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At least 1,207 records · Page 67Linked to original sources
PubMed2004

Video-assisted thoracoscopic esophagectomy with a voice-controlled robot: the AESOP system.

The authors attempted to clarify the feasibility and safety of thoracoscopic esophagectomy with a voice-controlled robot, the AESOP system (3000 HR), and further determine whether innovative surgical equipment could allow the performance of complex thoracoscopic esophagectomy. Thoracoscopic surgery with a voice-controlled robot system has already been used in single-surgeon lung resection. Intra-operative and postoperative outcomes were compared between patients receiving hand-assisted laparoscopic surgery (HALS) and video-assisted thoracoscopic surgery (VATS) with the AESOP system (n = 15) and patients receiving open surgery (n = 30). In the AESOP group, the volume of blood loss was significantly less, but the total operation time was longer than in the open group. There were no significant differences in postoperative outcomes or the incidences of morbidity and mortality between the two groups. The surgeon using the AESOP system could obtain a stable, close-up, and long-lasting operative view. Laparoscopic and thoracoscopic surgery with the AESOP system has the potential to enable a single surgeon to perform a complex surgical procedure like esophagectomy.

Carcinoma, Squamous Cell↗
PubMed2006

Robot-assisted laparoscopic resection of a large paraganglioma: a case report.

A 19-year-old female patient presented with headache, nausea, hypertension, visual impairment of the left eye and exertion-related complaints of palpitations since 1 year. Fundoscopy showed severe hypertensive retinopathy grade IV. A paraganglioma in the left para-aortic region was diagnosed by urinary screening and magnetic resonance imaging scanning. The tumor was resected by a robot-assisted laparoscopic procedure. The surgical operating time was 250 minutes and the blood loss was 150 mL. After surgery the blood pressure normalized and antihypertensive drugs were no longer required. Oral intake was resumed on the first postoperative day and the hospital stay was 3 days. Final pathology examination revealed a paraganglioma with pheochromocytomal features of 7x5.1x3.5 cm. Reports on laparoscopic resection of large paragangliomas are scarce. This case has demonstrated that the procedure is feasible and associated with rapid recovery from surgery. The surgical team experienced explicit support by the robot in the dissection of this highly vascularized tumor.

Abdominal Neoplasms↗
PubMed2003

Upper and lower extremity robotic devices for rehabilitation and for studying motor control.

PURPOSE OF REVIEW: The successful motor rehabilitation of stroke, traumatic brain-injured and spinal cord-injured patients requires an intensive and task-specific therapy approach. Budget constraints limit a hand-to-hand therapy approach, so that intelligent machines may offer a solution to promote motor recovery and obtain a better understanding of motor control. This new field of automated or robot-assisted motor rehabilitation has emerged since the 1990s. RECENT FINDINGS: This article will present clinically viable devices for upper and lower extremity rehabilitation. The MIT-Manus and the Mirror-Image Motion Enabler robot, which enable unrestricted unilateral or bilateral shoulder and elbow movement, consistently proved superior on the motor impairment level. The ARM guide, which assisted reaching in a straight-line trajectory, and the Bi-Manu-Track, which enabled the bilateral practice of a forearm and wrist movement, are currently being tested. For gait rehabilitation after stroke, the electromechanical gait trainer, GT I, has proved effective compared with treadmill training with body weight support. The Lokomat, consisting of a treadmill and a powered exoskeleton, lessened the therapeutic effort compared with manually assisted treadmill training in spinal cord-injured patients. Future developments will see more degrees of freedom, improved man-machine interaction and the implementation of virtual reality. SUMMARY: Technical possibilities are one aspect, but multi-centre trials and a consideration of the unsubstantiated fears among therapists of being replaced by machines will decide on the successful implementation of this most promising field to the benefit of patients.

Artificial Limbs↗
PubMed2006

Ant-inspired sorting by robots: the importance of initial clustering.

For engineers the prospect of scalable collective robot systems is very appealing. Such systems typically adopt a decentralized approach in their control and coordination mechanism, which employs local sensing and action as well as limited communication. Under these constraints and informed by research on Temnothorax ants, two puck sorting algorithms were tested in a combination of simulation and with real robots. Both algorithms employed puck density as a cue. Only the overall local density, irrespective of puck type, was found to be required which offers the prospect for a more simple mechanism than had been previously considered. For one algorithm, this density cue was used both for picking up and dropping items and is, therefore, referred to as the 'double density' algorithm (DD). In the second algorithm, density was used as a cue only for picking up. Depositing an item was governed by the distance travelled which was specific to the type of item being carried. This was referred to as the 'single density' algorithm (SD). Unlike the DD it was found that, for the SD, the clustering of items is a necessary pre-condition for sorting. Results from ant experiments also showed that sorting is carried out in two phases: a primary clustering episode followed by a spacing phase. This strongly suggests that clustering may also be a precondition for spacing in ants.

