Robotic Ultrasound/Photoacoustic Tomography

Co-robotic Ultrasound Tomography

Common ultrasound images (Bmode) provide qualitative image of mostly the boundaries using reflected signals. Ultrasound tomography is a new method of reconstructing quantitative images using transmission (rather than reflection) ultrasound. Currently available ultrasound tomography systems suggest utilizing cylindrical transducers that can be used for a specific organ such as the breast. In this project, our focus is on an alternative way of creating ultrasound tomographic images that could be used for other anatomies and more general applications. Such system consists of two conventional ultrasound probes facing each other while one or several of the transducers in one probe can act as the transmitter and the rest as the receiver. However, aligning the two ultrasound probes is a challenging task. To address this issue, we propose the robot assisted ultrasound tomography system in which one probe is operated as freehand or in cooperation with a robotic arm and the other one is operated by a robotic arm automatically aligning with the first probe.

Co-robotic photoacoustic tomography

co-robotic_photoacoustic_tomographyPhotoacoustic imaging (PA) is becoming a promising modality for pre-clinical and clinical application by providing functional information with high penetration depth. In particular, PA computed tomography (PACT) aims to visualize the photoacoustic source distribution by scanning ultrasound transducers around a surface of the structure. Placing transducers around the subject or rotating the subject with fixing transducer position are two major approaches to scan in circular arc trajectory, but both are not flexible and have their drawbacks. To resolve the problem, we propose a new scanning method based on the robotic tracking technique. High flexibility of the scanning geometry is available because the trajectory of the tracked transducer generated by robot motion will be regarded as the scanning path. A simulation study of proposed method is conducted, assuming a 6cm array ultrasound transducer was used as receivers. To replicate the scenario that the probe is moved by robot, the probe is placed at two positions across a designated rotation angle, and received signals at both positions are used to generate an image.



[1] Fereshteh Aalamifar, Rishabh Khurana, Alexis Cheng, Xiaoyu Guo, Iulian Iordachita, Emad M. Boctora, “Enabling technologies for robot assisted ultrasound tomography”, International Journal of Medical Robotics and Computer Assisted Srugeries, in press.

[2] Aalamifar, Fereshteh, Rishabh Khurana, Alexis Cheng, Russell H. Taylor, Iulian Iordachita, and Emad M. Boctor. “Enabling technologies for robot assisted ultrasound tomography: system setup and calibration.” In SPIE Medical Imaging, pp. 90401X-90401X. International Society for Optics and Photonics, 2014.

[3] Aalamifar, Fereshteh, Dengrong Jiang, Haichong K. Zhang, Alexis Cheng, Xiaoyu Guo, Rishabh Khurana, Iulian Iordachita, and Emad M. Boctor. “Co-robotic ultrasound tomography: dual arm setup and error analysis.” In SPIE Medical Imaging, pp. 94190N-94190N. International Society for Optics and Photonics, 2015.

[4] Aalamifar, Fereshteh, Haichong K. Zhang, Arman Rahmim, and Emad M. Boctor. “Image reconstruction for robot assisted ultrasound tomography.” In SPIE Medical Imaging. International Society for Optics and Photonics, 2016.

[5] Zhang, Haichong K., Fereshteh Aalamifar, Hyun Jae Kang, and Emad M. Boctor. “Feasibility study of robotically tracked photoacoustic computed tomography.” In SPIE Medical Imaging, pp. 941908-941908. International Society for Optics and Photonics, 2015.