A hypodermic pressure manometer utilizing the bonded wire resistance strain gauge.
The recent development of the bonded resistance wire strain gauge has led to its use as a device for measuring physiological pressure phenomena. Further application of the strain gauge has been as an instrument for measuring intravascular blood pressures and other pressure phenomena in biology and medicine.
Bone marrow pressure in leukemic and non-leukemic patients.
It has been a frequent observation that many patients with leukemia and multiple myeloma bleed freely through the marrow needle at the time of bone marrow aspiration although hemorrhagic tendencies may not be present clinically. In addition, throbbing bone pain and bone tenderness are not infrequently observed in these patients (1). Such clinical observations suggest that some degree of pressure elevation may be present in the marrow cavity in these diseases. It was believed of interest to determine the pressure relationships within the human marrow cavity under a variety of physiologic stimuli.
The Use of a Resistance Wire, Strain Gauge Manometer to Measure Intraarterial Pressure
Summary The use of a resistance wire, strain gauge to convert pressure to electrical energy in making direct measurements of arterial blood pressure is described. The electrical circuits involved are simple. Recording is by means of a galvanometer without the use of electronic amplifiers. The calibration of the manometer is linear, stable and relatively insensitive to temperature changes. The natural frequencies of the manometer and galvanometer are 60 and 40 cycles per second, respectively.