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At least 919 records · Page 51Linked to original sources

PubMed2007

The experimental humanoid robot H7: a research platform for autonomous behaviour.

This paper gives an overview of the humanoid robot 'H7', which was developed over several years as an experimental platform for walking, autonomous behaviour and human interaction research at the University of Tokyo. H7 was designed to be a human-sized robot capable of operating autonomously in indoor environments designed for humans. The hardware is relatively simple to operate and conduct research on, particularly with respect to the hierarchical design of its control architecture. We describe the overall design goals and methodology, along with a summary of its online walking capabilities, autonomous vision-based behaviours and automatic motion planning. We show experimental results obtained by implementations running within a simulation environment as well as on the actual robot hardware.

Artificial Intelligence↗

PubMed2007

How to make an autonomous robot as a partner with humans: design approach versus emergent approach.

In this paper, we discuss what factors are important to realize an autonomous robot as a partner with humans. We believe that it is important to interact with people without boring them, using verbal and non-verbal communication channels. We have already developed autonomous robots such as AIBO and QRIO, whose behaviours are manually programmed and designed. We realized, however, that this design approach has limitations; therefore we propose a new approach, intelligence dynamics, where interacting in a real-world environment using embodiment is considered very important. There are pioneering works related to this approach from brain science, cognitive science, robotics and artificial intelligence. We assert that it is important to study the emergence of entire sets of autonomous behaviours and present our approach towards this goal.

Artificial Intelligence↗

PubMed1997

Robots in space into the 21st century.

Describes the technological developments which are establishing the foundation for an exciting era of in situ exploration missions to planets, comets and asteroids with advanced robotic systems. Also outlines important concurrent terrestrial applications and spinoffs of the space robotics technology. These include high-precision robotic manipulators for microsurgical operations and dexterous arm control systems.

Electronics↗

PubMed1998

Anatomy-based registration of CT-scan and intraoperative X-ray images for guiding a surgical robot.

We describe new methods for rigid registration of a preoperative computed tomography (CT)-scan image to a set of intraoperative X-ray fluoroscopic images, for guiding a surgical robot to its trajectory planned from CT. Our goal is to perform the registration, i.e., compute a rotation and translation of one data set with respect to the other to within a prescribed accuracy, based upon bony anatomy only, without external fiducial markers. With respect to previous approaches, the following aspects are new: 1) we correct the geometric distortion in fluoroscopic images and calibrate them directly with respect to the robot by affixing to it a new calibration device designed as a radiolucent rod with embedded metallic markers, and by moving the device along two planes, while radiographs are being acquired at regular intervals; 2) the registration uses an algorithm for computing the best transformation between a set of lines in three space, the (intraoperative) X-ray paths, and a set of points on the surface of the bone (imaged preoperatively), in a statistically robust fashion, using the Cayley parameterization of a rotation; and 3) to find corresponding sets of points to the X-ray paths on the surfaces, our new approach consists of extracting the surface apparent contours for a given viewpoint, as a set of closed three-dimensional nonplanar curves, before registering the apparent contours to X-ray paths. Aside from algorithms, there are a number of major technical difficulties associated with engineering a clinically viable system using anatomy and image-based registration. To detect and solve them, we have so far conducted two experiments with the surgical robot in an operating room (OR), using CT and fluoroscopic image data of a cadaver bone, and attempting to faithfully simulate clinical conditions. Such experiments indicate that intraoperative X-ray-based registration is a promising alternative to marker-based registration for clinical use with our proposed method.

Arthroplasty, Replacement, Hip↗

PubMed1998

Performance statistics of a head-operated force-reflecting rehabilitation robot system.

