Who Engineers Biomedical Devices?

Transcript

ERIC: In an average lifetime, the human heart beats about two billion times. Biomedical engineers create and improve devices which can help us understand and support the complex biology of the human body such as the electrical currents that are behind every single one of those heartbeats.

Today on Pulsar, we talk with a biomedical engineering student about just what goes into imagining and creating those devices. I'm your host, Eric. Thanks to Facebook Boston for supporting this episode of Pulsar.

My guest is Akshita Rao, an undergraduate double major in Mechanical and Biomedical Engineering at Tufts University who will be graduating this year. Akshita, thanks for joining me.

AKSHITA: Yeah, I'm super excited to be here today and talk a little bit about my research.

ERIC: Some of our listeners may have met you before at the museum over the last few years.

AKSHITA: Yeah, me and the Museum of Science go way back. I started off as a volunteer in my sophomore year of high school and I worked my way up and I was a part time staff there until my sophomore year of college.

ERIC: When we ask what questions our listeners have about a subject, many times they want to know more about what that subject really is. So can you talk a little bit about what biomedical engineering really is?

AKSHITA: Sure, yeah. So it sounds like a very heavy term. So if were to just Google it, you probably get answers that biomedical engineering is a mix of biology and medicine with a lot of fabrication of engineering techniques.

And this is entirely true. So BME, which is just a short form of biomedical engineering, focuses on advancing health care and improving human health by using the engineering design process and other research methods.

And in my opinion, what I think makes BME so unique is that it's such a broad range of disciplines within the field itself. So you have so many engineers in the field that develop medical devices or prosthetics, which are basically implants that people wear on the human body.

And you also have biomedical signal processing. And even more on the nano level, you have even tissue and stem cell engineering. So BME truly covers all of the science and medicine aspects with a cool range of engineering skills involved with it as well.

ERIC: Biomedical engineering already has so much of the engineering discipline in it already. So why did you decide to also study mechanical engineering?

AKSHITA: So I initially joined Tufts with the intention to just major in biomedical engineer because biology was my favorite subject in high school. But I've always really liked the hands on aspect of mechanical engineering, so I was also part of the robotics team.

And, I don't know, I just always liked designing and actually tinkering around with tools. I did a couple of BME classes my freshman and sophomore year, but also some intro level engineering class that crossed over with mechanical engineering department.

And I think that halfway through my sophomore year I realized that I actually enjoyed my mechanical engineering classes just a little more than my biology classes.

And I realized it's because I've always been interested in how devices work and how they function. The mechanical engineering department here really focused on creating and designing devices that I was interested in.

ERIC: And why did you decide to keep both instead of switching to mechanical engineering?

AKSHITA: I didn't want to quit BME entirely because I still enjoy learning about the different biology applications and everything. Majoring in mechanical engineering has really given me a great exposure to all of the mechanics and structural materials that you learn through studying mechanical engineering.

ERIC: And do you think studying both gives you a unique approach to problems in biomedical engineering?

AKSHITA: I think it has really given me a more hands on perspective when it comes to BME. So I usually tend to sketch things out. And I think a lot of biology and BME majors think of things conceptually rather than designing and going through the engineering design process.

I think that's more a cool characteristic of mechanical engineering.

ERIC: We talk with a lot of scientists and engineers on the podcast who work at the intersection of multiple disciplines. Can you tell us how that can strengthen a project that lots of people are working on?

AKSHITA: This past summer, I interned at this medical device company called Insulet where they design diabetic insulin pumps. And it was really interesting because on the team we had a wide range of engineers who studied BME and mechanical engineering and even computer science.

The cross-functional aspect of all those different kinds of engineering intersected at what-- exactly the company was aiming to prototype at the end of the summer. I think it's really cool that when we say engineering, it's such a broad spectrum of different sciences and techniques that you learn.

The focus of biomedical engineering is that you learn certain tricks that a computer scientist wouldn't necessarily cover in their classes.

I think that intersection between all the different engineering backgrounds is what's important to making a-- team to be successful.

ERIC: The research that you've recently participated in involves looking at heart tissue. So can you give us some background?

AKSHITA: Cardiac dysfunction actually represents one of the largest causes of natural death in the United States. But due to the advances of regenerative medicine and biotech, there have been a lot of devices that have been made to replace defective heart tissues.

