Skinput is a technology developed by Microsoft Research that uses bio-acoustic sensing to detect finger taps on the skin and use the human body as an input surface. It involves wearing a sensor armband that can detect vibrations caused by taps and determine their location. This allows for an "always available" input method without needing to carry a separate device. The document provides background on Skinput and discusses its advantages over other mobile input methods in providing a large, portable input area using the human body and proprioception.

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SKINPUT
Seminar Report submitted in partial fulfilment of the
Requirement for the degree of
Bachelor of Technology
In
Computer science & engineering
Under the supervision of
Mr. Vipin Rai
Ms. Kritika Goel
By
HIMANSHU SINGH SAJWAN
To
Department of Computer Science & Engineering
IIMT COLLEGE OF ENGINEERING, GR. NOIDA
Utter Pradesh Technical University,
Lucknow
Session: 2014-15

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DECLARATION
This is to certify that Report entitled “SKINPUT ” submitted by Himanshu Singh Sajwan
which is submitted by me in partial fulfillment of the requirement for the award of degree
B.Tech. in Computer Sc. & Engineering/Information Technology to Deptt of Computer Sc &
Engg,IIMT College of Engg,Gr Noida, Uttar Pradesh Technical University, Lucknow
comprises only my own work and due acknowledgement has been made in the text to all other
material used.
Date: 20-04-2015 Name of Student : Himanshu Singh Sajwan
Approved By : Head Of Department, CSE, IIMT, Gr Noida

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ACKNOWLEDGEMENT
At the very outset, I take this opportunity to convey my heartfelt gratitude to those persons
whose co-operation, suggestions and support helped me to accomplish the project successfully.
I take immense pleasure to express my sincere thanks and profound gratitude to our respected
Dr. Prabhat Kr. Vishwakarma, H.O.D. and Mr. Vipin Rai, Mrs. Kirtika Goel, Department of
Computer Sciences Engineering, IIMT College of Engg., Gr. Noida for his kind co-operation and
able guidance, valuable suggestions and encouragement he rendered for completing the Seminar
topic.
I express my sincere thanks to all the faculty members of the Department of Computer Sciences
Engineering, for providing the encouragement and environment for the success of my topic.
In the end, I would be failing in my duties if I do not express my heartfelt gratitude to my family
whose constant inspiration and patience have helped me to complete this work. And last but not
the least I would like to thank God for all he has given me till today.

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CERTIFICATE
This is to certify that Report entitled “Modern Operating System” which is
submitted by Karan Panjwani in partial fulfillment of the requirement for the
award of degree B.Tech. in Computer Sc. & Engineering in IIMT College of
Engg,Gr Noida is a record of the candidate own work carried out by him under
my/our supervision. The matter embodied in this work is original and has not been
submitted for the award of any other degree.
Date: 20-04-2015
Mr. Vipin Rai
Ms. Kirtika Goel -------------------------------
Dr. Prabhat Kr. Vishwakarma
Seminar Guide H.O.D of CSE Dept.

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INDEX
1.INTRODUCTION…………………………………………………………….. ….7
2.WHAT IS SKINPUT?..............................................................................................8
2.1 Always available input…………………………………………………….9
2.2 Bio-Sensing………………………………………………………….…….10
2.3 Principles of Skinput……………………………………………………..12
3. TECHNOLOGIES IN SKINPUT……………………………………………… 13
3.1 Pico projector……………………………………………………………..14
3.2 Bluetooth………………………………………………………………….15
3.3 Bio-Acoustics and Sensors………………………………………………..16
4.HOW DOES IT WORK……………………………………………………...........18
4.1 Processing………………………………………………………………….19
5.ADVANTAGES OF SKINPUT………………………………………………......20
6.DISADVANTAGES OF SKINPUT……………………………………………. ..21
7.APPLICATIONS OF SKINPUT………………………………………………… 22
8.FUTURE IMPLICATIONS…………………………………………………….. .23
9.CONCLUSION…………………………………………………………………… 24
10.REFERENCES………………………………………………………………….. 25

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ABSTRACT
Skinput is an input technology that uses bio-acoustic sensing to localize finger
taps on the skin. When augmented with a Pico-projector, the device can provide a
direct manipulation, graphical user interface on the body. The technology was
developed by Chris Harrison, Desney Tan, and Dan Morris, at MicrosoftResearch's
Computational User Experiences Group. Skinput represents one way to decouple
input from electronic devices with the aim of allowing devices to become smaller
without simultaneously shrinking the surface area on which input can be
performed. While other systems, like Sixth Sense have attempted this with
computer vision, Skinput employs acoustics, which take advantage of the human
body's natural sound conductive properties (e.g., bone conduction). This allows
the body to be annexed as an input surface without the need for the skin to be
invasively instrumented with sensors, tracking markers, or other items.

