text: US Patent for Transducer for the simultaneous measurement of different physiological quantities Patent (Patent # 4,538,617 issued September 3, 1985) - Justia Patents Search
  Justia Patents US Patent for Transducer for the simultaneous measurement of different physiological quantities Patent (Patent # 4,538,617)
  For measurement purposes, the measuring head is, for example, stuck to the head or buttocks of the baby. The metal ring 3 embedded in nut 4 comes into contact with the skin, together with the diaphragm. Adhesion takes place by means of an adhesive paste applied in such a way that the latter also surrounds metal ring 3 and consequently prevents any access of amniotic fluid moisture thereto. As has already been stated, the metal ring 2 located on the measuring head body 6 is in conductive connection via metal ring 5 and bolts or pins 9 with the metal ring 3 on the foetal side embedded in the adhesive surface. Since the natural wetness of the foetus at the time of birth provides a conductive connection from the foetal body to electrode 1, but not to metal ring 3 as a result of the adhesive and, whilst taking account of the amniotic fluid, there is also an adequate spacing between the effective electrodes, this arrangement makes it possible to record the foetal electrocardiogram and by means of a R-peak analysis a beat-by-beat heart rate recording is made possible. In addition to this, the transcutaneous oxygen partial pressure pO.sub.2 can be measured, together with a previously unmentioned skin blood supply measurement, which is based on the measurement of the electric current required for producing the elevated skin temperature by means of the silver heating electrode. The better the perfusion of the skin, the greater the heat removal through the blood, and consequently the necessary heating current.
  The measuring head was tested under birth conditions, whilst measuring the foetal heart rate (using HEWLETT PACKARD 8030 cardiotocograph), labour pains (directly by means of HEWLETT PACKARD 8030 cardiotocograph), the relative local skin perfusion (via HELLIGE oxymonitor) and the transcutaneous foetal pO.sub.2 (via HELLIGE oxymonitor). All signals were satisfactorily recorded up to the actual time of birth.
  1. A device for the simultaneous measurement of at least two different physiological quantities of a human or animal body and being connectable to signal processing electronics, comprising:
  a measuring head containing a transducer for measuring a first physiological quantity and a contact surface means for engaging with said human or animal body;
  a first one of a pair of electrodes being located at the contact surface means to contact with said human or animal body together with said contact surface means and having means for electrically coupling to said signal processing electronics;
  a second one of said pair of electrodes being attached to the measuring head outside said contact surface means thereof and having connection means for electrically coupling to said signal processing electronics;
  a bipolar plug connection having first and second poles, said bipolar plug being removably fitted to said measuring head, said first pole being coupled to said second one of said pair of electrodes for coupling to said signal processing electronics by connection to said second one of said pair of electrodes and said second pole having means for electrically coupling to said signal processing electronics; and
  an adhesive electrode body having two insulated juxtaposed electrodes each of which are adapted for contact with said human or animal body, said adhesive electrode body including a further removable bipolar plug connection having third and fourth poles, said third pole being coupled to one of said juxtaposed electrodes and said first pole and said fourth pole being coupled to the other of one of said juxtaposed electrodes and said second pole.
  2. A device according to claim 1, wherein said second one of said electrodes is arranged on the side of the measuring head remote from the contact surface means.