Researchers in the rehabilitation engineering community have been designing and developing a variety of passive/active devices to help persons with limited upper extremity function to perform essential daily manipulations. Devices range from low-end tools such as head/mouth sticks to sophisticated robots using vision and speech input. While almost all of the high-end equipment developed to date relies on visual feedback alone to guide the user providing no tactile or proprioceptive cues, the "low-tech" head/mouth sticks deliver better "feel," because of the inherent force feedback through physical contact with the user's body. However, the disadvantage of a conventional head/mouth stick is that it can only function in a limited workspace and the performance is limited by the user's strength. It therefore seems reasonable to attempt to develop a system that exploits the advantages of the two approaches: the power and flexibility of robotic systems with the sensory feedback of a headstick. The system presented in this paper reflects the design philosophy stated above. This system contains a pair of master-slave robots with the master being operated by the user's head and the slave acting as a telestick. Described in this paper are the design, control strategies, implementation and performance evaluation of the head-controlled force-reflecting telestick system.

Adult↗

PubMed2004

Noninvasive brain-actuated control of a mobile robot by human EEG.

Brain activity recorded noninvasively is sufficient to control a mobile robot if advanced robotics is used in combination with asynchronous electroencephalogram (EEG) analysis and machine learning techniques. Until now brain-actuated control has mainly relied on implanted electrodes, since EEG-based systems have been considered too slow for controlling rapid and complex sequences of movements. We show that two human subjects successfully moved a robot between several rooms by mental control only, using an EEG-based brain-machine interface that recognized three mental states. Mental control was comparable to manual control on the same task with a performance ratio of 0.74.

Algorithms↗

PubMed2005

Speeding up the learning of robot kinematics through function decomposition.

The main drawback of using neural networks or other example-based learning procedures to approximate the inverse kinematics (IK) of robot arms is the high number of training samples (i.e., robot movements) required to attain an acceptable precision. We propose here a trick, valid for most industrial robots, that greatly reduces the number of movements needed to learn or relearn the IK to a given accuracy. This trick consists in expressing the IK as a composition of learnable functions, each having half the dimensionality of the original mapping. Off-line and on-line training schemes to learn these component functions are also proposed. Experimental results obtained by using nearest neighbors and parameterized self-organizing map, with and without the decomposition, show that the time savings granted by the proposed scheme grow polynomially with the precision required.

Algorithms↗

PubMed2006

Prune-able fuzzy ART neural architecture for robot map learning and navigation in dynamic environments.

Mobile robots must be able to build their own maps to navigate in unknown worlds. Expanding a previously proposed method based on the fuzzy ART neural architecture (FARTNA), this paper introduces a new online method for learning maps of unknown dynamic worlds. For this purpose the new Prune-able fuzzy adaptive resonance theory neural architecture (PAFARTNA) is introduced. It extends the FARTNA self-organizing neural network with novel mechanisms that provide important dynamic adaptation capabilities. Relevant PAFARTNA properties are formulated and demonstrated. A method is proposed for the perception of object removals, and then integrated with PAFARTNA. The proposed methods are integrated into a navigation architecture. With the new navigation architecture the mobile robot is able to navigate in changing worlds, and a degree of optimality is maintained, associated to a shortest path planning approach implemented in real-time over the underlying global world model. Experimental results obtained with a Nomad 200 robot are presented demonstrating the feasibility and effectiveness of the proposed methods.

Algorithms↗

PubMed2004

Evidence for improved muscle activation patterns after retraining of reaching movements with the MIME robotic system in subjects with post-stroke hemiparesis.

Previously, we reported that chronic stroke subjects had significant improvements in isometric strength, free reaching extent, and clinical evaluations of function after training in the mirror-image movement enabler (MIME) robotic device. Our primary goal in this analysis was to investigate the hypothesis that the robotic training promoted improved muscle activation patterns. To this end, we examined the interaction forces, kinematics, and electromyograms recorded during training of eight different movement patterns in active-constrained mode. In this mode, the robot constrained the reaching movements to be toward the target, and the movement velocity was proportional to the force produced along the trajectory. Thirteen chronic stroke subjects trained in MIME for 24 1-h sessions over an eight-week period. Work output was significantly increased by week five in all eight movement patterns. Low-level subjects increased their extent of reach, while high-level subjects increased their speed. Directional errors in force production were reduced in six of eight movement patterns. Electromyographic data provided evidence for improved muscle activation patterns in the four movement patterns that started at tabletop level and ended at shoulder level. In contrast, there was no evidence of improved muscle activation patterns in any of the tabletop movements, with increased activation of antagonists in two movement patterns. This dichotomy may have been related to compensation at the shoulder girdle during movements that remained at tabletop level. A simple biomechanical model will be introduced to demonstrate the likelihood of this possibility.

