A Critical Technology

The recent FDA approval of an electrically powered blood pump to be used as an alternative to cardiac transplantation will bring into focus a core WBI technology, methods for transcutaneous energy transmission (TET). Using this technology, no wires or tubes penetrate the skin to supply power to an implanted blood pump, and the problem of infection is significantly reduced.
Shown below is a photograph of a prototype TET system coil assembly. External electronics are used to convert battery power to a radio frequency that is applied to the external primary coil. A completely implanted secondary coil receives this energy and directs it to implanted power conditioning circuitry that produces a direct current which can be used by the motor of the blood pump. 
The original TET system was developed by Craig W. Sherman, now Vice President of R&D at WBI. The outer external primary coil is "worn" on the skin over the implanted secondary coil. Infection has been the most serious complication associated with blood pumps used for long periods of support that require percutaneous wires or tubes. TET preserves the integrity of the skin as a barrier to bacterial entry.

The implanted secondary coil of the TET is made with a dome shape so that when placed beneath the skin, it provides a simple way of properly align the coils. A TET secondary is shown below. In this configuration, developed at WBI for the new rotary blood pumps now entering clinical trials, the TET power conditioning circuitry is contained within the secondary coil assembly. WBI has developed TET systems suitable for virtually any implanted blood pump. Currently, we are working with 3 developers of fully implantable blood pumps to supply TET systems.