Changes in heart-rate, blood-pressure, and duration of systole resulting from bicycling / by Wilbur P. Bowen.
- Bowen, Wilbur Pardon, 1864-1928
- Date:
- [1904?]
Licence: Public Domain Mark
Credit: Changes in heart-rate, blood-pressure, and duration of systole resulting from bicycling / by Wilbur P. Bowen. Source: Wellcome Collection.
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![to the tambour by a ball and socket joint, and the other end inserted into a rounded block which rests against the opposite side of the neck. The receiving tambour is fifteen millimetres in diameter, and has a light rubber membrane which transmits its movements to the recording surface by a light celluloid lever. The recording surface consists of a strip of smoked paper 12.5 cen- timetres wide, and from four to five metres long, made into a loop which passes around two drums, one of which is actuated by clock- work. Above the pulse-curve a pneumograph records the respiratory movements. Below are the records made by three electromagnetic signals: one of these, connected with a fork or pendulum, records the time; another, the revolutions of the bicycle crank; the third, in circuit with a hand-key, is used to indicate when determinations of blood-pressure are made. Fig. 1 shows the general character of the records. WR 160 ie as oe. H ‘a ‘ f i 4 Pew \e \ Wye Ay ANN T N ‘, N Sto B soee BP ‘ 1 See aangs Peele nee wers 1S7 I1S7 185 160 jt Ss FIGURE 1]. — Portion of récord taken with slow drums. A, respiration; /, pulse; 7; time in seconds; B, revolutions of bicycle. VP, times at which determinations of blood-pressure were made. The figures written at these points give the pressure in millimetres of mercury. .S, times at which simultaneous records were taken on quick drum for determination of systole. The part here shown is at the close of a period of work, as indicated by record B. Read from left to right. The duration of systole is determined by recording the pulse along with a fork giving fifty vibrations per second. When this is the only record desired, the outfit just described is used. To determine these small time-intervals accurately the drums carrying the loop of paper must turn rapidly, the entire loop passing the writing points in from one to two minutes. When it is desired to study the duration of sys- tole along with pulse-rate, blood-pressure, etc., during experiments of longer duration, the drums carrying the long loop of paper are turned](https://iiif.wellcomecollection.org/image/b3343184x_0005.jp2/full/800%2C/0/default.jpg)
