Br Heart J 1987;57:190-3

Did Einthoven invent a string galvanometer?HOWARD B BURCHELL

From the Cardiovascular Division, University of Minnesota School of Medicine, Minneapolis, USA

Clinical electrocardiography belongs wholly to thiscentury and stems from a paper of Willem Eint-hoven "Un nouveau galvanomrtre" in 1901.' Theepochal work of Waller in 1887,2 which showed thatin man cardiac potentials could be recorded, hadaroused Einthoven's interest and he devoted a largepart of the next three decades to perfecting highfidelity methods of studying these potentials withinstruments of his design.

In a recent review paper Cooper3 opined thatEinthoven did not invent the string galvanometerand invited the inference that Einthoven did not giveproper priority and credit to Ader. This raisessemantic problems regarding the word "invent" andcasts doubts on the veracity of Einthoven's accountof his own work. It is not a new controversy andundoubtedly some writers, historically minded butnot necessarily historical scholars, have used theword "invent" loosely. The hearsay opinion hasbeen repeated in the literature: that Einthoven hadhis instrument built just by adapting already knownequipment to his purpose. For instance, Barker(1910) in a long paper extolling the great clinicalpossibilities of electrocardiography, states "Eint-hoven of Leyden devised his string galvanometerbased upon the suggestions of Ader."4My argument endorsing the propriety of the use

of the word "invent" for Einthoven's instrument isbased on the following points. The meaning of anyword is defined by its common use. When a persondoes something in a new and effective way he is saidto be inventive or ingenious. In the legal world, theword has implications for patent rights. There is noevidence that Einthoven had strong aspirations for acontrolling patent. Snellens mentioned that anysuch claims would be abrogated by the publicationin 1909 of the detailed specifications of his stringgalvanometer. I believe that within observed patentpractices Einthoven's string galvanometer couldhave been patented because it was designed for apurpose and was a success in obtaining objectivesnot previously achieved. It was not a discovery and

Requests for reprints to Dr Howard B Burchell, 260 WoodlawnAvenue, St Paul, Minnesota, 55105, USA.

Accepted for publication 13 November 1986

much more than a gadget, and I submit would meetone encyclopaedic definition of an invention.6 Eint-hoven (1903) condensed his views of his accom-plishments in these words. "I have constructed anapparatus ... specifically designed to give direct reg-istration of the human electrocardiogram which willgive true readings."7 Einthoven was generous ingiving credit to other investigators. When he read apaper before the Chelsea Medical Society (1912) hepraised Waller and Lewis, and credited Waller withcoining the term electrocardiogram: "It gives meespecial pleasure to bring to remembrance here thatthe human EKG was first recorded by a Londonphysiologist, Augustus D Waller, who also intro-duced the term 'electrocardiogram' into science."8Einthoven was unhappy with the editing of thispaper, as judged by his correspondence with Lewis.Many scientists have apparently felt comfortable

with the use of the word "invention" for the Eint-hoven instrument. Below is a list of short quotationsfrom papers in which the word "invent" was used.

Waller (1909): "Professor Einthoven's resultswith ... the extraordinarily sensitive galvanometerhe has invented ..."9Lewis (1911): "The string galvanometer in its

present form, the invention of Einthoven ...".'0 Inan obituary (1927) Lewis stated ". . . he moved to theprinciple of Ader's instrument ... constructed a gal-vanometer greatly surpassing all previous instru-ments . . . created a piece of apparatus ofunparalleled delicacy and accuracy."''A V Hill (1927) (in obituary): "The problem of

recording these small and fleeting changes ... wassolved in 1903 by the invention of the string gal-vanometer.""2H B Williams (1947): "Accordingly, I agree with

you (A E Cohn) that the record should leave nodoubts on the score that Einthoven was the inventorof the electrocardiograph."'3White (1949): "Finally in 1903 came the

announcement of the invention of the accurate andpracticable galvanometer (Einthoven)."' 4 (Curi-ously in the first and second editions of Heart Dis-ease the word used was "discovery"; this waschanged to "invention" in the third edition.)De Waart (1961): "Persevering in inventing and

constructing his string galvanometer."'5190

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Did Einthoven invent a string galvanometer?Burch and DePasquale (1964): "(Einthoven) will

always be remembered as the inventor of the stringgalvanometer." 16

Zachary Cope (1973): "The great development ofthis subject was largely due to the invention of thestring galvanometer by Einthoven."7

Snellen (1983): "The mathematical correction (ofthe capillary electrometer tracings) although satis-factory was cumbersome and Einthoven thereforeinvented a new instrument."18The following are excerpts from work by other

knowledgeable scientists. They are quoted becausethey use phrases or words that are equivalent to theword "invent":Wenckebach (1927) (obituary): "Seine Grosstat,

der er einen grossen Teil seines Lebens gewidmet,war das Saitengalvanometer."19

Samojloff (1930): "First of all, he is the creator ofelectrocardiography. "20Wilson (1940): (After work with capillary elec-

trometer) "He was then able to determine the char-acteristics which an instrument suitable for hispurpose (should have) and in 1903 he completed thefirst model of what has since been known as the

