchmark for safety due to the ability to
minimize impact of large bumps on terrain and in turn minimizing the irritation the baby feels
while sitting. A summary of some of the benchmarks and standards along with models can be
seen in the following table:
Table 9: Safety, Ease of Use, Maneuverability Benchmarks of Top Ranked Strollers
Model Safety/Maneuverability
Benchmark
Ease of Use Benchmarks
Britax B-Agile 4 Compact and sturdy Canopy with mesh
Easy fold/unfold
Chicco Activ3 Hand-operated brake
Performs on all terrain
Easy fold/unfold
Adjustable handle
Britax B-Agile 3 Compact and sturdy
Wide wheel base
Handle to lift up to
fold/collapse
Converter clips
Bugaboo Buffalo Very roomy seat
All terrain
Versatile suspension
Small hooks
Basket
Canopy
Easy fold/unfold
BOB Motion Rugged suspension system Lightweight
Compact
Looking at the bolded features, it is evidently clear that the benchmarks for a competitive stroller
in the market are easy folding, compactness, sturdiness, and high performance on all terrains
(ruggedness). An interesting point to note is that in the research process, reviews and reports
regarding stroller features were mostly written about ease of use and not about safety implying
that parents or guardians, when purchasing a stroller, assume that the product they are investing
in is safe. Regardless of the assumption that consumers make however, the above standards are
just some of the features that make a stroller competitive in its respective market, and building a
stroller around these features, or at least some of them, will help it penetrate the market better.
Key:
Bold: Features common among strollers listed
Source: Babylist, ConsumerReports, Ranker
(https://www.babylist.com/hello-baby/best-strollers)
(http://www.consumerreports.org/cro/strollers.htm?loginMethod=auto)
(http://www.ranker.com/list/stroller-brands/werner-brandes)

53
Figure 28: Basic lightweight umbrella stroller
Source: Toys R’ Us
(http://www.toysrus.com/product/index.jsp?p
roductId=70034306&gclid=CJONwaCqsdA
CFQyUaQodWlIKmw&camp=PLAPPCG-_-
PID22065439:BRUS&cagpspn=plab_220654
39&eESource=CAPLA_DF:70034306:TRUS
)
Figure 29: Bugaboo Cameleon 3 Stroller
Source: Bugaboo International
(https://www.bugaboo.com/US/en_US/st
rollers/create?sId=CAM3STD&gclid=CI
XLloyrsdACFZKCaQod66YDHA)
Changing Standards via Design Choices
The most successful firms are ones that make their brand visible to consumers. Evidenced by the
table above, features that consumers have considered when buying a stroller center around how
easy the product is to use and its safety and maneuverability. The features that high grossing
stroller companies have chosen to integrate are the features that make up the product benchmarks
on the stroller market. Though, certain brands, like Bugaboo, are introducing completely new
benchmarks that were previously not considered by companies.
Aesthetics
Aesthetics has become an integral part of how strollers get sold. Different brands have
undertaken challenges to divert from typical design choices. One example of this diversion is the
urban assault stroller. Urban assault strollers are
more common among younger parents and guardians
today. They are wider and offer bigger bases that do
not fit on normal sized street sidewalks. Urban
assault strollers are just one exhibit of nonconformist
designs in stroller companies. Diverging from the
typical stroller building path, with a simple metal
chassis with canvas seating, Bugaboo strollers break
the common stereotype of how a stroller should look
(Hogue, 2005). Bugaboo’s urban assault strollers are
versatile and rugged per Stuart Hogue of the Design
Management Review. Additionally, Hogue states
that “self-expressive products like the Bugaboo
succeed by producing cognitive dissonance in
observers.
Observers
experience
cognitive
dissonance as they
wrestle with the
tension between
their expectations
for a product and
its actual design. It used to be that a stroller needed only to
be lightweight and compact to be successful. People did not
expect Euro-styling and ruggedness in a category
traditionally defined by basic utility. By countering these
expectations, the Bugaboo relies on cognitive dissonance to
increase the amount of time observers spend considering the
product and its users (Hogue, 2005).” The first invention of
the stroller has evolved into what has been identified as the
standard stroller today. Now, identified as the standard
stroller because of its evolution from the original stroller,
the canvas seating and metal chassis design are considered
conformist due to their lack of originality.

