Accelerated life-test methods and results for implantable electronic devices with adhesive encapsulation.

We have developed and applied new methods to estimate the functional life of miniature, implantable, wireless electronic devices that rely on non-hermetic, adhesive encapsulants such as epoxy. A comb pattern board with a high density of interdigitated electrodes (IDE) could be used to detect incipient failure from water vapor condensation. Inductive coupling of an RF magnetic field was used to provide DC bias and to detect deterioration of an encapsulated comb pattern.

Neurostimulation Strategy for Stress Urinary Incontinence.

We have developed a percutaneously implantable and wireless microstimulator (NuStim) to exercise the pelvic floor muscles for the treatment of stress urinary incontinence. It produces a wide range of charge-regulated electrical stimulation pulses and trains of pulses using a simple electronic circuit that receives power and timing information from an externally generated RF magnetic field. The complete system was validated in vitro and in vivo in preclinical studies demonstrating that the NuStim can be successfully implanted into an effective, low threshold location, and the implant can be operated chronically to produce effective and well-tolerated contractions of skeletal muscle.