Design Of Low Cost Medical, Portable Oxygen Concentrator

Project Title

Design Of Low Cost Medical, Portable Oxygen Concentrator

Project Area of Specialization Biomedical EngineeringProject Summary

The novel coronavirus disease (COVID-19) pandemic that was started in china has now threatened the global human population, including in countries with resource-limited health facilities and adequate ventilator support is crucial for patient survival, In this scenario, the need for oxygen concentrators is high as oxygen concentrators provide supplementary oxygen for patients with chronic obstructive pulmonary disease (COPD) which limits the lung's limit to oxygenate blood by breathing atmospheric air, and, in higher concentrations, for severe chronic hypoxemia and pulmonary edema.

As India grappled with the Coronavirus pandemic, people were running from pillar to post to arrange hospitals, ICU beds, life-saving medications, ventilators, and most importantly ‘oxygen’, to save their loved ones. Arranging these necessities was so tough because the availability of all these things was way less than what the country required to win this battle. So at this crucial time, our project will turn out to be a savior for suffering patients. 

Oxygen concentrators are machines that pull room air through a series of filters to remove dust, germs, and other contaminants. The machine drives air into one of two cylinders containing a molecular "sieve" substance, where nitrogen is absorbed and concentrated oxygen (90 percent or more) and a tiny amount of other gases common in room air is left. Nitrogen is desorbed and sucked out of the atmosphere in the other cylinder at the same time. The cylinders' function is reversed in a timed cycle in the second stage, delivering a constant supply of oxygen to the patient. 

More than 80% oxygen concentration can be maintained with flow rates from 2 to 5 liters per minute (at sea level). In the past years, the oxygen (O2) concentrator utilizing pressure swing adsorption (PSA) innovation assumes a huge part in indoor and clinical applications, due to its advantages of cost-effectiveness, high O2 purity, safety, and negligible pollution. PSA units have very high importance in industrial processes and they cope with the set expectations. It contains 4 stages cycle pressurization, adsorption, blows down, and purge. Each stage requires specific pressure to complete the stage and proceed to the next stage of the cycle. As incompletion of any stage will affect oxygen production and its purity level.

In 2018, the worldwide market for medical oxygen concentrators was estimated to be worth USD 1.75 billion. Between 2019 and 2025, the market is expected to increase at a compound yearly growth rate of 7.4%. New home oxygen concentrators range in price from USD 595 to USD 2000, depending on batteries and other accessories. Oxygen concentrators that have been used are less expensive (USD 595–1500), depending on the number of hours, warranty, and condition of the equipment. On the contrary, our design is indigenous with the lowest cost possible estimated at 75,000 PKR.

Project Objectives

1)  To compress air at a specific pressure.

2) To control the level of temperature and humidity to get the maximum rate of adsorption (two pieces of equipment are used for cooling purposes Heat exchanger and a cooling fan and for humidity, a drier is set containing the beans of silica gel.)

3) To develop the control algorithm over micro-controller (Arduino in prototype) so it can control the pneumatic valves for handling pressure b/w molecular sieve beds and in the storage tank and take data from sensors to be used for including safeties and control actions.

(a) A flow rate sensor that measures the flow rate of the enriched gas product through the fluid line

(b) A temperature sensor coupled to the fluid line, wherein the temperature sensor measures ambient temperature

(c) A pressure sensor coupled to the fluid line, wherein the pressure sensor measures ambient pressure.

(d) A controller that selectively controls the first and second valves to control either of the periods of pressurizing and venting of the sieve beds based on at least two of the measured flow rate, ambient temperature, and ambient pressure

4) To regulate the level of output pressure to the patient, a pressure regulator is used.

5) To sustain the voltage and the current requirements of electronic components like alarms, pressure sensing controllers or Microcontrollers PCB design is essential.

6) To maintain the high accurate stage of safety and a spotless environment different types of filters are used at the locus point.

7) To set the safety hazards for the user, several safety parameters coordinate with PCB through a pressure sensor. (Instruments used for indications are an alarm and 3 led lights. Red light for stopping the oxygen concentrator from working, yellow light for warning (indicates the level of oxygen is low from standard), and green light for well-operation.)

8) To meet the requirements of markets with reduced cost, non-brands equipment is used with satisfactory testing.

Project Implementation Method

Project Implementation Method

For completing our FYDP successfully and on time we did the following actions

1. We put the specifics we've outlined into a foolproof action plan.
2. At every step of this cycle we documented every tiny detail, from decisions to results.
3. We tried to maintain an effective channel of communication with our external and internal supervisors.
4. Our action plan included that if there would be any necessity for a change of plan unexpectedly, we would make a swift choice.
5. Whenever we agree on the adjustments we put them in place right away.

In this stage of the project's implementation, we mainly focused on the three areas that are: Project Scope Management, Project Time Management, and Project Cost Management.

We worked on the simple technique called the classic technique, which is one of the simplest techniques for project management and implementation.  We made a schedule of implementing chores and then we calculated the time it will take to complete them by considering the resources we needed. Then we showed that timeline to our supervisor and received comments, as well as kept track of the deadline and quality of work.

Methodology

 As per composition air consist of 78% of Nitrogen, 21% of Oxygen, and 1% of Other gases, so the oxygen needed by patients of either Covid-19 or any other lung disease should be 90% -95% pure. We will use PSA (Pressure Swing Adsorption) process to filter nitrogen from the air to get pure oxygen. PSA process works on the principle of Adsorption; Adsorption is a process that creates a film of the adsorbate on the surface of the adsorbent. PSA process 5 main stages.

