Visual Feedback System Research Articles

High Ion-Conducting PVA Nanocomposite Hydrogel-Based Wearable Piezoelectric and Triboelectric Sensors for Harsh Environments.

Traditional hydrogel-based wearable sensors with flexibility, biocompatibility, and mechanical compliance exhibit potential applications in flexible wearable electronics. However, the low sensitivity and poor environmental resistance of traditional hydrogels severely limit their practical application. Herein, high-ion-conducting poly(vinyl alcohol) (PVA) nanocomposite hydrogels were fabricated and applied for harsh environments. MXene ion-conducting microchannels and poly(sodium 4-styrenesulfonate) ion sources contributed to the directional transport of abundant free ions in the hydrogel, which significantly improved the sensitivity and mechanical-electric conversion of the nanocomposite hydrogel-based piezoelectric and triboelectric sensors. More importantly, the glycerol as an antifreezing agent enabled the hydrogel-based sensors to function in harsh environments. Therefore, the nanocomposite hydrogel exhibited high gauge factor (GF) at -20 °C (GF = 3.37) and 60 °C (GF = 3.62), enabling the hydrogel-based sensor to distinguish different writing letters and sounding words. Meanwhile, the hydrogel-based piezoelectric and triboelectric generators showed excellent mechanical-electric conversion performance regardless of low- (-20 °C) or high- (60 °C) temperature environments, which can be applied as a visual feedback system for information transmission without external power sources. This work provides self-powered nanocomposite hydrogel-based sensors that exhibit potential applications in flexible wearable electronics under harsh environmental conditions.

Explore the effect of pressure and time of compression on the risk of intraoperatively acquired pressure injury based on theoretical framework: A prospective study.

Surgery is a high risk factor for the occurrence of pressure injury (PI). On the basis of theoretical research, pressure and duration of pressure are key factors affecting PI. Pressure is affected by the individual pressure redistribution capacity. So our study aims to explore how the surgery time and pressure intensity affect the occurrence of PI and what are the risk factors. A prospective study. A total of 250 patients who underwent elective surgery in a grade-A general hospital from November 2021 to February 2023 were selected and divided into a group of 77 patients with IAPI (intraoperatively acquired pressure injury) and a group of 173 patients with no IAPI. Visual pressure inductive feedback system and body composition analysis technology were used to record the local pressure value and change of patients before and after anaesthesia. Relevant data of the patients were collected to explore the influencing factors. The maximum pressure and average pressure at the pressure site of the same patient changed before and after anaesthesia, and the pressure after anaesthesia was significantly higher than that before anaesthesia. There was no statistical difference in the average pressure after anaesthesia (p > 0.05), but the maximum pressure in the IAPI group was higher than that in the non-occurrence group (p < 0.05). The average pressure multiplied by the operation time in IAPI group is significantly higher than that in the non-IAPI group (p < 0.01). Multiple linear regression analysis (stepwise regression) showed that fat-free weight, age, waist circumference, body mass index (BMI) and gender were taken as independent variables into the regression model, affecting the maximum pressure. In addition, operation time ≥4 h may be a high risk factor for IAPI. In future studies, more objective research tools can be applied to improve the accuracy of predicting the risk of IAPI. In addition to gender and BMI, follow-up studies may consider including measures such as waist circumference and fat-free body weight in IAPI risk assessment to guide the clinical nursing work more scientifically.

Usability of a visual feedback system to assess and improve movement disorders related to neck pain: Perceptions of physical therapists and patients

A prototype visual feedback system has been developed to assess and improve movement disorders related to neck pain. The aim of this study was to assess the usability of the prototype in a rehabilitation setting. Twelve physical therapists integrated the device into their regular therapy programs for 24 neck pain patients with movement disorders. Each patient performed three individual therapy sessions with the device under physical therapist supervision. Usability was assessed by the physical therapists and patients using therapy diaries, the System Usability Scale, and focus group or personal interviews.Based on an overall usability rating of marginally acceptable, the visual feedback system was generally found to be a device with the potential to assess and train neck pain patients but needs improvement.To become a useful adjunct to regular physical therapy, improvements in the hardware and software, and further system developments are required.

