FORCE-TORQUE MEASUREMENT SYSTEM FOR FRACTURE SURGERY

One of the more difficult tasks in surgery is to apply the optimal instrument forces and torques necessary to conduct an operation without damaging the tissue of the patient. This is especially problematic in surgical robotics, where force-feedback is totally eliminated. Thus, force sensing instruments emerge as a critical need for improving safety and surgical outcome. We propose a new measurement system that can be used in real fracture surgeries to generate quantitative knowledge of forces/torques applied by surgeon on tissues.We instrumented a periosteal elevator with a 6-DOF load-cell in order to measure forces/torques applied by the surgeons on live tissues during fracture surgeries. Acquisition software was developed in LabView to acquire force/torque data together with synchronised visual information (USB camera) of the tip interacting with the tissue, and surgeon voice recording (microphone) describing the actual procedure. Measurement system and surgical protocol were designed according to patient safety and sterilisation standards.The developed technology was tested in a pilot study during real orthopaedic surgery (consisting of removing a metal plate from the femur shaft of a patient) resulting reliable and usable. As demonstrated by subsequent data analysis, coupling force/torque data with video and audio information produced quantitative knowledge of forces/torques applied by the surgeon during the surgery. The outlined approach will be used to perform intensive force measurements during orthopaedic surgeries. The generated quantitative knowledge will be used to design a force controller and optimised actuators for a robot-assisted fracture surgery system under development at the Bristol Robotics Laboratory

Towards Robot-Assisted Fracture Surgery For Intra-Articular Joint Fractures

Background Treating fractures is expensive and includes a long post-operative care. Intra-articular fractures are often treated with open surgery that require massive soft tissue incisions, long healing time and are often accompanied by deep wound infections. Minimally invasive surgery (MIS) is an alternative to this but when performed by surgeons and supported by X-rays does not achieve the required accuracy of surgical treatment. Methods Functional and non-functional requirements of the system were established by conducting interviews with orthopaedic surgeons and attending fracture surgeries at Bristol Royal Infirmary to gain first-hand experience of the complexities involved. A robot-assisted fracture system (RAFS) has been designed and built for a distal femur fracture but can generally serve as a platform for other fracture types. Results The RAFS system has been tested in BRL and the individual robots can achieve the required level of reduction positional accuracy (less than 1mm translational and 5 degrees of rotational accuracy). The system can simultaneously move two fragments. The positioning tests have been made on Sawbones. Conclusions The proposed approach is providing an optimal solution by merging the fracture reduction knowledge of the orthopaedic surgeon and the robotic system's precision in 3D

Robot-Bone Attachment Device for Robot-Assisted Percutaneous Bone Fragment Manipulation

The treatment of joint-fractures is a common task in orthopaedic surgery causing considerable health costs and patient disabilities. Percutaneous techniques have been developed to mitigate the problems related to open surgery (e.g. soft tissue damage), although their application to joint-fractures is limited by the sub-optimal intra-operative imaging (2D-fluoroscopy) and by the high forces involved. Our earlier research toward improving percutaneous reduction of intra-articular fractures has resulted in the creation of a robotic system prototype, i.e. RAFS (Robot-Assisted Fracture Surgery) system. We propose a robot-bone attachment device for percutaneous bone manipulation, which can be anchored to the bone fragment through one small incision, ensuring the required stability and reducing the “biological cost” of the procedure. The device has been evaluated through the reduction of 9 distal femur fractures on human cadavers using the RAFS system

Image-Based Robotic System for Enhanced Minimally Invasive Intra-Articular Fracture Surgeries

Abstract: Robotic assistance can bring significant improvements to orthopedic fracture surgery: facilitate more accurate fracture fragment repositioning without open access and obviate problems related to the current minimally invasive fracture surgery techniques by providing a better clinical outcome, reduced recovery time, and health-related costs. This paper presents a new design of the robot-assisted fracture surgery (RAFS) system developed at Bristol Robotics Laboratory, featuring a new robotic architecture, and real-time 3D imaging of the fractured anatomy. The technology presented in this paper focuses on distal femur fractures, but can be adapted to the larger domain of fracture surgeries, improving the state-of-the-art in robot assistance in orthopedics. To demonstrate the enhanced performance of the RAFS system, 10 reductions of a distal femur fracture are performed using the system on a bone model. The experimental results clearly demonstrate the accuracy, effectiveness, and safety of the new RAFS system. The system allows the surgeon to precisely reduce the fractures with a reduction accuracy of 1.15 mm and 1.3°, meeting the clinical requirements for this procedure

