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PubMed2003

Robot-assisted arm trainer for the passive and active practice of bilateral forearm and wrist movements in hemiparetic subjects.

OBJECTIVE: To determine whether use of a robotic arm trainer for bilateral exercise in daily repetitive training for a 3-week period reduced spasticity and improved motor control in the arm of severely affected, chronic hemiparetic subjects. DESIGN: Before-after trial. SETTING: Community rehabilitation center in Germany. PARTICIPANTS: Consecutive sample of 12 chronic hemiparetic patients; minimum stroke interval 6 months; patients could maximally protract the affected shoulder, hold the extended arm, or slightly flex and extend the elbow. INTERVENTIONS: Additional daily therapy of 15 minutes with the arm trainer for 3 weeks; the 1 degree of freedom trainer enabled the bilateral passive and active practice of a forearm pronation and supination and wrist dorsiflexion and volarflexion; impedance control guaranteed a smooth movement. MAIN OUTCOME MEASURES: Patients' impressions, the Modified Ashworth Scale (MAS) score (range, 0-5) to assess spasticity, and the arm section of the Rivermead Motor Assessment (RMA) score (range, 0-15) to assess motor control were rated before therapy, after each 3-week interval, and at follow-up 3 months later. RESULTS: All patients had favorable impressions: the extremity felt more vivid, and 8 subjects noticed a reduction in spasticity, an ease of hand hygiene, and pain relief. The MAS score of the wrist and fingers joints decreased significantly (P<.0125) from a median of 3 (2-3) and 3 (3-4) to 2 (1-2) and 2.5 (2-3). The RMA score minimally increased in 5 cases without improvement in functional tasks. The median RMA score before therapy was 2.0 (1-2) and 2.0 (1-3.75) after therapy. There were no side effects. At follow-up, the effects had waned. CONCLUSIONS: The arm trainer made possible intensive bilateral elbow and wrist training of severely affected stroke patients. Future studies should address the treatment effect in subacute stroke patients and determine the optimum treatment intensity.

Adult↗

PubMed2004

Reinforcement learning algorithms for robotic navigation in dynamic environments.

The purpose of this study was to examine improvements to reinforcement learning (RL) algorithms in order to successfully interact within dynamic environments. The scope of the research was that of RL algorithms as applied to robotic navigation. Proposed improvements include: addition of a forgetting mechanism, use of feature based state inputs, and hierarchical structuring of an RL agent. Simulations were performed to evaluate the individual merits and flaws of each proposal, to compare proposed methods to prior established methods, and to compare proposed methods to theoretically optimal solutions. Incorporation of a forgetting mechanism did considerably improve the learning times of RL agents in a dynamic environment. However, direct implementation of a feature-based RL agent did not result in any performance enhancements, as pure feature-based navigation results in a lack of positional awareness, and the inability of the agent to determine the location of the goal state. Inclusion of a hierarchical structure in an RL agent resulted in significantly improved performance, specifically when one layer of the hierarchy included a feature-based agent for obstacle avoidance, and a standard RL agent for global navigation. In summary, the inclusion of a forgetting mechanism, and the use of a hierarchically structured RL agent offer substantially increased performance when compared to traditional RL agents navigating in a dynamic environment.

Algorithms↗

PubMed2006

Time-scaling of trajectories for point-to-point robotic tasks.

In order to improve the tracking performance in the practical robot task of time-optimal point-to-point motion when torque limits and model uncertainty are present, in this paper is introduced an algorithm for on-line time-scaling of the desired trajectories, which is used along with a conventional trajectory tracking controller. Numerical examples for a two-degrees-of-freedom arm are provided, which illustrate the tracking accuracy of the proposed method.

Algorithms↗

PubMed2000

Determination of deramciclane and N-desmethylderamciclane in human plasma by liquid chromatography-tandem mass spectrometry using off-line robotic sample pretreatment.

A rapid and highly sensitive LC-MS-MS method using deuterium-labelled internal standards was developed and evaluated for the simultaneous determination of deramciclane and its pharmacologically active metabolite (N-desmethylderamciclane). The sample preparation based on liquid-liquid extraction was carried out with an off-line robotic system. Evaluation of this analytical method shows that samples can be assayed with acceptable accuracy and precision in the 0.1 to 50 ng/ml concentration range for both compounds. The method was applied for the quantitative determination of deramciclane and its metabolite in human plasma samples during a food interaction pharmacokinetic study.

Calibration↗

PubMed1998

Accelerated recombinant protein purification process development automated, robotics-based integration of chromatographic purification and analysis.

Recovery of recombinant proteins from endogenous, host molecules can be an experimentally intensive and time-consuming task. Often the time to analyze material during development of recovery procedures is the rate-limiting step. Nowadays, modern techniques and equipment are being specifically engineered to make this effort much more efficient. We present a case study to illustrate how a new, automation tool, designed for easy, systematic methods development, can be used for very rapid process and analytical optimization. This tool uses robotics to integrate process development with rapid LC-based analysis requiring no user intervention. The methods and procedures described can be generalized to any recombinant protein recovery campaign.