Arm↗

PubMed2006

3-D ultrasound guidance of surgical robotics: a feasibility study.

Laparoscopic ultrasound has seen increased use as a surgical aide in general, gynecological, and urological procedures. The application of real-time, three-dimensional (RT3D) ultrasound to these laparoscopic procedures may increase information available to the surgeon and serve as an additional intraoperative guidance tool. The integration of RT3D with recent advances in robotic surgery also can increase automation and ease of use. In this study, a 1-cm diameter probe for RT3D has been used laparoscopically for in vivo imaging of a canine. The probe, which operates at 5 MHz, was used to image the spleen, liver, and gall bladder as well as to guide surgical instruments. Furthermore, the three-dimensional (3-D) measurement system of the volumetric scanner used with this probe was tested as a guidance mechanism for a robotic linear motion system in order to simulate the feasibility of RT3D/robotic surgery integration. Using images acquired with the 3-D laparoscopic ultrasound device, coordinates were acquired by the scanner and used to direct a robotically controlled needle toward desired in vitro targets as well as targets in a post-mortem canine. The rms error for these measurements was 1.34 mm using optical alignment and 0.76 mm using ultrasound alignment.

Animals↗

PubMed2003

Cyclic coordinate descent: A robotics algorithm for protein loop closure.

In protein structure prediction, it is often the case that a protein segment must be adjusted to connect two fixed segments. This occurs during loop structure prediction in homology modeling as well as in ab initio structure prediction. Several algorithms for this purpose are based on the inverse Jacobian of the distance constraints with respect to dihedral angle degrees of freedom. These algorithms are sometimes unstable and fail to converge. We present an algorithm developed originally for inverse kinematics applications in robotics. In robotics, an end effector in the form of a robot hand must reach for an object in space by altering adjustable joint angles and arm lengths. In loop prediction, dihedral angles must be adjusted to move the C-terminal residue of a segment to superimpose on a fixed anchor residue in the protein structure. The algorithm, referred to as cyclic coordinate descent or CCD, involves adjusting one dihedral angle at a time to minimize the sum of the squared distances between three backbone atoms of the moving C-terminal anchor and the corresponding atoms in the fixed C-terminal anchor. The result is an equation in one variable for the proposed change in each dihedral. The algorithm proceeds iteratively through all of the adjustable dihedral angles from the N-terminal to the C-terminal end of the loop. CCD is suitable as a component of loop prediction methods that generate large numbers of trial structures. It succeeds in closing loops in a large test set 99.79% of the time, and fails occasionally only for short, highly extended loops. It is very fast, closing loops of length 8 in 0.037 sec on average.

Algorithms↗

PubMedDate not supplied

Minimally invasive mitral valve repair with and without robotic technology in the elderly.

An increasing number of elderly persons require mitral valve surgery, primarily for mitral regurgitation. Minimally invasive mitral valve repair, including robotic surgery, has been shown to be feasible and safe in the general population. Minimally invasive cardiac surgery is especially beneficial in the elderly because it decreases trauma and speeds recovery. The authors conducted a retrospective review of 123 cases of minimally invasive mitral valve repair in elderly patients aged 70 years and older and five robotic mitral valve repairs using the da Vinci surgical system (Intuitive Surgical, Inc., Sunnyvale, CA) in one octogenarian. The authors review their 9 years of experience with minimally invasive mitral valve repair in the elderly and compare and contrast other forms of surgery in the elderly, including robotic mitral valve repair.

Aged↗

PubMed2006

Role of robotics in the management of secondary ureteropelvic junction obstruction.

