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National Academy of Engineering Memorial Tributes: National Academy of Engineering, Volume 10
Membership Directory
PublisherNational Academies Press
Copyright2002
ISBN978-0-309-08457-4
Memorial Tributes: National Academy of Engineering, Volume 10

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  • OTTO H.SCHMITT
    
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             OTTO H.SCHMITT                                           201
    
                             OTTO H.SCHMITT
    
    
                                      1913–1998
    
                    BY HERMAN P.SCHWAN AND DAVID B.GESELOWITZ
    
                OTTO HERBERT SCHMITT died on January 7, 1998, in Minne-apolis
            three months shy of his eighty-fifth birthday. Otto will be remembered for his
            scientific contributions to biophysics and biomedical engineering, for the crucial
            role he played in the establishment of these fields, and as a great inventor.
                Otto was born in St. Louis, Missouri, on April 6, 1913. He obtained his B.A.
            degree at Washington University (St. Louis) in 1934 and his Ph.D. degree in
            physics and zoology in 1937. He was a National Research Council Fellow and
            Sir Halley Stewart Fellow at the University College in London during 1938 and
            1939. During the war he served as a research engineer at Columbia (1942 to
            1943) and supervising engineer, Special Devices Division, Airborne Instruments
            Laboratory (1943 to 1947). He joined the University of Minnesota, Minneapolis,
            as an instructor of physics and zoology in 1939. He retired in 1983 as professor
            of biophysics, biomedical engineering, and electrical engineering, although he
            continued to teach and work in his laboratory.
                Otto was a leader of the emerging fields of biomedical engineering and
            biophysics. His interests covered many fields. His broad orientation was largely
            due to his inquisitive mind and his education, which was unusually diversified.
            Another important influence was his admired older brother, Frank Schmitt, an
            out
    
    
                 
    
    
             OTTO H.SCHMITT                                           202
    
             standing neuroscientist whose work was also broadly oriented. But most of all, he
             depended on his wife, Viola, whom he married in 1937 and who preceded him in
             death after a marriage of fifty-eight years. Viola was always at his side. She kept
             order in his incredible productivity. He was deeply in sorrow after her death.
                One of us (Herman P.Schwan) met Otto for the first time at a meeting of the
             American Physiological Society in Columbus in 1950. Herman was actively
             involved in a multisociety group responsible for planning the first
             interdisciplinary annual conferences concerned with engineering in medicine and
             biology. The annual conferences had started three years earlier and were
             primarily oriented toward x-ray technology and medical physics concerned with
             ionizing radiation. The attendance was poor and without perceptible growth.
             Reorientation toward medical electronics, electrophysiology, and biological
             impedance work was indicated. Otto Schmitt agreed to organize the eleventh
             annual conference. The meeting in Minneapolis was on computers in medicine
             and biology. It was a great success and nearly 400 persons attended. From then on
             things moved rapidly, ensuring a good future for the interdisciplinary field.
                About 1955 Otto and Herman attended a meeting at the Mayo Clinic
             concerned with potential hazards caused by microwave exposure. They discussed
             the need for a biophysical society. A few years later the first meeting of the
             Biophysical Society took place, organized by the “committee of four,” including
             Kacy Cole, E.Pollard, O.Schmitt, and S.Talbot. A few years later the Biomedical
             Engineering Society was formed, and Otto served as the initial caretaker
             president.
                Otto told David B.Geselowitz that as a youngster he built a Tesla coil but
             found that the available current from the local transformer was inadequate.
             Complaints to the power company were of no avail. So he inductively shorted the
             circuit at the fuse box, and the transformer burst into flames and was immediately
             replaced with one of higher capacity. At one point, his mother walked in while he
             was experimenting with the Tesla coil. Sparks were shooting from her son’s
            mouth and ears, and she fainted. In high school Otto rewired a motor used by a
            teacher to dem
    
    
                 
    
    