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1.INTRODUCTION
Devices with significant computational power and capabilities can now be easily
carried on our bodies. However, their small size typically leads to limited
interaction space (e.g. diminutive screens, buttons, and jog wheels) and
consequently diminishes their usability and functionality. Since it cannot simply
make buttons and screens larger without losing the primary benefit of small size,
consider alternative approaches that enhance interactions with small mobile
systems. One option is to opportunistically appropriate surface area from the
environmentfor interactive purposes. Thereis one surfacethat has been previous
overlooked as an input canvas, and one that happens to always travelwith us: our
skin. Appropriating the human body as an input device is appealing not only
because we have roughly two square meters of external surface area, but also
because much of it is easily accessible by our hands (e.g., arms, upper legs, torso).
Furthermore, proprioception – our sense of how our body is configured in three-
dimensional space – allows us to accurately interact with our bodies in an eyes-
free manner. For example, we can readily flick each of our fingers, touch the tip of
our nose, and clap our hands together without visual assistance. Few external
input devices can claim this accurate, eyes-free input characteristic and provide
such a large interaction area. In this paper, we present our work on Skinput – a
method that allows the body to be appropriated for finger input using a novel,
non-invasive, wearable bio-acoustic sensor.

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2.What is Skinput?
The Microsoft company have developed Skinput , a technology that appropriates
the human body for acoustic transmission, allowing the skin to be used as an input
surface. In particular, we resolve the location of finger taps on the arm and hand by
analyzing mechanical vibrations that propagate through the body. We collect these
signals using a novel array of sensors worn as an armband. This approach provides
an always available, naturally portable, and on-body finger input system. We
assess the capabilities, accuracy and limitations of our technique through a two-
part, twenty-participant user study. To further illustrate the utility of our approach,
we conclude with several proof-of-concept applications we developed

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2.1 Always-Available Input
The primary goal of Skinput is to provide an always available mobile input system
– that is, an input system that does not require a user to carry or pick up a device. A
number of alternative approaches have been proposedthat operate in this space.
Techniques based on computer vision are popular . These, however, are
computationally expensive and error prone in mobile scenarios (where, e.g., non-
input optical flow is prevalent). Speechinput is a logical choice for always-
available input, but is limited in its precision in unpredictable acoustic
environments, and suffers from privacy and scalability issues in shared
environments. Other approaches have taken the form of wearable computing. This
typically involves a physical input device built in a form considered to be part of
one’s clothing. Forexample, glove-based input systems allow users to retain most
of their natural hand movements, but are cumbersome, uncomfortable, and
disruptive to tactile sensation. A “smart fabric” system that embeds sensors and
conductors into a brick, but taking this approachto always-available input
necessitates embedding technology in all clothing, which would be prohibitively
complex and expensive. The Sixth-Sense project proposesa mobile, always
available input/output capability by combining projected information with a
colormarker-based vision tracking system. This approachis feasible, but suffers
from serious occlusion and accuracy limitations. Forexample, determining
whether, e.g., a finger has tapped a button, or is merely hovering above it, is
extraordinarily difficult. In the present work, we briefly explore the combination of
on-bodysensing with on-bodyprojection.

