By Helena Scutt

In theory, you should have a choice: one respirator is fit for hospital use only and requires expensive compressed oxygen, while the other is portable, uses ambient air, and costs 1% of the original. When you lack reliable electricity and the local hospital can barely afford to stay open, you would like to be able to choose the one most likely to save your child from pneumonia.

The fields of biomedical engineering and public health can seem opposite in their images. One is considered high-end and expensive, and the other resourceful by necessity, utilitarian, and focused on accessibility. The two fields may seem to work at different ends of the health spectrum, but in fact there is potential for important innovation at the intersection of biomedical engineering and public health.

Inspire Medical, a team of four Stanford d.school students, is on a mission “to reduce infant mortality through affordable critical-care technologies.”¹ Andrew Chang, Carey Lee, Pamela Bandyopadhyay Pavkov, and Karen Lum were in the Entrepreneurial Design for Extreme Affordability class when they began developing their low-cost breathing assistant, Inspire. Last spring break, the team paired with a hospital in Dhaka, the capital of Bangladesh, with the ultimate goal of reducing infant deaths from pneumonia.

Chang is the Clinical Director of Inspire Medical and a fourth year student at Stanford Medical School. “One of the things that really surprised us was that pneumonia kills more children every year than measles, malaria and AIDS combined,” Chang said. In fact, pneumonia is responsible for one in five child deaths and kills more children than any other illness in every region of the world.²

“Those deaths can be prevented by fairly simple interventions from a respiratory point of view,” Chang said. “The tragic thing is that it’s a lack of resources that causes these children not to make it. That’s where theextreme affordability comes in.”

Pneumonia is an acute lower respiratory infection where pus and fluid interfere with oxygen absorption in the lungs, making it difficult to breathe.³ Treatment with antibiotics is the most common approach due to its relatively low cost. However, Inspire Medical is attempting to lower the cost of intensive-care technology to make it an equal option to antibiotics. By making cost-effective technology, Chang hopes that Inspire Medical will create “a paradigm shift; you can have affordable and high levels of fairly intensive care.”

The hospital in Dhaka wanted to improve the existing ventilator for pediatric pneumonia, so the team spent some time in big cities discussing improvements. However, after more investigation, they honed in on rural areas, where inconsistent electricity access, the unavailability of compressed oxygen, and cost prevent the use of devices like the Dhaka hospital’s ventilator.

“So,” Chang said, “we thought, let’s create a device that works there.”

With trial-and-error and user feedback, they did just that. Inspire is a bubble continuous positive airway pressure (CPAP) device that works by using pressurized air and/or oxygen to expand patients’ lungs. Inspire’s pump draws in ambient air and filters, humidifies, and compresses it for the patient at an adjustable flow rate that is safe for an infant. Slightly bigger than a shoebox, it costs $200 instead of $20,000, can run off a car battery, and it does not require (but is fully compatible with) compressed oxygen. There is a beauty in the simplicity of the machine.

“There’s a trend in biomedical engineering towards bigger, more glamorous, and more expensive,” Chang said. “In our approach, we’re sh

ooting for cheap and simpler.”

However, the pursuit of cheap and simpler is not without its challenges, most notably, “finding the right pressure source,” according to Carey Lee, Inspire Medical’s chief technology officer. Power is scarce for most Inspire users, but pushing a lot of air through a small diameter breathing tube demands a lot of power. “It took a fair bit of experimentation to find a pressure source that was powerful, energy-efficient, and cheap.”

Experimentation must be practiced carefully, though. “One thing I want to clarify is that interventions and device development can be surprisingly easy since developing nations don’t have the FDA equivalent and regulations,” Chang said. Inspire is working hard to pass all US regulations before they ev

er strap the device onto a baby in the developing world.

Besides, “we would have been shocked and rather suspicious if we’d gotten it right on the first try,” Lee said. The team found that in rural Bangladesh, people were surprisingly hesitant to use wall power and much more comfortable using car batteries since fluctuations in wall power often lead to burn accidents.

“Surprises like this are why we prioritize direct interaction with the user so much,” Lee said. “Without these insights, our device would not be what it is today.”

Inspire is a fantastic example of biomedical engineering applied to public health, particularly with a cost-conscious perspective. Biomedical engineers “spend a lot of money and development time trying to come up with heavy duty devices for rare or complicated conditions,” Chang said. “The problem is that we lose sight of the fact that old problems need to be tackled in new ways.”

Innovators must revisit some of these issues and make solutions more affordable and more appropriate for settings that offer different challenges. “This is called disruptive design. Ultimately, smart design can trump the natural order of things,” Chang said.

However, Lee adds to this, “In my opinion, device creation is just the beginning, and training and follow-up is where the real impact is made. Otherwise, instead of saving lives, your device might just end up gathering dust in a corner.”

Biomedical engineering is one of the fastest growing fields, so even if just a small portion of the industry’s energy is dedicated to investigating public health solutions, many lives could be improved or saved. Chang speaks for the Inspire Medical team in his hope that “at the very least, we get people talking and thinking about solutions to pneumonia but also how we can use innovation to solve the developing world’s problems.”

 

Interviewee Bios

Andrew Young Chang is the Clinical Director of Inspire Medical and a fourth year student at Stanford Medical School. Andrew received his B.S. in Molecular, Cellular and Developmental Biology from Yale University. He worked as a founding intern at Nyaya Health, a health initiative focused on building a primary care and maternal health center in rural Nepal.

Carey Lee is the Chief Technology Officer and received her M.S. in Mechanical Engineering from Stanford after her B.S. in Mechanical Engineering at UC Berkeley. She is an alumnus of Stanford’s Biodesign program and currently seeking patents.⁴

Please visit inspiremedical.org and the Inspire Medical Facebook page for more information.

References

1. Inspire Medical: Welcome Web site. Available at: http://www.inspiremedical.org/Inspire/Welcome.html. Accessed November 1, 2011.

2.  Melinda Gates. World Pneumonia Day – Celebrating Interventions that Save Lives. Huff Post Impact. Available at: http://www.huffingtonpost.com/melinda-gates/world-pneumonia-day—cel_b_1093772.html. Accessed November 14, 2011.

3. The United Nations Children’s Fund and the World Health Organization. Pneumonia: The Forgotten Killer of Children, 2006. Available at: http://www.unicef.org/publications/files/Pneumonia_The_Forgotten_Killer_of_Children.pdf. Accessed November 1, 2011.

4. Inspire Medical: Team Web Site. Available at: http://www.inspiremedical.org/Inspire/Our_Team.html. Accessed November 1, 2011.