Chromatography, High Pressure Liquid↗

PubMed2006

Pediatric robot assisted laparoscopic dismembered pyeloplasty: comparison with a cohort of open surgery.

PURPOSE: We assessed the usefulness of RALP in children and compared an age matched cohort undergoing OPN to RALP for safety, efficacy, operative time, blood loss, in-hospital narcotic use and LOS. MATERIALS AND METHODS: We performed a retrospective case-control study from 2000 to 2004 of 33 patients undergoing RALP and 33 undergoing OPN. Average age of each group was not significantly different (RALP 7.8 years vs OPN 7.6 years, p = 0.75). Mean followup of RALP and OPN groups was 10 and 21 months, respectively. RESULTS: Etiology of the obstruction was not significantly different. Mean operative time was significantly less for OPN (181 minutes vs 219 minutes for RALP, p = 0.031). As RALP experience increased, operative times improved and approached the OPN experience. RALP complications included 1 patient requiring reoperative surgery vs no complications in the OPN group (p = 0.15). Patients undergoing RALP had a mean LOS of 2.3 days compared to 3.5 days for OPN (p <0.001). Total narcotic requirements were significantly less in the RALP group (p = 0.001). All patients in the OPN and 31 in the RALP group had either resolution of hydronephrosis, improvement in drainage or relief of symptoms. CONCLUSIONS: We documented the safety and efficacy of RALP in children. RALP showed advantages of decreased hospital stay, decreased narcotic use and operative times approaching those of open surgery. RALP is an option for pyeloplasty, and as robotic technology improves, this method of repair may become the minimally invasive treatment of choice.

Adolescent↗

PubMed2003

Robot-assisted gastric surgery.

In conclusion, robot-assisted gastric surgery is now considered to be feasible in patients with Stage IA (T1N0) and Stage IB (T1N1, T2N0) early gastric cancer. The optimal treatment modalities have yet to be identified, however, and therefore clinical trials are called for. The authors believe that this new technology will markedly increase the survival rate of such patients all over the world in the near future, while also helping to significantly decrease the complication rates and hospital stay of the patients, which will thus result in a major beneficial socioeconomic impact.

Endoscopy↗

PubMed2005

Robotic cloning and Protein Production Platform of the Northeast Structural Genomics Consortium.

In this chapter we describe the core Protein Production Platform of the Northeast Structural Genomics Consortium (NESG) and outline the strategies used for producing high-quality protein samples using Escherichia coli host vectors. The platform is centered on 6X-His affinity-tagged protein constructs, allowing for a similar purification procedure for most targets, and the implementation of high-throughput parallel methods. In most cases, these affinity-purified proteins are sufficiently homogeneous that a single subsequent gel filtration chromatography step is adequate to produce protein preparations that are greater than 98% pure. Using this platform, over 1000 different proteins have been cloned, expressed, and purified in tens of milligram quantities over the last 36-month period (see Summary Statistics for All Targets, ). Our experience using a hierarchical multiplex expression and purification strategy, also described in this chapter, has allowed us to achieve success in producing not only protein samples but also many three-dimensional structures. As of December 2004, the NESG Consortium has deposited over 145 new protein structures to the Protein Data Bank (PDB); about two-thirds of these protein samples were produced by the NESG Protein Production Facility described here. The methods described here have proven effective in producing quality samples of both eukaryotic and prokaryotic proteins. These improved robotic and?or parallel cloning, expression, protein production, and biophysical screening technologies will be of broad value to the structural biology, functional proteomics, and structural genomics communities.

Chromatography, Gel↗

PubMed2003

Robotic radical prostatectomy and the Vattikuti Urology Institute technique: an interim analysis of results and technical points.

We have performed >350 robotic radical prostatectomies in the last 2 years. A single surgeon (MM) performed 250 of these procedures using a technique developed at our institution, the Vattikuti Urology Institute. This article summarizes the technical highlights and interim results of the Vattikuti Institute Prostatectomy (VIP) technique. We prospectively collected baseline demographic data, such as age, race, body mass index (BMI), serum prostate-specific antigen values, prostate volume, Gleason score, percentage cancer, TNM clinical staging, and comorbidities. Urinary symptoms were measured with the International Prostate Symptom Score, and sexual health with the Sexual Health Inventory of Males. In addition, patients received the Expanded Prostate Inventory Composite at baseline and at 1, 3, 6, 12 and 18 months after the procedure via mail. Data collection is complete on 200 of the first 250 patient cases. Gleason score >or=7 was noted in 40% of patients. The average BMI was high (28), and 86% patients were classified as pathologic stage pT2a to pT2b. The mean operative time was 160 minutes and the mean blood loss was 153 mL. No patient required blood transfusion. At 6 months, 82% of the men who were <60 years of age and 75% of those >60 years of age had return of sexual function, and 64% and 38%, respectively, had sexual intercourse. At 6 months, 96% patients were continent.

