Vayun Aryan

This week I started as an engineering student in the Clinical Immersion Program in the Urology Department at UI Health. There was no waiting and we got right into in our first day.I observed multiple procedures including cystourethroscopies, cystograms, ureteroscopies, lithotripsy, retrograde pyelogram, and even a bladder chemodenervation using Botox. These were not just surgical procedures but were instances for me to observe how medical tools impact procedures, safety, and patient comfort. They highlighted where engineering still has work to do. Here, I reflect on one good and one bad design that stood out.

Unsatisfactory Design: Double J Ureteral Stent

• Activities: In the stent placement procedures, the blood present on the bladder end showed that patients experienced discomfort.
• Environment: The conversations with clinicians emphasized that patient comfort post-op is still a significant concern.
• Interactions: Bladder irritation from the stent was common, often leading to ongoing complaints during follow-ups.
• Objects: The stent itself is functionally effective in removing fluid from the kidneys however its shape must be redesigned to improve comfort at bladder end.
• Users: Patients recovering from urological procedures.

Good Design: Radiation Shielding Gear

• Activities: Majority of the procedures rely on continuous fluoroscopic (X-ray) imaging, like cystograms, requiring staff to remain exposed for extended periods.
• Environment: Despite long hours in the OR, the surgical team moved efficiently while staying protected.
• Interactions: Everyone: surgeons, residents, and even us observers used lead-lined aprons which were accessible in every OR.
• Objects: The radiation protection gear is well-integrated into the OR flow and offers safety from harmful rays.
• Users: Clinicians working in high-radiation environments multiple times per day. I used it for 3 out of 5 procedures in a single day in the OR.I am really enthusiastic heading into week 2 to learn more in-depth about the hospital workflow and more hands on learning.

One problem that was observed recurring in my initial week of work in the Urology department was patient discomfort due to the double J ureteral stent, particularly at the bladder end. Although the stent is highly effective at its function but its structure usually is a source of irritation and persistent discomfort. I found this issue interesting because it highlights how even commonly used devices can still negatively impact patient quality of life.

In Week 2, while most of my time was spent in the clinic, which was mostly consultations, I continued to notice how frequently stents were discussed during follow-up visits. Hence I decided to focus on the double J stent for this week.

A paper by Mosayyebi et al. (2018),  Advances in Ureteral Stent Design and Materials helped in contextualizing these concerns. The paper says how traditional stents are mechanically effective but often lead to complications such as pain, hematuria, and infection. It also reviews next-generation solutions including drug-eluting, biodegradable, and dual-durometer stents that can improve biocompatibility and patient comfort. What stood out to me the most was the emphasis on material flexibility and tip design as major factors to reduce bladder-end irritation.

The Polaris™ Loop Ureteral Stent by Boston Scientific works upon this problem. This stent features a proprietary dual-loop bladder design, which reduces the amount of material in the bladder by nearly 69% compared to traditional coils, as presented in their brochure. The goal is to minimize irritation while maintaining effective drainage. Additionally it has a tapered tip for atraumatic access and HydroPlus™ coating for ease of placement shows how industry is responding to real-world clinical and patient feedback. Seeing a commercially available device directly confront the problem that I saw firsthand made the connection between research, engineering, and clinical care seem very real.

Although though this week didn’t involve as many hands-on procedures, a particular standout being the single port robotic prostatectomy, but it was a valuable reminder that design innovation doesn’t always come from rare procedures, it can start with the discomfort patients mention in passing. Going forward, I’ll be paying closer attention to everyday tools like these, because they often hold the greatest potential for meaningful improvement.

For this week’s blog, I have decided to build upon the JJ stent I covered previous week. The stent causes consistent discomfort. It has been found that 80% of the patients overall reported bothersome symptoms due to the stent itself including persistent irritation. From a technical perspective, a 2018 review by Mosayyebi et al. summarizes the limitations of traditional ureteral stents and includes ways to improve them. These include using more biocompatible materials, adjusting stent shape, and exploring dual-durometer designs. Commercially, companies have started to come up with solutions. The Polaris™ Loop stent from Boston Scientific minimizes bladder irritation using a dual-loop tip design by nearly 70%. Another product, Medline’s Flexi-Stent, improves flexibility and ease of insertion, although it doesn’t directly target long-term patient comfort.

My needs statement is:

Urology patients undergoing ureteral stenting there is need to lessen bladder-end irritation and discomfort during recovery through improved stent design.

Urology patients undergoing ureteral stenting (Population), there is a need to lessen bladder-end irritation and discomfort during recovery (Opportunity) through improved stent design(Outcome).

Approximately 90-100K stents are placed in the USA every year. Taking the range of cost of a stent — device only , 266 – $500+ USD. Assuming the new stent is sold at a price of 550 USD after redesign, low end TAM (90K) would be 49.5M USD and higher end TAM (100K) would be 55M USD per year. I calculated this using top down method.

The problem may seem small—just a coil inside the bladder—but when multiplied across thousands of patients per year, the potential for impact is enormous.

Refrences:

Transparency Market Research (2024)

https://www.globenewswire.com/news-release/2024/07/05/2909009/32656/en/Rising-Incidence-of-Urinary-Tract-Disorders-Propels-Ureteral-Stents-Market-to-Achieve-USD-823-7-Million-by-2031-Transparency-Market-Research-Inc.html

PMC Article on Stent Design (2024)

https://pmc.ncbi.nlm.nih.gov/articles/PMC10672095/

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Dr. A glanced at the chart in his hand as he stepped into the exam room. “Hi, Ms. B. I see here you’ve been having some burning when you urinate, and maybe a little urgency?”

She nodded. “It started two days ago. I thought maybe it’d go away, but it hasn’t.”

He nodded, already anticipating his next move. “No problem. We’ll get a urine sample to check for a UTI.”

He turned to the nurse. “Let’s do a clean-catch.”

Ten minutes later, Ms. B stood alone in the clinic restroom. In one hand, a paper cup. In the other, a packet of antiseptic wipes. She’d been told to “clean yourself, catch the middle part of the stream, and bring it back.” That was it.

There was no shelf to set anything down. No paper instructions. No visual guide. Just a toilet, a sink, and a closed door. She looked down at what she was holding and let out a quiet sigh.

When she returned, she handed the nurse the cup and waited. Later that afternoon, the results came back: contaminated sample too much bacteria to get a clean read.

Dr. A called her back the next morning. “I’m sorry, but the sample was inconclusive. Could you come in to repeat it?”

Ms. B didn’t complain, “Okay. I’ll try to get off work again.”

By the time she returned the second sample this time with a little more guidance the infection had worsened. She was placed on antibiotics just in case. The follow-up results still weren’t perfect, but they were readable.

Dr. A made a note to maybe give more detailed instructions next time. The nurse made a note to maybe print out a visual guide. And Ms. B quietly returned to her day, hoping she wouldn’t have to come back for this again.
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This was a standard process a basic diagnostic tool used in clinics every day. But this story makes it clear that “routine” doesn’t mean “optimized.” It doesn’t even mean “clear.”

Ms. B didn’t mess up. The system gave her unclear tools for a task we expect precision from. It’s unreasonable to expect patients to collect a clinical-grade sample using an awkward cup, a vague phrase, and zero guidance all while standing in a restroom with no support.

There’s a clear opportunity here: improve the design of clean-catch urine collection to make it more intuitive, standardized, and accurate. Not just for patient comfort, but for clinical reliability. Because it’s not just about convenience it’s about making sure the right people get the right treatment at the right time, the first time.