History and Evolution of the Pacemaker

Transcription

1 History and Evolution of the Pacemaker Figure 1: Italian scientist Luigi Galvani. The famous frog experiment in the late 1700s involved the discovery that electrical energy applied to a frog s leg resulted in the muscle contracting. This fundamental concept paved the way for further research on electrical impulses stimulating the heart muscle. Eventually, this line of scientific inquiry lead to the development of a pacemaker. Figure 2: Frog experiment diagram. In the British Medical Journal, J. A. McWilliam reported on his experiment that involved applying electric impulses to a heart with no activity. This led to ventricular contraction and it was discovered that a heart rhythm of beats per minute could be attained by these impulses. Figure 3: J. A. McWilliam

2 Figure 4: Hyman s first artificial pacemaker. In 1932 Albert Hyman coined the term artificial pacemaker when he developed the machine pictured in Figure 4. It produced an electric current that was operated using a hand crank and a spring motor. The electricity was introduced to the heart via a needle plunged through the chest wall. In 1933 Hyman developed what is called the Hymanotor as seen in Figure 5. This was a huge improvement in terms of portability and other features such as a voltage control knob and a rate control mechanism for administering 30, 60, or 120 impulses per minute. The ethics of this device were heatedly debated during this time. It was questioned whether or not it was natural for an artificial device to be used to extend human life. Figure 5: The Hymanotor a much more portable version.

3 John A. Hopps designed the first catheter electrode for cardiac stimulation. With this device, Hopps was able to control the cardiac rate and stimulate stopped hearts to beat at a predetermined rate. Figure 6: A model of Hopps device. Paul M. Zoll designed an external pacemaker, which stimulated the heart without piercing the chest. It had a maximum voltage output of 150 and due to the painfulness and potential burns, patients were sedated. It did, however, revolutionize the industry. Figure 7: Zoll s PM-65 Pacemaker. Unlike Zoll s device which required a cart with a long enough extension cord to be moved around, Bakken developed a wearable pacemaker that was battery operated and small (See Figure 8).

4 1958 Figure 8: Earl Bakken with his first wearable pacemaker prototype. Earl Bakken founded Medtronic in He designed the wearable pacemaker after a patient died following a power outage using Zoll s pacemaker. Interestingly enough, the day after testing it successfully in the laboratory, he found it already being used on a patient since the FDA did not regulate medical devices at the time. Figure 9: Dr. Elmqvist (left) and Dr. Senning (center) with their first patient, Arne Larsson. Figure 10: Fully implantable pacemaker. Dr. Rune Elmqvist developed the first fully implantable pacemaker that was use on Arne Larsson. Larsson was born in 1915 and died in 2001 at the age of 86. After several heart attacks, Larsson underwent an emergency operation and was the first patient to ever receive a fully implanted pacemaker. He went through 26 pacemakers that all played a significant role in extending his life.

5 Figure 11: Chardack-Greatbatch Pacemaker. In 1960, Medtronic was extremely interested in William Chardack and Wilson Greatbatch s fully implantable pacemakers. They began production and within a couple months, there were orders placed for 50 of the $375 devices. Pacemakers were becoming more commonly accepted and accessible. Due to the short battery life of other pacemakers, Medtronic developed a pacemaker with a nuclear battery made of Plutonium. The expected life increased from approximately a year to 20 years. Later on, the Plutonium was replaced with Lithium which is still used today. Figure 12: (above) Nuclear powered pacemaker. Figure 13: (right) Plutonium battery.

6 2015 Figure 14: Present-day pacemaker. Pacemakers have radically advanced over the last few decades. They have grown smaller and more efficient. The mere function of the device has evolved into much more than simply controlling heart rate. The pacemaker continues to advance and become more reliable and effective. Those who have pacemakers live very normal lives. Figure 15: Present-day x-ray of an implanted pacemaker.