Surgery – Truss – Pad
Patent
1987-01-20
1990-01-16
Cohen, Lee S.
Surgery
Truss
Pad
128642, 204403, 204431, A61B 500
Patent
active
048936251
DESCRIPTION:
BRIEF SUMMARY
The present invention is directed to an insertion type electrode arrangement for continuous pO.sub.2 measurement in living skin tissue with an outer metal tube electrode and an electrically insulated platinum wire electrode arranged therein.
A process and an electrode arrangement for transcutaneous pO.sub.2 measurement has been developed by Lubbers and Huch (1960). While this process has shown good results in the intensive care of newborn, its application for instance in the province of birth assistance is problematical: For one the arrangement of the electrodes (external diameter 18 mm) provided by Lubbers and Huch is not simple, besides these electrodes are heated to 44.degree. C., so that indeed the "arterial" oxygen partial pressure can be measured, but on the other hand the heating process could cause changes in the skin after approximately 3 hours, with the consequence that the electrode has to be applied at another point.
A pCO.sub.2 electrode arrangement (Lubbers, Huch, 1980) also measures according to the transcutaneous process; the same applies for this measuring system as it did for the transcutaneous pO.sub.2 electrode arrangement.
The measurement of the oxygen partial pressure is based on the polarization phenomenon, meaning oxygen molecules which reach a platinum cathode generate an electric current which is proportional to the quantity of the oxygen molecules. The electrode is connected to a polarization voltage of for instance 750 mV and is constructed in such a way, that the oxygen from the blood or the tissue diffuses through a thin, electrically insulating, but gas-permeable membrane towards the platinum cathode. The current (polarization current) flowing through the electrode is measured by an ammeter. Said current is proportional to the oxygen partial pressure in the tissue at the electrode tip. Since, however, there exists no absolute reaction between the polarization current and the pO.sub.2 existing at the electrode tip, each oxygen electrode must be calibrated with calibration gases whose pO.sub.2 is known (0.9% NaCL solution with the known oxygen content--20%, 10%, 0% -0.9% -NaCl solution with nitrogen proportionally equilibrated]).
The general reaction is : electrode)
Overall Reaction
In the year 1956 Clark introduced a platinum electrode for measurement of the oxygen partial pressure. Since this time a series of pO.sub.2 electrode arrangements have been developed in accordance with Clark. Micro- and macroelectrodes as straight puncture eletrodes for pO.sub.2 measurement in human tissue have been increasingly used in surgery, internal medicine and pharmacology (First Symposium of Tissue Oxygen Pressure Measurement 1982, Second Tissue Oxygen Pressure Symposium 1983 in Frankfurt "Determination of Tissue Oxygen Pressure in Patient",Professor A. M. Ehrly, Pergamon-Press).
Puncture electrodes in straight form for pO.sub.2 measurement have been successful where the tissue of the patient or the child to be examined is relatively quiescent.
An insertion type electrode for continuous pO.sub.2 measurement in living skin tissue has for instance become known, consisting of a cathode, which is fused gas tight into the glass capillary and fixed in a hollow member, wherein the hollow member is connected in such a way through a grid with a shielding of the coaxial cable, that the grid completely surrounds the resin embedding, the connecting point, of the cathode with the copper core of the coaxial cable, said grid enclosing the connecting point on all sides, and in which a tube consisting preferably of silver is ground-in in cannula fashion and which exhibits a thickening at the other end, wherein a hook is rigidly connected with the tube and exhibits a contact face at the lower side of the electrode member, which has a recess on both sides beneath the front cavity of the hook (DD 88 835).
The particularity of this known insertion type electrode for continuous partial oxygen pressure measurement in living skin tissue is to be seen therein, that the external metal tube electrode serving as anode
REFERENCES:
patent: 3415730 (1968-12-01), Haddad
patent: 3476670 (1969-11-01), Weiner
patent: 4294258 (1981-10-01), Bernard
patent: 4320764 (1982-03-01), Hon
patent: 4582064 (1986-04-01), Sorger
Neuman et al, "Application of Oxygen Cathodes . . . ", 24th ACEMB-Las Vegas, Nev., Oct. 31-Nov. 4, 1971, p. 249.
Kopernik, "Die Ableitung . . . Skalpelektrode", Dtsch Gesundheitsu, 26: 1756-8, 9 Sep. 71.
Aarnoudse et al, "Fetal Subcutaneous Scalp pO.sub.2 . . . ", Am J ob Gyn, vol. 53, No. 5, Nov. 1, 1985, pp. 565-566.
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