             OTTO H.SCHMITT                                           203
    
             onstrate the effect of load on a dc motor. When the teacher grabbed the motor to
             apply a load, the motor increased its torque throwing the teacher off the podium.
                From 1931 (when he was eighteen years old) to 1939, Otto published some
             seventeen articles in the Review of Scientific Instruments and the Journal of
             Scientific Instruments describing a series of inventions, many of which are of
             exceptional importance. In 1934 he patented the idea of using a pentode as the
             plate resistor for a pentode, thus achieving a much higher gain. Otto told David
             B.Geselowitz that RCA infringed on the patent, but when his attorney approached
             RCA, he was advised to sue. The cost ($20,000) of such an action was
             prohibitive. Otto was bitter and did not patent many subsequent devices, which
             included the cathode follower, the differential amplifier, the chopper-stabilized
             amplifier, and the Schmitt trigger. During the Second World War he made
             important contributions, which were top secret. One of his inventions was a
             magnetic anomaly detector to pinpoint the presence of enemy submarines.
                Otto was an excellent engineer and biologist. The “Schmitt trigger” is an
            electronic circuit that produces an output when the input exceeds a predetermined
            threshold; it still appears in hundreds of applications. It is an excellent example
            of “bionumetics,” a term that Otto coined for a field that applies biological design
            principles to engineering. His work in the well-known laboratory of Bernhard
            Katz in London and his participation in the Cold Spring Harbor Symposia
            brought Otto in early contact with many leading electrophysiologists. His work
            with Airborne Instruments Laboratories on Long Island during the 1940s
            contributed to the development of his outstanding engineering talents.
                A few examples will serve to illustrate his wide-ranging interests. Shortly
            after the war he constructed an automatic instrument that could evaluate nerve
            preparations and could rapidly determine its cable properties on-line. He used the
            instrument to study and publish on the topic of dynamic negative admittance
            components in statically stable membranes. He and John J.Almasi constructed a
            highly precise impedance-measuring instrument that extended the frequency
            range down to a few
    
    
                 
    
    
             OTTO H.SCHMITT                                           204
    
             millihertz and provided very high resolution. It was a forerunner of the precision
             impedance analyzers to come. He also could not help but become interested in the
             debates about bioeffects of weak electric and magnetic fields. So he and Robert
             D.Tucker worked on the perception of magnetic fields. This work was quoted
             often to demonstrate the extent to which one must be willing to go to exclude
             spurious confounding effects (in their case, minute and weak vibrations of the
             magnets).
                After the war Otto turned his attention to the relationship between cardiac
             sources and the surface electrocardiogram. His laboratory was one of four that
             contributed to this effort to understand the volume conductor problem, and led to
             the development of lead systems for determining the heart vector. The others
             were Burger in Utrecht, Frank in Philadelphia, and McFee in Ann Arbor.
                One of us (David B.Geselowitz) got to know Otto well when we served
             together on an advisory board established by Hubert Pipberger in 1962 in
             connection with his efforts to develop a system for computer interpretation of the
             electrocardiogram. We also served on the American Heart Association
             Committee on Electrocardiography, which developed standards for
             electrocardiographs, addressing such issues as frequency response and electric
             safety. Otto’s suggestions were always insightful.
                It was at this time that David became aware of a game that Otto played.
            Often when he had an idea to propose, he couched it in obscure language. On
            many occasions he propounded these ideas to people who nodded politely
            without having any idea of what Otto was saying. When Otto was challenged to
            explain what he meant, he would rephrase his idea in a more intelligible form.
            When an understandable statement emerged, it was almost invariably a solid
            idea. Otto frequently offered ideas to others to develop.
                Otto believed in redundancy. He always carried about a dozen pens, no two
            of the same model to avoid simultaneous failures. He always seemed to be able to
            fish out from one of his innumerable pockets a gadget someone needed at the
            moment. He had several working tie clips, including one with a slide rule, one
            with an abacus, and one with a gun that could be charged
    
    
                 
    
    
             OTTO H.SCHMITT                                           205
    
             with gunpowder. On several occasions he brought dead silence to a large
             gathering by firing the gun.
                The tremendous range of Otto’s contributions is not easy to convey. It is
            best illustrated by a topical list indicated by his publications, his biography, and
            our personal experience: Nerve impulse mechanisms, tridimensional
            oscilloscopic displays, bivalent computers; biological tissue impedance analyses;
            electronic circuitry; direct current transformers; trigger circuits; electronic
            plethysmography; antenna radiation pattern measurements; stereovector-
            electrocardiography; phase space displays; bioastronautics; electromagneto-
            biology; technical optimization of biomedical communication and control
            systems, Santosh Index for quality of life, strand epidemiology, personally
            portable whole life medical history, and biomimetic science and technology.
                Otto was widely recognized for his outstanding achievements. He was
            elected to the National Academy of Engineering in 1979 and to the Minnesota
            Hall of Fame in 1978. Among his other honors are the Lovelace Award, 1960; the
            William J.Morlock Memorial Award, 1963; the John Price Wetherill Medal,
            1972; the Institute of Electrical and Electronics Engineers EMBS Career
            Achievement Award, 1987 and 1963; and the Medical Alley Award, 1988.
                Otto seemed to us to have an unlimited amount of energy and never grew
            tired of lively discussions. He also loved to laugh at others and himself and was
            always ready to tell great stories. Whenever he visited he offered to demonstrate a
            new gadget, which he had acquired. Otto had a wonderful mind, combining
            extensive knowledge with insight, originality, and humor. We met him for the
            last time at the fall meeting of the National Academy of Engineering four or five
            years ago and we spent a few hours together. He told Herman that his wife,
            Viola, was not well and it was obvious that he was worried. He was rather lonely
            after the death of Viola. We understand that his mind never gave up.
    
    
                 
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