GB2025057A - Percutaneous Blood-oxygen- concentration Measuring Sensor - Google Patents
Percutaneous Blood-oxygen- concentration Measuring Sensor Download PDFInfo
- Publication number
- GB2025057A GB2025057A GB7916833A GB7916833A GB2025057A GB 2025057 A GB2025057 A GB 2025057A GB 7916833 A GB7916833 A GB 7916833A GB 7916833 A GB7916833 A GB 7916833A GB 2025057 A GB2025057 A GB 2025057A
- Authority
- GB
- United Kingdom
- Prior art keywords
- membrane
- electrode
- electrode assembly
- end portion
- oxygen
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
- 239000012528 membrane Substances 0.000 claims abstract description 45
- 239000003792 electrolyte Substances 0.000 claims abstract description 6
- 239000012212 insulator Substances 0.000 claims abstract description 3
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 14
- 229910052760 oxygen Inorganic materials 0.000 description 14
- 239000001301 oxygen Substances 0.000 description 14
- 239000008280 blood Substances 0.000 description 7
- 210000004369 blood Anatomy 0.000 description 7
- 206010033675 panniculitis Diseases 0.000 description 4
- 210000004304 subcutaneous tissue Anatomy 0.000 description 4
- 238000005259 measurement Methods 0.000 description 3
- 238000000034 method Methods 0.000 description 3
- 230000035699 permeability Effects 0.000 description 3
- WCUXLLCKKVVCTQ-UHFFFAOYSA-M Potassium chloride Chemical compound [Cl-].[K+] WCUXLLCKKVVCTQ-UHFFFAOYSA-M 0.000 description 2
- BQCADISMDOOEFD-UHFFFAOYSA-N Silver Chemical compound [Ag] BQCADISMDOOEFD-UHFFFAOYSA-N 0.000 description 2
- 238000010438 heat treatment Methods 0.000 description 2
- 230000029058 respiratory gaseous exchange Effects 0.000 description 2
- 229910052709 silver Inorganic materials 0.000 description 2
- 239000004332 silver Substances 0.000 description 2
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 1
- 239000004411 aluminium Substances 0.000 description 1
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 1
- 229910052782 aluminium Inorganic materials 0.000 description 1
- 238000010276 construction Methods 0.000 description 1
- 229910052802 copper Inorganic materials 0.000 description 1
- 239000010949 copper Substances 0.000 description 1
- 238000009792 diffusion process Methods 0.000 description 1
- 238000003411 electrode reaction Methods 0.000 description 1
- 238000007254 oxidation reaction Methods 0.000 description 1
- 238000012856 packing Methods 0.000 description 1
- 235000011164 potassium chloride Nutrition 0.000 description 1
- 239000001103 potassium chloride Substances 0.000 description 1
- 238000006722 reduction reaction Methods 0.000 description 1
- 230000002940 repellent Effects 0.000 description 1
- 239000005871 repellent Substances 0.000 description 1
- 229920003002 synthetic resin Polymers 0.000 description 1
- 239000000057 synthetic resin Substances 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 1
- 238000003466 welding Methods 0.000 description 1
Classifications
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
- A61B5/00—Measuring for diagnostic purposes; Identification of persons
- A61B5/145—Measuring characteristics of blood in vivo, e.g. gas concentration or pH-value ; Measuring characteristics of body fluids or tissues, e.g. interstitial fluid or cerebral tissue
- A61B5/14542—Measuring characteristics of blood in vivo, e.g. gas concentration or pH-value ; Measuring characteristics of body fluids or tissues, e.g. interstitial fluid or cerebral tissue for measuring blood gases
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
- A61B5/00—Measuring for diagnostic purposes; Identification of persons
- A61B5/145—Measuring characteristics of blood in vivo, e.g. gas concentration or pH-value ; Measuring characteristics of body fluids or tissues, e.g. interstitial fluid or cerebral tissue
- A61B5/1468—Measuring characteristics of blood in vivo, e.g. gas concentration or pH-value ; Measuring characteristics of body fluids or tissues, e.g. interstitial fluid or cerebral tissue using chemical or electrochemical methods, e.g. by polarographic means
