Friday, March 22, 2013

Barouh Berkovits (1926-2012)

When my March 2013 issue of the journal Heart Rhythm arrived this week, I found in it an obituary for Barouh Berkovits, who died last year.
“Barouh Vojtec Berkovits passed away on October 23, 2012, at the age of 86 years. Berkovits was a master of science and an electrical engineer. Born in 1926 in Lucenec, Czechoslovakia (today Czech Republic), he worked as a technician behind the enemy lines. He escaped the Holocaust, but his parents and sister Eva perished in Auschwitz, Poland. In 1949 he immigrated to Israel and in 1956 to the United States… Berkovits invented and patented the first demand pacemaker capable of sensing the R wave…For his contributions to the treatment of cardiac arrhythmias, Berkovits received the ‘Distinguished Scientist Award’ in 1982 by the Heart Rhythm Society.”
The story of how Berkovits invented the demand pacemaker is told in Machines in Our Hearts, by Kirk Jeffrey.
“Barouh V. Berkovits (b. 1924), an engineer at the American Optical Company, was already well known as the inventor of the DC defibrillator and the cardioverter, a device that interrupts a rapid heart rate (tachycardia) with low-energy shocks. He knew that when the cardioverter discharged randomly into the tachycardia, it would ‘occasionally not only not stop the tachyarrhythmia…but would produce ventricular fibrillation.’ Cardioversion has to be synchronized to fall within the QRS complex and avoid the vulnerable period of the heartbeat. In 1963, Berkovits applied this principle to cardiac pacing. To solve the problem of competition [between the SA node and the artificial pacemaker], Berkovits in 1963 designed a sensing capability into the pacemaker. His invention behaved exactly like an asynchronous pacer until it detected a naturally occurring R wave, the indication of a ventricular contraction. This event would reset the timing circuit of the pacemaker, and the countdown to the next stimulus would begin anew. Thus the pacer stimulated the heart only when the ventricles failed to contract. It worked only ‘on demand.’ As an added benefit, non-competitive pacing extended the life of the battery.”
The 4th edition of Intermediate Physics for Medicine and Biology does not mention Berkovits by name, but Homework Problem 45 in Chapter 7 does analyze the demand pacemaker.
Problem 45 A patient with “intermittent heart block” has an AV node which functions normally most of the time with occasional episodes of block, lasting perhaps several hours. Design a pacemaker to treat the patient. Ideally, your design will not stimulate the heart when it is functioning normally. Describe
(a) whether you will stimulate the atria or ventricles
(b) which chambers you will monitor with a recording electrode
(c) what logic your pacemaker will use to determine when to stimulate. Your design may be similar to a “demand pacemaker” described in Jeffrey (2001), p. 132.
Of course, the reference is to Machines in Our Hearts. Berkovits’s phenomenal career is yet another example of how knowledge of engineering and physics can allow you to contribute to medicine and biology.

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