Method and apparatus for intentional impairment of gastric motility and /or efficiency by triggered electrical stimulation of the gastrointestinal tract with respect to the intrinsic gastric electrical activity

Abstract

A sensor based gastric stimulator system and method for gastric stimulation of a patient employing an implantable gastric stimulator, which includes an information processor, an electrical stimulator circuit, and telemetry circuitry. The implantable stimulator senses intrinsic, gastric electrical activity (slow waves and/or peristaltic waves) and delivers electrical stimulation to intentionally disrupt or disorganize that activity. The stimulation is triggered by (tracks) normal gastric electrical activity and can be delivered with a spatial offset to anticipate the propagating gastric electrical activity or may be delayed temporally to anticipate the next propagating slow or peristaltic wave. The stimulator may be programmed to disrupt/disorganize all or a percentage of the intrinsic, normal gastric electrical activity. The programmer (via radio frequency data link) may non-invasively program stimulation parameters and intervals. The stimulator may provide stimulation to one or a plurality of stimulation sites and may incorporate one or a plurality of independently programmable sensing and/or stimulation channels. The information processor of the implantable gastric stimulator uses the gastric stimulation information from the non-electrode sensor for determining periods or windows of susceptibility for application of the electrical signals conveyed with the stimulation electrode for conveying electrical signals from the electrical stimulator circuit to the stomach wall of the patient.

What is claimed is:  
     
         1 . A system for gastric stimulation of a patient comprising: 
 an implantable gastric stimulator, comprising an information processor, sensing circuitry, electrical stimulation circuitry, electrode switching circuitry, telemetry circuitry, a real time clock, and a power source;    a remote programmer operable with the telemetry circuitry of said implantable gastric stimulator for controlling the operation of the electrical stimulator and sensing circuitry with the information processor;    two or more electrodes for conveying electrical stimulation from the electrical stimulator circuit to the stomach wall of the patient; and    two or more electrodes for conveying sensed gastric electrical activity from the stomach wall to the sensing circuitry of the said implantable gastric stimulator.    
     
     
         2 . A system as recited in  claim 1 , comprising one or a plurality of elongated lead body sheaths having proximal end connectors for coupling said stimulation and sensing electrodes with said implantable gastric stimulator, the leads of said stimulation and sensing electrodes extending through the elongated lead body sheaths to their distal end, the distal end of the elongated lead body sheaths for electrical communication with the stomach wall of the patient and for positioning said stimulation and sensing electrodes on or in the stomach wall.  
     
     
         3 . A system as recited in  claim 1 , wherein said plurality of the stimulation and sensing electrodes are positionable at different locations of the stomach wall.  
     
     
         4 . A system as recited in  claim 1 , wherein the function of the electrodes is controlled by programmable electrode switching circuitry.  
     
     
         5 . A system as recited in  claim 1 , wherein the telemetry circuitry of said implantable gastric stimulator comprises a radio frequency telemetry transceiver provided for communication with said remote programmer.  
     
     
         6 . A system as recited in  claim 1 , wherein said information processor comprises a programmable microprocessor or microcontroller.  
     
     
         7 . A system as recited in  claim 1 , wherein the system may temporarily revert to a power conserve condition at programmable times of the day.  
     
     
         8 . A system as recited in  claim 1 , wherein said sensing electrodes communicate gastric electrical signals to the sensing circuitry of said implantable gastric stimulator for processing with the information processor for identifying interval, amplitude, and duration of the intrinsic electrical activity.  
     
     
         9 . A system as recited in  claim 8 , wherein said sensing electrodes communicate gastric electrical signals to the sensing circuitry of said implantable gastric stimulator for processing with the information processor for identifying the frequency spectrum of the intrinsic electrical activity.  
     
     
         10 . A system as recited in  claim 9 , wherein the information processor analyzes the electrical activity and classifies it as slow wave or peristaltic wave.  
     
     
         11 . A system as recited in  claim 10 , wherein the information processor analyzes the intrinsic electrical activity and classifies the activity as normal or abnormal.  
     
     
         12 . A system as recited in  claim 11 , wherein the system may temporarily revert to a power conserve condition in the absence of a programmable threshold of normal electrical activity.  
     
     
         13 . A system as recited in  claim 12 , wherein the stimulator delivery of electrical stimulation is triggered by electrical activity classified as normal.  
     
     
         14 . A system as recited in  claim 13 , wherein the stimulator may be programmed to deliver electrical stimulation on all or a percentage of normal events.  
     
     
         15 . A system as recited in  claim 14 , wherein the electrical stimulation may be delivered across the intrinsic electrical activity.  
     
     
         16 . A system as recited in  claim 14 , wherein the electrical stimulation may be delivered with a spatial offset to the intrinsic electrical activity.  
     
     
         17 . A system as recited in  claim 16 , wherein the electrical stimulation may be delivered with a temporal offset to the sensed intrinsic electrical activity.  
     
     
         18 . A system as recited in  claim 17 , wherein the electrical stimulation may be delivered in anticipation of the next normal electrical activity.  
     
     
         19 . A system as recited in  claim 18 , wherein the temporal offset is programmable.  
     
     
         20 . A system as recited in  claim 19 , wherein the temporal delivery of the electrical stimulation is adaptable based upon an algorithm considering a running history of recent predecessor electrical activity events.  
     
     
         21 . A system as recited in  claim 20 , wherein the polarity of the stimulation electrodes is programmable allowing stimulation between a single pair or a plurality of electrodes.  
     
     
         22 . A system as recited in  claim 21 , wherein the stimulator may be programmed to switch the polarity of one or a plurality of the various stimulation electrodes to accommodate multiphase stimulation.  
     
     
         23 . A system as recited in  claim 22 , wherein the electrical stimulation comprises one or a plurality of biphasic pulses programmable within the following parameters, comprising: 
 pulse amplitude between 0.0 to 15 V or 0.0 to 15 mA;    pulse width between 20 msec to 500 msec;    pulses per event between 1 and 5; and    first phase width between 25 to 100 percent of pulse width.    
     
     
         24 . A method for  claim 23 , wherein the pulse width is accommodated by switching between two or more capacitors in an array.  
     
     
         25 . A system as recited in  claim 22 , wherein the electrical stimulation comprises an alternating polarity pulse train programmable within the following parameters, comprising: 
 pulse amplitude between 0.0 to 15 V or 0.0 to 15 mA; pulse width between 100 μsec and 750 μsec;    pulses per second (frequency) between 10 to 120 Hz; and    duration of pulse train between 0.5 and 30 seconds.    
     
     
         26 . A system as recited in  claim 25 , wherein parameters comprising quantities, interval frequency, duration, amplitude, or the like for the sensed events and quantities of paced events are stored for subsequent recall.  
     
     
         27 . A system as recited in  claim 26 , wherein the sensed intrinsic waveforms can be telemetered to the external programmer to assist in establishing the appropriate stimulation parameters.  
     
     
         28 . A system as recited in  claim 1 , wherein the stimulator may incorporate one or a plurality of independently programmable stimulation or sensing channels.  
     
     
         29 . A system as recited in  claim 28 , wherein at least one stimulation channel may be programmable to parameters associated with nerve stimulation.