RAFS: A computer-assisted robotic system for minimally invasive joint fracture surgery, based on pre- and intra-operative imaging

The integration of minimally invasive robotic assistance and image-guidance can have positive impact on joint fracture surgery, providing a better clinical outcome with respect to the current open procedure. In this paper, a new design of the RAFS surgical system is presented. The redesign of the robotic system and its integration with a novel 3D navigation system through a new clinical workflow, overcomes the drawbacks of the earlier prototype. This makes the RAFS surgical system more suitable to clinical scenarios in the operating theatre. System accuracy and effectiveness are successfully demonstrated through laboratory trials and preliminary cadaveric trials. The experimental results demonstrate that the system allows the surgeon to reduce a 2-fragment distal femur fracture in a cadaveric specimen, with a reduction accuracy of up to 0.85 mm and 2.2°. Preliminary cadaveric trials also provided a positive and favorable outcome pointing to the usability and safety of the RAFS system in the operating theatre, potentially enhancing the capacity of joint fracture surgeries

Design and Evaluation of a Percutaneous Fragment Manipulation Device for Minimally Invasive Fracture Surgery

Reduction of fractures in the minimally invasive (MI) manner can avoid risks associated with open fracture surgery. The MI approach requires specialized tools called percutaneous fragment manipulation devices (PFMD) to enable surgeons to safely grasp and manipulate fragments. PFMDs developed for long-bone manipulation are not suitable for intra-articular fractures where small bone fragments are involved. With this study, we offer a solution to potentially move the current fracture management practice closer to the use of a MI approach. We investigate the design and testing of a new PFMD design for manual as well as robot-assisted manipulation of small bone fragments. This new PFMD design is simulated using FEA in three loading scenarios (force/torque: 0 N/2.6 Nm, 75.7 N/3.5 N, 147 N/6.8 Nm) assessing structural properties, breaking points, and maximum bending deformations. The PFMD is tested in a laboratory setting on Sawbones models (0 N/2.6 Nm), and on ex-vivo swine samples (F = 80 N ± 8 N, F = 150 ± 15 N). A commercial optical tracking system was used for measuring PFMD deformations under external loading and the results were verified with an electromagnetic tracking system. The average error difference between the tracking systems was 0.5 mm, being within their accuracy limits. Final results from reduction maneuvers performed both manually and with the robot assistance are obtained from 7 human cadavers with reduction forces in the range of (F = 80 N ± 8 N, F = 150 ± 15 N, respectively). The results show that structurally, the system performs as predicted by the simulation results. The PFMD did not break during ex-vivo and cadaveric trials. Simulation, laboratory, and cadaveric tests produced similar results regarding the PFMD bending. Specifically, for forces applied perpendicularly to the axis of the PFMD of 80 N ± 8 N deformations of 2.8, 2.97, and 3.06 mm are measured on the PFMD, while forces of 150 ± 15 N produced deformations of 5.8, 4.44, and 5.19 mm. This study has demonstrated that the proposed PFMD undergoes predictable deformations under typical bone manipulation loads. Testing of the device on human cadavers proved that these deformations do not affect the anatomic reduction quality. The PFMD is, therefore, suitable to reliably achieve and maintain fracture reductions, and to, consequently, allow external fracture fixation

Vortex nucleation in mesoscopic Bose superfluid and breaking of the parity symmetry

We analyze vortex nucleation in mezoscopic 2D Bose superfluid in a rotating trap. We explicitly include a weakly anisotropic stirring potential, breaking thus explicitly the axial symmetry. As the rotation frequency passes the critical value $\Omega_c$ the system undergoes an extra symmetry change/breaking. Well below $\Omega_c$ the ground state is properly described by the mean field theory with an even condensate wave function. Well above $\Omega_c$ the MF solution works also well, but the order parameter becomes odd. This phenomenon involves therefore a discrete parity symmetry breaking. In the critical region the MF solutions exhibit dynamical instability. The true many body state is a strongly correlated entangled state involving two macroscopically occupied modes (eigenstates of the single particle density operator). We characterize this state in various aspects: i) the eligibility for adiabatic evolution; ii) its analytical approximation given by the maximally entangled combination of two single modes; and finally iii) its appearance in particle detection measurements.Comment: 14 pages, 27 figure

