1. Evaluation of a Low-Cost Oxygen Analyzer in Urban and Rural Indian Hospitals
Clinical Background
Healthcare providers utilize a variety of medical devices, including life-saving respiratory
equipment. In developing countries, the quality of these devices can vary in quality and
accuracy. Our goal was to evaluate the use of a low-cost, versatile oxygen analyzer to help
providers detect malfunction in respiratory aids, thereby improving healthcare outcomes and
ensuring patient safety.
Oxygen therapy plays a central and versatile role in managing patients worldwide (Tables 1 and
2). One essential application of oxygen therapy is in the neonatal patient population, where it is
used to manage neonatal birth asphyxia, acute respiratory infections, and other life-threatening
conditions. Oxygen is a drug, however, and it should be given in a proper dosage in a proper
mode of delivery and duration (Jatana 2007). Overdelivery of oxygen (excessive FiO2) can also
be detrimental to neonates, who are most sensitive to exact concentrations of oxygen; one
particular complication of excessive oxygen concentrations is retinopathy of prematurity, a major
cause of blindness in premature infants under the age of five. For these reasons, ensuring the
effectiveness of respiratory aids is central to achieving United Nations’ Millennium
Development goal of reducing under five mortality by two-thirds by 2015.
The source and availability of concentrated oxygen can vary greatly, especially in rural areas of
developing nations (Table 1). Of particular interest in these settings is the oxygen concentrator,
which is a replenishable and less expensive source of oxygen than traditional oxygen cylinders
(Enarson 2008). Due to its potential financial and clinical benefits, the World Health
Organization has identified oxygen concentrators as an essential resource to be used in
developing countries (Enarson 2008, Perrelet 2004, WHO 1993).
As with any new technology, however, the proper training, usage, and routine maintenance must
be adhered to in order to ensure effective administration of oxygen to patients. A study by
Perrelet et al. (Perrelet 2004) demonstrated that in primary health care settings, neither the
provider’s knowledge of the various techniques for oxygen supply nor the maintenance of
service for oxygen concentrators was satisfactory. Different manufacturers and a lack of
standardization of delivery parameters further complicate the situation, and the use of an oxygen
analyzer to measure the oxygen concentration is recommended (Frey 2003). Thus, it may be
beneficial to combine the use of various oxygen delivery systems in developing nations with
maintenance and monitoring systems.
Table1. Sources of oxygen vary across different hospitals/countries
Oxygen source Use in developing countries
Central oxygen Most tertiary hospitals
Portable oxygen cylinders Rural, primary care centers
Oxygen concentrators** Rural, primary care centers, mainly in Africa (WHO, 2003)

2. **The World Health Organization has identified oxygen concentrators for use in developing
countries as a cheaper, more reliable alternative to oxygen cylinders (Enarson et al., 2008;
Perrelet et al., 2004; WHO, 1993)
Table 2. Oxygen delivery is not routinely monitored in neonates (Table 2)
Method of O2
delivery
Use in developing countries Monitoring of
O2 delivered
routine
Hood/headbox Enclosed box connected to oxygen source to
provide 2-3 L/kg/min of O2; well-tolerated; only
method that allows precise detection of FiO2 (Frey
and Shann, 2002)
No
Nasal cannula Nasal prongs connected to oxygen source to
provide 1-6 L of O2 per min, which generally
corresponds to an FiO2 of 25-35%
No
Continuous positive
airway pressure
(CPAP) mask
Mask connected to ventilator to apply pressure to
keep the airway open
No
Bubble CPAP mask Used in developing countries as a low-cost CPAP No
Mechanical ventilator Most sophisticated piece of equipment; provides a
variety of oxygen concentrations and pressures;
intubation is most invasive
Yes
Oxygen blender Blends oxygen and room air to control oxygen
concentration; can be combined with any of the
above devices to provide moderate FiO2
No
Currently, there are four common commercial devices on the market that measure oxygen. The
first and most popular method, is the electrochemical oxygen analyzer which relies on redox
reactions utilizing electron flow between an anode and cathode. Disadvantages of this system
include reliance on a polarographic cell which must be periodically replaced and high humidity
environments may cause a variability of measurements (Kacmarck 2005). The second method,
the paramagnetic oxygen analyzer, is based on the principle that oxygen is paramagnetic while
nitrogen is dimagnetic. Magnetic poles are present and the concentration of oxygen is determined
by measuring the interaction of oxygen with the magnetic field. The disadvantage of this system
is that it cannot be used for continuous measurements, and its fragility (Caro 2004). The third
method is called the Wheatstone bridge oxygen analyzer, which is based on the principle that
oxygen conducts heat faster than nitrogen. The difference in resistance provided, which differs
based on the oxygen concentration, is measured. However, the device generates a considerable
amount of heat and cannot be used in flammable environments (White 1992). The fourth method
is the zirconium oxide oxygen analyzer, which also relies on redox reactions. Briefly, the