Algorithms↗
PubMed2003

Modelling the world in real time: how robots engineer information.

Programming robots and other autonomous systems to interact with the world in real time is bringing into sharp focus general questions about representation, inference and understanding. These artificial agents use digital computation to interpret the data gleaned from sensors and produce decisions and actions to guide their future behaviour. In a physical system, however, finite computational resources unavoidably impose the need to approximate and make selective use of the information available to reach prompt deductions. Recent research has led to widespread adoption of the methodology of Bayesian inference, which provides the absolute framework to understand this process fully via modelling as informed, fully acknowledged approximation. The performance of modern systems has improved greatly on the heuristic methods of the early days of artificial intelligence. We discuss the general problem of real-time inference and computation, and draw on examples from recent research in computer vision and robotics: specifically visual tracking and simultaneous localization and mapping.

Artificial Intelligence↗
PubMed2003

New neural circuits for robot phonotaxis.

W. Grey Walter built robotic systems to improve understanding of biological systems. In that tradition, this paper reports ongoing work on a robot model of cricket sound localization. The main advances are the inclusion of a much larger range of neuroethological detail, and the investigation of multimodal influences on the behaviour. The former allows exploration of the functionality of identified neurons in the insect, including the possible roles of multiple sensory fibres, mutually inhibitory connections, and brain neurons with pattern-filtering properties. The latter focuses on the inclusion of an optomotor stabilization response, and how this might improve tracking, particularly under conditions of random disturbance.

Animal Communication↗
PubMed2007

Biologically inspired adaptive walking of a quadruped robot.

We describe here the efforts to induce a quadruped robot to walk with medium-walking speed on irregular terrain based on biological concepts. We propose the necessary conditions for stable dynamic walking on irregular terrain in general, and we design the mechanical and the neural systems by comparing biological concepts with those necessary conditions described in physical terms. PD-controller at joints constructs the virtual spring-damper system as the viscoelasticity model of a muscle. The neural system model consists of a central pattern generator (CPG), reflexes and responses. We validate the effectiveness of the proposed neural system model control using the quadruped robots called 'Tekken1&2'. MPEG footage of experiments can be seen at http://www.kimura.is.uec.ac.jp.

Animals↗
PubMed2007

Biped walking robots created at Waseda University: WL and WABIAN family.

This paper proposes the mechanism and control of the biped humanoid robots WABIAN-RIV and WL-16. WABIAN-RIV has 43 mechanical degrees of freedom (d.f.): 6 d.f. in each leg, 7 d.f. in each arm, 3 d.f. in each hand, 2 d.f. in each eye, 4 d.f. in the neck and 3 d.f. in the waist. Its height is about 1.89 m and its total weight is 127 kg. It has a vision system and a voice recognition system to mimic some of the capabilities of the human senses. WL-16 consists of a pelvis and two legs having six 1 d.f. active linear actuators. An aluminium chair is mounted on two sets of its telescopic poles. To reduce the large support forces during the support phase, a support torque reduction mechanism is developed, which is composed of two compression gas springs with different stiffness. For the stability of the robots, a compensatory motion control algorithm is developed. This control compensates for moments generated by the motion of the lower limbs, using the motion of the trunk and the waist that is obtained by the zero moment point concept and fast Fourier transform. WABIAN-RIV is able to walk forwards, backwards and sideways, dance, carry heavy goods and express emotion, etc. WL-16 can move forwards, backwards and sideways while carrying an adult weighing up to 60 kg.

Artificial Intelligence↗
PubMed2000

A robotic system for blood sampling.

A robotic system to take blood samples autonomously from the forearm is presented and preliminary results are discussed which demonstrate its feasibility. Force/position profiles, while pressing a flat-headed probe against the surface of the skin, enable the determination of a vein's location to within 1 mm on a phantom. When a needle is inserted, the characteristic force/position profile, on puncturing the vein wall, is distinctive enough to implement automatic needle withdrawal to prevent overshoot. Future developments of the project are presented that provide both an autonomous blood sampling robot and a force-feedback surgical trainer.

