Methods, systems and devices for optical stimulation of target cells using an optical transmission element

Abstract

Stimulation of target cells using light, e.g., in vivo, is implemented using a variety of methods and devices. In one such device, target cells are stimulated using an implantable device. The device includes a light source for producing light from electrical power. An optical transmission element is made from a material that is substantially transparent to the light from the light light source. This transmission element substantially encases the light source at a proximal end. The transmission element delivers light from the light source to a distal end. The shape and size of the transmission element facilitates implanting of the element within a patient. A fixation portion physically couples to the optical transmission element and secures the device to the patient. A heat dissipation portion removes heat from the near optical transmission element and the light source and dissipates the removed heat through the fixation portion.

What is claimed is: 
     
         1 . An optical delivery device for delivering light in vivo, the device comprising:
 a light source for producing light from electrical power;   an optical transmission element made from a material that is substantially transparent to the light from the light source, the material having an elongated shape that substantially encases the light source at a proximal end and that is for delivering the light from the light source to a distal end;   a fixation portion physically coupled to the optical transmission element for attachment to the patient; and   a heat dissipation portion having a thermally conductive path for removing heat from near the light source.   
     
     
         2 . The device of  claim 1 , wherein the optical transmission element is a lumen and the material is one of glass and plastic. 
     
     
         3 . The device of  claim 1 , wherein the lumen contains a substance having an index of refraction that is substantially the same as the material of the lumen. 
     
     
         4 . The device of  claim 1 , wherein the optical transmission element is rigid along a direction of transmission for the light. 
     
     
         5 . The device of  claim 4 , wherein the optical transmission element includes an outer layer of a second material that facilitates light traveling along the direction of transmission. 
     
     
         6 . The device of  claim 1 , further including a temperature sensor for sensing a temperature near the optical transmission element and a control circuit for controlling the activation of the light source in response to the sensed temperature. 
     
     
         7 . The device of  claim 1 , wherein the optical transmission element is configured to direct light along a longitudinal axis that extends from the proximal end to the distal and wherein the optical transmission element is configured and arranged to direct light leaving the transmission element at a non-zero angle relative to the longitudinal axis. 
     
     
         8 . The device of  claim 1 , wherein the fixation portion is configured and arranged to allow rotational movement, about the longitudinal axis, of the optical transmission element during implantation and to prevent the rotational movement after implantation. 
     
     
         9 . The device of  claim 1 , wherein the material of optical transmission element is glass that is coated with a reflective substance. 
     
     
         10 . The device of  claim 1 , further including an implantable signal source having a power supply, a control circuit for generating electrical signals that activate the light source and conductors for transmitting the electrical signals to the light source. 
     
     
         11 . The device of  claim 10 , wherein the implantable signal source is designed for placement within the chest cavity in connection with the optical transmission element being implanted within the brain. 
     
     
         12 . A method for stimulating target cells in vivo, the method comprising:
 engineering light-activated ion channels in one or more in vivo target cells;   surgically implanting a device having
 a light source for producing light from electrical power, 
 an optical transmission element made from a material that is substantially transparent to the light from the light source, the material having an elongated shape that substantially encases the light source at a proximal end and that is for delivering the light from the light source to a distal end, 
 a fixation portion physically coupled to the optical transmission element for attachment to the patient, and 
 a heat dissipation portion having a thermally conductive path for removing heat from near the light source; and 
   activating the light source to stimulate the target cells.   
     
     
         13 . The method of  claim 12 , wherein the step of engineering further includes expressing, one or more in vivo target cells, light-activated ion channels that are variants of at least one of ChR2 and NpHR. 
     
     
         14 . The method of  claim 12 , wherein the step of implanting further includes rotating the optical transmission element about a longitudinal axis; activating the light source to stimulate the one or more target cells; assessing the effectiveness of a rotational position as a function of stimulus results, and fixing a rotational position of the optical transmission element in response to the assessment. 
     
     
         15 . The method of  claim 12 , further including the step of disabling the light source in response to a temperature sensor. 
     
     
         16 . The method of  claim 12 , wherein the step of implanting is accomplished using stereotactic insertion of the optical transmission element. 
     
     
         17 . The method of  claim 12 , wherein the one or more in vivo target cells are neurons.