OxyJet CPAP - Simple Design and Low-Cost System for Non-Invasive Ventilation
Updated: Jun 7, 2021
06/07/2021: Open-source OxyJet flow-generator design available here.
A university faculty and a team of research students have created a low-cost device to provide non-invasive ventilation using a helmet or mask and an oxygen source. The OxyJet nozzle uses jet mixing or the “venturi” effect to pull in environmental air to generate a huge amount of flow. The plastic part can be 3-D printed and connected to a high-pressure oxygen tank using standard connecting equipment. The device works with a snorkel-type or CPAP mask, or a helmet.
Dr. Taufiq Hasan teaches in the Department of Biomedical Engineering at Bangladesh University of Engineering and Technology (BUET) in Dhaka, Bangladesh. As the COVID-19 pandemic took hold, they went to work trying to develop a low-cost system that would work in developing countries like their own.
Aurika Savickaite, a co-founder of HelmetBasedVentilation.com, interviewed Hasan and his team.
“At the beginning of the pandemic, we’ve all seen this situation where everybody was saying there’s a shortage of ventilators,” Hasan said. “We asked ourselves, ‘What can we do? We are biomedical engineers. We need to do something.’”
Critically ill patients (about 5 percent of all patients) need invasive mechanical ventilators, but the mortality rate is high for intubated patients, he said. Severely ill COVID-19 patients (14 percent) need a high flow oxygen system or noninvasive ventilators.
“These devices are very expensive, and so we wanted to develop low-cost non-invasive ventilators,” Hasan said. The team decided to focus on CPAPs (continuous positive airway pressure) because they could make a bigger impact by reducing ICU admissions, he said.
Bangladesh presents unique challenges: Unreliable electric power, cylinders often the only source of oxygen – even in hospitals – and scarcity of medical devices.
They tried a couple of designs but realized it needed to be lower cost and simpler. The OxyJet was created.
The cost for the system is $50, without the helmet. It provides a high flow with a PEEP (positive end-expiratory pressure) of up to 20 cm H2O. It can offer a maximum flow of 100 LPM, but is optimized at 65 LPM. If you need a really high oxygen concentration, it’s necessary to use two tanks.
OxyJet needs no electricity, and it’s very easy to use. The team created a user manual to go with it.
Clinical trials are planned at Dhaka Medical College and Hospital (DMCH) in Bangladesh, comparing OxyJet’s high flow with high-flow nasal oxygen, Hasan said.
“If that actually is established then … that means you can make huge savings, because our device, overall, it costs around $50, and you can have high flow nasal oxygen devices costing up to $5,000,” Hasan said.
When the device is approved, the team plans mass production with the help of an industrial partner. Its low cost could be beneficial in other developing countries, he said.
Team members noted the snorkel masks have more air leaks than helmets, but helmets are not readily available and are more expensive. However, helmets reduce aerosolization and are more comfortable, especially for extended wear. The team seeks sponsors and helmet donations.
Savickaite noted the “biggest issue that the people, especially in underdeveloped countries, have is to create that high oxygen flow that’s required for helmet ventilation. How to increase oxygen and keep flow at 60L or above per minute, to prevent CO2 rebreathing, that can be challenging,” she said, noting it should be used in a hospital setting. She also suggests the OxyJet could be used when transporting patients by ambulance or in the ER.
“If you can put this on the patient early in the disease, early in respiratory distress, you may avoid the progress of this, have fast recovery and the avoidance of intubation,” she said.
Hasan and his team are excited, but they wish they had reached this point earlier.
“We faced a lot of challenges,” he said. They would order parts, but they weren’t delivered. They didn’t have adequate testing equipment to measure parameters in the lab.
“We hope to get this working, no matter how long it takes. But it is what it is. In a developing country, you have different challenges, which are not present in developed ones, especially when you are trying to create something new. So, it took some time,” Hasan said.
Savickaite offered praise for OxyJet:
“I love it. It’s simple, it’s cheap, and it works!”
More info about the device: "OxyJet CPAP: Design and Evaluation of a Low-cost Non-Invasive Ventilator for COVID-19 patients"
Md Kawsar Ahmed, Meemnur Rashid, Kaisar Ahmed Alman, Farhan Muhib, Saeedur Rahman, and Tauﬁq Hasan. Department of Biomedical Engineering (BME), Bangladesh University of Engineering and Technology (BUET) Dhaka - 1000, Bangladesh.
Paper published by the team:
OxyJet: Design and Evaluation of A Low-Cost Precision Venturi Based Continuous Positive Airway Pressure (CPAP) System
Md. Kawsar Ahmed, Meemnur Rashid, Kaisar Ahmed Alman, Farhan Muhib, Saeedur
Rahman, and Taufiq Hasan
Open-source OxyJet flow-generator design available here.
Update 12/11/2020: Initially, the team wanted to open-source the design but this move will slow the mass-production of the OxyJet in Bangladesh. For that reason, OxyJet is not an open-source design.