Device and implantation system for electrical stimulation of biological systems
The present specification discloses devices and methodologies for the treatment of transient lower esophageal sphincter relaxations (tLESRs). Individuals with tLESRs may be treated by implanting a stimulation device within the patient's lower esophageal sphincter and applying electrical stimulation to the patient's lower esophageal sphincter, in accordance with certain predefined protocols. The presently disclosed devices have a simplified design because they do not require sensing systems capable of sensing when a person is engaged in a wet swallow and have improved energy storage requirements.
1. A system for normalizing a function of a patient's lower esophageal sphincter (LES), comprising:
at least one electrode in electrical communication with the LES;
a waveform generator coupled to the electrodes; and
a controller configured to electrically stimulate the LES to reduce at least one of a frequency of occurrence or intensity of transient lower esophageal sphincter relaxation (tLESR) or gastroesophageal reflux symptoms in the patient both during and after stimulation by controlling the waveform generator to repeatedly:
a) generate and apply an electrical pulse train to the LES through the electrodes for a stimulation period, wherein the electrical pulse train is defined by a pulse width, a pulse current, and a pulse frequency, and
b) terminate the electrical pulse train for a rest period, wherein the pulse width, the pulse current and the pulse frequency are defined such that swallowing of the patient is not hindered during said application of the electrical pulse train.
2. The system of claim 1 , wherein the pulse width, the pulse current and the pulse frequency are defined such that a pressure level of the LES does not induce dysphagia in the patient and allows the patient to swallow a bolus during both the stimulation period and rest period.
3. The system of claim 1 , wherein the controller is configured to determine parameters of the electrical pulse train that maintain an average pressure of the LES above a predefined pressure level during the rest period.
4. The system of claim 1 , wherein the pulse width has a range of 30 μsec to 5 msec and the pulse current has a range of 2 to 15 mAmp.
5. The system of claim 1 , wherein the controller is configured to adjust a length of the stimulation period and a length of the rest period to maintain an average pressure of the LES above a predefined pressure level.
6. The system of claim 1 , wherein the controller is not in communication with a sensor configured to sense physiological data of the patient.
7. The system of claim 1 , wherein the controller and the waveform generator are enclosed in a common housing and implanted in the patient.
8. The system of claim 1 , further comprising an external programming device for configuring the controller to adjust at least one of an amount of energy per stimulation period, a duration of the stimulation period, a frequency of the stimulation period, and a number of stimulation periods per day based on at least one of the frequency of occurrence or the intensity of tLESR or gastroesophageal reflux symptoms in the patient.
9. The system of claim 1 , further comprising a disposable battery coupled to the waveform generator and the controller configured to power the waveform generator and the controller.
10. The system of claim 1 , wherein the controller is configured to control the waveform generator to set the pulse width of the electrical pulse train in a range from 1 μs to 1 second.
11. The system of claim 1 , wherein the controller is configured to control the waveform generator to set the frequency of the electrical pulse train in a range from about 1 Hz to about 100 Hz.
12. The system of claim 1 , wherein the controller is configured to control the waveform generator to set the pulse current in the electrical pulse train in a range from 1 μAmp to 50 mAmps.
13. The system of claim 1 , further comprising a sensor coupled to the controller configured to sense physiological data of the patient; and a memory coupled to the controller for storing sensed data of the patient, wherein the controller is configured to control the waveform generator to adjust parameters of the electrical pulse train applied to the LES based on an analysis of the sensed data.
14. The system of claim 1 , further comprising at least one of an accelerometer or inclinometer coupled to the controller configured to sense posture data of the patient, wherein the controller is configured to control the waveform generator to adjust parameters of the electrical pulse train applied to the LES based on an analysis of the posture data.
15. The system of claim 1 , further comprising an antenna coupled to the controller configured to wirelessly receive instructions for instructing the controller to adjust parameters of the electrical pulse train applied to the LES, wherein the instructions are set by at least one of the patient or a trained professional.
16. The system of claim 1 , wherein the controller is configured to perform a diagnostic test on the patient by controlling the waveform generator to adjust an amount of electrical energy stimulating the LES over a treatment period based on at least one of the frequency of occurrence or the intensity of tLESR or gastroesophageal reflux symptoms in the patient.
17. The system of claim 1 , wherein, prior to stimulation, the stimulation period and the pulse current of the pulse train are configured to increase a pressure of the LES above a pressure level during the rest period.
18. The system of claim 1 , wherein, prior to stimulation, the controller is configured to determine a length of the rest period that allows a pressure of the LES to increase above a predefined pressure level and does not allow the pressure of the LES to decrease below the predefined pressure level.
19. The system of claim 1 , wherein the controller is configured with parameters of the electrical pulse train that produce a first increase in a pressure level of the LES during the stimulation period and a second increase in the pressure level of the LES during the rest period.