Potential difference and perfusion pressure catheter

• US 5,551,425 A
• Filed: 01/18/1995
• Issued: 09/03/1996
• Est. Priority Date: 05/13/1993
• Status: Expired due to Term

• Current Assignee: Medtronic Incorporated (Medtronic Plc)
• Original Assignee: Synectics Medical, Inc.
• Inventors: Essen-Moller, Anders
• Primary Examiner(s): Sykes, Angela D.
• Assistant Examiner(s): GILBERT, SAMUEL G
• Application Number:
  US08/375,209
• Time in Patent Office: 594 Days
• Field of Search: 128/635, 128/637, 128/642, 128/645, 128/656, 128/658, 128/691, 128/692, 128/748, 128/8, 607/115, 607/116, 607/120, 607/133, 604/264, 604/280, 606/45-48, 204/403, 204/404, 204/435
• US Class Current: 600/363
• CPC Class Codes: A61B 2562/0215 Silver or silver chloride containing
• CPC Class Codes: A61B 5/037 Measuring oesophageal pressure
• CPC Class Codes: A61B 5/392 Detecting gastrointestinal contractions
• CPC Class Codes: A61B 5/42 Detecting, measuring or recording for evaluating the gastrointestinal, the endocrine or the exocrine systems A61B1/00, A61B5/4857, A61B5/486, A61B5/4866, A61B5/4869 take precedence

Abstract

A perfusion catheter is designed to be used both as an exploring catheter for measuring potential difference across the gastrointestinal wall and for simultaneous measurement of pressure at the same site. The catheter includes a perfusion lumen into which an Ag/AgCl wire is inserted as an electrode thus avoiding the need of half cells and bridges. By perfusing saline around the wire, the environment is kept constant around the wire, a prerequisite for the electrode. The flow rate of the distal end of the lumen is altered by making the diameter of the outlet different to the diameter of the lumen. The perfused solution is also used to measure pressure.

Claims

1. A gastrointestinal catheter device comprising:

(a) a first catheter having a tubular body with a proximal end, a distal end, an interior, a length, an exterior, and a first lumen running through the interior of the tubular body for the length of the tubular body, the first lumen having a proximal end and a diameter,

(b) a wire electrode within the first lumen near the proximal end of the tubular body,

(c) a first outlet at the distal end of the tubular body, communicating from the first lumen to the exterior of the tubular body,

(d) a first luer connector, at the proximal end of the first lumen, connectable to a pressure transducer,

(e) an external shielded cable,

(f) a center wire in said external shielded cable,

(g) a second luer connector, adjacent to the proximal end of the first lumen, connecting the wire electrode to said external shielded cable,

(h) a pressure transducer,

(i) a perfusion pump,

(j) a tube connecting the first luer connector to the pressure transducer,

(k) a capillary connecting the pressure transducer to the perfusion pump,

(l) a second catheter, with a distal end, a proximal end, and an electrode at its distal end, and with a potential difference between the electrode at the distal end of the second catheter and the wire electrode within the first lumen running through the interior of the tubular body of the first catheter, and

(m) a potential difference measurement device connected to the proximal end of the second catheter and the external shielded cable, the potential difference measurement device electrically communicating with the electrode at the distal end of the second catheter and the wire electrode within the first lumen running through the interior of the tubular body of the first catheter.

2. The invention in claim 1, wherein the wire electrode comprises an Ag/AgCl wire.

3. The invention in claim 2, wherein

(a) the center wire in the external shielded cable is connected to and penetrates through the second luer connector,

(b) said center wire in the external shielded cable is soldered to said wire electrode at a solder point and said solder point is covered with glue,

(c) said wire electrode and said external shielded cable are formed as one integral part and are connectable to the second luer connector, and

(d) the second luer connector is connected to said first lumen and said wire electrode protrudes into the first lumen.

4. The invention in claim 1, wherein the center wire in the external shielded cable is connected to and penetrates through the second luer connector.

5. The invention in claim 1, wherein the first outlet at the distal end of the tubular body is of a different diameter than the diameter of the first lumen.

6. The invention in claim 1, and further comprising:

(a) an external device,

(b) a second lumen in the interior of the tubular body, running through the length of the tubular body, and having a proximal end and a distal end,

(c) a third luer connector, adjacent to the proximal end of the second lumen, connecting the second lumen to the external device, and

(d) a second outlet, at the distal end of the second lumen, from the second lumen to the exterior of the tubular body.

7. A gastrointestinal catheter comprising:

(a) a first catheter having a tubular body with a proximal end, a distal end, an interior, a length, an exterior, and a first lumen running through the interior of the tubular body for the length of the tubular body, the first lumen having a proximal end and a diameter,

(b) a wire electrode within the first lumen near the proximal end of the body,

(c) a first outlet at the distal end of the tubular body, communicating from the first lumen to the exterior of the tubular body,

(d) a first luer connector, at the proximal end of the first lumen, connectable to a pressure transducer,

(e) an external shielded cable,

(f) a center wire in said external shielded cable,

(g) a second luer connector, adjacent to the proximal end of the first lumen, connecting the wire electrode with said external shielded cable,

(h) a pressure transducer,

(i) a perfusion pump,

(j) a tube connecting the first luer connector to the pressure transducer,

(k) a capillary connecting the pressure transducer to the perfusion pump,

(l) an external device,

(m) a second lumen in the interior of the tubular body, running through the length of the tubular body, and having a proximal end and a distal end,

(n) a third luer connector, adjacent to the proximal end of the second lumen, connecting the second lumen to the external device,

(o) a second outlet, at the distal end of the second lumen, from the second lumen to the exterior of the tubular body,

(p) a second catheter, with a distal end, a proximal end, and an electrode at its distal end, and with a potential difference between the electrode at the distal end of the second catheter and the wire electrode within the first lumen running through the interior of the tubular body of the first catheter, and

(q) a potential difference measurement device connected to the proximal end of the second catheter and the external shielded cable, the potential difference measurement device electrically communicating with the electrode at the distal end of the second catheter and the wire electrode within the first lumen running through the interior of the tubular body of the first catheter.

8. A method for simultaneously measuring gastrointestinal electrical potential difference and pressure, at one site, comprising the steps of:

(a) inserting a first catheter, having a distal end and a proximal end, into a gastrointestinal area,

(b) inserting a second catheter having a distal end and an electrode at the distal end of the second catheter into a vein, so that the distal ends of the first and second catheters are electrically adjacent to each other across a gastro-intestinal wall,

(c) perfusing physiological saline solution through a lumen in the first catheter from an exterior of a patient into the proximal end of the first catheter, and out an outlet at the distal end of the first catheter, with an electrode near the distal end of the first catheter inserted into the physiological saline solution in the lumen,

(d) measuring an electrical potential between the electrode near the distal end of the first catheter and the electrode at the distal end of the second catheter, and

(e) simultaneously measuring pressure of the perfused saline solution.