3. zirconium oxide is heated which allows oxygen molecules to mobilize and conduct electrons
within the device. The disadvantages are its short lifetime and heat generation (Norton 1982).
The barriers to market in developing countries for all of these products are a high cost and need
for electricity. According to a survey of physicians in Maharashtra conducted by our team, the
cost of current oxygen analyzer devices on the market range from 15,000 to 20,000 rupees
(approximately US $220-300).
Proposed Solution
The Johns Hopkins University chapter of Engineering World Health designed a simple,
affordable, and customizable oxygen analyzer to ensure that optimal levels of oxygen are
reaching premature infants and patients on respiratory aid. To verify the concentration, the
device relies on a high precision comparator, a stable zinc-air battery that increases output
linearly with oxygen concentration, and a robust and versatile case that allows for interaction in a
broad range of environments.
Based on battery output and simple circuitry, this device is meant to save lives with a push of a
button. We designed a circuit board that could translate the voltage produced by the zinc-air
battery to an energy source for three LED lights. These three lights represent the different
concentration thresholds for developing world care. Should the oxygen concentration be between
85% and 95% the green LED will light, signaling the hospital staff that the concentrator is doing
its job. If the red LED lights, then the concentration is below 85%. If the concentration is above
95%, then the yellow LED is activated due to the risk of overoxygenization in certain patients.
In order for the circuit to work however, we needed to create a network of regulators and
comparators. This network, which needs an additional 9V battery as both a stable, long-lasting
power source and as a reference, creates a binary pathway for the voltage of the zinc-air battery
to travel. When the concentrated oxygen enters the circuit chamber, it interacts with the battery
to produce a charge measurable in Volts. This voltage then becomes the variable input for the
high precision comparators. The stable or constant input to the comparator is the pre-set output
voltage from the 9V battery. To obtain this pre-set, we tested a variety of battery types, and
calculated their voltage outputs at the different oxygen concentration thresholds. If, for example,
a zinc-air battery produced 1.431 V at 95% then we would regulate the 9V output so that the first
comparator uses that exact value as a reference. Once the comparator receives the variable input
it outputs a binary signal. If the voltage is below the constant value the comparator will not
produce a charge. If it is above the 95% threshold for example, it will send a charge and light the
corresponding LED. After this initial comparison, if the first LED is not lit, then the charge
travels down another series of dividers, regulators, and comparators that will power a red or
green LED light. In short, the LEDs follow transistor-transistor logic (TTL) to be turned on or
off in response to the variable zinc-air battery voltage. Ultimately our housed circuit will be able
to distinguish between the three thresholds and light the appropriate LED to notify staff, with a
single sample of the oxygen concentrator.
The prototype was tested on several functional oxygen concentrators to indicate its accuracy. The
criteria for functionality were based on regularly maintained oxygen concentrators provided to us