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2.2 Bio-Sensing
Skinput leverages the natural acoustic conduction properties of the human body to
provide an input system, and is thus related to previous work in the use of biological
signals for computer input. Signals traditionally used for diagnostic medicine, such as
heart rate and skin resistance, have been appropriated for assessing a user's emotional
state. These features are generally subconsciouslydriven and cannot be controlled with
sufficient precision for direct input. Similarly, brain sensing technologies such as
electroencephalography (EEG) & functional near-infrared spectroscopy (fNIR) have
been used by HCI researchers to assess cognitive and emotional state; this work also
primarily looked at involuntary signals. In contrast, brain signals have been harnessed
as a direct input for use by paralyzed patients, but direct brain computer interfaces
(BCIs) still lack the bandwidth requiredfor everyday computing tasks, and require
levels of focus, training, and concentration that are incompatible with typical
computer interaction.
There has been less work relating to the intersection of finger input and biological
signals. Researchers have harnessed the electrical signals generated by muscle
activation during normal hand movement through electromyography (EMG). At
present, however, this approach typically requires expensive amplification systems
and the application of conductive gel for effective signal acquisition, which would
limit the acceptability of this approach for most users. The input technology most
related to our own is that of Amento et al who placed contact microphones on a user's
wrist to assess finger movement. However, this work was never formally evaluated, as
is constrained to finger motions in one hand.
The Hambone system employs a similar setup, and through an HMM, yields
classification accuracies around 90% for four gestures (e.g., raise heels, snap fingers).
Performance of false positive rejection remains untested in both systems at present.
Moreover, both techniques required the placement of sensors near the area of

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interaction (e.g., the wrist), increasing the degree of invasiveness and visibility.
Finally, bone conduction microphones and headphones - now common consumer
technologies - represent an additional bio-sensing technology that is relevant to the
present work. These leverage the fact that sound frequencies relevant to human speech
propagate well through bone.
Bone conduction microphones are typically worn near the ear, where they can sense
vibrations propagating from the mouth and larynx during speech. Bone conduction
headphones send sound through the bones of the skull and jaw directly to the inner
ear, bypassing transmission of sound through the air and outer ear, leaving an
unobstructed path for environmental sounds

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2.3Principles of Skinput
 It listens to vibrations in your body.
 Skinput also responds to the various hand gestures.
 The arm is an instrument.

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3.Technologies in Skinput
There are Three technologies used for Skinput.
1. Pico-Projector
2. Bluetooth
3. Bio-Acoustics and Sensors

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3.1Pico-Projector
Pico-Projector is employed as Output device that show menu. It’s employed in
mobile and camera to show the project. Pico-projectors are small, but they can
show large displays (sometimes up to 100"). While great for mobility and content
sharing, pico-projectors offer low brightness and resolution compared to larger
projectors. It is a new innovation, but pico-projectors are already selling at a rate of
about a million units a year (in 2010), and the market is expected to continue
growing quickly.
pico projector in mobile phone
How do pico projectors work?
There are several companies developing and producing pico projectors, and there
are 3 major technologies: DLP, LCoS and Laser-Beam-Steering (LBS).
DLP and LCoS use a white light source, and some sort of filtering technique to
create a different brightness and color on each pixel:
 DLP (Digital Light Processing) the idea behind DLP is to use tiny mirrors on a
chip that direct the light. Each mirror controls the amount of light each pixel on the
target picture gets (the mirror has two states, on and off. It refreshes many times in
a second - and if 50% of the times it is on, then the pixel appears at 50% the
brightness). Color is achieved by a using a color wheel between the light source
and the mirrors - this splits the light in red/green/blue, and each mirror controls all
thee light beams for its designated pixel.
 LCoS (Liquid Crystal on Silicon): an LCoS projector uses a small liquid-crystal
display (LCD) to control how much light each pixel gets. There are two basic
designs to get color: Color-Filter (CF-LCoS) which uses 3 subpixels, each with its
own color (RGB) and a Field-Sequential-Color (FSC) which uses a faster LCD
with a color filter - so you split the image for the 3 main colors (RGB) sequentially

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and you refresh the LCD 3 times (once for each color). The light source for the
LCoS can be LED or diffused laser.
 Laser-Beam-Steering (LBS) projectors are different, creating the image
one pixel at a time, using a directed laser beam. You start with 3
different lasers (Red/Green/Blue), each at its required brightness, which
are combined using optics, and guided using a mirror (or two mirrors in
some designs). If you scan the image fast enough (usually at over 60Hz),
you do not notice this pixel-by-pixel design.
3.2Bluetooth
It’s used to connectthe Bio-Acoustic sensing element for mobile in order so that
information will be transferred to many being controlled devices like mobile, iPod
or laptop
Bluetoothis a wireless technology standard for exchanging data over short
distances (using short-wavelength UHF radio waves in the ISM band from 2.4 to
2.485 GHzfrom fixed and mobile devices, and building personal area
networks (PANs). Invented by telecom vendor Ericsson in 1994, it was originally
conceived as a wireless alternative to RS-232 data cables. It can connect several
devices, overcoming problems of synchronization.

