Accessible Incontinence Control Device Biomedical Engineering Senior Design Group 17: Zach Hawkins1, Kristen Heck1, Amy Klemm1, Amanda Streff1 Advisors: Professor Paul King1, Dr. Doug Milam2, Dr. John Enderle3 1Vanderbilt University School of Engineering, 2Vanderbilt University Medical Center Urologic Surgery, 3University of Connecticut School of Engineering Abstract Purpose Design an accessible incontinence control device that will comply with industry standards, can remain indwelling, and is easily operated. The goal was to improve on the current gold standard to better assist patients with other disabilities. Methods The device is operated by pressing a button to send a signal to an RC receiver. The receiver sends a signal to the servo which rotates, pushing the plunger. The increased pressure pushes the plunger attached to the other end of the tubing, collapsing the urethra. Another press of the button will release the plunger allowing for urine to flow. Conclusion Once the device is biocompatible and the status indicator is integrated with the device, it can be implanted for patient use. How It Works First, the cuff is secured around the urethra. To close the urethra: The user pushes up on the radio controller throttle stick to send a signal to the RC receiver. A second signal is sent from the receiver to the servo. The servo rotates clockwise pushing the miniature plunger down similar to how a piston moves. The pressure increase in the tubing forces the second plunger in the cuff to move, compressing the urethra. The device will remain in this position preventing urine flow until the device is activated again using the radio controller. To open the urethra: The signal will cause the servo to rotate counterclockwise pulling the plunger up and causing a decrease in pressure in the tubing. The second plunger releases pressure on the urethra allowing urine to flow out of the bladder.   Inspiration & Goals Inspired by the current gold standard, the AMS 800 (pictured on the right) Manually operated pump Pumping releases pressure in cuff. Cuff is refilled with saline from the pressure reservoir Goals Comply with industry standards for urological medical devices Be able to remain indwelling for 30 days Easily operated by patient with disabilities Allow emptying of the bladder when desired Prevent urine flow when not desired Provide an indication of the status of the bladder. Changes to assist patients with dexterity issues Pump eliminated. A radio controlled servo increases and decreases the pressure within a fluid filled tube The pressure causes a plunger to close off the urethra Background Figure 1: (A) Device (B) Servo (C) Top view of open cuff (D) Side view of open cuff (E) Drawing of device including RC receiver, battery, and controller *drawing not to scale Our Device   A B C D E Conclusions Accomplished the following design goals: Push button operation makes it easier for patients with disabilities to use. Empties and prevents urine flow the bladder when desired. The potential to be implanted in a patient, thus be indwelling for well over 30 days.* Comply with industry standards for urological medical devices.* *with minor modifications Future Directions Further miniaturize the device Coat the entire device in silicone to ensure biocompatability The external button should be equipped with an interface to display the bladder volume status Safety and Cost Estimate Safety Issues Urethral erosion Excessive pressure Biocompatibility Electrical hazard (i.e. shock) Battery malfunction Circuit error Improper sealing $95.70 Total ----- Tubing 0.21 10ml syringe 0.19 3ml syringe (2) 20.00 Battery 8.50 Crystal 34.90 RF receiver 31.90 Servo Cost Supplies Urinary Anatomy Internal urethral sphincter: involuntary External urethral sphincter: voluntary Bladder: empty- a deflated balloon, full-a pear shape that rises in the abdominal cavity. Normal function Urine made by kidneys, travels through the ureters to the bladder. Bladder stretches to accommodate filling. At approximately 250-300cc, stretch receptors in the bladder wall send a signal to the nervous system. Detrusor muscle in the bladder wall contracts and internal urinary sphincter relaxes. The external sphincter contracts until the individual consciously relaxes it to void usually every 4-12 hours. Types of Urinary Incontinence Urge: Involuntary loss of urine associated with abrupt and strong desire to void Stress: Involuntary loss of urine during coughing, sneezing, laughing, etc. Overflow: Involuntary loss of urine associated with over distension of bladder Functional Incontinence: No recognition of need to void, inability to make it to the toilet in time