Visual Feedback System Research Articles

NAO humanoid robot: Analysis of calibration techniques for robot sketch drawing

The strength of the NAO humanoid robot is discussed with several challenges in the arena of human portrait and sketch drawing. These challenges include extracting feature points from the input image, defining these points with respect to end effector, finding the inverse kinematics solution and designing a visual feedback system. This paper mainly addresses the fundamental issue of defining a relationship between the points of the image plane and NAO end effector position. This relationship enables NAO to perceive points of image plane with respect to its body coordinate system. Three different techniques based on the principles of fundamental matrix, pseudo inverse and Artificial Neural Network based regression analysis are applied to handle the calibration difficulties on NAO robot. A comprehensive study on sample points collected from NAO end effector position and corresponding image points has been made to understand the effectiveness of each technique. The degree of performance ability of each technique has been measured using time complexity, and mean square error metrics.

ロボットハンド遠隔操作のためのARによる物体提示システムの構築

Various robot hand has been developed so far. A multi-finger robot hand can perform delicate or intricate tasks. When an operator tele-operates this kinds of robot hand smoothly, it is necessary to feedback various information to operator, such as visual, or force. Therefore, we build robot hand tele-operation system with the visual feedback system, using Kinect v2, Oculus Rift DK2, and Ovrvision. By using this system, an operator can feel sense of reality. Finally, we verify the measurement accuracy of this system and how high the sense of reality.

Implementation of an in-house visual feedback system for motion management during radiation therapy.

In this Technical Note, we describe an in‐house video goggles feedback system assembled using several commercially available products. This goggle video feedback system is currently being used at University of Louisville and Mayo Clinic for both CT simulation and linac treatment delivery. The setup details, including specific recommendations, are provided, along with an alternative option for using the video goggles system.PACS number: 07.07Hj

SU‐E‐J‐196: Implementation of An In‐House Visual Feedback System for Motion Management During Radiation Therapy

Purpose:To describe an in‐house video goggle feedback system for motion management during simulation and treatment of radiation therapy patients.Methods:This video goggle system works by splitting and amplifying the video output signal directly from the Varian Real‐Time Position Management (RPM) workstation or TrueBeam imaging workstation into two signals using a Distribution Amplifier. The first signal S[1] gets reconnected back to the monitor. The second signal S[2] gets connected to the input of a Video Scaler. The S[2] signal can be scaled, cropped and panned in real time to display only the relevant information to the patient. The output signal from the Video Scaler gets connected to an HDMI Extender Transmitter via a DVI‐D to HDMI converter cable. The S[2] signal can be transported from the HDMI Extender Transmitter to the HDMI Extender Receiver located inside the treatment room via a Cat5e/6 cable. Inside the treatment room, the HDMI Extender Receiver is permanently mounted on the wall near the conduit where the Cat5e/6 cable is located. An HDMI cable is used to connect from the output of the HDMI Receiver to the video goggles.Results:This video goggle feedback system is currently being used at two institutions. At one institution, the system was just recently implemented for simulation and treatments on two breath‐hold gated patients with 8+ total fractions over a two month period. At the other institution, the system was used to treat 100+ breath‐hold gated patients on three Varian TrueBeam linacs and has been operational for twelve months. The average time to prepare the video goggle system for treatment is less than 1 minute.Conclusion:The video goggle system provides an efficient and reliable method to set up a video feedback signal for radiotherapy patients with motion management.

A new visual feedback-based magnetorheological haptic master for robot-assisted minimally invasive surgery

In this study, we developed a novel four-degrees-of-freedom haptic master using controllable magnetorheological (MR) fluid. We also integrated the haptic master with a vision device with image processing for robot-assisted minimally invasive surgery (RMIS). The proposed master can be used in RMIS as a haptic interface to provide the surgeon with a sense of touch by using both kinetic and kinesthetic information. The slave robot, which is manipulated with a proportional-integrative-derivative controller, uses a force sensor to obtain the desired forces from tissue contact, and these desired repulsive forces are then embodied through the MR haptic master. To verify the effectiveness of the haptic master, the desired force and actual force are compared in the time domain. In addition, a visual feedback system is implemented in the RMIS experiment to distinguish between the tumor and organ more clearly and provide better visibility to the operator. The hue-saturation-value color space is adopted for the image processing since it is often more intuitive than other color spaces. The image processing and haptic feedback are realized on surgery performance. In this work, tumor-cutting experiments are conducted under four different operating conditions: haptic feedback on, haptic feedback off, image processing on, and image processing off. The experimental realization shows that the performance index, which is a function of pixels, is different in the four operating conditions.