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3.3Bio-Acoustics and Sensors:
When a finger taps the skin, several distinct forms of acoustic energy are produced.
Some energy is radiated into the air as sound waves; this energy is not captured by
the Skinput system. Among the acoustic energy transmitted through the arm, the
most readily visible are transverse waves, created by the displacement of the skin
from a finger impact (Figure 1).
Figure 1
When shot with a high-speed camera, these appear as ripples, which propagate
outward from the point of contact. The amplitude of these ripples is correlated to
both the tapping force and to the volume and compliance of softtissues under the
impact area. In general, tapping on soft regions of the arm creates higher amplitude
transverse waves than tapping on boney areas (e.g., wrist, palm, fingers), which
have negligible compliance. In addition to the energy that propagates on the
surface of the arm, some energy is transmitted inward, toward the skeleton. These
longitudinal (compressive) waves(Figure 2). travel through the softtissues of the
arm, exciting the bone, which is much less deformable then the softtissue but can
respond to mechanical excitation by rotating and translating as a rigid body.

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Figure 2
Bio-Acoustics: Sensing
 These signals need to be sensed and worked upon.
 This is done by wearing the wave sensorarm band.

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4.HOW DOES IT WORK
The operating of this Skinput Technology depends on the show and detects
principle that uses all 3 parts to producethe result.
Step 1. Oncea user faucets on skin surface then Armband Bio-Acoustics sensing
element detects the activated or touched part of the skin surface by measure the
sound frequency variations in bodydensity, size, mass and impact of sentimental
tissues and joints. These variations are then reborn into a digital signal kind.
Step 2. Currently a wireless property technology Bluetooth is employed to attach
the Armband Bio-Acoustics sensing element to Mobile, iPod and computers in
order that the data/command will be transmitted to those devices that are being
controlled. For this software system that matches the sound frequencies of a
particular skin surface location is employed. Different correspondingoperations
are distributed within the device to producethe result.
Step 3. The final step involves the purposeof the show. A Pico-projector is
employed during this step as output shows devices operating as a projector to show
the menu. This sort of the projectors is employed in mobiles and cameras to show
the project.

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4.1.Processing

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5.ADVANTAGES OF SKINPUT
 No need to interact with the gadget directly. Easy to access when your phone
is not available
 Don’t have to worry about keypad.
 People with larger fingers get trouble in navigating tiny buttons and keypads
on mobile phones. With skinput this problem disappears.
 The projected interface can appear much larger than it ever could on a
device’s screen. One can also bring his arm closer to the face (or vice versa)
to see the display close up. Dimming the lights creates an even greater color
contrast if skin and the text are too similar in color during daylight.
 Allows users to interact more personally with their device

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6.DISADVANTAGES OF SKINPUT
 If the user has more than a 30% Body Mass Index Skinput is reduced to 80%
accuracy
 The arm band is currently bulky
 The visibility of the projection of the buttons on the skin can be reduced if
the user has a tattoo located on their arm

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7.APPLICATIONS OF SKINPUT
 Mobile
 Gaming
 I-pods
 An aid to paralyzed persons.

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8.Future Implications
 With small sized Pico-projectors, Skinput oriented systems, are an emerging
trend.
 Research is carried out for smaller wrist watch sized sensor arm band.

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9.CONCLUSION
Through Skinput, a technological approach to use human body as an input surface
is achieved. The wearable bioacoustic sensor array used in the skinput plays a fine
role here. The Skinput approach is proved to be useful and better for different
gestures when the body is in motion. As a future work, many features like taps
with different parts of the finger, single handed gestures and differentiating
between objects and materials are being explored and researched with Skinput.
Last but not the least, the different applications of Skinput helps us to give a clear
idea at what extent we can use this technology effectively. Likewise, Sixth
sense also projects information on varied surfaces thus extending the limits of
projection from screen to the physical world.

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10.REFERENCES
 "Skinput:Appropriating the Body as an Input Surface". Microsoft Research
Computational User Experiences Group
 Skinput “Wikipedia”
 "Skinput: Appropriating the Body as an Input Surface". www.Youtube.com
 www.google.com