Analog-Digital Conversion↗
PubMed2001

Compensation of hand movement for patients by assistant force: relationship between human hand movement and robot arm motion.

As some functional diseases in the brain, such as cerebellum dysfunction and Parkinson's disease, cause the disability related to human movement control, a compensation method was developed for improving the performance of hand movement. The compensation can be carried out by adding assistant force, which is generated from artificial equipment attached to a human arm. From the experiment of visual target tracking, the tracking trajectories recorded from both healthy persons and patients with movement disability were analyzed. It was found that the tracking trajectories were represented sufficiently by a dynamic model of a robot arm in which the differences between healthy persons and patients were characterized by the model parameters. Based on the model, it was demonstrated that the hand movement of patients could be improved by introducing an appropriate compensation. The effectiveness of the proposed compensation method was verified from a simulation study of a robot arm. The design of artificial equipment for compensating the hand movement was also presented and discussed.

Biofeedback, Psychology↗
PubMed2006

Stable neurovisual servoing for robot manipulators.

In this paper, we propose a stable neurovisual servoing algorithm for set-point control of planar robot manipulators in a fixed-camera configuration an show that all the closed-loop signals are uniformly ultimately bounded (UUB) and converge exponentially to a small compact set. We assume that the gravity term and Jacobian matrix are unknown. Radial basis function neural networks (RBFNNs) with online real-time learning are proposed for compensating both gravitational forces and errors in the robot Jacobian matrix. The learning rule for updating the neural network weights, similar to a back propagation algorithm, is obtained from a Lyapunov stability analysis. Experimental results on a two degrees of freedom manipulator are presented to evaluate the proposed controller.

Algorithms↗
PubMed2005

Perceptual limits for a robotic rehabilitation environment using visual feedback distortion.

Imperceptible visual distortion, in the form of a disguised progression of performance goals, may be a helpful addition to rehabilitation after stroke and other brain injuries. This paper describes work that has been done to lay the groundwork for testing this hypothesis. We have constructed and validated an experimental environment that provides controllable visual distortion and allows precise force and position measurements. To estimate the amount of visual distortion that should be imperceptible, we measured the limits for force and distance/position perception in our rehabilitation environment for young and elderly unimpaired subjects and for a single traumatic brain injury (TBI) patient. We found the Just Noticeable Difference (JND) for produced force to be 19.7% (0.296 N) and the JND for movement distance/finger position to be 13.0% (3.99 mm) for young subjects (ages 18-35). For elderly subjects (ages 61-80), the JND for force was measured to be 31.0% (0.619 N) and the JND for distance/po'sition was 16.1% (5.01 mm). JNDs of 46.0% (0.920 N) and 45.0% (14.8 mm) were found for the motor-impaired individual. In addition, a subject's rating of effort was found to be profoundly influenced by visual feedback concerning the force magnitude. Even when this feedback was distorted, it accounted for 99% of the variance of the effort rating. These results indicate that substantial visual distortions should be imperceptible to the subject, and that visual feedback can be used to influence the subject's perceived experience in our robotic environment. This means that we should be able to use imperceptible visual distortion to alter a patient's perception of therapeutic exercise in a robotic environment.

Adolescent↗
PubMed2004

Automatic sensor placement for model-based robot vision.

This paper presents a method for automatic sensor placement for model-based robot vision. In such a vision system, the sensor often needs to be moved from one pose to another around the object to observe all features of interest. This allows multiple three-dimensional (3-D) images to be taken from different vantage viewpoints. The task involves determination of the optimal sensor placements and a shortest path through these viewpoints. During the sensor planning, object features are resampled as individual points attached with surface normals. The optimal sensor placement graph is achieved by a genetic algorithm in which a min-max criterion is used for the evaluation. A shortest path is determined by Christofides algorithm. A Viewpoint Planner is developed to generate the sensor placement plan. It includes many functions, such as 3-D animation of the object geometry, sensor specification, initialization of the viewpoint number and their distribution, viewpoint evolution, shortest path computation, scene simulation of a specific viewpoint, parameter amendment. Experiments are also carried out on a real robot vision system to demonstrate the effectiveness of the proposed method.

Algorithms↗
PubMed2005

Intelligent robust control for uncertain nonlinear time-varying systems and its application to robotic systems.