• Compressed air (78% nitrogen, 21% oxygen, < 1% argon) is filtered, degreased, and dried and the production pressure is automatically regulated.
• Air passes through the molecular sieves where nitrogen is adsorbed by the zeolite, increasing oxygen concentration up to 95%.
• Out of the molecular sieve, the oxygen produced is sent through the storage tank via a multifunction block. Nitrogen is released by a de-absorption process.  
• Part of the oxygen produced is used to help the nitrogen desorption of one vessel while the other ensures oxygen production (and vice versa).
• An automatic and pneumatic vessels balance system ensures a continuous oxygen flow.

Benefits of the Project

1. User-Friendly: Our device is easy-to-understand, and a clean control panel is provided which will allow you to monitor your liter flow and battery life easily. It will also make adjustments as simple as pressing one button.
2. Maintain oxygen levels while being in home isolation: The coronavirus situation in the country can be at its peak again, as many gasps for breath amid the oxygen crisis while medical experts stress the need to maintain oxygen saturation in COVID[1]19 patients. There may be a shortage of beds and oxygen cylinders in hospitals so it is easier for the patient to fulfill his oxygen needs while being at home in isolation.
3. Low Cost as per market demand: Overall cost of an oxygen concentrator in the market is usually in the range of 2-3 lacs which is quite unaffordable for a common man so, in this respect, we will design a low-cost concentrator indirectly comforting people and also provide support to our country’s economy.
4. Mobility: It is easy to carry along with patients other than covid-19, having lung diseases such as; asthma, COPD, infections like influenza, pneumonia, and lung cancer on an urgent basis traveling which is of primary need for such patients.
5. Import substitute: Oxygen concentrator is imported till date from foreign countries, our project fulfills this requirement and removes the need for import as we have designed this project with our ideas and techniques.

Other Benefits:

We will construct an oxygen concentrator to be lightweight, noise-free, and energy-efficient thanks to today's cutting-edge technology. Our technology will provide these benefits to patients who require continuous medical grade oxygen for breathing.

Compressed gas canisters can be replaced by oxygen concentrators. They contribute to the production of 90-95 percent of the oxygen in indoor air. 

Some patients require a constant supply of oxygen, which is usually given via an oxygen concentrator. They are utilized for long-term O2 treatment at home. They have become a popular choice among patients since they are reasonably affordable and need fewer hospital visits. 

No pricey tanks, containers, or oxygen refills are used in our oxygen concentrators. 

It helps you breathe by using the air around you and in your house to provide concentrated oxygen. 

Oxygen concentrators provide numerous advantages, some of which are listed below:
• Higher survival rates for respiratory illnesses

• Increased mental alertness

• Improves endurance

• A more positive attitude

Technical Details of Final Deliverable

Pressure Swing Adsorption (PSA) Technology and cycle Description

PSA(Pressure Swing Adsorption) technology is used to separate some gas species from a gas mixture under pressure according to the specific molecular characteristics and affinity for an adsorbent material. This process operates at near-ambient temperatures[5]. Compare to other methods PSA is more effective due to controlled tempreture[6]. It requires 4 stages pressurization, adsorption, blowdown, and purging as shown in Figure 1. Each stage requires specific pressure to complete the stage. As incompletion of any stage will affect oxygen production and its purity level.  

Figure 1. Four stages of the Pressure Swing Adsorption Cycle (PSA)

Figure 2. Control of PSA cycle using 3/2 way valves (a) Pressurization and adsorption in Molecular sieve bed T1 and desorption and purging in Molecular sieve bed T2. (b) Pressurization and adsorption of Molecular sieve bed T2 and desorption and purging of Molecular sieve bed T1.

Figure 3. Draft prototype of an oxygen concentrator

S.No1234567891011121314151617181920 Final Deliverable of the Project Hardware SystemCore Industry HealthOther Industries Medical , Manufacturing Core Technology OthersOther TechnologiesSustainable Development Goals Good Health and Well-Being for PeopleRequired Resources

Elapsed time in (days or weeks or month or quarter) since start of the project	Milestone	Deliverable
Month 1	Literature of design of oxygen concentrator	Complete knowledge about the dynamics of the project. About the uses of zeolite, Pressure swing adsorption technology.
Month 2	Literature of design of oxygen concentrator	Among many available zeolites available in the market the best suited zeolite is LiX.
Month 3	Literature for the Mechanical parts of oxygen concentrator	Bought many mechanical parts. Example: Compressor, pressure transducer, Silica gel, storage tank, Molecular sieve beds, humidifier bottle, pneumatic regulator, pipes and fittings, particle filter and pressure equalizer.
Month 4	Literature for the Electrical parts of oxygen concentrator	Bought many electrical parts. Example: Wires and jumpers, drill machine, cooling fan, hour meter, Arduino boards, ADS1115, Vero board, PCB, DC Power Supply and transformer.
Month 5	Design implementation of proposed Oxygen Concentrator	Many trials on the proposed design using pressure swing adsorption technology.
Month 6	Design of control circuitry	Made electrical design first on Vero board then developed same design on PCB.
Month 7	Hardware development and assembly	After successful circuit designing and trials finally developed complete hardware prototype.
Month 8	Final prototype , containing all the significant control and hardware interface	Complete assembly of the prototype in the body.
Month 9	Report Writing	Complete report writing under the supervision of supervisor