Patients with recurrent ureteropelvic junction obstruction (UPJO) present a treatment dilemma to urologists. Second-line therapies have previously been shown to fail at a higher rate than the initial therapeutic procedure. We report our experience with robotic-assisted, dismembered pyeloplasty in patients with secondary UPJO. Since November 2002, 44 robotic-assisted laparoscopic pyeloplasties (RALPs) have been performed at our institution. Of these, seven patients had undergone previous definitive treatment for UPJO. Anderson-Hynes-dismembered pyeloplasty was the preferred reconstructive technique in all patients. The patients were divided into two groups: primary pyeloplasty patients (group 1) and secondary pyeloplasty patients (group 2). Variables examined include operative time, estimated blood loss (EBL), length of hospital stay (LOS) and success rates. All operations were completed laparoscopically, and there were no conversions to open surgery in either group. Mean operative time was 60 min longer in the secondary pyeloplasty group compared with primary cases, but the EBL, LOS and success rates were similar. A patent UPJ was confirmed in both groups by renal scan and/or excretory urography (intravenous pyelogram) examinations. RALP is a viable option in select patients with recurrent UPJO after previous endoscopic or open surgical repair. As expected, operative times were longer in these patients due to a more challenging dissection (p < 0.05). However, the magnification afforded by the robot allows for a precise dissection, and subsequently, there was no significant increase in blood loss, hospital stay or perioperative morbidity in our series (p > 0.05).

Adolescent↗

PubMed2005

Urological robotic surgery: preliminary experience with the Zeus system.

AIM: We performed robotic or robotically-assisted laparoscopic surgery for urological diseases, and evaluated the ef ficacy and safety of this surgery. METHODS: Between November 2003 and June 2004, we performed laparoscopic surgery with the Zeus system in eight cases. Three adrenalectomy cases of cortical adenoma presenting with Cushing syndrome and primary aldosteronism, and two cases of nephrectomy for renal cell carcinoma in dialyzed patients were performed solely with Zeus. In two cases of ureteral stenosis, Zeus was used for ureteral anastomosis after partial ureterectomy by manual laparoscopy. In one prostatectomy case, vesico-urethral anastomosis was performed with Zeus after extraperitoneal prostatectomy by manual laparoscopy. RESULTS: All of the cases were successfully treated without any complications during or after operation. All patients were discharged from hospital within 12 days postoperatively. As for adrenalectomy, nephrectomy and pyeloplasty, this may be the fi rst report in Japan. CONCLUSIONS: Our preliminary experiences suggest that such a robot system, which is being developed day by day, might become more beneficial in future in urological laparoscopic surgery.

Adult↗

PubMed2005

Concomitant management of renal calculi and pelvi-ureteric junction obstruction with robotic laparoscopic surgery.

OBJECTIVE: To present technical recommendations for robotic-assisted laparoscopic pyeloplasty (RALP) and stone extraction, as patients with kidney stones proximal to a pelvi-ureteric junction obstruction (PUJO) present a technical challenge, and have traditionally been managed with open surgery or percutaneous antegrade endopyelotomy. PATIENTS AND METHODS: From November 2002 to April 2005, 55 patients had RALP for PUJO; eight of these had concomitant renal calculi. Stone burden and location were assessed with a preoperative radiological examination. Before completing the PUJO repair, one robot working arm (cephalad one) was temporarily undocked to allow passage of a flexible nephroscope into the renal pelvis and collecting systems under direct vision. Stones were extracted with graspers or basket catheters and removed via the port. The surgical-assistant port in the subxiphoid area was used to introduce laparoscopic suction and other instruments. RESULTS: The Anderson-Hynes dismembered pyeloplasty was the preferred reconstructive technique in all patients. Operations were completed robotically with no conversions to open surgery. All patients were rendered stone-free, confirmed by imaging, and there were no intraoperative or delayed complications during a mean (range) follow-up of 12.3 (4-22) months. The mean operative time was 275.8 min, 61.7 min longer than in patients who did not have concomitant stone removal. CONCLUSIONS: Concurrent stone extraction and PUJO repair can be successful with RALP. Operative times are longer than in patients with isolated PUJO repair, but this is to be expected as there is an additional procedure.

