Patient-Centric Approach Helps Bioengineering Students Simplify Self-Catheterization

Born with spina bifida, the young college student was paralyzed from the waist down. Unable to empty her bladder voluntarily, she struggled to self-catheterize multiple times each day and night. Even though her dexterity was good, she had a hard time accessing her urethra and contracted numerous urinary tract infections each year.

While this particular patient was a fictitious creation of Stanford urologist Dr. Craig Comiter, he wrote her story based on years of working with patients with neurogenic bladder, a condition in which the patient lacks bladder control because of a brain, spinal cord, or nerve problem.

The vignette was one of several prepared for students in the Bioengineering Senior Capstone Design course, a two quarter class in which students work in teams to identify a specific healthcare problem, define a meaningful outcome to achieve, and then use everything they have learned in the bioengineering major to develop a novel solution.

“The Capstone Course is the most challenging lab-based endeavor of the bioengineering major,” said Ross Venook, one of the leaders of the course who also directs engineering at Stanford Biodesign. “Each student team has a clinical mentor, like Dr. Comiter, a course mentor, in this case Dr. Richard Fan, and access to extensive industry resources. But there isn’t a go-to person who knows the answers to the problem they’re trying to solve because it’s never been done before.”

After reading the vignettes, the students choose their favorites, and the course staff forms them into teams based on student interest and diversity of background experience.  Senior bioengineering students Maria Iglesias, Amada Urke, Gabe Ho, and Issac Justice all gravitated towards the young college student. “I think we were drawn to the idea of wanting to improve her quality of life,” said Iglesias. “There was a sense that while we personally couldn’t really understand what this patient was going through, we recognized that our lives would be very different if we had this amount of difficulty with a simple task that we take for granted.”

The team started by researching different forms of urinary incontinence. They decided to focus on patients with neurogenic overflow incontinence (characterized by the involuntary release of urine from an overfull bladder), which meant their solution would not only help spina bifida patients, but potentially others with the same problem due to other causes.

Next the team started thinking about what they could do that would measurably improve quality of life for patients unable to void voluntarily. “We had lots of flashy ideas like using electrical stimulation of the bladder to treat the condition,” said Urke. “But we forced ourselves to stay solution-agnostic, and ultimately focused on the very impactful problem of urinary tract infections. If our solution could reduce UTIs, not only would that improve the patient’s quality of life by reducing discomfort, extra doctor’s visits, and antibiotic use, but it would attract the interest of stakeholders like physicians and hospitals.”

The team knew from their research that it was ideal for patients to be able to perform self-catheterization so they didn’t have to resort to more invasive and expensive surgical methods like an indwelling or suprapubic catheter. And they knew that self-catheterization was difficult. “But,” said Justice, “we didn’t really understand why.”

Tasked with finding a way to understand the patient experience, Justice uncovered a technique called journey mapping, which walks a patient through a particular process or standard of care and has the patient rank the difficulty of each step. The team created a detailed questionnaire around self-catheterization and reached out on social media to a support group for urinary incontinence. “We ended up with nearly 50 responses,” Justice said. “The results clearly highlighted the most difficult parts of the process. The top one for females was the difficulty of locating the urethra for insertion of the catheter.”

“Dr. Comiter had said that, in his opinion, this was the most difficult step and also one of the major reasons females get UTIs – they miss the urethra, the catheter becomes contaminated, and when they insert it again the external bacteria enters the urinary tract and causes the infection,” said Iglesias. “But it was awesome to see the problem validated by real patients,”

The team also learned that for females, locating the urethra often requires strapping a mirror on their leg, an additional step that can make the process even more time-consuming. “It made us think about how, through the mechanism of use, we could help the patient be certain they were on target,” said Urke.  She added, “It also brought home the importance of conducting surveys and actually speaking to patients before you get into the design of a solution.”

With a thorough understanding of the problem, the team began considering solutions. After experimenting with several techniques, they decided that the easiest and most intuitive approach for women would be to use the vagina as an anatomical landmark to help locate the urethra and position the catheter at its entrance. They developed more than 40 prototypes of a handheld device to accomplish this objective and then 3D printed the most promising designs.

Testing the designs, however, proved challenging. “It’s an invasive process that doesn’t appeal to healthy volunteers,” said Iglesias. “So we got creative. We made a pair of shorts with a faux vagina and urethra, and used the shorts to test each prototype on ourselves. And from that we could tell pretty quickly when one of our prototypes just wasn’t going to work.” The team also recruited outside volunteers, since their actions revealed other design flaws, such as when they inadvertently grabbed the vaginal insert instead of the handle. The process helped them narrow to three final options. After more than 40 blindfolded and non-blindfolded self-catheterizations using the shorts model with each, the team had their top design.

By the end of the spring quarter, the students had a working prototype of their device.  They filed a provisional patent and, with extension funding from Stanford Biodesign’s NEXT extension funding program, produced an even more refined device using medical-grade plastic. Guided by Venook, they entered the VentureWell DEBUT competition, sponsored by the NIH, and won the $15,000 Venture Prize. Buoyed by interest in the solution, they are currently exploring regulatory pathways and planning next steps to advance the device, including usability testing with real patients. 

Interestingly, the team didn’t initially plan to take their solution forward until they realized its potential. “Because it’s a patient-facing solution, it needed to be low cost and low tech to be accessible,” said Ho. “And that approach – that focus on the needs of the patient – led to the design of a product that is simple and elegant enough to have real potential to help thousands of patients.”

“It’s a device that could help many people,” said Comiter. “The patient still has to find a private location, transfer from the wheelchair, remove clothing, and perform an invasive procedure. But it is a simple, low-cost approach that can save time, make a frustrating process easier for females and decrease their risk of missing the urethra and causing an infection. It really showcases the power of fresh thinking and an interdisciplinary approach. When doctors hear about infection, our solution is antibiotics. When these engineering students were confronted with infection, their response was, ‘let’s find a way to prevent the contamination of the catheter in the first place.’”