Tracked 'Pick-up' Ultrasound for Robot-assisted Minimally Invasive Surgery

Goal: We present a novel “pick-up” ultrasound transducer for intra-abdominal robot-assisted minimally invasive surgery. Such a “pick-up” ultrasound transducer is inserted through an abdominal incision at the beginning of the procedure and remains in the abdominal cavity throughout, eliminating the need for a dedicated port or a patient bedside surgical assistant. The transducer has a handle that can be grasped in a repeatable manner using a da Vinci Pro-Grasp tool, allowing the transducer to be accurately manipulated by the surgeon using the da Vinci Robot. This is one way to enable 3D tracking of the transducer and thus mapping of the vasculature. The 3D vascular images can be used to register pre-operative CT to intra-operative camera images. Methods: To demonstrate the feasibility of the approach, we use an ultrasound vessel phantom to register a CT surface model to extracted ultrasound vessel models. The 3D vascular phantom images are generated by segmenting B-mode images and tracking the pick-up ultrasound transducer with the da Vinci kinematics, internal electromagnetic (EM) sensor or visible fiducials suitable for camera tracking. Results: Reconstruction results using da Vinci kinematics for tracking give a target registration error of 5.4 1.7mm.