This paper addresses the problem of designing adaptive fuzzy-based (or neural network-based) robust controls for a large class of uncertain nonlinear time-varying systems. This class of systems can be perturbed by plant uncertainties, unmodeled perturbations, and external disturbances. Nonlinear H(infinity) control technique incorporated with adaptive control technique and VSC technique is employed to construct the intelligent robust stabilization controller such that an H(infinity) control is achieved. The problem of the robust tracking control design for uncertain robotic systems is employed to demonstrate the effectiveness of the developed robust stabilization control scheme. Therefore, an intelligent robust tracking controller for uncertain robotic systems in the presence of high-degree uncertainties can easily be implemented. Its solution requires only to solve a linear algebraic matrix inequality and a satisfactorily transient and asymptotical tracking performance is guaranteed. A simulation example is made to confirm the performance of the developed control algorithms.

Algorithms↗
PubMed2006

Routine left robotic-assisted laparoscopic donor nephrectomy is safe and effective regardless of the presence of vascular anomalies.

The classic approach to donor nephrectomy consists of preferential procurement of the kidney without vascular anomalies. We studied the effect of routine procurement of the left kidney regardless the presence of multiple arteries on the outcomes of robotic-assisted laparoscopic living donor nephrectomy (LLDN) with particular reference to the incidence of urological complications. From August 2000 to July 2005, 209 left LLDNs were performed. We analyzed the outcomes of donors and recipients in relation to the presence of multiple vessels versus normal anatomy. We divided the patients into two groups: group A (n = 148) with normal vascular anatomy and group B (n = 61) with vascular anomalies. In the donors, no significant difference in conversion to open surgery rate, blood loss, length of stay, was noted between the two groups; operative time and warm ischemia time were slightly higher in group B. One-year patient survival was 98% in both groups while the 1-year graft survival was 96.6% in group A and 96% in group B. Only one urological complication was noted in the group with normal anatomy (0.7%) versus none in the group with multiple arteries. Left kidney procurement using robotic-assisted laparoscopic technique is safe and effective, even in the presence of vascular anomalies.

Adolescent↗
PubMed1998

Robotic ocular ultramicrosurgery.

BACKGROUND: There is an increasing need for improved microsurgical techniques in the eye. Delivery of small quantities of chemicals or cells into specific retinal locations, for example, cannot be achieved with hand-held instruments. The present paper describes the design principles used in the development of a robotic ocular ultramicrosurgical system and the results from preliminary animal trials. METHODS: We have developed a robotic ocular ultramicrosurgical system and a range of instruments for specific intraocular applications. RESULTS: We have successfully used the system for intravascular (< 70 microm) drug delivery, implantation of microdrainage devices and the intraretinal manipulation of microelectrodes with minimal damage. CONCLUSION: A clinically usable system using the same principles appears feasible.

Animals↗
PubMed2006

Athermal Robotic Technique of prostatectomy in patients with large prostate glands (>75 g): technique and initial results.

OBJECTIVE: To report our experience with robotic radical prostatectomy (rRP) for prostate glands of >75 g, as this technique is developing rapidly. PATIENTS AND METHODS: Between January 2005 and November 2005, 30 men with prostates of >75 g had rRP. Their clinicopathological and operative data were reviewed. Technical considerations for successful rRP in patients with large glands are discussed, including the importance of surgical exposure and multiple traction sutures. RESULTS: The mean (range) specimen weight was 116.1 (75.3-346.0) g, the patient age 65.0 (56-72) years, the body mass index 28.4 (21-41) kg/m2, the preoperative International Prostate Symptom Score 10 (0-32), and the prostate-specific antigen (PSA) level 7.54 (1.9-20.1) ng/mL. The clinical stage was T1c in 26 men and T2a in four. The biopsy Gleason scores were 3 + 3 = 6 in 25 men, 3 + 4 = 7 in four and 4 + 3 = 7 in one. The mean (range) estimated blood loss was 208 (100-600) mL and the operative duration 193 (150-270) min. The cancer was organ-confined in all patients and all surgical margins were negative. The mean (range) duration of indwelling catheterization was 12.7 (11-14) days. There were no complications during or after rRP, and the PSA level was undetectable in all patients after surgery. CONCLUSIONS: RP for patients with large prostates is technically challenging. The robotic approach does not appear to compromise oncological control. We show the feasibility of rRP for men with large glands.

Aged↗