54
Analysis
Quantitative data targeting market share, specific competitors, and market growth reveal that the
stroller market is on the rise. Additionally, the data highlights changing preferences among
different groups of consumers geographically. The varying interests among consumers also
motivates companies to diverge from their typical manufacturing processes to produce strollers.
Instead, companies are on the verge of designing atypical products to create and establish new
benchmarks to attract users. Bugaboo’s wide base design of their urban assault stroller is
indicative of how changing the overall design of the chassis can have an impact on the
consumer’s choice. The design choices that Bugaboo made for their urban-assault stroller is an
example of using nonconformist design to appeal to consumers. We can draw influence from
Bugaboo by building parts, and a stroller that stands out from typical strollers in the industry
right now to gain a competitive edge. Lastly, it is important to target a specific consumer with
our design problem. Safety is the number one priority of our design; however, it is imperative to
build or modify a stroller that targets a niche group of consumers with a certain lifestyle all while
maintaining the benchmarks that current strollers on the market have set, or creating or own.
Discussion
It is blatantly clear that the stroller market is not as simple as initially anticipated. As noted
above, some companies are attempting to break typical designs and processes to stand out in a
market that is divided among numerous stroller producing firms. Designing a safer stroller is not
the only dry way to address the design problem at hand. After conducting research, it must be
noted that there are many factors to consider when designing our stroller with a priority on
safety:
● How does the stroller appeal to the kid and guardian?
● Can the stroller’s design be considered atypical?
● How can we build a stroller that increases the barrier to entry in the hyper competitive
stroller market?
● Can our stroller meet or exceed the standards/benchmarks that are set by current strollers
on the market?
o If so, how?
These are all questions that need to be considered when working and designing in the future, and
answering these types of questions will prove beneficial in ultimately solving the design problem
at hand: building a safer stroller.

55
Works Cited
BabyGearLab. (2016). Best Baby Strollers of 2016 | BabyGearLab. Retrieved November 18,
2016, from http://www.babygearlab.com/Best-Stroller
Babylist. (2016). Best Strollers. Retrieved November 18, 2016, from
https://www.babylist.com/hello-baby/best- strollers
Brandes, W. (2016). The Best Stroller Brands. Retrieved November 18, 2016, from
http://www.ranker.com/list/stroller-brands/werner- brandes
Bugaboo International. (2016). The story of us. Retrieved October 24, 2016, from
https://www.bugaboo.com/US/en_US/about
ConsumerReports. (2016). Top Stroller Reviews | Best Stroller – Consumer Reports. Retrieved
November 18, 2016, from http://www.consumerreports.org/cro/strollers.htm
Hogue, S. (2005). Making Designs Dissonant. Design Management Review, 16(4), 34–38,86.
IBISWorld. (2015). Durable Baby Goods Stores (IBISWorld iExpert Industry Summary No.
OD4386). Melbourne, Australia: IBISWorld Services. Retrieved from
http://clients1.ibisworld.com.turing.library.northwestern.edu/reports/us/iexpert/default.as
px?entid=4386
Newswire, P. R. (2015, December 30). Global Baby Stroller And Pram Market 2016-2020.
Retrieved November 18, 2016, from https://www.thestreet.com/story/13409619/1/global-
baby-stroller- and-pram- market-2016- 2020.html
Technavio. (2016, February 18). Improved Functionality and Performance Will Drive Global
Baby Stroller and Pram Market Until 2020, Says Technavio | Business Wire. Retrieved
November 18, 2016, from
http://www.businesswire.com/news/home/20160218005039/en/Improved-Functionality-

56
Performance-Drive- Global-Baby- Stroller
Thule. (2016). About the Thule brand | Thule | USA. Retrieved October 24, 2016, from
https://www.thule.com/en-us/us/about- thule/about-the- thule-brand

