Urinary incontinence is defined as the complaint of involuntary leakage of urine. It affects at least 13 million people in the United States and this number is expected to increase sharply with the aging of the baby boomers. Urodynamic studies are often used to diagnose the cause of urinary incontinence and consist of measurements of the storage and voiding functions of the urinary bladder and outlet. This project proposes the development of a novel instrumented urethral catheter that will enable significant enhancements to current urodynamic diagnosis. The instrumented catheter will enable measurement of urethral occlusion profiles during provocative maneuvers in both clinical as well as ambulatory environments. This will help determine structural and neurological causes of urinary incontinence, provide instantaneous and continuous measurements of functional urethral length, and help in determining appropriate rational procedures for surgical intervention. The proposed urethral catheter will contain sensors to allow simultaneous measurement of a) Urinary bladder pressure b) Sphincter EMG c) Distributed urethral closure pressures during filling cystometry The catheter will utilize novel device design and micro-fabrication technologies to create the distributed micro- sensors that enable measurement of EMG signals and closure pressure at multiple urethral locations. Embedded signal lines will transfer signals to a single interface at the distal end of the catheter, eliminating the need for wires to individual sensors. The developed catheter will first be tested in a hydraulic pressure chamber in which the fluid pressure can be controlled to different static values and also changed to track dynamic pressure profiles. The linearity of the sensor measurements, repeatability from sensor to sensor, sensor range, sensor resolution and dynamic sensor bandwidth will be evaluated. Finally the sensors will be evaluated in an IACUC approved canine study and an IRB approved clinical study. In the clinical study, we expect to find that the artifactual pressure and EMG signals observed during provocative maneuvers with single site catheters are greatly reduced with the new distributed sensing catheter. The research team for the project includes engineering experts in sensor design and fabrication, surgeons in urology and a professor in urology who has co-founded leading urologic device companies.

Public Health Relevance

This project will develop and evaluate an inexpensive catheter that can be used for improved diagnosis of urinary incontinence. The catheter will help differentiate between structural and neurological causes of urinary incontinence, and will help in determining appropriate rational procedures for surgical intervention.

National Institute of Health (NIH)
National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
Exploratory/Developmental Grants (R21)
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Urologic and Kidney Development and Genitourinary Diseases Study Section (UKGD)
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Bavendam, Tamara G
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University of Minnesota Twin Cities
Engineering (All Types)
Schools of Engineering
United States
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Ahmadi, Mahdi; Rajamani, Rajesh; Sezen, Serdar (2017) Transparent Flexible Active Faraday Cage Enables In Vivo Capacitance Measurement in Assembled Microsensor. IEEE Sens Lett 1:
Ahmadi, Mahdi; Rajamani, Rajesh; Timm, Gerald et al. (2017) Instrumented Urethral Catheter and Its Ex Vivo Validation in a Sheep Urethra. Meas Sci Technol 28:
Ahmadi, Mahdi; Rajamani, Rajesh; Timm, Gerald et al. (2015) Flexible Distributed Pressure Sensing Strip for a Urethral Catheter. J Microelectromech Syst 24:1840-1847
Ahmadi, Mahdi; Rajamani, Rajesh; Timm, Gerald et al. (2015) Distributed pressure sensors for a urethral catheter. Conf Proc IEEE Eng Med Biol Soc 2015:7610-3