Thomas Neff

Towards MRI-Based Autonomous Robotic US Acquisitions: A First Feasibility Study.

Robotic ultrasound has the potential to assist and guide physicians during interventions. In this work, we present a set of methods and a workflow to enable autonomous MRI-guided ultrasound acquisitions. Our approach uses a structured-light 3D scanner for patient-to-robot and image-to-patient calibration, which in turn is used to plan 3D ultrasound trajectories. These MRI-based trajectories are followed autonomously by the robot and are further refined online using automatic MRI/US registration. Despite the low spatial resolution of structured light scanners, the initial planned acquisition path can be followed with an accuracy of 2.46 ± 0.96 mm. This leads to a good initialization of the MRI/US registration: the 3D-scan-based alignment for planning and acquisition shows an accuracy (distance between planned ultrasound and MRI) of 4.47 mm, and 0.97 mm after an online-update of the calibration based on a closed loop registration.Robotic ultrasound has the potential to assist and guide physicians during interventions. In this work, we present a set of methods and a workflow to enable autonomous MRI-guided ultrasound acquisitions. Our approach uses a structured-light 3D scanner for patient-to-robot and image-to-patient calibration, which in turn is used to plan 3D ultrasound trajectories. These MRI-based trajectories are followed autonomously by the robot and are further refined online using automatic MRI/US registration. Despite the low spatial resolution of structured light scanners, the initial planned acquisition path can be followed with an accuracy of 2.46 ± 0.96 mm. This leads to a good initialization of the MRI/US registration: the 3D-scan-based alignment for planning and acquisition shows an accuracy (distance between planned ultrasound and MRI) of 4.47 mm, and 0.97 mm after an online-update of the calibration based on a closed loop registration.

Automatic force-compliant robotic ultrasound screening of abdominal aortic aneurysms

Ultrasound (US) imaging is commonly employed for the diagnosis and staging of abdominal aortic aneurysms (AAA), mainly due to its non-invasiveness and high availability. High inter-operator variability and a lack of repeatability of current US image acquisition impair the implementation of extensive screening programs for affected patient populations. However, this opens the way to a possible automation of the procedure, and recent works have exploited the use of robotic platforms for US applications, both in diagnostic and interventional scenarios. In this work, we propose a system for autonomous robotic US acquisitions aimed at the quantitative assessment of patients vessel diameter for abdominal aortic aneurysm screening. Using a probabilistic measure of the US quality, we introduce an automatic estimation of the optimal pressure to be applied during the acquisition, and an online optimization of the out-of-plane rotation of the US probe to maximize the visibility of the aorta. We evaluate our method on healthy volunteers and compare the results to manual acquisitions performed by a clinical expert, demonstrating the feasibility of the presented system for AAA screening.

OpenIGTLink interface for state control and visualisation of a robot for image-guided therapy systems

Purposexa0xa0xa0The integration of a robot into an image-guided therapy system is still a time consuming process, due to the lack of a well-accepted standard for interdevice communication. The aim of this project is to simplify this procedure by developing an open interface based on three interface classes: state control, visualisation, and sensor. A state machine on the robot control is added to the concept because the robot has its own workflow during surgical procedures, which differs from the workflow of the surgeon.MethodsA KUKA Light Weight Robot is integrated into the medical technology environment of the Institute of Mechatronic Systems as a proof of concept. Therefore, 3D Slicer was used as visualisation and state control software. For the network communication the OpenIGTLink protocol was implemented. In order to achieve high rate control of the robot the “KUKA Sunrise. Connectivity SmartServo” package was used. An exemplary state machine providing states typically used by image-guided therapy interventions, was implemented. Two interface classes, which allow for a direct use of OpenIGTLink for robot control on the one hand and visualisation on the other hand were developed. Additionally, a 3D Slicer module was written to operate the state control.ResultsUtilising the described software concept the state machine could be operated by the 3D Slicer module with 20xa0Hz cycle rate and no data loss was detected during a test phase of approximately

Robot, has peltier element connected with electrical and/or electronics component with electric current flown by peltier element more coldly than laminar side in heat conducting manner, where two laminar sides opposite to each other

270,s

Einen roboter aufweisende vorrichtung, medizinischer arbeitsplatz und verfahren zum registrieren eines objekts

270s (13,640 packages). Furthermore, the current robot pose could be sent with more than 60xa0Hz. No influence on the performance of the state machine by the communication thread could be measured.ConclusionSimplified integration was achieved by using only one programming context for the implementation of the state machine, the interfaces, and the robot control. Eventually, the exemplary state machine can be easily expanded by adding new states.