Devices, systems, and methods for identifying a target medical device implant
Methods and devices for improving pelvic floor dysfunction in a patient suffering therefrom by electrically modulating neural tissue in a minimally invasive fashion using an electrical micro stimulator are provided.
1. A method of intra-operatively identifying a target medical device implant site adjacent to a target nerve in a patient comprising:
advancing a medical device along a surgical pathway to the target medical device implant site;
delivering to the target nerve a stimulation signal having a baseline amplitude greater than zero;
detecting a resulting baseline EMG signal in response to the stimulation signal;
delivering to the target nerve a subsequent stimulation signal having the baseline amplitude;
detecting a subsequent resulting EMG signal in response to the subsequent delivered stimulation signal;
delivering to the target nerve a further stimulation signal having a reduced amplitude compared to the baseline amplitude if the subsequent resulting EMG signal stays the same or increases above the baseline evoked electrical signal,
wherein the delivering and detecting steps are performed during the advancing step;
determining if a further resulting EMG signal is elicited by the further stimulation signal and remains constant for a pre-determined time period; and
identifying the target medical device implant site when the further resulting EMG signal remains constant for the pre-determined time period thereby identifying the target medical device implant site while avoiding a painful motor or sensory response from the patient; and
positioning the medical device at the target medical device implant site.
2. The method of claim 1 , wherein the stimulation signal, the subsequent stimulation signal and the further stimulation signal are delivered continuously as the stimulation device is advanced along the surgical pathway until the target medical device implant site has been identified.
3. The method of claim 1 , wherein the stimulation signal, the subsequent stimulation signal or the further stimulation signal is a single pulse stimulus waveform, a bipulse stimulus waveform, an alternating bipulse stimulus waveform, a sweep stimulus waveform, or a burst stimulus waveform.
4. The method of claim 1 , further comprising applying to the target nerve another stimulation signal having the baseline amplitude if the further resulting EMG signal is no longer detected or decreases below the baseline evoked electrical signal.
5. The method of claim 1 , wherein advancing the stimulation device and delivering the stimulation signal having the baseline amplitude comprises:
inserting a delivery tool carrying the medical device into the patient, the delivery tool or medical device comprising stimulating electrodes; and
activating the stimulating electrodes to apply the stimulation signal having the baseline amplitude to the target nerve as the delivery tool is advanced along the surgical pathway.
6. The method of claim 1 , wherein the medical device is an electrical microstimulator.
7. A method of improving a medical condition comprising the method of claim 6 and further comprising:
activating the electrical microstimulator to apply a therapy electrical signal to the target nerve to improve the medical condition.
8. The method of claim 7 , wherein the medical condition is an overactive bladder.
9. The method claim 7 , wherein the medical condition is peripheral pain.
10. The method of claim 1 , wherein the target nerve is the posterior tibial nerve.