Improving medical devices Collaboration by design

Image caption: Clare Donohue at Medical Device Sandbox redesign session. Credit: Lauren Stuart.

by Kim Roth

The design of health-related and medical devices directly impacts patient safety, and engineers and clinicians designing, and using, medical devices depend upon each other’s expertise.

A new experiential learning opportunity at U-M, the Medical Device Sandbox (MDS), helps both BME students and health care learners, including medical students, residents, nurses, and other health providers, collaborate across disciplines to improve device design and, ultimately, patient safety.

“Interprofessional collaboration and shared learning between BME students and health care learners is absolutely critical to designing and using medical devices in the clinic that are effective and safe for patients,” says John Gosbee, MD, a lecturer in the Departments of Biomedical Engineering and Internal Medicine and a human factors engineering and patient safety consultant.

“Interprofessional collaboration and shared learning between BME students and health care learners is absolutely critical to designing and using medical devices in the clinic that are effective and safe for patients,” -John Gosbee

Gosbee conceived of the MDS and, working closely with colleagues, BME Professor Jan Stegemann and BME Lecturer Rachael Schmedlen, has held more than two dozen MDS sessions to date.

The guided, structured, and interdisciplinary sessions begin in a simulated patient examination or hospital room at either the U-M Center for Experiential Learning and Assessment or the Clinical Simulation Center. Gosbee presents the group – typically four to six BME students and four to six medical learners – with a realistic scenario that involves the use of a medical device.

Guided by the instructor, the students identify potential design flaws, use errors, and safety issues.

During a recent session, Gosbee asked a participant to climb on and off the examination table, just as doctors routinely ask patients to do. The other students observed. Gosbee continued to prompt students with probable scenarios – the patient has a twisted ankle, the patient is short, the patient’s hands slip on the paper as they try to climb on.

BME students and health care learners constructing prototypes of their redesign ideas. Credit: John Gosbee and Jennifer Lee.

Next, the group brainstorms possible solutions. In the case of the exam table, students suggested moving the step to the side of the table, adding an extra step, and adding handrails.

Interactivity is key. Instead of simply talking about or sketching the changes they would make, students use prototyping materials – items such as foam core, scrap fabric, glue, and tape – to build a three-dimensional representation of their ideas. Participants then share their ideas with the group, and Gosbee helps them synthesize takeaway lessons.

Sessions have included a range of devices and scenarios, including layperson use of an automated external defibrillator, a pulse oximeter found in a first responder’s medical bag, and a medication organizer a patient would use at home.

Students also have brought course projects to the sessions, for example, a liver biopsy simulator from BME 450 and an existing and redesigned EKG device, brought by internal medicine residents.

The MDS name, fittingly, refers to sandbox mode in gaming, where players are freed from the usual rules and constraints.

“Bringing learners from these two disciplines together has transformative potential,” says Gosbee. “Having a creative physical and intellectual space where this kind of interaction can take place brings everyone closer to their shared goal of safer, more effective devices.”

To date, about 100 medical learners and 136 BME students – from BME 450, 452, 499, 599, and M-HEAL – have participated. BME undergraduate Jennifer Lee (’17) played an important role in organizing and running sessions and ensuring as many BME students as possible participated.

BME students who have taken part in the MDS have said it’s helped them think more about patient safety and usability testing as a crucial part of the design process – and that working with health care learners was a key way to better incorporate their expertise.

Other students said they no longer felt resigned to work with products as they currently exist and felt empowered by the redesign process.

In the words of one participant, “Redesign is an outlet for change.”

The MDS has been supported by the Third Century Initiative at U-M and by the National Institute of Biomedical Imaging and Bioengineering of the National Institutes of Health under Award Number R25-EB019898.


Cancer decoy could capture malignant cells and warn of relapse A small, implantable device that researchers are calling a cancer “super-attractor” could eventually give doctors an early warning

A small, implantable device that researchers are calling a cancer “super-attractor” could eventually give doctors an early warning of relapse in breast cancer patients and even slow the disease’s spread to other organs in the body.

The sponge-like device developed at the University of Michigan is designed to attract the cancer cells that emerge in the bloodstream during the early stages of cancer’s recurrence—before tumors form elsewhere in the body. A new study in mice shows that the device attracts detectable numbers of cancer cells before they’re visible elsewhere in the body. It also shows that the cancer cells spread to the lungs 88 percent more slowly in the mice that received the implants. Cancer cells also spread more slowly to the liver and other organs. The team’s findings are reported in a new paper published in the journal Nature Communications.

Researchers envision the super-attractor being implanted just beneath the skin of breast cancer patients. Doctors could monitor it using a non-invasive scan and it could enable them to detect and treat relapse sooner. It also has the potential to be used as a preemptive measure in those who are at high risk for breast cancer.