Image-Guided Surgical Robotic System for Percutaneous Reduction of Joint Fractures

Complex joint fractures often require an open surgical procedure, which is associated with extensive soft tissue damages and longer hospitalization and rehabilitation time. Percutaneous techniques can potentially mitigate these risks but their application to joint fractures is limited by the current sub-optimal 2D intra-operative imaging (fluoroscopy) and by the high forces involved in the fragment manipulation (due to the presence of soft tissue, e.g., muscles) which might result in fracture malreduction. Integration of robotic assistance and 3D image guidance can potentially overcome these issues. The authors propose an image-guided surgical robotic system for the percutaneous treatment of knee joint fractures, i.e., the robot-assisted fracture surgery (RAFS) system. It allows simultaneous manipulation of two bone fragments, safer robot-bone fixation system, and a traction performing robotic manipulator. This system has led to a novel clinical workflow and has been tested both in laboratory and in clinically relevant cadaveric trials. The RAFS system was tested on 9 cadaver specimens and was able to reduce 7 out of 9 distal femur fractures (T- and Y-shape 33-C1) with acceptable accuracy (≈1 mm, ≈5°), demonstrating its applicability to fix knee joint fractures. This study paved the way to develop novel technologies for percutaneous treatment of complex fractures including hip, ankle, and shoulder, thus representing a step toward minimally-invasive fracture surgeries

Tecnologias sociais: as organizações não governamentais no enfrentamento das mudanças climáticas e na promoção de desenvolvimento humano

De acordo com o quarto relatório do Intergovernmental Panel on Climate Change (IPCC), as regiões semiáridas do mundo estarão entre as mais afetadas pelos impactos das mudanças climáticas globais. Estudos realizados pelo Ministério do Meio Ambiente (MMA), em 2007, confirmam que, no Nordeste brasileiro, não apenas choverá menos e mais irregularmente, mas, também, haverá mais secas, devido ao aquecimento da temperatura. Diante dos diversos impactos sociais, ambientais e econômicos possíveis nesses cenários, é de fundamental importância a verificação de alternativas sustentáveis para o semiárido brasileiro. Este artigo tem por objetivo avaliar o potencial de algumas das tecnologias sociais (TS) de convivência com o semiárido, desenvolvidas por diversas organizações, para a mitigação das mudanças climáticas e a promoção de desenvolvimento humano. Constata-se que as TS tem grande potencial para auxiliar na mitigação e na adaptação das mudanças climáticas, ao mesmo tempo que promovem melhorias na qualidade de vida das localidades onde estão sendo desenvolvidas

Intra-operative fiducial-based CT/fluoroscope image registration framework for image-guided robot-assisted joint fracture surgery

Purpose Joint fractures must be accurately reduced minimising soft tissue damages to avoid negative surgical outcomes. To this regard, we have developed the RAFS surgical system, which allows the percutaneous reduction of intra-articular fractures and provides intra-operative real-time 3D image guidance to the surgeon. Earlier experiments showed the effectiveness of the RAFS system on phantoms, but also key issues which precluded its use in a clinical application. This work proposes a redesign of the RAFS’s navigation system overcoming the earlier version’s issues, aiming to move the RAFS system into a surgical environment. Methods The navigation system is improved through an image registration framework allowing the intra-operative registration between pre-operative CT images and intra-operative fluoroscopic images of a fractured bone using a custom-made fiducial marker. The objective of the registration is to estimate the relative pose between a bone fragment and an orthopaedic manipulation pin inserted into it intra-operatively. The actual pose of the bone fragment can be updated in real time using an optical tracker, enabling the image guidance. Results Experiments on phantom and cadavers demonstrated the accuracy and reliability of the registration framework, showing a reduction accuracy (sTRE) of about 0.88 ±0.2mm (phantom) and 1.15±0.8mm (cadavers). Four distal femur fractures were successfully reduced in cadaveric specimens using the improved navigation system and the RAFS system following the new clinical workflow (reduction error 1.2±0.3mm, 2±1∘). Conclusion Experiments showed the feasibility of the image registration framework. It was successfully integrated into the navigation system, allowing the use of the RAFS system in a realistic surgical application