CATHETER FOR MEASURING CHEMICAL PARAMETERS, IN PARTICULAR FOR INTRODUCING BIOLOGICAL TISSUES, LIQUIDS OR THE LIKE

• US 20030060751A1
• Filed: 01/07/2000
• Published: 03/27/2003
• Est. Priority Date: 04/09/1997
• Status: Active Grant

• Current Assignee: Disetronic Licensing Ag (Roche Holding AG)
• Original Assignee: Hans Haindl
• Inventors: HAINDL, HANS
• Granted Patent: US 6,616,625 B2
• Time in Patent Office: Days
• US Class Current: 604/27
• CPC Class Codes: A61B 5/14528 invasively
• CPC Class Codes: A61B 5/14532 for measuring glucose, e.g. by tissue impedance measurement
• CPC Class Codes: A61M 2025/0031 characterized by lumina for withdrawing or delivering, i.e. used for extracorporeal circuit treatment
• CPC Class Codes: A61M 25/003 characterized by features relating to least one lumen located at the distal part of the catheter, e.g. filters, plugs or valves catheter tips A61M25/0067

Abstract

A catheter used to measure chemical parameters, in particular to be inserted into biological tissue, fluids or the like, comprising a feed duct running longitudinally through the catheter to its outer end for the purpose of feeding a liquid, further a return duct running through the catheter to return the liquid and a partly permeable tubular membrane at the end of the catheter and enclosing the flow path between the end of the feed duct and the return duct. This catheter is characterized in that the feed duct (26) substantially coaxially encloses the return duct (4), or vice-versa, in that the tubular membrane (16) forms at least in the vicinity of the catheter end an inner wall (10) of the radially external return duct or the radially external feed duct (26), that the feed duct (26) and the return duct (4) communicate with each other at the catheter end by at least one radial aperture (24) and in that spacers are provided which brace the inner wall (10) of the radially external tubular part (12) and/or of the tubular membrane (16) against the external wall (6) of the inner tubular part (2).

The catheter can be manufactured in simple and economical manner and makes possible 15 a small diameter and small dead space and allows measurement without substantial time-delay at a high measurement level.

Claims

1. Chemical-parameter measuring catheter, in particular for insertion into biological tissue, fluids or the like, comprising

a feed duct running longitudinally through the catheter to its outer end and used to feed a liquid,

a return duct running the through the catheter to return the liquid, and

a partly permeable hose-like membrane at the end of the catheter and enclosing the flow space between the end of the feed duct and the return duct, characterized in that

the feed duct (26) substantially coaxially encloses the return duct (4) or vice-versa,

the hose-like membrane (16) forms at least in the region of the catheter end an inner wall (10) of the radially external return duct or of the radially external feed duct (26),

the feed duct (26) and the return duct (4) communicate with each other at the catheter end by at least one radial aperture (24), and

spacers are used which brace the innerwall (10) of the radially external tubular part (12) and/or the hose-like membrane (16) against the external wall (6) of the inner tubular part (2).

2. Catheter as claimed in claim 1, characterized in that the spacers are formed by ribs (8) on the outer wall (6) of the inner tubular part (2).

3. Catheter as claimed in claim 1, characterized in that the ribs (8) run in the longitudinal direction of the catheter.

4. Catheter as claimed in claim 1, characterized in that the ribs (8) are in the form of helical ribs (28).

5. Catheter as claimed in claim 4, characterized in that the helical ribs (28) are a separate component seated on the radially inner tubular part (2).

6. Catheter as claimed in one of claims 2 through 5, characterized in that the ribs (8, 28) resp. radially fill the external feed duct (30) and the return duct (6) in such manner that a helical channel is formed between them.

7. Catheter as claimed in claim 1, characterized in that the diameters of the hose-like membrane (16) and of the catheter are substantially equal.

8. Catheter as claimed in claim 1, characterized in that the tubular part (12) is made of membrane material over its full length and is fitted as far as the front end zone of the catheter with an impermeable layers.

9. Catheter as claimed in claim 8, characterized in that the layer is mounted on the external and/or inner side of the tubular part.