Effects of Treadmill Walking with Visual Feedback on Gait Outcomes in People Post-Stroke

Compromised gait is prevalent in people post-stroke. Gait training is one of the major components in stroke rehabilitation. Treadmill walking is often used for gait training in people post-stroke. Limited studies have examined the effects of a visual feedback system in combination with treadmill-based gait training. PURPOSE: The purpose of this study was to investigate the effects of treadmill walking with real-time visual feedback on gait outcomes in people post-stroke. METHODS: A randomized control study was used with 24 participants (age 58.7+/-11.2 years old) who were a minimum of six months post-stroke. Both groups performed 30 minutes of treadmill walking, three times a week, for eight weeks. The control group performed the training with no visual feedback (NVF). Only the treatment group received real-time visual feedback (VF). Data collection was performed before and after the eight weeks. The kinematic and spatiotemporal variables were recorded and analyzed using a motion analysis system (VICON Bonita System). Data process and analysis was performed using VICON Polygon software. RESULTS: Mixed model ANOVA showed significant group interactions in gait symmetry index of cadence, stance-swing ratio, and hip joint kinematics (all p values <.05). VF group showed greater improvements in the variables as compared to control. Within group analysis showed that VF group significantly increased gait symmetry index of cadence, stride length, stance-swing ratio and joint kinematic symmetry in the knee and hip(all p values <.05). In addition control group showed significant improvements in cadence symmetry and hip joint kinematic symmetry (all p values <.05). CONCLUSION: The findings indicate that gait training with visual feedback can be more effective in improving gait symmetry than conventional treadmill walking.

Drivers’ ability to learn eco-driving skills; effects on fuel efficient and safe driving behaviour

Whilst driving is inherently a safety–critical task, awareness of fuel-efficient driving techniques has gained popularity in both the public and commercial domains. Green driving, whether motivated by financial or environmental savings, has the potential to reduce the production of greenhouse gases by a significant amount. This paper focusses on the interaction between the driver and their vehicle – what type of eco-driving information is easy to use and learn whilst not compromising safety. A simulator study evaluated both visual and haptic eco-driving feedback systems in the context of hill driving. The ability of drivers to accurately follow the advice, as well as their propensity to prioritise it over safe driving was investigated. We found that any type of eco-driving advice improved performance and whilst continuous real-time visual feedback proved to be the most effective, this modality obviously reduces attention to the forward view and increases subjective workload. On the other hand, the haptic force system had little effect on reported workload, but was less effective that the visual system. A compromise may be a hybrid system that adapts to drivers’ performance on an on-going basis.

Passivity-based visual feedback control with dynamic compensation of mobile manipulators: Stability and [formula omitted]-gain performance analysis

This paper addresses the problem of visual dynamic control based on passivity to solve the target tracking problem of mobile manipulators with eyes-in-hand configuration in the 3D-workspace. The redundancy of the system is used for obstacles avoidance and singular configuration prevention through the system’s manipulability control. The design of the stable control system is based on its passivity properties. A robustness analysis and an L2-gain performance analysis are also presented. Finally, simulation and experimental results are reported to verify the stability and L2-gain performance of the dynamic visual feedback system.

1P2-N01 ロボットハンド遠隔操作のための把持感覚提示システムの構築

An operator cannot obtain feeling of grasping in robot hand tele-operation with motion-capture data of operator's hand, because an operator does not grasp an object actually. If an operator cannot obtain feeling of grasping, an operator may move his fingers by mistake. Therefore, we build robot hand tele-operation system with pseudo grasping sense feedback by using the haptic device and the visual feedback system. By using this system, an operator can feel as though he grasped an object with own hand, when a robot hand grasps an object in the tele-operation with motion-capture data of his hand. Finally, we test the usability of this system.

B310 Moving Horizon Estimationによる視覚フィードバックを用いた車両ロボットの目標経路追従制御(GS2 同定・推定)

In these days, motion capture cameras can achieve localization of moving objects with high accuracy. However, it has some problems, for example, it may fail to measurement due to occlusion and the quantization error. In addition, the measurement data with noise or lack of data disturbs the control performance of visual feedback systems. Thus, it is necessary to estimate states suppressing the influence of the noise and occlusion. In this study, we achieve high accuracy of state estimation using Moving Horizon Estimation (MHE) which is able to consider measurement data during the finite-time. We implement MHE with the actual experimental system of 3D static cameras and show the effectiveness for visual feedback control of MHE.

