A family of passive echogenic markers is presented by which the position and orientation of a surgical instrument can be determined in a 3-D ultrasound volume, using simple image processing. Markers are attached near the distal end of the instrument so that they appear in the ultrasound volume along with the instrument tip. They are detected and measured within the ultrasound image, thus requiring no external tracking device. This approach facilitates imaging instruments and tissue simultaneously in ultrasound-guided interventions. Marker-based estimates of instrument pose can be used in augmented reality displays or for image-based servoing. Design principles for marker shapes are presented that ensure imaging system and measurement uniqueness constraints are met. An error analysis is included that can be used to guide marker design and which also establishes a lower bound on measurement uncertainty. Finally, examples of marker measurement and tracking algorithms are presented along with experimental validation of the concepts.

This paper presents a robotic system capable of using three-dimensional ultrasound to guide a surgical instrument to a tracked target location. Tracking of both the surgical instrument and target was done using image based algorithms on the real-time 3D ultrasound data. The tracking techniques are shown to be especially amenable for execution on powerful graphics processor units. By harnessing a graphics card, it was possible to detect both a surgical instrument and a surgical target at a rate of 25 Hz. The high update rate permits the use of tracked instrument and target locations for controlling a robot. Validation of the system was done in a water tank, where the robot moved the instrument to the target site with a mean error of 1.2 mm

This paper presents a real-time 3D ultrasoundguided robotic system, designed to autonomously navigate a surgical instrument to surgeon-specified target points. The system tracks the instrument in real-time (2 Hz) using image processing. Thus, it does not require tracking of the ultrasound scan head. It makes use of a line detection algorithm and a passive instrument marker, which together report the instrument's position and orientation (6 d.o.f.) from a single ultrasound image. Validation experiments are presented. The system controlled instrument position in a variety of image locations with a mean error of 0.8 mm

Properly selected port sites for robot-assisted coronary artery bypass graft (CABG) improve the efficiency and quality of these procedures. In clinical practice, surgeons select port locations using external anatomic landmarks to estimate a patient's internal anatomy. This paper proposes an automated approach to port selection based on a preoperative image of the patient, thus avoiding the need to estimate internal anatomy. Using this image as input, port sites are chosen from a grid of surgeon-approved options by defining a performance measure for each possible port triad. This measure seeks to minimize the weighted squared deviation of the instrument and endoscope angles from their optimal orientations at each internal surgical site. This performance measure proves insensitive to perturbations in both its weighting factors and moderate intraoperative displacements of the patient's internal anatomy. A validation study of this port site selection was performed. cardiac algorithm also Six surgeons dissected model vessels using the port triad selected by this algorithm with performance compared to dissection using a surgeon-selected port triad and a port triad template described by Tabaie et al., 1999. With the algorithm-selected ports, dissection speed increased by up to 43% (p = 0.046) with less overall vessel trauma. Thus, this algorithmic approach to port site selection has important clinical implications for robot-assisted CABG which warrant further investigation.