(109) Transdermally Powered, MRI Conditional Pump-in-Reservoir Implant Inflator System: Preclinical Studies

Abstract

Abstract Introduction Inflatable medical implants have been used in the treatment of erectile dysfunction and both urinary and fecal incontinence. However, commercially available devices have required manual operation, which present difficulty in their use for patients lacking strength and dexterity to use such pumps. In women with urinary incontinence, anatomical constraints limit the use of manually operable inflatable devices. Objective The aim of this study was to conduct preclinical testing of a wirelessly powered inflatable medical implant system consisting of a medical provider software application, a patient external controller, and a magnetic resonance imaging (MRI)-conditional nonferrous pump-in-reservoir implant system. Methods An inflatable medical implant system was designed and tested. Serial prototypes designs included a nonferrous, reservoir-submerged package containing electronic motor and pump with piezoelectric valves, and an external controller resembling a TV remote. The implant system was evaluated after being connected to commercially available penile prosthetic cylinders. Power settings were tested at various thresholds; testing requirements considered to be clinically applicable were set as fluid transfer of 60 ml of normal saline at 25 psi within 45 seconds. The effectiveness of power transmission across the human abdominal wall was tested using an interface of a steak slab placed between the external controller and the implant system. Results Device testing at 24 and 36 volts determined that the latter was more efficient and afforded a smaller motor and pump package. Full penile cylinder inflation was recorded at 23 seconds. Effective power transmission was demonstrated across steak slabs. Conclusions A nonferrous pump-in-reservoir medical implant inflator system for penile prostheses is legitimate. It offers an improvement over manually operated inflatable devices, and because it eliminates a manual pump component there is feasibility of constructing a modified device for fluid transfer of urethral cuffs for treating urinary incontinence in men and women. The pump package within the reservoir is advantageous as a heatsinking feature that may limit implant overheating. Finally, the device design without ferrous components affords MRI compatibility. Disclosure Any of the authors act as a consultant, employee or shareholder of an industry for: Boston Scientific, Novartis