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U-M Researchers construct cancer "super-attractor" scaffolds from mouse tissue, using a tumor as a control in the experimental process at the NCRC. Photo by: Joseph Xu

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U-M Researchers construct cancer "super-attractor" scaffolds from mouse tissue, using a tumor as a control in the experimental process at the NCRC. Photo by: Joseph Xu

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“Breast cancer is a disease that can recur over a long period in a patient’s life, and a recurrence is often very difficult to detect until the cancer becomes established in another organ,” said Jacqueline Jeruss, an associate professor of surgery in the U-M Comprehensive Cancer Center and an author on the paper. “Something like this could be monitored for years and we could use it as an early indicator of recurrence.”

Jeruss said the idea for the super-attractor was born from the knowledge that cancer cells don’t spread randomly. Instead, they’re attracted to specific areas within the body. So the team worked to design a device that exploited that trait.

“We set out to create a sort of decoy—a device that’s more attractive to cancer cells than other parts of the patient’s body,” explained Lonnie Shea, the William and Valerie Hall Department Chair of Biomedical Engineering at U-M and an author on the paper. “It acts as a canary in the coal mine. And by attracting cancer cells, it steers those cells away from vital organs.”

The device takes advantage of interaction that naturally takes place between cancer and the body’s immune system. Cancer co-opts the immune system, turning a patient’s immune cells into drones that gather in specific organs to prepare them for the arrival of cancer cells. The immune cells then act like a beacon in the body that attracts cancer to that location. In essence, the team has built a brighter beacon.

When the super-attractor was implanted just beneath the skin of the mice in the study, their cancer-compromised immune systems responded as they would to any foreign object, sending out cells to attack the intruder. Cancer cells were then attracted to the immune cells within the device, where they took root in tiny pores designed to be hospitable to them. The study also found that the cells captured by the implant didn’t group together into a secondary tumor, as they normally would.

Grace Bushnell, BME PhD Student, and Shreyas Rao, BME Research Fellow, look at efficacy results of the cancer "super-attractor." Photo by: Joseph Xu

Grace Bushnell, BME PhD Student, and Shreyas Rao, BME Research Fellow, look at efficacy results of the cancer "super-attractor." Photo by: Joseph Xu

Grace Bushnell, BME PhD Student, and Shreyas Rao, BME Research Fellow, look at efficacy results of the cancer "super-attractor." Photo by: Joseph Xu

Grace Bushnell, BME PhD Student, and Shreyas Rao, BME Research Fellow, look at efficacy results of the cancer "super-attractor." Photo by: Joseph Xu

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“We were frankly surprised to see that cancer cells appeared to stop growing when they reached the implant,” Shea said. “We saw individual cells in the implant, not a mass of cells as you would see in a tumor, and we didn’t see any evidence of damage to surrounding tissue.

The team is evaluating non-invasive scanning technologies that could be used to monitor the device. They’re looking at ultrasound as well as a light-based technology called optical coherence tomography. Such a technology could enable doctors to detect cancer cells in the implant simply by holding a probe to a patient’s skin.

The device’s spongy structure is particularly attractive to circulating cancer cells. It’s made of an FDA-approved material that’s already widely used in surgical sutures and harmlessly dissolves in the body over time. The device implanted in the mouse study was only a few millimeters in diameter; a human-sized version might be a bit larger than a pencil eraser.

While it’s likely several years away from being used on patients, Shea believes the technology could potentially be used for other types of cancer as well, including pancreatic and prostate cancer. The device could also be an important tool in the emerging field of precision medicine, where cells captured in the device could be analyzed to identify the best therapies for individual patients. The team is now working to gain a better understanding of why cancer cells are attracted to specific areas of the body and why they’re so strongly attracted to the device. Shea believes that this information could lead to new insight into how cancer metastasizes and how to stop it.

Shreyas Rao, BME Research Fellow, shows the cancer "super-attractor" in the NCRC. Photo by: Joseph Xu

Shreyas Rao, BME Research Fellow, shows the cancer "super-attractor" in the NCRC. Photo by: Joseph Xu

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Shreyas Rao, BME Research Fellow, shows the cancer "super-attractor" in the NCRC. Photo by: Joseph Xu

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“A detailed understanding of why cancer cells are attracted to certain areas in the body opens up all sorts of therapeutic and diagnostic possibilities,” he said. “Maybe there’s something we can do to interrupt that attraction and prevent cancer from colonizing an organ in the first place.”

The paper is titled “In vivo capture and label-free detection of early metastatic cells.” Funding was provided by the National Institutes of Health (grant number R01CA173745) and the Northwestern H Foundation Cancer Research Award. The university is pursuing patent protection for the intellectual property and is seeking commercialization partners to help bring the technology to market.