How Can Learners Learn from Experience? A Case Study in Blended Learning at Higher Education

 Abstract—E-learning is prevalent and it is changing the learning paradigm in the higher education. This results in less face-to-face contact with educators, lecturers, facilitators and tutors. Therefore capturing and utilizing experiences of learners to make it available or sharable to peers can help to create better environment for learning to improve learning outcomes and quality. Accordingly, learning especially at higher education, involves the interaction of human, technology and knowledge. In this paper, we use the scenario of a typical blended learning at a university setting to highlight the different types of learning experiences that can be harnessed and used for better learning. We also use the scenario to scaffold and formulate a novel framework of blended learning technological architecture to show how to harness learning experiences to be analyzed and possibly be used in a feedback system. We used analytics to produce our output from the analysis of LEs and the visual feedback system received favorable comments from learners.

視覚フィードバック手法による手すり荷重低減支援システムの開発

視覚フィードバック手法による手すり荷重低減支援システムの開発

Measuring Vestibular Evoked Myogenic Potential Using Two Different Procedures.

Latest developments in technology has equipped the clinician’s ability to evaluate otolithic function through VEMP testing. The present study was taken up to investigate the changes in the VEMP parameters while recording VEMP response with visual feedback system to control EMG. VEMP testing was administered on 20 participants between 20-40 years of age. The study results showed no statistically significant difference in amplitude and latency of cVEMP and oVEMP responses with and without visual feedback system. However, with visual feedback system standard deviations were observed to be reduced for both cVEMP and oVEMP responses. Hence we can conclude that using the visual feedback system to monitor the muscle contraction in otological disorders is easier and more reliable than testing without visual feedback.

Information modalities and timing of ecological driving support advices

Within this study the outcomes of two driving simulator studies are reported. In the first study, three different human–machine-interaction modalities for an ecological driving support system were compared concerning driving behaviour, workload and user acceptance parameters in order to find out whether a haptic acceleration/deceleration and gear shifting advice improved the ecological driving style additionally to a visual feedback system. Results showed that the combination of the visual and haptic modality led to the fastest reaction times and smallest deviations from the optimal acceleration and gear-shift behaviour. Yet, the results of the acceptance questionnaires revealed that the participants preferred the visual display, whereas the haptic feedback showed the best results regarding the workload scores. The second study dealt with the timing of the feedback. When should ecological coasting advices be presented in order to reach a high-user acceptance? As an outcome, the participants decelerated earlier receiving a coasting advice. However, if the advice was given too early the acceptance of the participants was low.

AUTOMATIC MICROINJECTION SYSTEM USING STEREOSCOPIC MICROSCOPE

In this paper, we describe a visual feedback system using a stereoscopic microscope that controls a micromanipulator so that a needle head may pierce a target as much length as desired. At first, we developed an image processing algorithm for the tip of needle head to touch the target. Secondarily, we developed an algorithm for prediction of the tip position of the needle head within the target. By performing a preoperation, the shape of the needle head is preserved as a reference pattern. When the needle head piercing the target, the shape of the needle head within the target is predicted by pattern matching. Thus, we developed a microinjection system that axially pierces the target. Experimental results show that the proposed system may be useful in micromanipulation such as microinjection to brain areas in neuroanatomy.

THU0343 Visual Feedback of Bilateral Bite Force Coordination to Assess Motor Control of the Mandible

BackgroundThe muscle impairment in Temporomandibular disorders (TMDs)1, frequently observed in patients with different rheumatic diseases, contribute to diminished recruitment and force tuning ability. The quantitative assessment of the motor function...

Reliability of a Novel Visual Feedback System Developed for Increasing the Efficiency of Posterior Pelvic Tilt Exercise

AbstractObjectives: This study aimed to develop and assess the reliability of a visual feedback system intended to improve the patient’s perception and the performance of posterior pelvic tilt [PPT] exercises. The feedback setup designed and constructed by the authors included a bed covered with a mat with three embedded force sensors corresponding to the lumbosacral region of the subject lying supine; a data acquisition card to collect and convert data; and two monitors, one above the subject and one on the physician’s table. Software was developed to monitor the force exerted vertically upon the force sensors during PPT to be followed both by the physician and the subject.Methods: Fifteen healthy volunteers were enrolled for a relability trial. The subjects were asked to perform five consecutive PPT with maximum effort. Each subject was evualated three times by two physicians. Intraclass correlation coefficients (ICC) were computed to determine the intrarater and interrater reliability of the maximum fo...