191string galvanometer."21Barron (1950): "Realising the limitation of this

method (capillary electrometer), he devised a moresimple sensitive and accurate means of recordingthese fluctuating potentials."22Wiggers (1961): "Einthoven, therefore, under-

took careful mathematical studies of the character-istics of moving coil galvanometers which eventuallyled him to employ the principle that a wire placedbetween two magnets bows when traversed by anelectric current."23Adrian et al (1976): "Einthoven introduced the

string galvanometer in 1901. ,24The Nobel Committee, as is reflected by the

presentation speech of Professor Johanssen,25avoided any controversy: the justification of theaward was for Einthoven's "discovery of the mech-anism of the electrocardiogram" (a somewhatambiguous phrase), and Einthoven's name was"linked to the design of a physical instrument" (thestring galvanometer). Einthoven's Nobel lecture wasgiven in German, but there is an English translationin the published Nobel lectures. The title of Eint-hoven's address was "The string galvanometer and

Figure A photograph taken in Einthoven's laboratory in about 1908 given to the author by Dr George Fahr. The stringgalvanometer in the background is obscured. Dr Fahr is the young man on the left and Dr Einthoven is appropriately in thecentre and at the front.

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192the measurement of the action currents of theheart." This oration, as Snellen has pointed out,"constitutes an important review of a lifetime'swork." All the 26 figures also reflect the high tech-nical quality which he demanded in his records.Those of us who have worked with a string gal-

vanometer may be at a disadvantage when it comesto objectively assessing this instrument; love andadmiration for the instrument may have engendereda bias. As well as saying that Einthoven "did notinvent the string galvanometer" Cooper also statesthat "he was not the first to describe the electro-cardiogram."3 The claim that the PQRST waveform that was calculated by Einthoven from recordstaken on the capillary electrometer is the first truedescription of the electrocardiogram is not withoutsupport, as Professor Johanssen said in the Nobelpresentation speech: "Einthoven can thus be namedthe discoverer of the real electrocardiogram." Eint-hoven added the U wave later in 1903. This was acontribution of the string galvanometer. Wallerexpressed his admiration for Einthoven's records,and mentioned specifically that with his own 1887apparatus, "the P wave was not discernible."9 Is itreally correct to claim that Ader's galvanometer"was the type of instrument that Einthoven laterused to introduce clinical electrocardiography": theimplication being that Einthoven's instrumentresembled that of Ader. It was many thousand timesmore sensitive, not merely an adaptation of the Aderinstrument. Einthoven's credits to Ader in both his1901 and 1909 papers' 26 seem adequate to me. It isnot reasonable to equate Einthoven's considerableimprovements of the capillary electrometer with theprofound changes that were needed to create hisstring galvanometer electrocardiograph from exist-ing galvanometers. George Fahr, talking with me inhis later years ofhis period with Einthoven, was can-did in mentioning that Einthoven had rather clumsyhands and was somewhat secretive about his instru-ment when visitors came (this is contrary to thestatements ofothers) (fig). Fahr, however, never saidanything to impugn Einthoven's integrity or toimply that Einthoven had adapted Ader's instru-ment. In the late years (1920) there was somesecrecy; access to the laboratory was forbidden onFridays because of experimental wireless trans-missions from Einthoven's son who was in theDutch East Indies.Burch and DePasquale recount a story, the source

of which is not given, that Edelman manufacturedthe first galvanometers of the Einthoven designunder an arrangement whereby Einthoven was toreceive a $25 royalty for each instrument that wassold.'6 After adapting the instrument and using hisknowledge of an existing Ader galvanometer Edel-

Burchellman reneged on payment of the royalty. Whateverthe details of the falling out with Edelman, the eventdid initiate the development of companies inEngland23 and the United States'3 to manufacturethe string galvanometer with Einthoven's "bless-ing." Here then is prima facie evidence of a cor-porate acknowledgement of Einthoven's rights to apatent.

Einthoven would probably have approvedCooper's assertion that Bosscha "provided both atheoretical and practical support for Einthoven'swork"; however, it still seems an exaggeration ofBosscha's role. He was not a teacher of Einthoven.The labelling of the wave forms according to the

PQRST convention was never explained in writingby Einthoven. Waller tried to maintain his originalrubric "Vi and "V2" but he was unsuccessful ingaining disciples of his cause. I believe that Hensongives the best description of the origins of thePQRST nomenclature, which was based on the geo-metrical convention of Descartes (by coincidence ina book published in Leiden in 1637).27My admiration ofWillem Einthoven does not pre-

clude a suspicion that he might have been possessiveabout "his" string galvanometer and that this atti-tude could have contributed to his estrangementfrom Edelman and the break up of his relationshipwith the clinicians in his hospital. Fahr relates28 thatthe termination of the collaboration with the hospi-tal physicians was engendered by an argument aboutwho was to pay for the telephone line linking thehospital with the physiology laboratory for thetransmission of electrocardiograms; another storywas that "his occasional electrocardiographic argu-ments displeased the clinicians so much that in duecourse, the latter severed the connection."Wiggers23 mentions in his encomium that OttoFrank once remarked "that in visit to Leiden,Einthoven had never invited him into his laboratory.It may be added parenthetically that Einthovenmade a similar remark about Otto Frank."