- A61B5/1477—Measuring characteristics of blood in vivo, e.g. gas concentration or pH-value ; Measuring characteristics of body fluids or tissues, e.g. interstitial fluid or cerebral tissue using chemical or electrochemical methods, e.g. by polarographic means non-invasive
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N27/00—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means
- G01N27/26—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating electrochemical variables; by using electrolysis or electrophoresis
- G01N27/403—Cells and electrode assemblies
- G01N27/404—Cells with anode, cathode and cell electrolyte on the same side of a permeable membrane which separates them from the sample fluid, e.g. Clark-type oxygen sensors
Landscapes
- Health & Medical Sciences (AREA)
- Life Sciences & Earth Sciences (AREA)
- Physics & Mathematics (AREA)
- Molecular Biology (AREA)
- Chemical & Material Sciences (AREA)
- General Health & Medical Sciences (AREA)
- Pathology (AREA)
- Animal Behavior & Ethology (AREA)
- Optics & Photonics (AREA)
- Medical Informatics (AREA)
- Biomedical Technology (AREA)
- Surgery (AREA)
- Engineering & Computer Science (AREA)
- Biophysics (AREA)
- Public Health (AREA)
- Veterinary Medicine (AREA)
- Heart & Thoracic Surgery (AREA)
- Chemical Kinetics & Catalysis (AREA)
- General Chemical & Material Sciences (AREA)
- Electrochemistry (AREA)
- Analytical Chemistry (AREA)
- Biochemistry (AREA)
- General Physics & Mathematics (AREA)
- Immunology (AREA)
- Measurement Of The Respiration, Hearing Ability, Form, And Blood Characteristics Of Living Organisms (AREA)
- Investigating Or Analysing Biological Materials (AREA)
Abstract
A percutaneous blood-oxygen- concentration measuring sensor has an electrode assembly with a cathode 1 and an anode 3 which are insulated from each other by an insulator 2. An electrode membrane 5 is supported by a supporting member 6 and is arranged to hold electrolyte 8 between itself and the end portion of the electrode assembly. The membrane 5 is preformed to conform with the configuration of the end portion of the electrode assembly. <IMAGE>
Description
SPECIFICATION
Percutaneous Blood-Oxygen-Concentration
Measuring Sensor
This invention relates to an improvement in which the construction of a sensor used in an instrument which performs the percutaneous measurement of the concentration or partial pressure of oxygen in arterial blood.
It is very important for the respiration control of a baby or a seriously ill patient who needs artificial respiration, to determine the concentration or partial pressure of oxygen in their blood, especially in their arterial blood. A percutaneous oxygen measuring method is known in the art, in which, unlike a direct oxygen measuring method carried out by taking a sample of the arterial blood, oxygen diffused through the subcutaneous tissue from the blood is monitored on the surface of the skin so that data with regard to the diffusion of the oxygen is measured continuously.
However, the sensors used at present do not give consistent and repeatable results and these inconsistent results stem, at least in part, from distortions and irregularities of a permeable membrane in the sensor.
According to this invention a percutaneous blood-oxygen-concentration measuring sensor comprises an electrode assembly with a cathode and an anode insulated from one another, and an electrode membrane supported by a supporting member and arranged to hold an electrolyte between it and the end portion of the electrode assembly being non-planar and the electrode membrane being preformed to conform with the non-planar configuration of the end portion of the electrode assembly.
A particular example of two sensors in accordance with this invention will now be described and contrasted with earlier sensors with reference to the accompanying drawings; in which:
Figure 1 (a) and 1 (b) are vertical sections through two conventional percutaneous bloodoxygen-concentration measuring sensors;
Figure 2 is a vertical section through an electrode membrane and fin electrode membrane holder of a conventional sensor, before assembly; and
Figures 3(a) and 3(b) are vertical sections through an electrode membrane and an electrode membrane holder for use with a sensor in accordance with this invention.
