Materials and Approaches for Optical Stimulation of the Peripheral Nervous System

Abstract

A variety of methods, devices, systems and arrangements are implemented for stimulation of the peripheral nervous system. Consistent with one embodiment of the present invention, method is implemented in which light-responsive channels or pumps are engineered in a set of motor units that includes motor units of differing physical volumes. Optical stimuli are also provided to the light-responsive channels or pumps at an optical intensity that is a function of the size of motor units to be recruited. In certain implementations, the intensity of the optical stimuli is increased so as to recruit increasingly larger motor units.

What is claimed is: 
     
         1 . A method comprising:
 engineering light-responsive channels or pumps in a set of motor units that includes motor units having respective motor neurons of different physical sizes;   determining an optical stimulus profile as a function of a recruitment order of the set of motor units that corresponds to the different physical sizes of the motor neurons; and   providing the optical stimulus profile to the light-responsive channels or pumps.   
     
     
         2 . The method of  claim 1 , wherein the step of determining an optical stimulus profile includes correlating an activation of increasingly larger physical sizes of the motor neurons to the optical stimulus profile. 
     
     
         3 . The method of  claim 1 , wherein the step of determining an optical stimulus profile includes correlating a muscle fatigue factor to the optical stimulus profile. 
     
     
         4 . The method of  claim 1 , wherein the step of providing optical stimulus profile includes increasing an intensity of providing optical stimulus profile to recruit motor units having increasingly larger motor neurons. 
     
     
         5 . The method of  claim 1 , wherein the step of providing the optical stimulus profile is implemented using a curved optical delivery device that at least partially surrounds the motor neurons of the set of motor units. 
     
     
         6 . The method of  claim 1 , wherein the step of engineering includes
 engineering, in fast twitch motor units, first light-responsive channels having a first optical response profile; and   engineering, in slow twitch motor units, second light-responsive channels having a first optical response profile, wherein the first optical response profile and the second optical profile have respective peak sensitivities to different wavelengths of light.   
     
     
         7 . The method of  claim 6 , wherein the step of providing the optical stimulus profile includes providing an optical stimulus at a wavelength sufficient to activate the slow twitch motor units without activating the fast twitch motor units. 
     
     
         8 . The method of  claim 1 , further including the step of sensing a neural activation signal and wherein the step of providing optical stimuli is responsive to the sensed neural activation signal. 
     
     
         9 . The method of  claim 1 , further including the step of calibrating the optical stimulus profile as a function of contractile strength of the motor units in response to the optical stimulus profile. 
     
     
         10 . The method of  claim 1 , further including the step of sensing spastic motion of a portion of the body and wherein the step of providing the optical stimulus profile is responsive to the sensed spastic motion and mitigates the spastic motion. 
     
     
         11 . The method of  claim 1 , wherein the light-responsive channels or pumps are one of ChR2, NpHR and variants thereof. 
     
     
         12 . A method comprising:
 engineering light-responsive channels or pumps in a set of motor units that includes motor units having respective motor neurons of different physical sizes; and   providing optical stimuli to the light-responsive channels or pumps at an optical intensity that is a function of the different physical sizes of the motor neurons to be recruited.   
     
     
         13 . A method comprising:
 engineering light-responsive channels or pumps in a set of peripheral afferent nerves; and   providing optical stimuli to the light-responsive channels or pumps to mitigate pain.   
     
     
         14 . The method of  claim 13 , wherein the step of engineering includes engineering NpHR in the peripheral afferent nerves and the step of providing optical stimuli is responsive to an external control signal indicating a desired stimulus profile. 
     
     
         15 . The method of  claim 13 , wherein the step of providing optical stimuli includes providing an optical stimulus pattern to modify pain recognition in the central nervous system. 
     
     
         16 . A method comprising:
 engineering light-responsive channels or pumps in a set of vagal fibers associated with the gastrointestinal system; and   providing optical stimuli to the light-responsive channels or pumps to mitigate appetite.   
     
     
         17 . The method of  claim 16 , wherein the step of engineering includes engineering NpHR in the set of vagal fibers and wherein the step of providing optical stimuli is responsive to an indication of meal time. 
     
     
         18 . A method comprising:
 engineering light-responsive channels or pumps in a set of skeletal muscle stem cells;   implanting the set of skeletal muscle stem cells at a target location within a muscle to repopulate the muscle; and   providing optical stimuli to the light-responsive channels or pumps to cause activation of the muscle at the target location.   
     
     
         19 . The method of  claim 18 , wherein the step of implanting includes implanting the set of skeletal muscle stem cells for myocardial repair.