US1857567A - Blood pressure tourniquet - Google Patents

Description

May 10, 1932. PLESCH 1,857,567

BLOOD PRES SURE TOURNIQUET 7 1 Filed May 27, 1931 2 Sheets-Shet 1 May 10, 1932.

J. PLESCH BLOOQ PRESSURE TOURNIQUET 2 Sheets-Shet 2 Filed May 27, 1931 Patented May 10, 1932 UNITED STATES P JOHANN PLESCH, OEBERLIN, sear/mm, 1

BLoonPREssURn monnivroun'r Application filed May 27, 1931, Serial No, 5&Q42'3, and in Germany June 8, 1939. I

the strap. In the otherkind the strap forms an air cushion throughout its length, and makes more than a complete turn round the arm, according to the thickness of the latter. There may be two or more complete turns in the case of a child. This leads to inaccurate hydrodynamic results when making the measurement. Put shortly, the air cushion is too small in one case and too large in the other.

The object of my invention is to remove this defect, and to this end I use a strap which is inflatable throughout its length but only becomes effective, as an air cushion, tothe extent of whatever portion thereof is required to make one turn round the arm. For this purpose the strap has attached to one end thereof a fastener through which the other end is drawn to tighten the strap, and the fastener, when put into operation, applies a grip across the strap, so that the loose portion ofthe air cushion, drawn through the fastener, is shut off from the remaining part.

Another advantage of the improved tourniquet is that the fastener can operate at any desired angle across the part which it grips, so that the strap can accommodate itself closely to the arm, more so than is the case with the usual fasteners.

After inflation the whole circumference of the arm is effective for enabling pulsation to be observed.

To ensure that the air pressure compresses only the arm, without bulging the outside wall of the cushion and giving a wrong impression in regard tothe pulse action, the outside wall is reinforced by a non-extensible lining, e. g. wire fabric, thin sheet metal or the like, which does not interfere with the transverse shutting off of part of the air cushion, but even' assists it. The inflated strap consequently only bulges'inwards, instead of assuming a bi-convex shape, as was hitherto the case.

A blood pressure tourniquet according to the inventionis shownin the accompanying 1; T OFFICE] f1 drawings, 'F ljibeinga cross-section theneof, 2 and 5 being elevations, and Figs.

'3 and 4 being cross-sections showing the fastener in two positions.

L .The-eover-a'i-s placed ron-n-da strip biof metal,-so that ean-notbe stretched longi taudinally, and'also cannot be stretched transversely if; the strip 6 is of woven wire or sheet metal. There is aniinside layer cvoff rubber, leaving a cavity 4 communicating with a tube 6, for inflation by means of air or other gas, or for-introducing a liquid, e. .g.

glyee-rine. v I a I strap has at one end a loop fiyvhereby itis engaged with part ,g'ofthe'fastening device. The fastening device consists m'pa rt.

of {a tribe 1 with portions of itswall' cut away to afford a passage forthe fnee end of the .strap'b Thegpartjg aportion offlhe tube wall; between the twogaps. At t the. ends of the tube there are caps 9n, n, and within the tube is a rod 2' of circular cross-section, having at its ends excentric pivots whereby it is mounted in .thesaid caps. The free end of the strap passes through the tube between the tube Wall and the excentrically mounted rod '5, and by turning the rod the strap canbe squeezed against the'tube wall and thusfastened. The rod 'is'rotated by means of a handle at one of itsends, and it has upon it a rotatable sheath 1" enabling the strap to slide over it easily when not squeezed. There is a thick bead s at the free end of the strap, preventing its complete withdrawal from the tube h.

Fig. 4 shows the rod 5 ma position allowit ing the free end of the strap toslide freely thereon, when adjusting it on the patients arm. After adjustment the strap is tightened as required, and the handle is is then rotated to the'position shown in Fig. 3, causing the rod d to squeeze the free end of the strap, and

hold it fast. If thepatients arm is approximately cylindrical at the part to which the strap is applied the strap assumes a corresponding shape, as shown in Fig.2. If the arm is tapered the strap assumes the conical shape shown in-Fig. 5. i

When the strap is worn out, or is to be an i c in said tube for excentric rotatiomthe part changed for one of a different size, the fastener need not be discarded. The cap a can be'removed, after unscrewing a screw u by means of which it is held, and the loop f can then be slipped off the part 9, a fresh strap being substituted, whereupon the cap n is replaced. o

What is claimed is: y

1. A blood-pressure tourniquet, forming an air cushion throughout its length, charaoterized in that the strap has at one end a fastener, through which the other end passes and by which said other end can be gripped along a transverse portion thereof, so that the air cushion is closed by the grip, and the 7 portion of the strap drawn through the fastener is not inflated, said portion drawn through the fastener having an enlargement (s) preventing complete withdrawal thereof from the fastener. i

2. A blood pressure tourniquet according to claim 1, characterized in that its outer layer is soreinforced by a non-extensible but flexible inlay b) that when under pressure the strap-can only expand inwards;

3. A'blood pressure tourniquet according to claim 1, characterized in that the fastener comprises a'tube. cut away so as to leave only two longitudinal parts (h, g), with two caps (m, n) on said tube, and a rod mounted h) of the tube forming a seat against which the strip is gripped, and the part (9) having the strap attached thereto. g The foregoing specification signed at-Berlin, Germany, this 15th day of May, 1931.

' JOHANN= PLESCH.

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