Successful individuals rarely receive universalacclaim for being true gentlemen as did Einthoven.It is worth repeating a few sentences from the con-cluding paragraphs of his Nobel address:

". . . Thomas Lewis who has played a great partin the development of electrocardiography ... Idoubt that without his valuable contributions, Ishould have the privilege of standing before youtoday", ... "in addition, innumerable otherworkers in the field of electrocardiography havegained great merit ... investigators of the wholeworld have worked together ... a new chapterhas been opened in the study of heart diseases,not by the work of a single investigator, but bythat of many talented men . . ."

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Did Einthoven invent a string galvanometer? 193Einthoven's "invention", the instrument that he

bequeathed to us, endures. If one needed a highfidelity, high sensitivity galvanometer with nearlyperfect square wave response over a remarkable fre-quency range (perhaps to celebrate a diamond jubi-lee of the beginnings of electrocardiography inAmerican hospitals), one could confidently take anancient string apparatus off the shelf and expect it towork superbly.References

1 Einthoven W. Un nouveau galvanometre. Arch NeerlSc Ex Nat 1901;6:625-33.

2 Waller AD. A demonstration on man of electromotivechanges accompanying the heart's beat. J Physiol(Lond) 1887;8:227-34.

3 Cooper JK. Electrocardiography 100 years ago: origins,pioneers, and contributors. N Engl J Med1986;315:461-4.

4 Barker LF. Electrocardiography and phono-cardiography. A collective review. Bull JohnsHopkins Hosp 1910;21:358-89.

5 Snellen HA. Selected papers on electrocardiography ofWillem Einthoven, with bibliography, biographicalnotes and comments. Leiden: Leiden University Press,1977:14.

6 Hall AR, Smith NAF. Invention. Encyclopedia Ameri-cana. New York: Americana Corporation, 1970;15:326-38.

7 Einthoven W. Die galvanometrische Registrirung desmenschlichen Elektrocardiogramms, zugleich eineBeurteilung der Anwendung des Capillar-Elektrometers in der Physiologie. Pflugers Arch1903;9:472-80.

8 Einthoven W. The different forms of the human elec-trocardiogram and their signification. Lancet1912;i:853-61.

9 Waller AD. The electrocardiogram of man and dog asshown by Einthoven's string galvanometer. Lancet1909;i:44-50.

10 Lewis T. The mechanism of the heart beat. London:Shaw and Sons, 1911:18.

11 Lewis T. Willem Einthoven [Obituary]. Br Med J1927;ii:664-5.

12 Hill AV. Einthoven [Obituary]. Nature 1927;120:591.13 Williams HB. (In paper by Cohn) Recollections con-

cerning early electrocardiography in the UnitedStates. Bull Hist Med 1955;29:469-74.

14 White PD. Heart disease. 3rd ed. New York: Mac-millan, 1949:173.

15 De Waart A. Einthoven commemoration. Am Heart J1961;61:357-60.

16 Burch GE, DePasquale NP. A history of electro-cardiography. Chicago: Year Book Medical Publish-ers, 1964.

17 Cope ZA. Auguste Desire Waller (1856-1922). MedHist 1973;17:380-6 (p 384).

18 Snellen HA. Two pioneers of electrocardiography. Thecorrespondence between Einthoven and Lewis1908-1926. Rotterdam: Donker Academic Publish-ers, 1983:11.

19 Wenckebach K. Willem Einthoven. Dtsch Med Wschr1927;53:2176.

20 Samojloff A. Reminiscences of the late ProfessorWillem Einthoven. Am Heart J 1930;5:545-8.

21 Wilson FN. The electric currents associated with theheart beat. Selected papers. 1940. Ann Arbor:Edwards Brothers, 1954:1-10.

22 Barron SL. The development of the electrocardiogramin Great Britain. Br Med J 1950;i:720-5.

23 Wiggers CJ. Willem Einthoven (1860-1927). Somefacets of his life and work. Circ Res 1961;9:225-34.

24 Adrian RH, Channell RC, Cohen T, Noble D. TheEinthoven string galvanometer and the inter-pretation of the T wave of the electrocardiogram. JPhysiol (Lond) 1976;63:67P-70P.

25 Johanssen JE. Nobel lectures. Physiology or medicine.1922-1941. Amsterdam: Elsevier, 1965:89.

26 Einthoven W. Die Konstruktion des Saitengalvano-meters. Pfluigers Arch Ges Physiol 1909;130:287-321.

27 Henson JH. Descartes and the ECG lettering series. JHist Med Allied Sci 1971;26:181-6.

28 Fahr G. Einthoven. Ik wilde weten. George Fahr Fes-tschrift. 80th birthday. Minneapolis: Lancet, 1962.

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