Neurocranial electrostimulation models, systems, devices and methods

Abstract

Methods, systems, and apparatus, including computer programs encoded on a computer storage medium, for developing transcranial electrical stimulation protocols are disclosed. In one aspect, a method includes the actions of accepting an image model of target tissue, obtaining a forward model having a first electrode configuration and first electrical stimulation parameters based on electrical stimulation of the target tissue, accepting electrode configuration changes or electrical stimulation parameter changes resulting in a second electrode configuration or second electrical stimulation parameters, determining an optimized tissue model using a least square methodology and based on the second electrode configuration or second electrical stimulation parameter changes, comparing the optimized tissue model with a desired outcome, and providing a confirmation of the optimized model with the desired outcome.

1 . A method performed by data processing apparatus, the method comprising:
 obtaining an image of target tissue;   assigning to the image tissue electrical conductance values;   arranging a plurality of stimulation electrodes around the target tissue;   computing, from the locations of electrodes and tissue electrical conductances, a forward model of the response of the tissue to applied currents;   defining desired tissue response;   optimizing one or more electrical stimulation parameters using the forward model to obtain the desired tissue response.   
     
     
         2 . The method of  claim 1  wherein the desired tissue response includes field intensities or currents in a portion of the target tissue and minimal stimulation of a second, different part of the tissue. 
     
     
         3 . The method of  claim 1  wherein the desired tissue response includes a change in the volume of tissue activated or a physiological response of the target tissue. 
     
     
         4 . The method of  claim 1  wherein the desired tissue response includes a change in the volume of tissue activated or a physiological response of tissue or muscle that is separate and different from the target tissue. 
     
     
         5 . The method of  claim 1  wherein the desired tissue response includes strict constraints of maximum allowable currents of field intensities at various tissue locations. 
     
     
         6 . The method of  claim 1  wherein the forward model is computed using an finite-element model of the tissue properties. 
     
     
         7 . The method of  claim 1  wherein the electrical conductance are non-isotropic and or non-uniform. 
     
     
         8 . The method of  claim 1  wherein the parameters altered include changing the voltage, current, activation time, location, sequence or number of electrodes. 
     
     
         9 . The method of  claim 1  where desired response is optimized with a minimum number of electrodes. 
     
     
         10 . The method of  claim 1  wherein the step of optimizing a new electrical stimulation pattern adjusts the results of the forward model using least squares methodology and any of its derivative forms such as constrained least squares, penalizes least squares, ridge regression, elastic nets, etc. 
     
     
         11 . The method of  claim 7  wherein the step of optimizing a new electrical stimulation pattern determines a volume of tissue activated that is different than the volume of tissue activated to determine the forward model. 
     
     
         12 . The method of  claim 1  wherein the image is derived from a pre-existing image library or a target tissue specific image. 
     
     
         13 . The method of  claim 1  wherein the image is derived from a fluoroscopic image, an MRI image, a CT image, or a combination of imaging techniques. 
     
     
         14 . The method of  claim 1  wherein the target tissue is transcranial tissue. 
     
     
         15 . The method of  claim 1  wherein the electrodes comprise at least two or more electrodes. 
     
     
         16 . The method of  claim 1  wherein the electrodes comprise at least 10 or more electrodes. 
     
     
         17 . The method of  claim 1  wherein the electrodes comprise at least 100 or more electrodes. 
     
     
         18 . The method of  claim 1  wherein the electrodes comprise at least 200 or more electrodes. 
     
     
         19 . The method of  claim 1  wherein the electrodes comprise at least 256 or more electrodes. 
     
     
         20 . The method of  claim 1  wherein the plurality of electrodes are place around the target tissue based on anatomical landmarks. 
     
     
         21 . The method of  claim 18  wherein the plurality of electrodes are placed around the target tissue using the International 10-20 System. 
     
     
         22 . The method of  claim 1  wherein the plurality of electrodes are placed around the target tissue in a pattern on the skin, below the skin or within the target tissue. 
     
     
         23 . The method of  claim 1  wherein the electrical stimulation applied is a direct current of 0 to 10 mA. 
     
     
         24 . The method of  claim 1  wherein the electrical stimulation applied is an alternating current of 0-10 mA and 0 H-1 kHz. 
     
     
         25 . The method of  claim 1  wherein the electrical stimulation applied is the same for each electrode in the plurality of electrodes. 
     
     
         26 . The method of  claim 1  wherein the electrical stimulation applied is different for each electrode in the plurality of electrodes. 
     
     
         27 . A computer storage medium encoded with a computer program, the program comprising instructions that when executed by data processing apparatus cause the data processing apparatus to perform operations comprising:
 accepting an image model of target tissue;   obtaining a forward model having a first electrode configuration and first electrical stimulation parameters based on electrical stimulation of the target tissue;   accepting electrode configuration changes or electrical stimulation parameter changes resulting in a second electrode configuration or second electrical stimulation parameters;   determining an optimized tissue model using a least square methodology and based on the second electrode configuration or second electrical stimulation parameter changes;   comparing the optimized tissue model with a desired outcome; and   providing a confirmation of the optimized model with the desired outcome.   
     
     
         28 . The computer storage medium of  claim 24  wherein the image model of target tissue comprises a standard library image, a target tissue specific image, a fluoroscopy image, an MRI image, a CT image or a combination of images. 
     
     
         29 . The computer storage medium of  claim 24  wherein the forward model is pre-calculated. 
     
     
         30 . The computer storage medium of  claim 24  wherein the forward model is calculated utilizing a processor or processors in communication with the storage medium. 
     
     
         31 . The computer storage medium of  claim 24  wherein the forward model is a finite element model. 
     
     
         32 . The computer storage medium of  claim 24  wherein the first and second electrode configurations are positions of electrodes around or in the target tissue. 
     
     
         33 . The computer storage medium of  claim 24  wherein the first and second electrical stimulation parameters comprise voltage, amperage, current, duration, timing, or sequence of the electrical stimulation. 
     
     
         34 . The computer storage medium of  claim 24  wherein the optimized tissue model is determined using a linear least squares methodology. 
     
     
         35 . The computer storage medium of  claim 24  wherein the desired outcome comprises a change in the volume of tissue activated, a physiological response of the target tissue, a physiological response of tissue or muscle separate and different from the target tissue. 
     
     
         36 . The computer storage medium of  claim 24  wherein the target tissue is transcranial tissue.