
Thomas Lewis’ electrocardiograph
1930
1930
1890-1930
1880-1920
1915-1925
1884-1900
1886-1927
1895-1904
1890-1914
1914-1918
1925-1930
1890-1910
1890-1910
c.1912
c.1912
1892-1902
1893
1907
1899
1901
1901
1896
circa 1880
1830 (original); 1967 (model)
1926
1925-1930
1879
1920-1930
1884
1880-1930
1909-1910
circa 1904-1914
1889
1880
1935
1935
1919
1934
1908
1935
1916
circa 1900
1925
1925
1901-1911
1905
1899
1880-1920
1902
1880
1772 (original); 1919 (model)