Who made the control unit for the pacemaker?

The control unit for the pacemaker was developed by Dr. Paul Zoll in the 1950s, who created the first external pacemaker. However, the first fully implantable pacemaker was designed by Dr. Rune Elmqvist and Dr. Åke Senning in 1958. Their collaboration led to the creation of a device that could regulate heart rhythm without external power sources.