Controlling for out-of-plane lumbar moments during unidirectional trunk efforts: Learning and reliability issues related to trunk muscle activation estimates

To assess the electromyographic (EMG) activation of trunk muscle during exertions performed in one primary plane (sagittal, frontal, transverse), we previously proposed a protocol allowing minimizing out-of-plane efforts (coupled moments – CMs) with the use of a static dynamometer combined with a visual feedback system. The aims of this study were to go further by testing motor learning and reliability issues related to such a protocol. Three identical sessions were conducted, where maximal voluntary contractions and submaximal ramp contractions were performed in six different directions while standing in the dynamometer. Two feedback conditions were tested, the simple 1D-feedback in the primary plane and the full 3D-feedback in all planes simultaneously. Surface EMG signals were collected from back and abdominal muscles and EMG amplitude and CMs were computed during the ramp contractions. Providing a 3D feedback to minimize CMs did not improve EMG reliability or in other words, did not reduce the within-subject variability. Providing three assessment days had practically no effect (no learning) on CMs and EMG variables. Overall, the reliability of EMG was at best moderate. However, although this limits its use on an individual basis, it still allows within- and between-group comparisons for research applications.

Electromagnetic Steering of a Magnetic Cylindrical Microrobot Using Optical Feedback Closed-Loop Control

Control of small magnetic machines in viscous fluids may enable new medical applications of microrobots. Small-scale viscous environments lead to low Reynolds numbers, and although the flow is linear and steady, the magnetic actuation introduces a dynamic response that is nonlinear. We account for these nonlinearities, and the uncertainties in the dynamic and magnetic properties of the microrobot, by using time-delay estimation. The microrobot consists of a cylindrical magnet, 1 mm long and 500 µm in diameter, and is tracked using a visual feedback system. The microrobot was placed in silicone oil with a dynamic viscosity of 1 Pa.s, and followed step inputs with rise times of 0.45 s, 0.51 s, and 1.77 s, and overshoots of 37.5%, 33.3%, and 34.4% in the x, y, and z directions, respectively. In silicone oil with a viscosity of 3 Pa.s, the rise times were 1.04 s, 0.72 s, and 2.19 s, and the overshoots were 47.8%, 48.5%, and 86.8%. This demonstrates that closed-loop control of the magnetic microrobot was better in the less viscous fluid.

Cardiopulmonary performance testing using a robotics-assisted tilt table: Feasibility assessment in able-bodied subjects

Robotics-assisted tilt table technology was introduced for early rehabilitation of neurological patients. It provides cyclical stepping movement and physiological loading of the legs. The aim of the present study was to assess the feasibility of this type of device for peak cardiopulmonary performance testing using able-bodied subjects. A robotics-assisted tilt table was augmented with force sensors in the thigh cuffs and a work rate estimation algorithm. A custom visual feedback system was employed to guide the subjects' work rate and to provide real time feedback of actual work rate. Feasibility assessment focused on: (i) implementation (technical feasibility), and (ii) responsiveness (was there a measurable, high-level cardiopulmonary reaction?). For responsiveness testing, each subject carried out an incremental exercise test to the limit of functional capacity with a work rate increment of 5 W/min in female subjects and 8 W/min in males. 11 able-bodied subjects were included (9 male, 2 female; age 29.6 ± 7.1 years: mean ± SD). Resting oxygen uptake (O<formula>_{2}</formula>) was 4.6 ± 0.7 mL/min/kg and O<formula>_{2}</formula>peak was 32.4 ± 5.1 mL/min/kg; this mean O<formula>_{2}</formula>peak was 81.1% of the predicted peak value for cycle ergometry. Peak heart rate (HRpeak) was 177.5 ± 9.7 beats/min; all subjects reached at least 85% of their predicted HRpeak value. Respiratory exchange ratio (RER) at O<formula>_{2}</formula>peak was 1.02 ± 0.07. Peak work rate) was 61.3 ± 15.1 W. All subjects reported a Borg CR10 value for exertion and leg fatigue of 7 or more. The robotics-assisted tilt table is deemed feasible for peak cardiopulmonary performance testing: the approach was found to be technically implementable and substantial cardiopulmonary responses were observed. Further testing in neurologically-impaired subjects is warranted.