The arrangement of earlier sensors is shown in
Figures 1 (a) and 1(b). The sensors comprise a cylindrical silver anode 3 separated from the cathode by an insulator 2, and an electrode holder 4 holding the electrode assembly. An electrode membrane 5 is arranged to cover the end portion of the electrodes 1 and 3. A cylindrical electrode membrane holder 6 is fixed to the periphery of the electrode membrane 5. A packing 7 is arranged between the electrode membrane holder 6 and the electrode holder 4 and a thin layer of electrolyte 8 is interposed between the electrode membrane 5 and the end portion of the electrode assembly. A heating body 10 made from aluminium or copper having a high thermal conductivity includes a heater element 9.
The electrode membrane is made of a water repellent and oxygen-permeable synthetic resin.
The electrolyte 8 typically contains potassium chloride KCI.
Such a sensor is placed on the skin of a person to be examined, and the subcutaneous tissue under the heating body 10 is heated by the heater 9, and as a result is partially arterialised. Thus, oxygen in the subcutaneous tissue diffuses through the surface of the skin and passes through the electrode membrane 5. The oxygen diffuses into the electrolyte 8. Typically, a low voltage of say 0.5 to 0.8 volts, is applied across the two electrodes, and then an oxygen reduction reaction takes place at the cathode 1, while a silver oxidation reaction takes place at the anode 3. As a result of these an electrolytic current gives an indication of the concentration of the oxygen in the subcutaneous tissue and accordingly in the arterial blood.
To make the oxygen permeability of the electrode membrane consistent and repeatable it is important to provide a substantially constant tension in the electrode membrane 5 so that the latter is not excessively elongated or slackened.
To try and achieve this, a method has been used as disclosed in co-pending application No.
791 5343 in which, as shown in Figure 1 (b) the periphery of the electrode membrane 5 is fixed to an annular electrode membrane holder 6. The holder 6 with the electrode membrane 5 surrounds the outside of the electrode assembly and the end portion of the electrode assembly extends downwards and distorts the electrode membrane 5.
However, the above-described conventional sensor has a disadvantage since the electrode assembly distorts the electrode membrane. Thus the thickness of the membrane is not uniform.
Therefore, the oxygen permeability of the electrode membrane is not uniform over its entire surface and as a result, the measurement is inconsistent and unreliable.
The specific feature of a sensor in accordance with this invention is shown in Figure 3, wherein the electrode membrane 5 is preformed to conform to the configuration of the end portion of the electrode assembly. The membrane shown in
Figure 3a is intended to be used with a sensor as shown in Figure 1a and the membrane in Figure 3b with a sensor as shown in Figure 1 b. The electrode member 5 is preformed to the extent that, when the preformed electrode member 5 is mounted in the sensor, it is slightly but not excessively stretched or tensioned. The preformed electrode member 5 is fixed to the electrode membrane holder 6 by welding or bonding its periphery to the holder 6. The assembly of the holder 6 and the membrane 5 is fitted around the electrode assembly in the usual manner.
As shown in Figure 2, the membrane 5 as used previously is slightly tensioned with respect to its holder 6. Its lower surface is flat and stretched.
When the electrode membrane is positioned in the holder the protruding end portion of the electrode assembly contacts, and the membrane stretches it further.
However, distortion of the membrane occurs since the contact pressure is not uniform over the entire surface of the electrode assembly.
In accordance with this invention, the membrane has as initial shape corresponding to that of the electrode assembly. As a consequence of this configuration, the membrane has a substantially uniform tension and consequently a substantially uniform thickness all over the surface of the electrode assembly since the contact pressure is initially uniform. Thus, stretching is uniform since the membrane does not have to first distort in shape to conform to that of the electrode assembly.
Since the electrode membrane is preformed as described above, when the sensor according to the invention is assembled, the end portion of the electrode assembly, especially the end of the cathode 1, is in close contact with the electrode membrane 5 without the electrode membrane 5 being excessively stretched. That is, the thickness of the electrode membrane is maintained substantially uniform. Accordingly, stable oxygen permeability and a stable electrode reaction can be obtained which, in turn, leads to accurate and stable measurement of the concentration or partial pressure of oxygen in arterial blood and enables repeatable and consistent results to be obtained.
