The international journal of medical robotics + computer assisted surgery : MRCAS最新文献

Background: The objective of this study was to evaluate the safety and feasibility of robot-assisted thoracoscopic surgery (RATS).

Methods: From May 2009 to May 2013, 48 patients with intrathoracic lesions underwent RATS with the da Vinci® Surgical System was reported (11 lobectomies, 37 mediastinal tumour resections).

Results: RATS was successfully and safely completed in all 48 patients. Conversion of the operation to open surgery was not needed in any patient. The average operation time was 85.9 min, average blood loss 33 ml, and average hospital stay 3.9 days. No patient required blood transfusion. The only recognized adverse event was the development of a bronchopleural fistula in one patient.

Conclusions: RATS appears feasible and safe in thoracic surgery. More investigation will be needed in order to determine its possible long-term benefits and cost effectiveness.

Background: Femoral tunnel positioning is a difficult, but important factor in successful anterior cruciate ligament (ACL) reconstruction. Computer navigation can improve the anatomical planning procedure besides the tunnel placement procedure.

Methods: The accuracy of the computer-assisted femoral tunnel positioning method for anatomical double bundle ACL-reconstruction with a three-dimensional template was determined with respect to both aspects for AM and PL bundles in 12 cadaveric knees.

Results: The accuracy of the total tunnel positioning procedure was 2.7 mm (AM) and 3.2 mm (PL). These values consisted of the accuracies for planning (AM:2.9 mm; PL:3.2 mm) and for placement (about 0.4 mm). The template showed a systematic bias for the PL-position.

Conclusions: The computer-assisted templating method showed high accuracy for tunnel placement and has promising capacity for application in anatomical tunnel planning. Improvement of the template will result in an accurate and robust navigation system for femoral tunnel positioning in ACL-reconstruction.

Background: High-frequency electricity is used in the majority of surgical interventions. However, modern computer-based training and simulation systems rely on physically unrealistic models that fail to capture the interplay of the electrical, mechanical and thermal properties of biological tissue.

Methods: We present a real-time and physically realistic simulation of electrosurgery by modelling the electrical, thermal and mechanical properties as three iteratively solved finite element models. To provide subfinite-element graphical rendering of vaporized tissue, a dual-mesh dynamic triangulation algorithm based on isotherms is proposed. The block compressed row storage (BCRS) structure is shown to be critical in allowing computationally efficient changes in the tissue topology due to vaporization.

Results: We have demonstrated our physics-based electrosurgery cutting algorithm through various examples. Our matrix manipulation algorithms designed for topology changes have shown low computational cost.

Conclusions: Our simulator offers substantially greater physical fidelity compared to previous simulators that use simple geometry-based heat characterization.

Background: There is scanty experience concerning robot-assisted Ivor-Lewis oesophagectomy, so every new experience is helpful.

Methods: We describe the techniques and short-term results of Ivor-Lewis oesophagectomy using a laparoscopic approach and robot-assisted thoracoscopy, and an observational study of prospective surveillance of the first 14 patients treated for oesophageal cancer. A gastric tube was created laparoscopically. Oesophagectomy was performed through a robot-assisted thoracoscopy followed by hand-sewn intrathoracic anastomosis.

Results: There were no conversion cases. Mortality was zero. Six patients had a major complication. There were no cases of respiratory complication or recurrent laryngeal nerve palsy. Three patients had a radiological fistula (21.4%), successfully treated by endoscopic stenting, and one (7.1%) had an anastomosis leak needing reoperation. There were two cases of chylothorax (14.3%).

Conclusions: Our initial results suggest that the reported technique is safe and satisfies the oncological principles. It provides the advantages of minimally invasive surgery by overcoming some limitations of conventional thoracoscopy.

Background: The existing methods in dental clinical operations for hard tissue removal have several drawbacks which affect the long-term success of the dental treatment.

Methods: In this paper, we introduce a miniature robotic device called LaserBot, which can manipulate a femtosecond laser beam to drill/burr a decayed tooth to realize clinical tooth crown preparation. In order to control the 3D motion of the laser focal point on the surface of a tooth, three miniature voice-coil motors with optical grating rulers are utilized to drive the 2D pitch/yaw rotation of a vibration mirror and 1D translation of a protruding optical lens. This method can provide high-resolution control of the laser beam. In order to maintain the small size of the robot, a parallel five linkage mechanism combined with a slider-rocker mechanism is developed to realize 2D pitch/yaw rotation of the vibration mirror.

Results: Experiment results show that the movement range and resolution of the laser beam point can meet the requirement of typical dental operations. The size of the working end of the device that enters the mouth is 25 × 22 × 57 mm (height × width × length), which is small enough to be mounted on any tooth. The average repeatability error of the laser focal point is about 40 µm. Ablation experiments on wax-resin material and on tooth validate that a femtosecond laser can be used for tooth ablation.

