Myocardial contraction is triggered whenever a wave of electrical impulses passes through the heart. The pattern of electrical excitation spreads coordinately over the structure of the heart. This results in a measurable change in potential across the surface of the body of a subject. The recording of the resultant signal from specific body points is known as an electrocardiogram (ECG). Students can directly record an ECG signal from the headset input of a smartphone with an electric lead and a suitable sound app. This allows interdisciplinary teaching by applying physics concepts to physiology.

1.
J. E.
Hall
, and
A. C.
Guyton
,
Guyton and Hall Textbook of Medical Physiology
(
Elsevier
,
Philadelphia, PA
,
2016
).
2.
B.
Taccardi
, “
Distribution of heart potentials on the thoracic surface of normal human subjects
,”
Circulation Res.
12
(
4
),
341
352
(
1963
).
3.
S. S.
Barold
, “
Willem Einthoven and the birth of clinical electrocardiography a hundred years ago
,”
Cardiac Electrophysiol. Rev.
7
,
99
104
(
2003
).
4.
A.
Albulbul
, “
Evaluating major electrode types for idle biological signal measurements for modern medical technology
,”
Bioeng.
3
(
3
),
20
(
2016
).
5.
M. A.
Ahamed
,
M. K.
Hasan
, and
M. S.
Alam
, “
Design and implementation of low cost ECG monitoring system for the patient using smartphone
,” in
International Conference on Electrical & Electronic Engineering (ICEEE) (IEEE
,
2015
), pp.
261
264
;
G. A.
Baquero
,
J. E.
Banchs
,
S.
Ahmed
,
G. V.
Naccarelli
, and
J. C.
Luck
, “
Surface 12 lead electrocardiogram recordings using smart phone technology
,”
J. Electrocardiol.
48
(
1
),
1
7
(
2015
);
K.
Forinash
and
R. F.
Wisman
, “
Smartphones as portable oscilloscopes for physics labs
,”
Phys. Teach.
50
,
242
243
(April
2012
);
B.
Patel
and
D.
Shah
, “
Evaluating ECG capturing using sound-card of PC/laptop
,” arXiv preprint arXiv:1402.3651 (
2014
).
6.
Traditional medical terminology
, see
J. W.
Hurst
, “
Naming of the waves in the ECG, with a brief account of their genesis
,”
Circulation
98
,
1937
1942
(
1998
).
7.
Thinklabs Medical LLC
,
Thinklabs Stethoscope app
, https://itunes.apple.com/app/id346239083 (
2013
).
The successor is now available for iOS and Android at
https://www.thinklabs.com/wave-c1rrd.
8.
L.-J.
Thoms
,
G.
Colicchia
, and
R.
Girwidz
, “
Phonocardiography with a smartphone
,”
Phys. Educ.
52
(
2
),
023004
(
2017
).
10.
K.
Hochberg
,
J.
Kuhn
, and
A.
Müller
, “
Using smartphones as experimental tools—Effects on interest, curiosity, and learning in physics education
,”
J. Sci. Educ. Technol.
59
(
2
),
215
(
2018
).
11.
J.
Kirstein
and
V.
Nordmeier
, “
Multimedia representation of experiments in physics
,”
Eur. J. Phys.
28
(
3
),
S115
S126
(
2007
).
12.
P.
Klein
,
M.
Hirth
,
S.
Gröber
,
J.
Kuhn
, and
A.
Müller
, “
Classical experiments revisited. Smartphones and tablet PCs as experimental tools in acoustics and optics
,”
Phys. Educ.
49
(
4
),
412
(
2014
).
13.
Tutorial for improved and more stable smartphone-ecg electrodes
: https://www.en.didaktik.physik.uni-muenchen.de/materials/ecgtutorial.pdf.
14.
H.
Theyβen
, and
D.
Schumacher
, “
Experimente zum Verständnis der Entstehung des Elektrokardiogramms
,”
PdN-Ph.
8
(
53
),
7
(
2004
).
AAPT members receive access to The Physics Teacher and the American Journal of Physics as a member benefit. To learn more about this member benefit and becoming an AAPT member, visit the Joining AAPT page.