Integration of a surgical robotic arm to the connected operating room via ISO IEEE 11073 SDC.

PURPOSE: Since 2019, intraoperative networking with ISO IEEE 11073 SDC has, for the first time, enabled standardized multi-vendor data exchange between medical devices. For seamless plug-and-play integration of devices without previous configuration, further specifications for device profiles ("device specializations") on top of the existing core standards must be developed. These generic interfaces are then incorporated into the standardization process. METHODS: An existing classification scheme of robotic assistance functions is being adopted and used as a baseline to derive functional requirements for a universal interface for modular robot arms. Additionally, the robot system requires machine-machine interfaces (MMI) to a surgical navigation system and a surgical planning software in order to carry out its function. Further technical requirements are derived from these MMI. The functional and technical requirements motivate the design of an SDC-compatible device profile. The device profile is then assessed for feasibility. RESULTS: We present a new modeling of a device profile for surgical robotic arms intended for neurosurgery and orthopedic surgery. The modeling in SDC succeeds for the most part. However, some details of the proposed model cannot yet be realized within the framework of the existing SDC standards. Some aspects can already be realized, but could be better supported in the future by the nomenclature system. These improvements are being presented as well. CONCLUSION: The proposed device profile presents a first step toward a uniform technical description model for modular surgical robot systems. The current SDC core standards lack some functionality to fully support the proposed device profile. These could be defined in future work and then included in standardization efforts.

MINARO HD: control and evaluation of a handheld, highly dynamic surgical robot.

PURPOSE: Current surgical robotic systems are either large serial arms, resulting in higher risks due to their high inertia and no inherent limitations of the working space, or they are bone-mounted, adding substantial additional task steps to the surgical workflow. The robot presented in this paper has a handy and lightweight design and can be easily held by the surgeon. No rigid fixation to the bone or a cart is necessary. A high-speed tracking camera together with a fast control system ensures the accurate positioning of a burring tool. METHODS: The capabilities of the robotic system to dynamically compensate for unintended motion, either of the robot itself or the patient, was evaluated. Therefore, the step response was analyzed as well as the capability to follow a moving target. RESULTS: The step response show that the robot can compensate for undesired motions up to 12 Hz in any direction. While following a moving target, a maximum positioning error of 0.5 mm can be obtained with a target motion of up to 18 mm/s. CONCLUSION: The requirements regarding dynamic motion compensation, accuracy, and machining speed of unicompartmental knee arthroplasties, for which the robot was optimized, are achieved with the presented robotic system. In particular, the step response results show that the robot is able to compensate for human tremor.

Usability of cooperative surgical telemanipulation for bone milling tasks.

PURPOSE: Cooperative surgical systems enable humans and machines to combine their individual strengths and collaborate to improve the surgical outcome. Cooperative telemanipulated systems offer the widest spectrum of cooperative functionalities, because motion scaling is possible. Haptic guidance can be used to assist surgeons and haptic feedback makes acting forces at the slave side transparent to the operator, however, overlapping and masking of forces needs to be avoided. This study evaluates the usability of a cooperative surgical telemanipulator in a laboratory setting. METHODS: Three experiments were designed and conducted for characteristic surgical task scenarios derived from field studies in orthopedics and neurosurgery to address bone tissue differentiation, guided milling and depth sensitive milling. Interaction modes were designed to ensure that no overlapping or masking of haptic guidance and haptic feedback occurs when allocating information to the haptic channel. Twenty participants were recruited to compare teleoperated modes, direct manual execution and an exemplary automated milling with respect to usability. RESULTS: Participants were able to differentiate compact and cancellous bone, both directly manually and teleoperatively. Both telemanipulated modes increased effectiveness measured by the mean absolute depth and contour error for guided and depth sensitive millings. Efficiency is decreased if solely a boundary constraint is used in hard material, while a trajectory guidance and manual milling perform similarly. With respect to subjective user satisfaction trajectory guidance is rated best for guided millings followed by boundary constraints and the direct manual interaction. Haptic feedback only improved subjective user satisfaction. CONCLUSION: A cooperative surgical telemanipulator can improve effectiveness and efficiency close to an automated execution and enhance user satisfaction compared to direct manual interaction. At the same time, the surgeon remains part of the control loop and is able to adjust the surgical plan according to the intraoperative situation and his/her expertise at any time.

A new approach for safe planning transfer using semi-automatically adjustable instrument guides.

Accurate planning transfer is a prerequisite for successful operative care. For different applications, diverse computer-assisted systems have been developed and clinically evaluated. This paper presents the implementation and evaluation of a new modular concept. The approach is based on passive application specific kinematics that are semi-automatically adjusted using a universal hand-held computer controlled Smart Screw Driver. The system was realized for pedicle screw instrumentation and evaluated according to IEC 60601-1-6 (usability engineering). The accuracies of the drill holes achieved were comparable with robotic approaches, while operation time and radiation were reduced compared with conventional operation techniques. The adjustment procedure has proven high learnability and user satisfaction. The next step will be optimization of the kinematic structure and fixation to the patient in order to increase accuracies of planning transfer as well as evaluation of the overall system by medical staff in preclinical and clinical studies.

Miniaturized multi-coil arrays for functional planar imaging with a single-sided NMR sensor.

Nowadays most low-field NMR sensors, such as the single-sided Profile NMR-MOUSE®, still suffer from poor sensitivity, either resulting from low magnetic field strengths and correspondingly low NMR frequencies, or lack of sensitivity. Generally, micro-coils can improve sensitivity, but due to their small size, and thus small inductance, they are mainly used for high-field NMR. Their main application field is parallel imaging, where those coils are typically assembled to receive-only coil-arrays and increase the field-of-view. Prominent signal combination techniques such as GRAPPA and SENSE are used to combine the spatially independent NMR signals to images in order to increase acquisition speed. A decisive disadvantage of today's single-sided NMR probes is the limited accessibility for NMR imaging. Although it is possible to use flat gradient coils on top of the NMR-MOUSE® to apply imaging techniques, such images can only be recorded with very long acquisition times, excluding the NMR-MOUSE® for lateral imaging of time-dependent processes. In this study sensitivity improved micro-structured RF coils, optimized for low frequencies, and correspondingly arrays of these coils, were employed to improve sensitivity and gave access to lateral spatial resolution within the sensitive plane at several observation points at the same time. Recently developed three- and four-coil arrays were combined with a Profile NMR-MOUSE® and characterized in terms of coil coupling, noise correlation and signal combination. The three-coil array was used for lateral imaging of moisture transport in travertine rock samples and to study the one-dimensional drying of paint.