Page 586 - Handbook of Biomechatronics

578 Graham Brooker

Fig. 7 Schematic diagram showing the principle components required for demand
pacing.

primary cells as well as nuclear power sources. The nuclear option was
developed to allow young people to receive a single implant that would last
a lifetime (some are still operating after nearly 30 years). However, the
advent of good lithium batteries, with lifetimes in excess of a decade and
the fact that as technology progresses, it is often expedient to upgrade,
resulted in the demise of the nuclear option. A range of pacemaker types
is shown in Fig. 8.

Fig. 8 Advances in pacemaker technology: (A) an early demand pacemaker, (B) an
example of a nuclear powered pacemaker, and (C) an early CMOS integrated circuit
pacemaker. (Photo courtesy David Prutchi.)