Robert Boesecke

Development and First Patient Trial of a Surgical Robot for Complex Trajectory Milling

Objective: Todays surgical robots normally perform “simple” trajectories, e.g., assisting as tool-holding devices in neurosurgery, or milling linear paths for cavities in total hip replacement. From a clinical point of view, it is still a complex undertaking to implement robots in the operating room. Until now, robot systems have not been used in patient trials to mill “complex” trajectories, which involve many positional and orientation changes and are often necessary in cranio-maxillofacial (CMF) surgery. This paper presents the RobaCKa surgical robot system, which allows more precise execution of surgical interventions and milling of “complex” trajectories. Materials and Methods: The main components of the RobaCKa system are a (former) CASPAR robot system, a POLARIS system, and a force-torque sensor. Results: In the first patient trial (April 2003) the planned trajectory was executed with an error of 0.66 ± 0.2 mm. Conclusions: The use of former industrial robots for surgical applications is possible but complex. The advantages are improved precision and quality and the possibility of documentation. The use of such systems is normally limited to research institutions or large clinics, because it is hardly possible to implement the necessary technical and logistic efforts in routine surgical work.

System Design of a Hand-Held Mobile Robot for Craniotomy

This contribution reports the development and initial testing of a Mobile Robot System for Surgical Craniotomy, the Craniostar. A kinematic system based on a unicycle robot is analysed to provide local positioning through two spiked wheels gripping directly onto a patients skull. A control system based on a shared control system between both the Surgeon and Robot is employed in a hand-held design that is tested initially on plastic phantom and swine skulls. Results indicate that the system has substantially lower risk than present robotically assisted craniotomies, and despite being a hand-held mobile robot, the Craniostar is still capable of sub-millimetre accuracy in tracking along a trajectory and thus achieving an accurate transfer of pre-surgical plan to the operating room procedure, without the large impact of current medical robots based on modified industrial robots.

Risk analysis for a reliable and safe surgical robot system

Abstract This paper shows the basic methods of quality assurance and risk analysis. It is particularly intended for researchers in the clinical field who have to implement safe systems with minimal resources and staff. The methods were applied to the robot system RobaCKa for craniotomies. Since surgical robots are complex mechatronic systems, it is important to apply systematic approaches for fault-free design, error detection and quality assurance. In universities and research centers, it is not often possible to apply the same measures for software design and error analysis as what is usually required for suppliers of medical products. Nevertheless, it is necessary to maintain basic regulations particularly for in vivo studies and clinical investigations. It makes sense to apply quality management right in the very beginning of a project, which would facilitate the its possible transformation into a commercial product later.

Robot Assistant for Dental Implantology

We introduce a method to apply a preoperative 3D plan for inserting dental implants with an assisting medical robot. The treatment plan is based on the 3D visualization of the CT data of the patients maxilla and mandible, and supplies the location of the implants in the patients coordinates. The plan is then transferred to the surgical robots coordinate system. The robot guides the tool, a drill guide. Position, orientation, and depth of the initial drilling is defined with the tool held by the robot while the surgeon drills. The robot assists the dentist, and the optimal treatment plan will be applied directly to the patient.

Kinematic path-following control of a mobile robot on arbitrary surface

This paper outlines a method for applying a kinematic path following control of a mobile robot without any regard for surface structure. Background. A great deal of mobile robotics kinematics analysis is based on the movement of the robot on a two dimensional flat surface. Our application for precision surgery required a new approach to a system that would operate on a highly non-linear surface; this specific system was a surgical robot that would conduct craniotomies while moving over highly irregular and often deformed skulls. Methods. The approach used an abstract view of the operating environment that would totally ignore the surface, instead determining the control parameters based only on the robot and the desired cutting trajectory. The approach was then evaluated in a 3D environment using a series of predefined surfaces to determine bounding limits in the control theory. These limits were then tested in a second series of tests using real data from the CT preoperative imagery of previous patients and phantoms. The simulation results were then compared with the actual performance of the robot on phantoms and cadavers. Results. The approach has been successfully implemented on the first medical robot to position itself through spiked wheels on the surface of the skull. Testing has to date been successful in both a simulation environment, and on initial phantom and cadiever trials, with accuracies equal to that of the larger industrial modified surgical robots.

Feasibility and Medical Impact Assessment of Handheld-Mobile-Robot usage in Image Guided Craniotomy

Purpose - Craniostar is a handheld mobile robot designed for the support of surgical craniotomies. The system is designed as a means of conveying high precision craniotomy path profiles directly to the patient, with minimum modifications to the surgeons workflow, and without the large impact on the Operating Room (OR) of current Surgical Robots. Performed here is an assessment on how feasible this mobile robot is in attaining adequate traction on the surface of the patient’s skull, without any negligible medical impact on the patient. Method - A technical study was performed where the system was tested with a number of trajectory profiles cut into a swine skull. The capability of the system in maintaining traction and accuracy was tested along with the medical impact of a mobile robot moving over the bone, both visually and with a FARO Arm, surface laser scanner. Results - The system showed an ability to maintain traction on the skull without any visible or assessable damage due to wheel traction. Conclusions - The results of this study have shown that the system’s demonstrated potential warrants pursued interest in the field of mobile robots for surgery, with a system that maintains the high precision of Image Guided Surgery, but without the impact in the OR of large industrial robotics as is common in the current generation surgical robot systems.

Chirurgieroboter für Kraniotomien – Risikoanalyse und erster Patientenversuch (Surgical Robot for Craniotomies – Risk Analysis and First Patient Trial)

Abstract Innerhalb des Sonderforschungsbereiches SFB 414 — Informationstechnolgie in der Medizin: Rechner- und Sensorgestützte Chirurgie — wurde RobaCKa = Roboter-assistiertes Chirurgiesystem Karlsruhe) entwickelt. Es dient beispielsweise zum Fräsen von Trajektorien im knöchernen Schädel in der cranio-maxillofacialen Chirurgie. Da es sich bei Robotern um komplexe mechatronische Systeme handelt, ist eine systematische Analyse für fehlerfreies Design, Fehlerdetektion und Qualitätssicherung unumgänglich. In Universitäten und Forschungszentren kann hierfür nicht derselbe Aufwand wie in der Industrie bei der Fertigung von Medizinprodukten betrieben werden, da oft nur ein bis zwei Wissenschaftler an solchen Projekten arbeiten. Trotzdem ist es notwendig, ein Qualitätmanagement zu etablieren, nicht zuletzt da ein solches auch für klinische Studien vorgeschrieben ist. Außerdem vereinfacht es später den möglichen Technologietransfer. Außer den Risikomanagementmethoden werden in dieser Arbeit die Tests an Phantomen, Probanden und eine erste Operation am Patienten beschrieben und die Ergebnisse diskutiert.