EP0437789A2
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A system, respectively a method, for measuring the concentration of a substance in a solution or dispersion thereof, whereby the substance consists of a compound which is non-electrically conducting or very slightly conducting
Assignee: Gambro AB
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Filing: 1990-12-20
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Granted: —
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Expires: 2010-12-20
Abstract
Abstract The present invention relates to a system, respectively a method for measuring the concentration of a substance in a solution or dispersion thereof, whereby the substance consists of a compound which is non-electrically conducting or very slightly conducting. The invention is primarily intended to be used for measuring the concentration of compounds or substances of medical interest, for example urea concentration in blood of a patient during for example hemodialysis, hemofiltration or hemodiafiltration. The conversion of the compound hereby occurs with a help of urease. <IMAGE>
Inventors
- 👤 Hakan Hakansson
- 👤 Bo Mattiasson
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-08 09:01
CPC Classifications
C; C12; C12Q; C12Q1/00; C12Q1/58; C12Q1/34
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
62 words
System for measuring the concentration of a substance in a solution or dispersion thereof, whereby the substance consists of a compound which is non-electrically conducting or very slightly conducting, characterized by means (15) for converting the substance in such a way that electrically conducting ions appear, and by means (17) for measuring these ions which are proportional to said degree of concentration.
Claim 2
Dependent Claim
20 words
System according to claim 1, characterized in that said means for converting the substance consists of an enzyme column (15).
Claim 3
Dependent Claim
23 words
System according to claim 1 or 2, characterized in that said means for measuring the appearing ions consists of a conductivity meter (17).
Claim 4
Dependent Claim
49 words
System according to anyone of the previous claims, whereby said substance occurs in an electrically conducting solution, characterized by means (8) for transferring the substance in its original form, or after converting appearing ions, to an electrically non-conducting or very slightly conducting solution before the measuring of the ions.
Claim 5
Dependent Claim
31 words
System according to claim 4, characterized in that said means for transferring the substance consists of a dialyzer, a filter or similar (8), whereby the transferring occurs by diffusion and/or filtration.
Claim 6
Dependent Claim
63 words
Method for measuring the concentration of a substance in a solution or dispersion thereof, whereby the substance consists of a compound which is non-electrically conducting or very slightly conducting, characterized in that the compound is converted in such a way that electrically conducting ions appear and that these ions are measured, the ions being proportional to the degree of concentration of the substance.
Claim 7
Dependent Claim
34 words
Method according to claim 6, characterized in that the conversion occurs with a help of an enzyme column (15) and the measuring of the appeared ions with a help of a conductivity meter (17).
Claim 8
Dependent Claim
38 words
Method according to either of claims 6 and 7, whereby said substance occurs in an electrically conducting solution, characterized in that this is first transferred to a non-electrically conducting or very slightly conducting solution before the measuring occurs.
Claim 9
Dependent Claim
18 words
Method according to claim 8, characterized in that both the conversion and the measuring occur after the transferring.
Claim 10
Dependent Claim
27 words
Method according to anyone of claims 6-9, characterized in that the measuring is carried out in a water solution which is prepared with, for example, distilled water.
Claim 11
Dependent Claim
22 words
Method according to anyone of claims 6-10, characterized in that the measuring is carried in a solution of low or non-conducting aminoacide.
Claim 12
Dependent Claim
33 words
Method according to claim 11, characterized in that the measuring occurs in a solution of anyone of the following aminoacides; L and/or D-alanine, L and/or D-histidine, L and/or D-serine or glycine, preferably glycine.
Claim 13
Dependent Claim
34 words
Method according to anyone of claims 6-12, characterized in that the substance to be measured consists of urea, for example in blood, whereby the conversion preferably occurs with the help of the enzyme urease.
Claim 14
Dependent Claim
55 words
Method according to anyone of claims 7-12, characterized in that an enzyme is used which is active on carbon-nitrogen bonds for measuring the present substance in anyone of the following combinations; Asparaginase - L-Asparagine Glutaminase - L-Glutamine Penicillin amidase - Penicillin Aminoacylase - N-acyl-amino acid Citrullinase - L-Citrulline Glutamin-(asparagin-)ase - L-Glutamine preferably Urease - Urea.
References Cited (Backward Citations)
No citation records indexed.
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