Implantable monitoring probe

Abstract

Disclosed is an ambulatory system for monitoring one or more physiological parameters in a body lumen, such as the esophagus. The system includes an implantable probe having a sensor for the physiological parameter and a transmitter for transmitting data to an external receiver. The probe may be used for monitoring any of various physiological parameters, including pH, temperature, and pressure, within the esophagus or other body lumens. Methods and deployment catheters are also disclosed.

Description

BACKGROUND OF THE INVENTION [0001] This application is a divisional application of U.S. application Ser. No. 09 / 544,373, filed Apr. 6, 2000, now issued as U.S. Pat. No. 6,689,056, which is a continuation-in-part of U.S. application Ser. No. 09 / 287,617, filed Apr. 7, 1999, now issued as U.S. Pat. No. 6,285,897. The entire content of each of these U.S. applications is incorporated herein by reference. FIELD OF THE INVENTION [0002] The present invention relates to minimally invasive physiological monitoring systems. More particularly, the present invention relates to an implantable probe for monitoring one or more parameters in the esophagus, such as pH, in connection with the detection of gastroesophageal reflux disease. [0003] 2. Description of the Related Art [0004] Gastroesophageal reflux is a condition in which gastric acid refluxes, or flows in the direction opposite to the normal flow, from the stomach into the esophagus. Frequent reflux episodes may result in a potentially seve...

AI Technical Summary

Benefits of technology

[0022] The monitoring device in one embodiment comprises a microprocessor and non-volatile memory. The microprocessor controls the various functions of the monitoring device circuits. The monitoring device sends a digital signal that is coded to contain a variety of information. The digital message contains code to uniquely identify the monitoring device. This allows multiple devices to be used and inhibits erroneous or stray signal reception. The digital message also indicates what type of information is being sent and a corresponding data packet. The message also includes a checksum to help insure that the data transmission was correctly sent and received.

[0023] The monitoring device provides the ability to power itself off and on. This feature conserves battery power and extends the useful life of the monitoring device. The monitoring device also powers up the microprocessor and transmitting circuit up separately from the sensor circuit and alternates the active circuit. This feature further minimizes power consumption and further extends the useful life of the power supply.

Problems solved by technology

Frequent reflux episodes may result in a potentially severe problem known as gastroesophageal reflux disease (GERD).

Another cause of GERD is decreased resting tone of the LES, which produces incompetence (incomplete closing) of the LES.

Such pH changes, however, can be difficult to prove to be caused by true gastroesophageal reflux, and in some instances may not be caused by reflux.

The use of radioactive material and the expense of stationary or ambulatory gamma cameras make the radioisotope method for detection of reflux unattractive.

Almost invariably, the catheter's presence is very uncomfortable to patients, who frequently develop a sore throat and rhinorrhea (runny nose) because of local irritation of oropharyngeal and nasopharyngeal mucous membranes, respectively, from the catheter.

In addition, many patients are embarrassed to be seen in public with the catheter assembly attached to their faces.

This increased swallowing introduces a significant amount of air into the stomach, which can cause abdominal discomfort.

Finally, increased swallowing in response to the catheter's presence may erroneously raise a patient's intraesophageal pH readings because saliva is alkaline.

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