Mechanical loading of rigid intramuscular implants

Several groups are developing different versions of a new class of leadless, permanently implanted electronic devices with a size and form factor that allows them to be injected into muscles (BIONs™). Their circuitry is protected from body fluids by thin-walled hermetic capsules made from rigid and brittle materials (glass or ceramic) that include feedthroughs to their electrodes. These packages experience repetitive stresses from the very contractions that they excite. We here provide a worst-case analysis of such stresses and methods for testing and validation of devices intended for such usage, along with the failure analysis and remediation strategy for a design that experienced unanticipated failures in vivo.