Early Pacemakers

I've attached this link to a 2010 article that outlines the early history of the pacemaker.

https://www.ajconline.org/article/S0002-9149%2810%2901042-8/fulltext

It's extraordinary that the first device was developed as a result of choosing the wrong component in the circuit.

The first device ran on watch batteries (cells) connected in series to give about 8-volts.

if you include the battery, the circuit in the article has nine components, a transformer, two transistors, some capacitors and resistors. Modern pacemakers will have thousands to millions of transistors in the processor alone. There will be many more components built into the chips themselves.

The circuit is an oscillator, a blocking oscillator, that continuously produces a pulse every second.

The timing is a result of the values of the components.

Once implanted, there would be no means of adjusting any of the parameters. Later models could be adjusted by inserting needles through the skin or rotating magnets.

The same circuit could be reproduced today from easily available components for a few pounds. even adding a microprocessor would only add a pound or two.

The big difference between the early pacemakers and modern is that early types were hardware driven and modern types are software driven. A modern device won't do much until it is loaded with code and programmed.

1 Comments

Early and future pacemakers

by Gemita - 2024-09-08 13:41:56

An excellent article Piglet and how things have changed.  I see that the first successful human cardiac pacemaker implantation was carried out in the United States in Buffalo, New York on 6th June, 1960.  Dr. William Chardack implanted a pacemaker, designed and built by Wilson Greatbatch, an electrical engineer and inventor, in a 77-year old man with complete atrioventricular block, extending the patient's life by a mere 18 months.  Clearly things have already moved on since the article was first published in 2010, but how far we have come since those very early days.  Would anyone want to go back?  

Just imagine living in a period when settings were managed and accessed using special needles inserted percutaneously to adjust rate and output.   Alternatively, some pulse generators had magnetic bi-stable switches. Magnet movement in either direction caused the rate to change from 70 to 100 beats/min, depending on patient preference.  The devices were much larger then and no doubt extremely uncomfortable.

Looking to the future, I see from the link that biologic pacing research is a promising area.  To design pacemakers that will not need battery changes or lead insertion and can offer a stable physiologic rhythm with innate autonomic responsiveness, several gene and cell therapy researchers have been attempting to “build” a biologic pacemaker. The model for this therapy is the sinoatrial node; the goal is to recreate its structure and function.   Why biologic pacing given the excellent performance and reliability of the current electronic pacemaker models, the link asks?  Why expend research time and resources on the pursuit of biologic pacing?  The answer seems to be “because we have the imagination, the beginning tools, the will, and the possibility that maybe, just maybe, one can recreate the normal function of the heart using entirely biological materials".  

Where will all of this end, I wonder?  Thank you for posting Piglet

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I'm 35 and got my pacemaker a little over a year ago. It definitely is not a burden to me. In fact, I have more energy (which my husband enjoys), can do more things with my kids and have weight because of having the energy.