pH electrode
OwnerDavid M. Band, David G. Penman +1inventors
InventorsDavid M. Band, David G. Penman, Jiri Kratochvil
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Abstract
A pH electrode suitable for in vivo use is provided in a cannula 10, and comprises a reference electrode 14 consisting of a chloridized silver wire surrounded by a solid unbuffered internal reference material 16 comprising potassium chloride, silver chloride, citric acid and sorbitol as a hygroscopic agent. The material 16 is surrounded by a PVC sleeve 12. The tip of the cannula 10 has a pH sensitive polymer-based membrane 20 across its end. The reference material has a pH when hydrated of about 2 which is below the range of pH response of the membrane 20.
Claims14
A pH electrode comprising an internal reference electrode, a layer of internal reference material and a pH sensitive polymer-based membrane, characterized in that the membrane has a limited range of pH response, and in that the internal reference material has a pH outside the range of pH response of the membrane.
A pH electrode comprising an internal reference electrode, a layer of internal reference material comprising a hygroscopic material, and a pH sensitive polymer-based membrane, characterized in that the membrane has a limited range of pH response, and in that the internal reference material has a pH outside the range of pH response of the membrane.
Dependencies are inferred from the claim text.