Minimally invasive surgical approaches have revolutionized surgical care and considerably improved surgical outcomes. The instrumentation has changed significantly from open to laparoscopic and robotic surgery with various usability and ergonomics qualities. To establish guidelines for future designing of surgical instruments, this study assesses the effects of current surgical approaches and instruments on the surgeon. Furthermore, an analysis of surgeons' preferences with respect to instrument handles was performed to identify the main acceptance criteria. In all, 49 surgeons (24 with robotic surgery experience, 25 without) completed the survey about physical discomfort and working conditions. The respondents evaluated comfort, intuitiveness, precision, and stability of 7 instrument handles. Robotic surgery procedures generally take a longer time than conventional procedures but result in less back, shoulder, and wrist pain; 28% of surgeons complained about finger and neck pain during robotic surgery. Three handles (conventional needle holder, da Vinci wrist, and joystick-like handle) received significantly higher scores for most of the proposed criteria. The handle preference is best explained by a regression model related only to comfort and precision (R(2) = 0.91) and is significantly affected by the surgeon's background (P < .001). Although robotic surgery seems to alleviate physical discomfort during and after surgery, the results of this study show that there is room for improvement in the sitting posture and in the ergonomics of the handles. Comfort and precision have been found to be the most important aspects for the surgeon's choice of an instrument handle. Furthermore, surgeons' professional background should be considered when designing novel surgical instruments.

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Sensory function is essential for functional post-stroke recovery and control of basic hand movements like grasping. Despite this fact, therapy focuses strongly on motor aspects of rehabilitation, requiring active participation and thus excluding stroke patients with severe paresis. The aim of our novel therapeutic approach combining virtual reality, based on clinically proven mirror therapy, and tendon vibration of hand and wrist muscles is to induce neuroplastic changes leading to improved hand function. This paper presents the further development and evaluation of a robotic device, which can apply vibrations at precise locations on the finger flexor tendons to create illusions of extension movements and visualize the movements with a virtual hand. A preliminary study including 16 healthy subjects investigated the influence of the virtual reality on the perception of proprioceptive illusory movements. The experimental results provided evidence that the addition of the virtual reality enhanced the perception of the illusory movement generated by tendon vibration, by inducing movements with significantly higher extension (+4.5%, p < 0.05). Furthermore, the virtual reality allowed a better controlled temporal elicitation of the illusion. These findings indicate the potential of this novel strategy for a more effective therapy, especially for severely impaired patients.

The large volume and reduced dexterity of current surgical robotic systems are factors that restrict their effective performance. To improve the usefulness of surgical robots in minimally invasive surgery (MIS), a compact and accurate positioning mechanism, namedDionis, is proposed in this paper. This spatial hybrid mechanism based on a novel parallel kinematics is able to provide three rotations and one translation for single port procedures. The corresponding axes intersect at a remote center of rotation (RCM) that is the MIS entry port. Another important feature of the proposed positioning manipulator is that it can be placed below the operating table plane, allowing a quick and direct access to the patient, without removing the robotic system. This, besides saving precious space in the operating room, may improve safety over existing solutions. The conceptual design of Dionis is presented in this paper. Solutions for the inverse and direct kinematics are developed, as well as the analytical workspace and singularity analysis. Due to its unique design and kinematics, the proposed mechanism is highly compact, stiff and its dexterity fullfils the workspace specifications for MIS procedures.