Image-to-robot registration is a typical step for robotic image-guided interventions.
If the imaging device uses a portable imaging probe that is held by a robot, this registration is constant and has been commonly named probe calibration. The same applies to probes tracked by a position measurement device. We report a calibration method for two dimensional (2D) ultrasound probes using robotic manipulation and a planar calibration rig. Moreover, a needle-guide that is attached to the probe is also calibrated for ultrasound-guided needle targeting. The method is applied to a transrectal ultrasound (TRUS) probe for robot-assisted prostate biopsy. Validation experiments include TRUS-guided needle targeting accuracy tests. The paper outlines the entire process from the calibration to image-guided targeting. Freehand TRUS-guided prostate biopsy is the primary method of diagnosing prostate cancer, with over 1.2 million procedures performed annually in the US alone. However, freehand biopsy is a highly challenging procedure with subjective quality control. As such, biopsy devices are emerging to assist the physician. Here, we present a method that uses robotic TRUS manipulation. A 2D TRUS probe is supported by a 4 degree of freedom (DoF) robot. The robot performs ultrasound scanning, enabling 3D reconstructions. Based on the images the robot orients a needle-guide on target for biopsy. The biopsy is acquired manually through the guide. In-vitro tests showed that the 3D images were geometrically accurate, and image-based needle targeting accuracy was 1.55mm. These validate the probe calibration presented and the overall robotic system for needle targeting. Targeting accuracy is sufficient for targeting small, clinically significant prostatic cancer lesions, but actual in-vivo targeting will include additional error components that will have to be determined.
Written by:
Kim C, Chang D, Petrisor D, Chirikjian G, Han M, Stoianovici D. Are you the author?
Reference: IEEE Trans Biomed Eng. 2013 Jan 21. Epub ahead of print.
doi: 10.1109/TBME.2013.2241430
PubMed Abstract
PMID: 23358940
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