System and method of bladder and sphincter control
A method and system for bladder control are disclosed. In embodiments, a method for bladder control is provided that comprises coupling an electrode to an afferent nerve that is related to the bladder. Applying a plurality of pulse burst stimulations via the electrode causes voiding of urine from the bladder. In embodiments, the plurality of pulse burst stimulations to the afferent nerve reduces external urethral sphincter (EUS) contractions and evokes bladder contractions to expel urine from the subject. In embodiments, the plurality of pulse burst stimulations to the afferent nerve evokes bladder contractions alone to expel urine from the subject. In embodiments, a system for bladder control is provided that comprises an electrode for applying a pulse burst stimulus to an afferent nerve or dermatome to reduce reflex contractions and a signal generator for generating the pulse burst stimulus.
1. A method for bladder control, comprising:
electrically coupling a first electrode to an afferent nerve that is anatomically related to the bladder, wherein the afferent nerve, when active, reduces external urethral sphincter contractions;
electrically coupling a second electrode to an efferent nerve that is anatomically related to the bladder, wherein the efferent nerve, when active, evokes bladder contractions;
stimulating the afferent nerve by applying a first series of intermittent pulse bursts by the first electrode to reduce external urethral sphincter contractions;
concurrently stimulating the efferent nerve by applying a second series of intermittent pulse bursts by the second electrode to evoke bladder contractions;
wherein periods of the first series of intermittent pulse bursts and the second series of intermittent pulse bursts are synchronized so that during a period, one of the first series of intermittent pulse bursts or the second series of intermittent pulse bursts has an on time that a positive integer greater than or equal to two multiple of an on time of the other of the first series of intermittent pulse bursts and the second series of intermittent pulse bursts; and
voiding urine from the bladder via the urethra through the external urethral sphincter in response to the first series of intermittent pulse bursts and the second series of intermittent pulse bursts.
2. The method of claim 1 , wherein each pulse burst of the first series of intermittent pulse bursts comprises a first pattern and each pulse burst of the second series of intermittent pulse bursts comprises a second pattern.
3. The method of claim 1 , wherein the first electrode and the second electrode are selected from the group consisting of a cuff electrode, a subcutaneous electrode, a spiral electrode, a helical electrode, and a needle electrode.
4. The method of claim 1 , wherein the first electrode is selected from the group consisting of a surface electrode, and a subcutaneous needle electrode.
5. The method of claim 4 , wherein the first series of intermittent pulse bursts is applied to a dermatome.
6. The method of claim 1 , wherein the afferent nerve is an intradural portion of a sacral dorsal root and the efferent nerve is an intradural portion of a sacral ventral root.
7. The method of claim 1 , wherein the first series of intermittent pulse bursts comprises an inter-burst frequency of about 0.25 to about 50 Hz, wherein each of the pulse bursts comprises between 2 and 20 individual pulses, a width of about 10 to about 300 microseconds, and an intra-burst pulse frequency of about 10 Hz to about 250 Hz.
8. A system, comprising:
a signal generator that generates a first series of intermittent pulse bursts and a second series of intermittent pulse bursts, wherein periods of the first series of intermittent pulse bursts and the second series of intermittent pulse bursts are synchronized so that one of the first series of intermittent pulse bursts or the second series of intermittent pulse bursts has an on time that a positive integer greater than or equal to two multiple of an on time of the other of the first series of intermittent pulse bursts and the second series of intermittent pulse bursts;
a first electrode to apply the first series of intermittent pulse bursts to an afferent nerve that is anatomically related to the bladder; and
a second electrode to apply the second series of intermittent pulse bursts to an efferent nerve that is anatomically related to the bladder concurrently to the first electrode applying the first series of intermittent pulse bursts to the afferent nerve.
9. The system of claim 8 , wherein the first series of intermittent pulse bursts is configured to reduce external urethral sphincter contractions; and
wherein the second series of intermittent pulse bursts is configured to evoke bladder contractions.
10. The system of claim 8 , wherein the first electrode is a skin electrode or a subcutaneous electrode.
11. The system of claim 10 , wherein the first series of intermittent pulse bursts is applied to a dermatome via the first electrode.
12. The system of claim 8 , wherein the afferent nerve is an intradural portion of a sacral dorsal root and the efferent nerve is an intradural portion of a sacral ventral root.
13. The system of claim 8 , wherein the first series of intermittent pulse bursts comprises an inter-burst frequency of about 0.25 to about 50 Hz, wherein each of the pulse bursts comprises between 2 and 20 individual pulses, a width of about 10 to about 300 microseconds, and an intra-burst pulse frequency of about 10 Hz to about 250 Hz.