4. by a local hospital. In order to show that the zinc-air battery can detect a change in oxygen
concentration, we sealed our circuit in a ziplock bag with an iron-based hand warmer (that
absorbs oxygen from the ambient air) for 12 hours. This allowed us to gain a voltage level in the
absence of oxygen for experimental purposes (0.28V). We then inserted a tube from the oxygen
concentrator into the bag, and let the oxygen fill the bag for five to ten minutes. The prototype
was tested on several concentrators from the Johns Hopkins Hospital to validate its accuracy. All
tests yielded the same result; after the five to ten minutes the output voltage reached
approximately 0.98V.
With further testing, the team determined the actual voltage outputs as the oxygen concentration
varied from a range of 75 to 100 percent on three different brands of zinc-air batteries, Duracell,
Energizer, and Rayovac. A ziplock bag was filled with oxygen and a commercial oxygen
concentration analyzer was put inside to read the percentage of oxygen present. To get a clear
trend for how the batteries would react, the team carried out three trials using 16 batteries of each
brand and placed 14 within the bag and 2 outside as controls. After the team allowed the batteries
to acclimate to the oxygen concentration inside for five to ten minutes, we measured the voltage
given off by the batteries using voltmeters. We then increased the oxygen concentration by five
percent, allowed the batteries to acclimate, and measured again until we reached 100% oxygen
concentration. This was done a total of three times per battery per oxygen concentration. Using
this raw data, the team found the averages of each trial. For instance, an 85% oxygen
concentration yielded an average of 1.42699±00799volts from an Energizer battery. After
comparing the averaged results, the team found that the Energizer brand was the most
predictable and accurate in the presence of different concentrations of oxygen. The ziplock
plastic bag was used only for testing purposes; the actual device will have a modulable plastic
casing created by a 3D printer.
From our meetings with various hospitals and medical distributors, the evaluation team found
numerous applications for this device. The first is its usage as an early indication of machine
malfunction. A point estimate of FiO2 oxygen delivery, a direct way to see if the correct
percentage of oxygen is being administered without having to hook the patient up to the device.
This use can be administered on a wide array of respiratory aid devices such as oxygen
concentrators, oxygen blenders, and ventilators. This usage has two main target audiences,
neonatal, where an exact percentage of oxygen is critical for newborns, and geriatric, where the
constant worry about the improper level of oxygen can be lessened for the elderly. Another
unexpected application dealt with recreational use especially among scuba divers and mountain
climbers who require air tanks and time to react if something is wrong with their equipment.
Simplicity is a basic requirement that most healthcare worker would appreciate and this device is
as simple as they come. No graphs to interpret, no values to plug in, and no hassle to deal
with. This means that minimal training is required to determine what concentration percentage is
being shown through the LED system. And as the device’s main means of communication at the
moment is through LED lights, there is no language barrier to overcome. In addition, the oxygen
analyzer is battery operated, meaning that no external electricity source is required which is
crucial as power outages are frequent in rural and primary settings.
To truly impact the developing world, the price of the device also had to be within reach. The
cheapest price for a commercial oxygen analyzer is $220. This current price tag is something that

5. neither rural hospitals can afford nor get enough of. However, the estimated manufacturing price
for the proposed device cost is just over $5. With marketing and distribution costs, the team
estimated a commercial price of $15. This not only reinforces the fact that this device is cheaper
but can also be bought in mass quantities for numerous devices instead of just one.
Marketing in India
Product:
Need
Healthcare providers use a range of life-saving respiratory apparatus; the quality of these devices
can vary greatly in quality and precision. Our goal was to help providers detect breakdown in
respiratory aids, thus improving treatment and ensuring patient safety.
Product
Our design is a simple, affordable, and customizable oxygen analyzer to ensure that optimal
levels of oxygen are patients on respiratory aid. To verify the concentration, the device relies on
a high precision comparator, a stable zinc-air battery that increases output linearly with oxygen
concentration, and a robust and versatile case that allows for interaction in a broad range of
environments.
Differentiation from Competitors
Currently, in developing countries, there are no few maintenance and monitoring devices for
oxygen delivery systems. Simplicity is the strength of our product. There is minimal training is
required, and there is no language barrier, as concentration percentages are indicated with
illumination of different color LED lights. Battery operated; hence eliminating external source of
electricity.
Place:
Distributors
Our product will available to the markets such as India through medical device distributors.
Major customers for our products are primary and tertiary care health providers; they procure
devices directly from distributors or manufacturers.
Local Manufacturers
The alternative is to give licensing rights to Indian medical device manufacturers; this will
eliminate the need to protect intellectual property and also help reach a wider audience at a
cheaper cost.
Home use
Home care users of this product would also prefer to purchase these devices from
distributors/manufacturers on recommendation from their physicians.
Exclude Pharmacies/retail shops
Pharmacies/medical shops will not be considered, as the market is very fragmented, and it will
be very difficult to market to individual pharmacies. This will increase the cost of getting the
product to the market because each member in the distribution chain will add their margin and

