| CPC A61B 8/085 (2013.01) [A61B 8/12 (2013.01); A61B 8/483 (2013.01); A61B 8/5223 (2013.01)] | 12 Claims |
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1. A method of generating and displaying the location and contour of neural structures within a psoas muscle of a human patient on a B-mode ultrasound image of the patient during a lateral-access spine surgery, comprising:
advancing a distal end of an ultrasound probe through an incision in the patient's skin to a superficial aspect of the psoas muscle that is between the patient's skin and a surgical target sit within the patient's spine such that the distal end of the probe is in direct contact with the psoas muscle without penetrating the psoas muscle, the probe having a proximal end, the distal end, an electronic communication element, and a transducer array positioned near the distal end, the transducer array including at least one emitting element that emits high-frequency sound waves within a field of view comprising a proximity of the distal end in a direction away from the distal end, the transducer array further comprising at least one sensing element that receives reflected sound waves and converts the reflected sound waves to radio frequency data;
upon positioning the probe such that the distal end is in direct contact with the psoas muscle and without penetrating the psoas muscle, performing ultrasound imaging to generate a B-mode image of the psoas muscle within the field of view from the radio frequency data obtained by the probe;
displaying the B-mode image of the psoas muscle on a display device;
generating a map of nerve tissue within the psoas muscle in the field of view; and
displaying the generated map of nerve tissue within the psoas muscle in the field of view on the display device to indicate the location and contour of the nerve tissue in relation to the psoas muscle and identify a path through the psoas muscle that avoids nerve tissue from the distal end to the surgical target site;
wherein the step of generating a map of nerve tissue within the psoas muscle in the field of view comprises:
receiving, from the transducer, image data representative of a region of the psoas muscle;
analyzing, by execution of a classification algorithm, the image data to identify an anatomical structure located within the region, wherein the classification algorithm identifies the anatomical structure by comparing a b-mode scan line from the image data to a plurality of known b-mode scan lines, each known b-mode scan line having been associated with a corresponding type of anatomical structure, and wherein the analyzing by execution of a classification algorithm comprises:
thresholding a b-mode image of the image data to generate a binary map of intensity values;
after thresholding the b-mode image, filtering the b-mode image with a smoothing filter;
identifying contiguous regions in the filtered b-mode image having a pixel count above a minimum threshold and below a maximum threshold;
comparing the identified contiguous regions to an area of an ellipse outlining the contiguous regions; and
classifying the identified contiguous regions as a nerve based on the comparison;
receiving radio frequency (RF) backscatter reflected from the tissue region;
converting the RF backscatter into a voltage signal;
based on the voltage signal, determining a power spectrum of the RF backscatter; and
determining, based on the image data and the power spectrum, that the tissue region includes nerve tissue; and
outputting an indication of the image data depicting a location of the nerve tissue.
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