The Forgotten History of Semi-Implanted Radiofrequency- and Inductive-Powered Cardiac Pacing Systems.

Radiofrequency-powered and inductively coupled semi-implanted pacemakers offered an early alternative to battery-powered implantable pulse generators by transferring energy across intact skin to a small, implanted receiver. This review summarizes key clinical and engineering developments from the first reported radiofrequency-powered pacing in 1959 through subsequent refinements and commercial implementations, including the Cutler-Hammer and Cordis Transicor RF systems, and it places these efforts alongside the Abrams/Lightwood inductively coupled device commercialized by Joseph Lucas Ltd. These systems reduced implanted size and allowed external servicing, but they imposed major human factors and safety constraints because pacing depended on correct placement and continuous operation of external hardware. As implantable-grade batteries, hermetic packaging, and lead technology improved, fully implantable pacemakers became clinically dominant. The historical experience nonetheless established durable principles of transcutaneous energy transfer that continue to inform modern externally powered implantable therapies where brief interruptions are clinically tolerable.