Ambulatory reflux monitoring system

• US 5,833,625 A
• Filed: 12/19/1995
• Issued: 11/10/1998
• Est. Priority Date: 10/21/1993
• Status: Expired due to Fees

• Current Assignee: Medtronic Incorporated (Medtronic Plc)
• Original Assignee: Synectics Medical AB (Medtronic Plc)
• Inventors: Essen-Moller, Anders
• Primary Examiner(s): HINDENBURG, MAX F
• Application Number:
  US08/574,917
• Time in Patent Office: 1,057 Days
• Field of Search: 128/632, 128/634, 128/635, 128/642, 128/733, 128/734, 128/780
• US Class Current: 600/547
• CPC Class Codes: A61B 5/037 Measuring oesophageal pressure
• CPC Class Codes: A61B 5/0535 Impedance plethysmography for measuring blood flow A61B5/0295
• CPC Class Codes: A61B 5/0538 invasively, e.g. using a catheter
• CPC Class Codes: A61B 5/14539 for measuring pH
• CPC Class Codes: A61B 5/14542 for measuring blood gases A61B5/14551 takes precedence
• CPC Class Codes: A61B 5/1473 invasive, e.g. introduced into the body by a catheter A61B5/1482 takes precedence
• CPC Class Codes: A61B 5/4211 Diagnosing or evaluating reflux

Abstract

An ambulatory system for recording and analyzing gastroesophageal reflux is presented. The system includes a digital recorder, an analysis software package and a catheter for measurement of changes in esophageal impedance. For the first time, gastroesophageal reflux can be detected with a pH above 4 (called alkaline reflux), which is the normal pH environment of the healthy esophagus. In addition, one embodiment of the invention allows for the determination of the direction of flow of the detected material in the esophagus, thus enabling the system to distinguish between swallowed saliva and alkaline gastroesophageal reflux. In yet a further embodiment, the present invention allows for recording and analysis of reflux on a non-invasive basis, by using pairs of externally worn impedance sensors. In another embodiment, the invention measures impedance simultaneously with other bio-parameters, such as pH or pressure.

Claims

1. A system for monitoring gastroesophageal reflux comprising:

(a) a gastroesophageal catheter with a distal end and a proximal end, with a first impedance sensor attached to the catheter near the distal end, such sensor electrically communicating with an electrical connector at the proximal end,

(b) an ambulatory recorder connected to such electrical connector adapted to record impedance data generated by such sensor and communicated to the recorder through such connector,

(c) executable software, resident in the recorder, adapted to analyze and graphically project impedance data generated by such first sensor and communicated to such recorder through such connector,

(d) an output device for the data recorded in the recorder, the output device being any of (1) a display on the recorder, (2) a printer electrically connected to the recorder, (3) a modem electrically connected to the recorder, and (4) a connector electrically connected to the recorder, and

(e) a second impedance sensor attached to the catheter, near to the first sensor but closer to the proximal end of the catheter than the first sensor, such second sensor electrically communicating with the electrical connector,

(f) said software further being adapted to analyze and graphically project impedance data generated by such second sensor and communicated to such recorder through such connector,

(g) said recorder being further adapted to record impedance data generated by such second sensor and communicated through such connector,

(h) the first sensor and the second sensor further comprising a pair of metal rings encircling the outer surface of the catheter, about 2 mm apart, each metal ring electrically communicating to the electrical connector through a wire,

(i) the first sensor being separated from the second sensor by about 1 cm,

(j) said recorder being further adapted to record impedance data generated by the metal rings in the sensors and communicated through such connectors, and

(k) said software being further adapted to analyze and graphically project impedance data generated by each such sensor and communicated to such recorder through such connector.

2. The invention in claim 1, further comprising:

(a) a single metal ring, encircling the outer surface of the catheter, about 2 mm closer to the proximal end of the catheter than said first sensor, and electrically communicating to such electrical connector through a wire, and adapted to act variously as a pair with the first ring of the first sensor or the second ring of the first sensor as an alternate configuration of such first sensor, wherein the single metal ring may be of a material selected from (1) gold and (2) stainless steel.

3. The invention in claim 1, where:

(a) the pair of metal rings may be of a material selected from (a) gold and (2) stainless steel.

4. A system for monitoring gastroesophageal reflux comprising:

(a) a gastroesophageal catheter with a distal end and a proximal end, with a first impedance sensor attached to the catheter near the distal end, such sensor electrically communicating with an electrical connector at the proximal end,

(b) an ambulatory recorder connected to such electrical connector adapted to record impedance data generated by such sensor and communicated to the recorder through such connector,

(c) executable software, resident in the recorder, adapted to analyze and graphically project impedance data generated by such first sensor and communicated to such recorder through such connector,

(d) an output device for the data recorded in the recorder,

(e) a second impedance sensor attached to the catheter, near to the first sensor but closer to the proximal end of the catheter than the first sensor, such second sensor electrically communicating with the electrical connector,

(f) said software further being adapted to analyze and graphically project impedance data generated by such second sensor and communicated to such recorder through such connector, and

(g) said software being further adapted to analyze and graphically project impedance data generated by each such sensor and communicated to such recorder through such connector.

5. The invention in claim 4, further comprising:

(a) a single metal ring, encircling the outer surface of the catheter, about 2 mm closer to the proximal end of the catheter than said first sensor, and electrically communicating to such electrical connector through a wire, and adapted to act variously as a pair with the first ring of the first sensor or the second ring of the first sensor as an alternate configuration of such first sensor, wherein the single metal ring may be of a material selected from (1) gold and (2) stainless steel,

(b) the output device being any of (1) a display on the recorder, (2) a printer electrically connected to the recorder, (3) a modem electrically connected to the recorder, and (4) a connector electrically connected to the recorder,

(c) said recorder being further adapted to record impedance data generated by such second sensor and communicated through such connector,

(d) the first sensor and the second sensor further comprising a pair of metal rings encircling the outer surface of the catheter, about 2 mm apart, each metal ring electrically communicating to the electrical connector through a wire,

(e) the first sensor being separated from the second sensor by about 1 cm, and

(f) said recorder being further adapted to record impedance data generated by the metal rings in the sensors and communicated through the such connectors.

6. The invention in claim 4 wherein:

(a) the pair of metal rings may be of a material selected from (1) gold and (2) stainless steel.