6. price the product. The length of the distribution chain is directly proportional to increase in price
of the product. Targeting a fragmented pharmacy/retail shops will require a large sales force; this
is a cost no distributor/manufacturer will be willing to incur.
Price:
Competition
The cheapest price for a commercial oxygen analyzer is $220.
Cost of production
Estimated manufacturing price for the basic proposed device cost is just over $5. This can be
reduced if manufactured in local countries. The local cost of manufacturing will need to be
assessed on country basis.
Estimation of selling price
With marketing and distribution costs, the team estimated a price of $15 for the basic unit;
customization of the device by adding features would change the price.
Customer’s price-point
Customers are price sensitive, based on our interactions with different healthcare providers; they
were willing to pay $20 for a basic unit.
Hospitals in urban settings preferred more customized units and were ready to pay $35-$40 for
each unit.
Promotion:
Physicians/Biomedical department
Our products will be directly marketed to physicians and biomedical departments of hospitals.
Biomedical department is responsible for maintenance of all medical devices.
Unspoken route to generate “pull” force
There is an unspoken way to generate as pull force for this device in hospitals by educating
nurses on the benefits of this device. This is an indirect way of generating a pull for this device
from physicians at these hospitals. Many physicians do not have time to listen to sales pitch for
these devices, and hence targeting nurses will be an effective way of generating sales.
Effective mode of communication
Instead of printing pamphlets for our product we feel a short two-minute video showing benefits
of our device will be more effective, economical, and environment-friendly while also generating
chatter about the marketing and increase recall rate.
Inclusion in maintenance protocols
We should look at making this device mandatory in maintenance protocols of respiratory
devices.

7. New Innovations
As with most devices, improvements in design and function were needed and numerous
modifications were recommended from both healthcare workers and distributors to make this
product more desirable. Some of the basic features that the experts recommended involved a
numeric or digital readout instead of the LED system. In addition, they mentioned that a visual or
audible alarm would greatly benefit the staff by alerting them when the concentration of oxygen
was inadequate. For the outer protective case, the doctors suggested the case might be better
suited if it were directly incorporated into the respiratory aid machines. Some of the main
devices that they mentioned were oxygen concentrators and even oxygen blenders, as these do
not come with or have analyzers to verify the precise FiO2 readings.
The evaluation team also discovered unexpected uses for this product. We originally intended
this product to be utilized specifically for rural hospitals, but found that it could also be used for
recreational, home, and research purposes For recreational use we discovered that the main target
audiences are scuba divers and mountain climbers. As human beings enter hostile environments,
a precise measurement is crucial to survival because if they are already deep down in the sea or
nearing the summit of a mountain it’s too late to do anything. As for home use, the device could
be installed in cars, houses, and even corporate offices, preventing asphyxiation due to carbon
monoxide and other unseen dangers. As for research use, it could be used to monitor anaerobic
bacteria growth or other experiments where oxygen measurement is essential.
This trip also focused on other needs of the hospitals and local community as well. Due to their
budget deficiency most requests dealt with a simplified or less costly version of a device already
on the market. For instance, an oxygen blender is a device that mixes room air with 100%
compressed oxygen either from a wall outlet or tank. However in rural settings, a more accurate
and inexpensive alternative is needed to provide adequate care to broad spectrum of patients.
Next, an oxygen concentrators use a material such as Zeolite to absorb nitrogen. The health care
workers showed an interest in a device with a cheap alternative to reusable air filters that also
provide means to humidify the oxygen using distilled water prior to delivering to patients.
Another main interest was a child-safe insulin pump. The number of diabetics around the world
are steadily increasing along with the need of a low-cost device to deliver rapid-acting insulin
continuously throughout the day using a catheter. They requested a smaller, more accurate, and
easy to control version. And this was the same criteria with most of the devices asked for
including, CO2 monitors, sterilizers, pulse oximeters, and infusion pump.
There was also a need for devices and methods for problems that have not been adequately cared
for. One was a HIV virus or antigen test in breast milk for early detection. Another was an early
indication, screening, detector for deep vein thrombosis. Another interesting concept was a
commercially available fibrinogen to use when blood is in short supply and a temporary solution
is needed.
Conclusion
The healthcare workers and distributors showed interest in the concept and idea, but we found
that there is actually no need for this product in the Indian state of Maharashtra. We did not come
across any oxygen concentrators in the hospitals we visited. Moreover, pulse oximetry is widely

8. used, even in rural settings and ambulances in the field, providing perhaps the most specific way
of measuring oxygenation. Most hospitals claimed they own at least one oxygen concentration
analyzer but failed to specify where they kept it, indicating that it is rarely used if at all. While
not needed in India, this device could potentially be used in lower-resource African countries
where oxygen analyzers are the norm even today.

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