Adolescent↗

PubMed2006

The use of robotically assisted surgery for treating urachal anomalies.

OBJECTIVE: To report the management of urachal anomalies using a robotically assisted approach. PATIENTS AND METHODS: Between January 2005 and February 2006, five patients (mean age 51 years, range 24-68) were diagnosed with urachal anomalies. Two basic robot-assisted surgical approaches were used for excising the urachal anomalies: excision of the urachal remnant via partial cystectomy, and radical cystectomy for excision of urachal adenocarcinoma. RESULTS: All five cases were successful and the excised specimens were assessed histologically. The short-term oncological outcome in the three patients with histologically confirmed moderately differentiated adenocarcinoma showed no evidence of recurrent disease within a median interval of 8 months. Surveillance follow-up cystoscopy in the patients who had a partial cystectomy showed a well-healed bladder mucosa with no evidence of recurrence. CONCLUSIONS: Radical excision of the urachal tract with partial cystectomy or radical cystectomy using the da Vinci robot is safe, effective and technically feasible.

Adult↗

PubMedDate not supplied

Robot-assisted isolation of the pulmonary veins with microwave energy.

BACKGROUND: Ablation of the left atrium to isolate the pulmonary veins has been shown to interrupt electrical foci that may induce atrial fibrillation. This study evaluated the feasibility of performing a minimally invasive left atrial isolation on a beating heart using the da Vinci Robotic Surgical System and a flexible microwave probe (Flex 10 by AFx, Inc., Fremont, CA, USA), and the reliability of exit block pacing to confirm transmurality of the lesions created. METHODS: On six canines, the Flex 10 probe was passed around the left atrium posterior to the superior vena cava, through the transverse sinus, and back through the oblique sinus via a right-chest-only approach using the da Vinci Robotic Surgical System. Prior to ablation, pacing outside the atrial cuff was confirmed. Ablation was then carried out on the beating heart and repeated (as needed) until electrical isolation was demonstrated by exit block pacing. Probe position was confirmed at the completion of the procedure via sternotomy. Analysis included acute histologic and gross examination of the targeted area. RESULTS: There was no significant difference (p = 0.110) in procedure time, although it decreased 39.6% from the first three cases to the last three cases. Electrical evidence of electrical left atrial isolation was achieved in all subjects. Acute histologic examination confirmed transmurality inconsistently. Additionally, in two animals, the Flex 10 probe was found to be anterior to the left atrial appendage. All animals survived the procedure. CONCLUSION: A minimally invasive left atrial isolation procedure using monopolar microwave energy with the da Vinci Robotic Surgical System is simple and feasible. However, despite creating an electrical block, transmurality was not demonstrated consistently and further confirmation of catheter positioning is necessary during a right-chest-only approach.

Animals↗

PubMed2000

Computer- and robot-assisted total knee replacement: analysis of a new surgical procedure.

This paper describes a nonstandard procedure for total knee replacement (TKR), based on the use of modern tools such as computers, electronic sensors, and robots, to achieve accurate and optimal implant results. The intervention is planned on a standard PC connected to the CT scanner. Dedicated software shows the surgeon limb alignment and knee status and assists in the choice of the best prosthesis. The intervention is then performed with a new device and surgical procedure. At first the femur and the tibia are fixed to the operating table with a special clamp and the knee bones are exposed with the standard technique; then the surgeon digitizes the shape of the joint and the computer transfers the planned surgical strategy to a dedicated surgical robot. Resections are performed by the surgeon on a constrained guide held by the robot. In this paper we summarize the main results on the system performances, and discuss the clinical implications of this new technology in the operating room. Preliminary experiments on cadavers and volunteers show that this methodology can improve the accuracy of the implant to 2.5 mm and 20, reduce operating time and surgical errors, and may represent a challenging alternative methodology for TKR.

Arthroplasty, Replacement, Knee↗