Tumor localization in traditional lung resection surgery requires manual palpation of the deflated lung through a thoracotomy. It is a painful procedure that is not suitable for many patients. Therefore, a multisensory mechatronic device was designed to localize tumors using a minimally invasive approach. The device is sensorized with tactile, ultrasound and position sensors in order to obtain multimodal data of soft tissue in real time. This paper presents the validation of the efficiency and efficacy of this device via an ex vivo experimental study. Tumor pathology was simulated by embedding iodine-agar phantom tumors of varying shapes and sizes into porcine liver tissue. The device was then used to palpate the tissue to localize and visualize the simulated tumors. Markers were then placed on the location of the tumors and fluoroscopic imaging was performed on the tissue in order to determine the localization accuracy of the device. Our results show that the device localized 87.5% of the tumors with an average deviation from the tumor center of 3.42 mm.

The reduced access conditions present in Minimally Invasive Surgery (MIS) affect the feel of interaction forces between the instruments and the tissue being treated. This loss of haptic information compromises the safety of the procedure and must be overcome through training. Determining the skill level of trainees is critical for ensuring patient safety. The objective of this work was to evaluate the usefulness of force information for skills assessment during MIS. Experiments were performed using a set of sensorized instruments capable of measuring instrument position and tissue interaction forces. The results show that experience level has a strong correlation with force-based metrics. The proposed metrics can be automatically computed, are completely objective, and measure important aspects of performance.

An integrated system for minimally invasive robot-assisted image-guided lung brachytherapy has been developed. The system incorporates an experimental setup for accurate radioactive seed placement with commercially available dosimetry planning software. The end result is a complete system that allows planning and executing a brachytherapy procedure with increased accuracy. The results of the in vitro seed placement evaluation show that seed misplacement has a significant effect on the volume receiving more than 200% of the dose (V200), and the minimum dosage received by 90% of the volume (D90).

Minimally invasive surgery is a technique that provides numerous benefits to the patient, but presents challenges to the surgeon in that dexterity, hand-eye coordination and haptic perception are compromised. Robot-assisted minimally invasive approaches have addressed the problems of dexterity and coordination; however, the lack of kinesthetic and tactile feedback remains a significant drawback. Despite many advances in this area, little is currently known about what level of feedback performance is adequate to allow the surgeon to palpate tissue to detect an underlying tumour. This paper describes experiments that were conducted on ex-vivo porcine lung, using artificial tumours, to elucidate one measure of sensor performance required to detect the presence of a tumour. The results indicate that a force- sensitive probe with a sensing range of 0 to 10 N and a resolution of 0.01 N would allow a tumour to be localized via palpation using kinesthetic feedback.

An experimental test-bed for robot-assisted image-guided minimally invasive lung brachytherapy has been developed. The setup includes surgical robots, a device to accurately drop brachytherapy seeds, an ultrasound system, electromagnetic trackers, and navigational software. An evaluation using the test-bed was performed to compare the open procedure and the video-assisted thoracoscopic procedure with the proposed robot-assisted minimally invasive procedure under ultrasound image guidance and electromagnetic tracking. The results show that the use of robotic systems and image guidance can provide improved seed placement accuracy as compared to open surgery, while reducing the invasiveness of the procedure and trauma to the patient's body.

A device for robot-assisted brachytherapy has been designed for use with a minimally-invasive surgical robot such as the ZEUStrade It may be loaded with a standard brachytherapy needle allowing the robot to position its tip at a specified location within cancerous tissue. The device accurately retracts a hollow needle loaded with radioactive seeds while a stationary plunger pushes the seeds out into the tissue. The position error when retracting the needle is less than 0.05 mm. The use of this device, together with image-guidance for needle placement, can improve radiation dose delivery when treating certain types of lung cancer. The incorporation of this device into robotic systems that are already approved for clinical use can potentially allow it to be commercialized much sooner than competitive technology