Cardiac patches have been used to treat defective heart tissue after heart attacks. They're seeded into heart tissue, basically, and onto three dimensional scaffolds. And then, they're implanted inside a patient to replace damaged tissue.

ERIC: Are there any limitations to this kind of tissue implant?

AKSHITA: There's no feedback that the doctor can get to see whether the patient's heart is recovering after a heart attack because there's no like proper electronic integration. So once it's implanted, it's just in there. And you just have to assume that it will work for the best.

The goal for our research was to try to create a device for pharmaceutical companies and doctors to see how certain drug assays actually work in heart tissue. So that way they get a better idea of how they can improve clinical treatments for our heart patients of the future.

So for my research, we focused on constructing something that's called a 32 channel, multi electrode array. So I'm going to call it an MEA for short. But basically, these are small chips that allow us to measure electrical heart activity on the surface level of tissues.

ERIC: So this research was really about measuring our body's electricity.

AKSHITA: Essentially, there are multiple cells in our body that create electrical currents. And they create changes in voltage that are known as action potentials. And the goal with these chips are to, essentially, collect these changes in voltage.

And the devices will create these graphs that show the change of the voltage along with time.

So essentially, when you add some sort of stress or put the cardiac cells under a situation like hypoxia where there's no oxygen, you would expect to see changes in these recordings of beating.

It just makes it easier for doctors to understand how heart tissue would react under certain cardiac stimulation environments.

ERIC: How did it go, actually building this heart on a chip?

AKSHITA: There's a lot of trial and error these devices and trying to reduce the noise from the signals that we were collecting.

But yeah, eventually, by the end of the research, we were able to conclude that these MEAs fulfilled their purpose of collecting accurate live readouts from heart tissue.

ERIC: And then, this wasn't improving an existing device. This was actually taking an outstanding medical question and building a brand new device to try and get an answer.

AKSHITA: Exactly, right. And I think what the coolest part about research is that it's not an idea that just popped into my head one day. It took a lot of background research and reading a lot of previous literature that had talked about future ideas that could be implemented.

And I think we adopted an initial idea from a paper that they were saying, oh, we could probably do this in the future. I'm like, OK, why don't we try and solve that?

So yeah, so I think a lot of the research stems from previous work that's already been done in the field.

ERIC: So what's next for this research? What's the next step?

AKSHITA: This year I'm actually working on a senior honors thesis. So I'm going to be carrying forward the work that I've been doing. And so, basically, these chips that we created are two dimensional.

So we want to see whether we can convert these channels into creating three dimensional devices. So you could just collect more accurate readouts because the human body is three dimensional and not two dimensional.

This time, we want to design the device so it's more flexible. And so we can use it on, actually, neural tissue, so brain cells. Because neurons also exchange action potentials and have voltage changes. So we want to make sure that our devices are applicable for various kinds of cells in the human body.

So our next goal is to make it a flexible three dimensional device. And the best model for that is a three dimensional brain model. Yeah, so we're slowly moving on from the heart to the brain and using the same idea of collecting for signals from brain cells.

ERIC: And finally, why do you think it's so important to continue to improve medical technology and engineer new devices?

AKSHITA: I'm definitely super-biased when I say medical technology is by far the coolest thing. And I think it's really cool because it's always improving and changing the future of health care.

I've always wanted to help people. That's the reason why I joined engineering and wanted to study in college.

And I think it's just creating devices that can improve the quality of life is one of the main benefits of creating innovations in medical technology. And especially medical devices, a lot of patients use them to live a longer life and try not to spend as much time in the hospital.

So I think it's always important to not only create new technology but also to improve on what we have. And I just think, especially, in times like during the pandemic now, we've been using so much like medical technology to try to recover patients as soon as possible.

So I don't know. I just think it's really important to stress how important it is that medical scientists and doctors are just continually doing research and testing new procedures to develop things like vaccines, which also count as medical technology.

I just think it's a really important field and I can't wait to see how it just continues growing in the future.

ERIC: Well, we're really excited to see what you'll do. Akshita, thanks so much for talking with me today.

AKSHITA: Yeah, thank you so much for having me.

ERIC: You can learn more about the biology of the human body in the green wing of the Museum of Science in our Hall of Human Life. Visit engage.mos.org to support the Museum of Science and MOS at home.

Until next time, keep asking questions.