CS262057B1 - Microprobe for long lasting measuring of oxygen partial pressure in tissues in gas and water medium - Google Patents

Abstract

Micro probe for long-term measurement of par-. oxygen pressure in the gaseous tissues and the aquatic environment. The essence of the microneedon is the cathode (1) ve glass capillaries (2). The capillary surface is silver-plated and form an anode (3). Exit end capillaries (2) with anode (3) and cathode (lj is covered by membrane (5) and space between glass capillary (2) and membrane (5) is filled with electrolyte (6), for example potassium chloride solution.

Description

The invention relates to a microprocessor for the long-term measurement of the oxygen partial pressure in tissues in gaseous and aqueous environments.

Known embodiments of the tissue oxygen probes for long term monitoring are made of an insulated, polarizable metal, i.e. platinum or gold (Pt, Au) in the form of a wire whose one end is stripped of insulation and forms the active surface of the measuring electrode, i.e. the cathode. The electrode is operatively inserted into the tissue and its other end is connected directly or via the connector base to the negative pole of the polarizing voltage. The second electrode - anode - is made of silver sheet, which is placed on the skin of the examined object through an electrically conductive base, for example salt solution. The electrical conductor from the anode is connected to a positive voltage source. Upon voltage input, molecular oxygen reduction occurs at the cathode and the depolarizing current flowing is proportional to the partial oxygen pressure in the vicinity of the cathode.

Long-term exposure of the uncovered cathode to the tissue leads to considerable contamination of its surface with proteins, which make it impossible to objectively assess the oxygen level in the tissues. Also, separate placement of the anode at different distances from the cathode is often a source of many measurement failures and instabilities.

These disadvantages of the electrodes used hitherto are overcome by a microprobe with a cathode in a glass capillary and an anode formed by a silver coating deposited on the outer surface of the capillary, the principle being that the outlet end of the capillary with cathode and anode is covered by a membrane an electrolyte, for example a potassium chloride solution.

The micro-probe retains the advantages of using a miniature cathode, the anode is still at the same distance from the cathode, the electrochemical action - oxygen reduction - takes place in a defined electrolyte environment, the membrane permits only gases and protects the cathode from protein poisoning. surgically introduced into the tissue, for example under the skin, muscle, etc., allowing long-term monitoring of changes in oxygen supply to tissues under various physiological and pathological conditions.

BRIEF DESCRIPTION OF THE DRAWINGS The invention is illustrated in greater detail in the accompanying drawing, in which a micro probe is indicated in axial section.

The micro probe, as shown in the attached figure, consists of a cathode 1 made of platinum wire sealed into a glass capillary 2. The surface of the capillary 2 is silver-plated at the outlet end and forms an anode 3 which is connected to a lead wire 4 sealed to the side of the capillary 2. the end of the capillary 2 with the cathode and the anode 3 is covered by a gas permeable membrane 5, for example of polypropylene, polyethylene, PVC, etc. The space between the membrane 5 and the wall of the glass capillary 2 is filled with electrolyte 6, for example potassium chloride solution. electrochemical action - reduction of molecular oxygen. The diaphragm 5 is fixed to the surface of the capillary 2 by a ring 7 or is adhered to the surface of the capillary 2. The inlet end of the capillary 2 with the lead wires is covered with insulation 8. The microchondes thus treated are operatively inserted into living tissues and connected to a measuring instrument e.g.

The micro probe is designed especially for long-term measurement of oxygen in tissues of experimental biomodels.

Claims (1)

Microscope for long-term measurement of partial oxygen in tissues in gaseous and aqueous environments, with a cathode in a glass capillary and an anode consisting of a silver coating deposited on the outer surface of the capillary, characterized in that the outlet end BACKGROUND OF THE INVENTION The capillary (2) with cathode (1) and anode (3) is covered by a membrane (5), fastened by a ring (7) or by gluing, and between it and the capillary wall (2) is an electrolyte (6).