Joshua G. Petersen

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In hands-on robotic surgery, the surgeon controls the motion of a tool mounted on the end effector by applying forces directly to the robot. The mass and inertia properties of the robot at the end effector thus contribute to the ability of the surgeon to move the tool and consequently, the performance of the surgery. As redundant robots have varying(More)
Toward the goal of developing a hands-on robotic surgery control strategy which simultaneously utilizes the various strengths of both the surgeon and robot, we present a dynamic active constraint approach tailored for hands-on surgery. Forbidden region active constraints are used to prevent motion into areas which have been deemed dangerous by the surgeon,(More)
In hands-on robotic surgery, the surgical tool is mounted on the end-effector of a robot and is directly manipulated by the surgeon. This simultaneously exploits the strengths of both humans and robots, such that the surgeon directly feels tool-tissue interactions and remains in control of the procedure, while taking advantage of the robot's higher(More)
Human tissue factor pathway inhibitor (TFPI) and three derivatives with deletions of: 1) the complete COOH-terminal third of the polypeptide including the third Kunitz domain, 2) the third Kunitz domain alone, or 3) the penultimate basic COOH-terminal region alone were expressed in yeast as secreted products. High expression yield was obtained only with the(More)
Human tissue factor pathway inhibitor (TFPI) is a plasma protease inhibitor that consists of three tandem Kunitz-type inhibitor domains flanked by a negatively charged NH2 terminus and a positively charged COOH-terminal tail. Previous studies have shown that the first and second Kunitz-type domains in TFPI are involved in the inhibition of factor VIIa and(More)
Steerable needles can improve many medical procedures through their ability to reach targets behind critical or impenetrable anatomical structures, such as blood vessels and bones. However, path planning in real-time is challenging due to complicated kinodynamic constraints and tissue deformation. This paper introduces a parallel path planning algorithm(More)
The aim was to investigate whether a truncated recombinant Tissue Factor Pathway Inhibitor (TFPI1-161), which lacked the third Kunitz-type domain and the basic c-terminal region, had an antithrombotic effect comparable to LMWH in a randomised double-dummy study. The experimental thrombosis was induced in jugular veins, in a total of 40 rabbits by a(More)
Tissue factor pathway inhibitor (TFPI) is a feed back inhibitor of the initial activation of the extrinsic pathway of coagulation. In humans, injection of heparin results in a 2-6 fold increase in plasma TFPI and recent studies suggest that TFPI may be important for the anticoagulant activity of heparin. Full length (FL) TFPI, but not recombinant two-domain(More)
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