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

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.

Background: Cosmesis is of increasing importance to the otolaryngology patient population. This is the first report of clinical outcomes of robot-assisted neck dissection by North American groups.

Methods: This is a retrospective case-control study. Cases included three patients who underwent isolated, ipsilateral robot-assisted neck dissection. Operative time, estimated blood loss, lymph node retrieval, total drainage, hospital stay and complications from this group were compared against the outcomes of six consecutive patients who underwent conventional neck dissection.

Results: Operative times were longer in robot-assisted neck dissection (mean 234 min) compared with the conventional neck dissection (mean 110 min). There were no significant differences between the two groups in other outcomes.

Conclusions: Robot-assisted selective neck dissection of levels II-IV is feasible through a modified facelift incision. Our initial data suggest that this procedure is surgically sound. It should be applied by experienced surgeons who wish to avoid a cervical incision.

Background: The objective of this study was to describe our early experience with robot-assisted partial nephrectomy (RAPN) incorporating selective arterial clamping, using an image overlay navigation system.

Methods: Three-dimensional images were reconstructed from computed tomography using open source processing software, OsiriX, and were directly visualized on the screen of a da Vinci surgeon's console with TilePro multi-input display functions. Using this imaging system, RAPN with selective arterial clamping was performed in 17 patients with renal tumours.

Results: The intraoperative image overlay navigation system made it possible to clearly show the tumour position and vascular supply within the console's field of view, and facilitate selective arterial clamping during RAPN, resulting in a mean decrease in estimated glomerular filtration rates at both 1 and 4 weeks after RAPN < 10 ml/min/1.73 m(2) .

Conclusions: RAPN with selective arterial clamping using this innovative imaging system could be a useful alternative to conventional RAPN.

Background: Surgical robotic systems have been proven to be accurate and dexterous during minimally invasive surgery (MIS). However, single incision laparoscopic surgery (SILS) requires more compact robotic arms with sufficient dexterity and output.

Methods: A shape memory alloy (SMA)-actuated instrument was adopted to assist operations. The instrument fixed at the slave site had three degrees of freedom (DOFs) and was driven by SMA wires, pitch, yaw, and grip, with an 8 mm diameter; a passive hydraulic support mechanism was placed in vitro.

Results: In vitro, the maximum force, velocity and accuracy were proven to be sufficient for medical application. In an animal study, the system was inserted into the abdomen; three more generic constraints were tested: medical gesture, safety, and implementation.

Conclusions: The robot was feasible and safe for multi-angle monitoring, grasping, and holding an organ. The SMA-actuated system was accurate and dexterous with minimal system volume.

Background: This literature review focuses on the potential benefits and eventual limitations of robotic surgery with respect to the traditional minimally invasive laparoscopic surgical technique for gastric cancer.

Methods: A literature survey was performed using specific search phrases in PubMed. Series including < 10 cases and series including only an 'open group' of patients in comparison with the 'robotic group' were excluded. Characteristics such as patient demographics, perioperative outcomes and oncological results were analysed.

Results: According to the analysis of 12 series, robotic gastric surgery has been shown to be a safe and feasible method. However, a considerable number of studies are composed of early-stage gastric cancer cases and there seems to be a lack of randomized controlled studies.

Conclusions: Large prospective randomized studies are still required in order to demonstrate the exact benefits of robotic surgery and its effects on survival in gastric cancer.