57
Appendix M: Individual Research| Jaelon Woodard
The inquiry explains what the long term effects of brain trauma are and how they affect
the individual later in their lifetime. By knowing the gravity of the safety issues that can arise
when manufacturing a stroller, companies then know how to better manufacture strollers in order
to avoid brain damage accidents to infants.
Search Methods
The search method implemented for this inquiry was to examine scientific databases
focusing on biological experiments and databases dealing with engineering and manufacturing.
The databases used include ebscohost and scopus. Key words used to help find preliminary
articles include: stroller, head, trauma, concussion, brain, infant, development, disabilities,
impairment and learning. One issue that arose with this method is that the information returned
was simply a large amount to sift through. Therefore, exclusion criteria needed to be more
precise in order to avoid information overload. Therefore, the date of the scientific lab and how
recent it was became important for deciding whether or not to use a source. Findings were
limited to experiments of the last fifteen years, or the beginning of the century. Also, if a lab
sought to explain on a highly esoteric level the physical changes that occurred to the brain, it was
also excluded. This is due to the fact that the inquiry seeks to explore the psychological effects of
brain trauma, and not the rearranging of minute body parts. This effectively cut down the sheer
number of articles returned, but the material in the articles were also filled with terms most likely
uncommon for everyday use and so more research was needed in order to fully understand the
implications and findings of some of the more detailed experiments. Abstracts were read and
used to determine whether an experiment contributed information of worth or if the article could
be ignored. The chosen articles were then kept and read in more detail to understand them fully.
In the end, a total of three sources were kept to be implemented into this research appendix out
of over the initial hundreds of articles as they were deemed to have a large potential impact on
our design.
Findings:
Fall Height Threshold:
One article investigated how high an infant can fall without suffering an injury that affects their
structural integrity. The study looked at infants less than 48 months old who had checked into the
hospital following a fall from less than three meters. They then compared these infants to
children with skull fractures or intracranial injuries (ICI) and children with minor head injuries.
Also noted were the surface of impact, where on the head impact was made, and the height of the
fall. The mean fall height for infants with minor head trauma was found to be significantly lower
than those with ICI. For children who fell from a height less than 2 feet, there was no head
trauma or ICI found. This height is based on the infant’s head’s center of gravity. Skull fractures
were more likely in children older than twelve months who landed on wood surfaces, and made
impact with their temporal or occipital region of their skulls. This means an infant that falls from

58
less than two feet and doesn’t make impact with their occipital or temporal skull region is
significantly less likely to sustain a serious head injury.
Figure 30
Social Functioning:
One article found on Scopus details how the relationship between parent and child is altered
following TBI, or traumatic brain injury and the social functioning ability of the infant. There
were 130 children between the ages of 18-60 months observed. Some of the children had minor
TBI (47), some of the children had no injury (56), and the rest of the children had an orthopedic
injury (27). In order to examine the quality of parent-child interaction, the study examined
infants 6 months after their initial injury using the Mutually Responsive Orientation (MRO)
scale. The MRO rates the dyadic nature of parent-child interactions. Dyadic just means they’re
communicating solely with each other, and that if one party in the relationship doesn’t put effort
into the relationship, then the communication fails and the social group falls apart. Another
standard used to investigate was the Parental Stress Index questionnaire. The study found
significant differences between the TBI group of infants and the non-injured children on the
MRO. This means that the child’s interactions with their parental figure deteriorated as the infant
wasn’t as responsive or put in effort to respond when stimulated.
Adult Cognitive Ability:
The final study used investigated the relationship between infant head trauma and the likelihood
of success by measure of how much education they complete. The level of education completed
as well as the scores on a cognitive ability test were used to measure the level of success. The
data was collected from 130,298 men through the Danish draft board. 6146 had at some point
been admitted to the hospital briefly for a concussion. Of these, 406 had suffered two
concussions, while 48 had suffered three or more concussions. The study found that as the
number of concussions suffered increased, the cognitive ability decreased for the men and that
the younger the age at which they suffered the concussion, the greater the negative impact on
their cognitive ability and their education level. This means that despite the fact that concussions
do not generally show long term effects, there’s still a risk factor for infants sustaining such an
injury as it impacts their cognitive potential.
Suggestions For a Design:
Based upon the findings from these studies, the stroller should not have the infant’s head’s center
of gravity higher than 2 feet from the ground and that the temporal and occipital lobes be offered
some sort of protection from the ground in a potential falling scenario. With these precautions

59
taken, the infant shouldn’t suffer a serious intracranial injury or have their cognitive ability
decreased by repeated concussions.

60
Works Cited
Hughes J, Maguire S, Jones M, Theobald P, Kemp A. Biomechanical characteristics of head
injuries from falls in children younger than 48 months. Archives Of Disease In Childhood
[online]. April 2016;101(4):310-315. Accessed November 4, 2016.
Lalonde, G, Bernier, A, Beaudoin, C, Gravel, J, Beauchamp, M.H. Investigating social
functioning after early mild TBI: The quality of parent-child interactions. Journal of
Neuropsychology [online]. Accessed November 4, 2016.c
Teasdale T, Frøsig A, Engberg A. Adult cognitive ability and educational level in relation to
concussions in childhood and adolescence: A population study of young men. Brain
Injury [online]. December 2014;28(13/14):1721-1725. Accessed November 4, 2016.

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