Conclusions: The developed robotic device achieved precise 3D motion control of a laser focal point and is small enough to be used in the narrow workspace of the oral cavity. Limitations of the prototype have been identified, and quantified specifications are identified for designing the next generation prototype.

Background: There are several complications associated with Stent-assisted Coil Embolization (SACE) in cerebral aneurysm treatments, due to damaging operations by surgeons and undesirable mechanical properties of stents. Therefore, it is necessary to develop an in vitro simulator that provides both training and research for evaluating the mechanical properties of stents.

Methods: A new in vitro simulator for three-dimensional digital subtraction angiography was constructed, followed by aneurysm models fabricated with new materials. Next, this platform was used to provide training and to conduct photoelastic stress analysis to evaluate the SACE technique.

Results: The average interaction stress increasingly varied for the two different stents. Improvements for the Maximum-Likelihood Expectation-Maximization method were developed to reconstruct cross-sections with both thickness and stress information.

Conclusions: The technique presented can improve a surgeon's skills and quantify the performance of stents to improve mechanical design and classification. This method can contribute to three-dimensional stress and volume variation evaluation and assess a surgeon's skills.

Background: Robotic-assisted minimally invasive surgery (MIS) can benefit both patients and surgeons. However, the learning curve for robotically assisted procedures can be long and the total system costs are high. Therefore, there is considerable interest in new methods and lower cost controllers for a surgical robotic system.

Methods: In this study, a knife-master and a forceps-master, shaped similarly to a surgical knife and forceps, were developed as input devices for control of a master-slave surgical robotic system. In addition, a safety strategy was developed to eliminate the master-slave orientation difference and stabilize the surgical system.

Results: Master-slave tracking experiments and a ring-and-bar experiment showed that the safety tracking strategy could ensure that the robot system moved stably without any tremor in the tracking motion. Subjects could manipulate the surgical tool to achieve the master-slave operation with less training compared to a mechanical master.

Conclusions: Direct manipulation of the small, light and low-cost surgical tools to control a robotic system is a possible operating mode. Surgeons can operate the robotic system in their own familiar way, without long training. The main potential safety issues can be solved by the proposed safety control strategy.

Background: Accurate localization of bone surfaces remains a challenge hampering adoption of ultrasound guidance in computer-assisted orthopaedic surgery. Local phase image features have recently been proven efficacious for segmenting bone surfaces from ultrasound images, but the quality of the processing depends on numerous filter parameters that are currently set through a trial and error process that is tedious, unintuitive and subject to large inter-user variability.

Methods: A method is presented for automatically selecting parameters of Log-Gabor filters used to extract bone surfaces from 3D ultrasound volumes that is based on properties estimated directly from the specific image.

Results: A 15% and 69% average improvement in bone surface localization accuracy on phantom and clinical data, respectively, is demonstrated compared with empirically-set parameters.

Conclusions: These findings imply that Log-Gabor filter parameter optimization is necessary for accurate extraction of bone surfaces from ultrasound data.

Background: Our main aim was to evaluate the value of medical image three-dimensional visualization system (MI-3DVS) in pancreaticoduodenctomy patients with hepatic artery variance.

Methods: 114 patients who had undergone pancreatoduodenectomy were retrospectively summarized and analyzed. Clinical data of 64-slice multidetector CT angiography (64-MDCTA) scanning was introduced into MI-3DVS for procedural segmentation, registration and 3-dimensional (3D) reconstruction. The findings were compared with those found during the operation and by postoperative digital subtraction angiography (DSA) of coeliac artery.

Results: The 3D model demonstrated the origination and bifurcations of blood vessels, and the relationships among neoplasms, organs and blood vessels efficiently. About (14/114 cases, 12.3%) had variant. The sensitivity, specificity and accuracy of MI-3DVS in variant hepatic artery diagnosis were 100%. It assisted in preoperative procedural planning that was consistent with intraoperative findings.

Conclusions: MI-3DVS can be applied for accurate diagnosis of hepatic artery variance. It also provides detailed preoperative guidance for individualized procedural planning.

Background: A transanal approach for total mesorectal excision (TME) using a single incision port is feasible. The disadvantages are technical difficulties associated with limited manoeuvrability.

Methods: We present our first experience with robotic-assisted transanal total mesorectal excision. A 48 year-old woman with a tumour 8 cm from the anal verge was successfully operated using a transanal approach. A complete mesorectal excision was performed through a single incision port, using two robot arms.

Results: TME was performed successfully and the patient recovered quickly without any complications. The histological report showed a complete mesorectal excision with free distal and circumferential margins. A sigmoidoscopy showed an intact anastomosis and the patient was planned for reversal of her ileostomy.

Conclusions: Transanal total mesorectal excision using the robot is feasible. Robotics may help to overcome technical difficulties associated with the single incision port.