Adenocarcinoma↗

PubMed2000

A robotic manipulator for the characterization of two-dimensional dynamic stiffness using stochastic displacement perturbations.

Experimental techniques for estimating the two-dimensional dynamic stiffness of the human arm over a wide range of conditions have been developed. A robotic manipulator has been developed to create loads against which subjects perform various tasks and also to impose perturbations onto the endpoint of the arm to allow estimation of its mechanical properties. The manipulator can produce static endpoint forces exceeding 220 N in any direction in its plane of motion, and this plane can be vertically translated and tilted over wide ranges to study arm dynamic stiffness in many functionally relevant planes. It can impose stochastic position and force perturbations whose bandwidth exceeds that of the arm. These random perturbations avoid undesirable volitional reactions and allow the efficient estimation of stiffness dynamics using experimental trials of short duration. The ability of this manipulator to characterize inertial-viscoelastic systems was tested using several two-dimensional physical systems whose properties were independently characterized. The endpoint dynamic stiffness properties of a human arm were estimated as an example of the use of the manipulator in studying upper limb mechanical properties. The system properties characterized by these methods will be useful in probing normal neural arm control strategies and in developing rehabilitation interventions to improve arm movements in disabled individuals.

Arm↗

PubMed1998

Rapid and highly automated determination of adenine and pyridine nucleotides in extracts of Saccharomyces cerevisiae using a micro robotic sample preparation-HPLC system.

An ion-pair reversed-phase chromatography method was adapted for the simultaneous separation and quantification of adenine and pyridine nucleotide concentrations in cell extracts of Saccharomyces cerevisiae. Microbial extracts including metabolites, macromolecular constituents and inorganic compounds were loaded onto a ODS pre-column in the presence of triethylamine phosphate (TEA-Pi) resulting in a selective binding of the nucleotides and removing of interfering compounds. After washing the enrichment cartridge with 30 mM TEA-Pi buffer, adenine and pyridine nucleotides were eluted with a gradient of Mg(II), the competing hetaeron. This combined cleaning and concentration step leads to remarkable improvement of the detection limit for all nucleotides of interest and column lifetimes. The clean up and separation procedures were performed automatically with a micro robotic-system and a control software package written in PASCAL. The paper reports about the application of the proposed method to separation of adenine and pyridine nucleotides in cells extracts of S. cerevisiae grown anaerobically in a continuous culture (D = 0.1 h-1). Rapidity of analysis, high sensitivity as well as reproducibility of the system and the accurate evaluation of the adenine and pyridine nucleotide concentrations make this method particularly useful for routine analysis.

Adenine Nucleotides↗

PubMed2003

Local evolvability of statistically neutral GasNet robot controllers.

In this paper we introduce and apply the concept of local evolvability to investigate the behaviour of populations during evolutionary search. We focus on the evolution of GasNet neural network controllers for a robotic visual discrimination problem, showing that the evolutionary process undergoes long neutral fitness epochs. We show that the local evolvability properties of the search space surrounding a group of statistically neutral solutions do vary across the course of an evolutionary run, especially during periods of population takeover. However, once takeover is complete there is no evidence for further increase in local evolvability across fitness epochs. We also see no evidence for the neutral evolution of increased solution robustness, but show that this may be due to the ability of evolutionary algorithms to focus search on volumes of the fitness landscape with above average robustness.

Adaptation, Physiological↗

PubMed1996

Sensitive high-performance liquid chromatographic determination of nifedipine in dog plasma using an automated sample preparation system with laboratory robot.

Nifedipine, a calcium-channel blocking drug was analysed in dog plasma after oral dosing with two different formulations. Sample preparation was automated with a laboratory robot. Quantitative determination of the drug was performed on a reversed-phase HPLC system with electrochemical detection (ED) using an internal standard. Validation of the analytical method showed that the system is well suited for pharmacokinetic studies on dogs. The assay was linear in the range 1-50 ng/ml. Inter-day and intra-day variability were between 6.43-18.15% C.V. and 1.57-5.53% C.V., respectively.

Animals↗

PubMed2003

Automated determination of selected water-soluble vitamins in tablets using a bench-top robotic system coupled to reversed-phase (RP-18) HPLC with UV detection.

