Control Circuit for DIY Ventilator Empowers Patients
When Georgia Tech mechanical engineering students created a 3-D-printed ventilator to help the shortage caused by the Covid-19 pandemic, it was the work of School of Computer Science (SCS) Ph.D. student Prithayan Barua that made their design standout.
Barua created the control circuit that enables the ventilator to be run remotely.
When lockdown started in early March, Barua’s friend Prasoon Suchandra, a Ph.D. student in mechanical engineering, reached out for volunteers to develop a control circuit for their emergency low-cost ventilator project led by Devesh Ranjan, a professor in the George W. Woodruff School of Mechanical Engineering.
“I had some experience in developing such circuits and programming the controllers, so I decided to help them,” said Barua, who normally works on program analysis and compiler optimizations for SCS Professor and incoming Chair Vivek Sarkar’s Habanero Extreme Scale Software Research Lab.
Power of the control circuit
Since the Covid-19 pandemic started, people across the world have been building makeshift ventilators, but most of them have no or minimal controls and work only on sedated patients.
“Without the control circuit, a medical professional has to manually monitor and control all such parameters for patient safety,” Barua said.
A control circuit makes it possible to control and monitor all the different vitals that doctors need for any ventilator to be useful: respiration rate, tidal volume — a measure of how much air is inhaled in a breath — inspiration and expiration ratio, and pressure on lungs.
Yet the control circuit also empowers the patient. Barua added sensors and a RaspberryPi controller that reads the sensors, performs some numerical computations, and updates a user interface continuously in a loop, eliminating the need for a medical professional to be present.
A patient can support the volume of air delivered, time their breathing, and cough without fighting the ventilator. In effect, the ventilator reduces the involvement of a medical professional.
Future of the ventilator
Making a functional ventilator was one of the goals of the project.
“Our entire team has spent a lot of effort on developing a design that can be really useful in the current situation,” Barua said. “We have interacted with different doctors and hospitals and taken their feedback into account.”
The team has also ensured that it can be manufactured cheaply with easily available raw materials almost anywhere in the world. They hope to openly release the design, so that anyone can mass manufacture it. They are also exploring partnering with a few potential companies around the world to manufacture the ventilator. Whoever manufactures it will get the required certifications and have legal liability for the device.
Research to reality
Although the work doesn’t overlap much with his typical research, Barua applied some approaches he uses in his work on optimizing the memory access patterns on graphics processing units (GPUs). For the ventilator project, he selected, updated, and processed appropriate data structures to optimize the program. He also applied simple parallelization methods like multiprocessing to achieve the right sampling rate for the RaspberryPi.
“It was interesting to see the ventilator being built from scratch in the workshop, working with oscilloscopes to debug our circuit in the electronics lab, and developing programs to control actual mechanical systems,” he said.
For Barua, the main goal was having a positive impact during the pandemic and collaborate on a real-world problem.
“This project was also unique since we were remotely collaborating with a very big team from different departments including the Georgia Tech Research Institute. It was a great learning experience.”