The inventor of the Pacemaker is John Hopps.

Explanation:

- John Hopps was a Canadian electrical engineer and physicist who is credited with inventing the first cardiac pacemaker.
- He developed the pacemaker in the late 1940s and early 1950s while working on a project to find a way to use radio frequency heating to treat hypothermia.
- While conducting experiments on hypothermia, Hopps discovered that an electrical pulse could stimulate the heart to beat.
- This breakthrough led him to develop the world's first external cardiac pacemaker, which was a device that used electrical impulses to regulate the heartbeat.
- Hopps' pacemaker was a significant advancement in medical technology, as it provided a way to manage and control irregular heart rhythms, which can be life-threatening.
- His invention paved the way for the development of modern pacemakers, which are now implanted into the body and can regulate the heart's rhythm internally.
- John Hopps' invention of the pacemaker revolutionized the field of cardiology and has saved countless lives since its introduction.

In conclusion, the inventor of the pacemaker is John Hopps, who developed the first external cardiac pacemaker in the late 1940s and early 1950s. His invention has had a profound impact on the field of cardiology and has been instrumental in saving numerous lives.