spoonful of sugar

According to the American Diabetes Association, the CDC estimates that nearly 1.6 million Americans have type 1 diabetes. For those diagnosed with type 1 diabetes, the body does not produce insulin which is a hormone that helps blood sugar enter the cells in your body where it can be used for energy.

The burden of type 1 diabetes is considerable. Sufferers rely on lifestyle changes and are dependent on insulin therapy in order to manage their condition. For people like Villhauer and his wife who recently welcomed their first daughter, Cecilia Christine Villhauer on July 9, 2020, it’s important that his wife be able to manage her diabetes in the most productive
way possible.

We recently caught up with Villhauer to discuss his research and to learn more about how his work could be used to improve the lives of those diagnosed with type 1 diabetes.

Q1: How can your Autonomous Artificial Pancreas System (AAPS) help those with type 1 diabetes?

The Autonomous Artificial Pancreas System (AAPS) will help patients with type 1 diabetes manage their blood sugar by replicating the functions of a healthy pancreas.

A normal functioning pancreas is responsible for controlling the human body’s blood glucose level by releasing insulin or glucagon into the bloodstream when it detects changes in the amount of glucose in the bloodstream. Individuals with type 1 diabetes, which is often referred to as juvenile diabetes, have a pancreas that is incapable of adequately controlling blood glucose level.

Q2: How did this problem come to your attention?

My wife, Marie, has type 1 diabetes. For a long time, she had to manage her blood sugar levels by administering insulin and then periodically check her blood sugar level using a finger stick to determine additionally actions were necessary. She was diligent about managing her blood sugar, but even so, she struggled to regularly keep her blood sugar levels within the target range.

For someone with diabetes, failing to keep their blood sugar within range can lead to some very serious health complications. If someone’s blood sugar level gets too high, it can lead to infections in the near-term and other complications in the long-term. If their blood sugar drops too low, there is a risk of loss of consciousness or even death. On a handful of occasions, I’ve had to call the paramedics because Marie had lost consciousness due to extreme hypoglycemia (low blood sugar level).

Marie started using a Continuous Glucose Monitor (CGM) about two years ago, and it has really helped her stay on top of her blood sugar levels. However, there is still a need for her respond to the changes in her blood sugar levels that are detected by the CGM by administering insulin manually. There’s still a ton of room for improvement.

The objective of the AAPS is to close the control loop and significantly reduce the burden on patients with type 1 diabetes for managing their blood sugar by having the system autonomously respond to changes in blood sugar levels. This would both enhance a patient’s quality of life and facilitate better blood sugar level management.

Q3: How did you approach solving this problem as a system engineer?

In order to solve this problem as a system engineer, I started by trying to understand the needs of patients with type 1 diabetes. In order to do this, I walked through the different scenarios in the concept of operations (CONOPS), which included tasks like managing blood glucose level, and responding to hypoglycemia. This helped me visualize what the AAPS needs to be capable of.

From there it was a matter of identifying currently available tools/products/systems that can be used to support part of the CONOPS, piecing them together, and identifying gaps that would need to be filled in during the design and development of the AAPS. This process was iterative and was repeated until I was able to drill down to the right level of detail.

Q4: How does the AAPS system do a better job of helping those with type 1 diabetes than systems already in use, or others that are on the market?

The solution that I came up with for the AAPS loops the blood sugar monitoring functionality of a CGM with the insulin delivery functionality of an insulin pump and adds the ability to deliver glucagon. Glucagon is a hormone that is involved in controlling blood sugar (glucose) levels.

This is an improvement over readily available systems because it integrates blood sugar monitoring with both insulin and glucagon delivery to autonomously manage patient blood sugar levels. All 3 of these functions are available today through disparate products.

The AAPS builds on these technologies and adds value by integrating them together in a single system.

Q5: Do you think your solution is a realistic option?

The AAPS is a realistic option because it is largely composed of technologies that exist today. The capability to integrate these technologies is a big step forward, but it’s a reasonable step forward because it doesn’t require the invention of new medical techniques.

Q6: How have your studies in the Systems Engineering program played a role in the project development?

Working on this project helped reinforce the value of the JHU Systems Engineering program. I had been exposed to many of the different aspects of Systems Engineering throughout my career, and the JHU SE program helped to tie all those aspects together.

After completing the project, I realized that I really do have command of the SE process, and going through the JHU SE program has a lot to do with that.

The Systems Engineering program at Johns Hopkins Engineering regularly highlights the design projects and in-depth thesis research of its students. We will continue to make these presentations available so that they can benefit the entire systems engineering community.