Claims (5)
1. A percutaneous blood-oxygen-concentration measuring sensor comprising an electrode assembly with a cathode and an anode insulated from one another, and an electrode membrane supported by a supporting member and arranged to hold an electrolyte between it and the end portion of the electrode assembly, the end portion of the electrode assembly being non-planar and the electrode membrane being preformed to conform with the non-planar configuration of the end portion of the electrode assembly.
2. A sensor in accordance with claim 1, wherein the membrane has a flat portion corresponding to the shape of the supporting member in addition to the portion which conforms to the shape of the end portion of the electrode assembly.
3. A sensor according to claim 1 or 2, wherein the portion which conforms to the end portion of the electrode assembly includes a frusto-conical region.
4. A sensor according to any one of the preceding claims, wherein the membrane conforms to at least the configuration of the end portion of the cathode and the insulator of the electrode assembly.
5. A sensor according to claim 1, constructed substantially as described with reference to
Figures 1 and 3 of the accompanying drawings.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1978066930U JPS5613935Y2 (en) | 1978-05-18 | 1978-05-18 |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| GB2025057A true GB2025057A (en) | 1980-01-16 |
| GB2025057B GB2025057B (en) | 1982-11-03 |
Family
ID=13330188
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB7916833A Expired GB2025057B (en) | 1978-05-18 | 1979-05-15 | Percutaneous blood-oxygen-concentration measuring sensor |
Country Status (6)
| Country | Link |
|---|---|
| JP (1) | JPS5613935Y2 (en) |
| DE (1) | DE2920038C2 (en) |
| FR (1) | FR2425835A1 (en) |
| GB (1) | GB2025057B (en) |
| IT (2) | IT7935845V0 (en) |
| SE (1) | SE7904391L (en) |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4303076A (en) * | 1979-12-31 | 1981-12-01 | Air Shields, Inc. | Probe for transcutaneous sampling |
| DE10315962B4 (en) * | 2003-04-06 | 2006-05-24 | Ground Zero Gmbh | Woofer |
| DE102006022854B4 (en) * | 2006-05-16 | 2008-04-17 | Albert-Ludwig-Universität Freiburg | Implantable blood oxygen sensor |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE2640987C3 (en) * | 1976-09-11 | 1982-06-09 | Drägerwerk AG, 2400 Lübeck | Transducer for the transcutaneous measurement of gases in the blood |
| JPS5613933Y2 (en) * | 1978-05-12 | 1981-04-01 |
-
1978
- 1978-05-18 JP JP1978066930U patent/JPS5613935Y2/ja not_active Expired
-
1979
- 1979-05-15 GB GB7916833A patent/GB2025057B/en not_active Expired
- 1979-05-16 IT IT7935845U patent/IT7935845V0/en unknown
- 1979-05-16 IT IT7949059A patent/IT1116100B/en active
- 1979-05-17 FR FR7912599A patent/FR2425835A1/en active Granted
- 1979-05-17 DE DE2920038A patent/DE2920038C2/en not_active Expired
- 1979-05-18 SE SE7904391A patent/SE7904391L/en not_active Application Discontinuation
Also Published As
| Publication number | Publication date |
|---|---|
| GB2025057B (en) | 1982-11-03 |
| FR2425835A1 (en) | 1979-12-14 |
| JPS54183189U (en) | 1979-12-25 |
| DE2920038A1 (en) | 1979-11-22 |
| SE7904391L (en) | 1979-11-19 |
| FR2425835B1 (en) | 1984-02-17 |
| IT1116100B (en) | 1986-02-10 |
| JPS5613935Y2 (en) | 1981-04-01 |
| DE2920038C2 (en) | 1982-06-03 |
| IT7949059A0 (en) | 1979-05-16 |
| IT7935845V0 (en) | 1979-05-16 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PCNP | Patent ceased through non-payment of renewal fee |
Effective date: 19960515 |