The determination of folic acid, nicotinamide, nicotinic acid, riboflavin, riboflavin-5'-phosphate, pyridoxine and thiamine in tablets has been successfully automated using a bench-top robotic system (Zymark Tablet Processing Workstation II) coupled to reversed-phase (RP-18) HPLC with UV-detection. The new automated methods have been validated and were found to be applicable in routine analysis for all common types of multivitamin tablets. The precision is exemplified by relative standard deviations of 5.4% for folic acid, 2.1% for nicotinamide, 1.6% for pyridoxine, 0.7% for riboflavin and 1.1% for thiamine using film-coated tablets as sample. Mean recoveries obtained during spiking experiments were in the range of 95.2-103.9%.

Autoanalysis↗

PubMed2000

Methods for kinematic modeling of biological and robotic systems.

The main objective is to develop methods that automatically generate kinematic models for the movements of biological and robotic systems. Two methods for the identification of the kinematics are presented. The first method requires the elimination of the displacement variables that cannot be measured while the second method attempts to estimate the changes in these variables. The methods were tested using a planar two-revolute-joint linkage. Results show that the model parameters obtained agree with the actual parameters to within 5%. Moreover, the methods were applied to model head and neck movements in the sagittal plane. The results indicate that these movements are well modeled by a two-revolute-joint system. A spatial three-revolute-joint model was also discussed and tested.

Algorithms↗

PubMed2002

Assessment of a three-dimensional robotic model for biomechanical-data acquisition of human movement.

The use of a kinematic robotic model has not been implemented in the biomechanical-data acquisition protocol, as it has in workplace analysis, ergonomics and design. The purpose of this paper was to assess the use of a kinematic model to retrieve frames of human movements from data obtained at a low sampling frequency. From experimental trials with an original sampling frequency of 60 Hz, the data were sampled again at two lower frequencies, 5 Hz and 10 Hz. The model was then used to reconstitute the data to its original frequency (60 Hz). The results demonstrated that it was possible to retrieve a full 3-D human movement from a sampling rate lower than normal without sacrificing accuracy. It was observed from both reduced sampling frequencies that the error level was comparable to the usual accuracy of a DLT 3-D reconstruction technique. It was therefore concluded that the data retrieved from these two frequencies were very similar to the original data sampled at 60 Hz.

Activities of Daily Living↗

PubMed1999

Use of robotic technology for diathrodial joint research.

Knowledge of diarthrodial joint mechanics and specific function of the ligaments are needed in order to understand injury mechanisms, improve surgical procedures and design better post-surgical rehabilitation protocols. To facilitate these needs, a robotic/universal force-moment sensor (UFS) testing system was developed to measure joint kinematics in multiple degree-of-freedom and the in situ forces in the ligaments. When operated in the position control mode, the testing system applies a known load to the intact joint while the motion and force data are recorded. After transection of a ligament, the recorded motion for the intact joint is repeated and new force and moment data is recorded by the UFS. Since the robot reproduces the identical initial position as well as path of joint motion before and after a ligament is transected, the in situ force in the ligament is the difference between the two sets of force and moment data. In force control mode, a known force is applied to the intact knee while the kinematics are recorded. After ligament transection, the same force is applied while the changes in kinematics are again recorded. Testing in this mode is similar to a clinical examination that diagnoses ligament injury. To date, this testing system has been used for experimental studies that examine the anterior cruciate ligament & posterior cruciate ligament of the knee and ligaments of the shoulder. A three-dimensional finite element model has also been constructed based on CT/MRI scans of a knee specimen and validated using data obtained with the testing system. Once in vivo kinematics (such as during gait analysis or throwing activities) are available, the robotic/UFS testing system can be programmed to reproduce these joint kinematics on young human cadaveric specimens in order to generate a database for in situ forces in the ligaments, or Ligament replacement grafts. With appropriate computational models, the stresses and strains in these tissues in vivo can also be determined. Potential applications of this combined approach include pre-operative surgical planning, improvement of surgical procedures as well as development of appropriate post-operative rehabilitation protocols.

Biomechanical Phenomena↗

PubMed2001

Robot printing of reverse dot blot arrays for human mutation detection.

We report on a generally useful, partially automated, human mutation detection method based upon printing moderate density oligonucleotide arrays using a biorobot on activated nylon membranes. The Beckman Biomek 2000 was adapted to this task through fabrication of aluminum membrane filter holders and the development of an addressable Tool Command Language (Tcl) program, which can be invoked through BioScript. During program execution, a robot arm is moved along the x, y, and z axes to expel liquid, without dripping, from disposable barrier pipette tips and then to touch the drops on preactivated membranes. Printed arrays consist of alternating rows of oligonucleotides containing normal and mutant sequences. Hybridization of biotin labeled polymerase chain reaction products derived from human patient genomic DNA samples are visualized using chemiluminescent or chromogenic indicators. This technique allows unequivocal genotyping of 32 mutations at the beta-thalassemia locus (11p15.5) and of 34 mutations and one polymorphism at the cystic fibrosis transconductance membrane regulator locus (7p35).

Chromosomes, Human, Pair 11↗