The Design, Fabrication and Testing of a High Frequency, Angled Ultrasound Endoscope for Minimally Invasive Spine Surgery

Abstract

Minimally invasive spine surgery is often used to alleviate the symptoms of pathologies that compress the neural structures within the spine, creating a need for better imaging guidance within the limited surgical space. An angled, high-resolution, small form factor ultrasound endoscope was designed, fabricated, and tested in-lab to provide ultrasound guidance during minimally invasive spine decompression surgeries. The probes were tested for safety and their ultrasound parameters characterized. Images were taken of a human volunteer’s wrist and an ex vivo porcine spine. Two probes were characterized to have an axial resolution of 33- 45 µm, a lateral resolution of 130-116 µm, and secondary lobes suppressed to under 60 dB. The probes then demonstrated the capability to delineate both wrist and spinal canal anatomy, where power Doppler visualized blood flow in the wrist and B-mode visualized deformations of the spinal cord’s contour upon manipulation by surgical instruments.