Validation of a hand hygiene visual feedback system to improve compliance with drying time of alcohol-based hand rub in a neonatal intensive care unit: the Incubator Traffic Light system

IntroductionCompliance with the recommended 30-second drying time of alcohol-based hand rub (ABHR) is often suboptimal. To increase hand hygiene compliance at a Neonatal Intensive Care Unit (NICU), we installed an Incubator Traffic Light (ITL) system which shows ‘green light’ to open incubator doors after the recommended drying time. This study aims to measure the impact of this visual feedback system on NICU healthcare professionals’ compliance with the recommended ABHR drying time. MethodsTen Traffic Light systems were installed on incubators at a NICU, five of which provided visual feedback, and five, serving as a control group, did not provide visual feedback. During a two-month period, the systems measured drying time between the moment of dispensing ABHR and opening the incubator’s doors. We compared the drying times of the incubators with and without feedback. ResultsOf the 6422 recorded HH events, 658 were valid for data analysis. Compliance with correct drying time reached 75% (n=397/526) for incubators equipped with visual feedback versus 36% (n= 48/132, p< 0.0001) for incubators lacking this feature. ConclusionsThe Incubator Traffic Light improves compliance with the recommended 30 sec ABHR drying time in a NICU setting.

Designing and Manufacturing an Affordable and Easy to Use Visual Bio Feedback Device to Fix Forward Head Posture: A Pilot Study Involving Female Students

Forward Head Posture (FHP) is when the head leans forward due to factors such as heavy backpacks or poor computer ergonomics. FHP can lead to neck strain and discomfort as well as potential long-term issues such as arthritis. Treatment options include specialized exercises, orthopedic devices, manual therapy, physical exercises, and visual feedback techniques, along with guidance from specialists in physical medicine and rehabilitation. In this study, a visual feedback-based approach was used to address FHP in female students. The study spanned ten days and included a visual feedback group and a control group. The results showed significant improvements in maximum head angle deviation in the visual feedback group compared to the control group; however, there was no significant change in the DFA number, indicating stability in policy control by the central nervous system. The study demonstrated that visual feedback sessions led to immediate benefits, with participants progressively acquiring skills involving the maintenance of proper head positioning. The test results indicated that the neck angle decreased to less than 15 degrees, indicating a return to a normal state. The versatility of the developed affordable and easy-to-use device and the potential for using smartphone motion sensors for similar visual feedback systems are discussed in this paper as well. The study suggests the promising potential of visual feedback in healthcare, including remote monitoring and smartphone-based solutions.

The Development of a Rehabilitation Orthotic Walker with a Real-time Visual Feedback System of the Gait Symmetry

Patients who suffer from a disability or face temporary walking difficulty due to accidents or medical conditions have to go through rehabilitation treatment, which requires them to use an orthotic walking assistive device such as a walker, cane, or crutches. It is estimated that there are more than 7.4 million people in the world who depend on walkers to assist them in their walking either due to a disability, old age, or as a part of their rehabilitation following accidents or medical conditions. The use of orthotic assistive devices may last for several weeks or months and encourage patients to keep the weight off the injured or weak limb and exert more force on the healthy limb. Such prolonged use of walking assistive devices and heavy reliance on healthy lower limbs may cause negative gait disorders for patients. Negative gait disorders are due to unbalanced gait because of the lack of continuous feedback to patients about their gait. Physical therapist feedback to patients is limited to their physical presence with patients; hence, it is not practical to give the patient corrective feedback about their gait with every walking step. Hence, to overcome this pitfall, a visual feedback system of the gait symmetry, which could be installed on any traditional rehabilitation orthotic walker, was designed, developed, and proven. The visual feedback system was 3D modeled utilizing SolidWorks 2021, and parts were 3D printed utilizing the Original Prusa i3 MK3S+ 3D printer. This real-time visual feedback system relies on load cells installed in the tips of the orthotic walker legs to measure the force and weight being exerted on each side of the orthotic walker. The visual feedback system was tested to give the patients visual feedback, encouraging them to correct their unbalanced gait by shifting their weight bearing on either of their two lower limbs. This novel and innovative system mitigates the negative effects of the traditional orthotic walker on the overall gait and helps to mitigate negative gait disorders in patients.

Development of a real-time RGB-D visual feedback-assisted pulmonary rehabilitation system

BackgroundFollowing surgery, perioperative pulmonary rehabilitation (PR) is important for patients with early-stage lung cancer. However, current inpatient programs are often limited in time and space, and outpatient settings have access barriers. Therefore, we aimed to develop a background-free, zero-contact thoracoabdominal movement-tracking model that is easily set up and incorporated into a pre-existing PR program or extended to home-based rehabilitation and remote monitoring. We validated its effectiveness in providing preclinical real-time RGB-D (colour-depth camera) visual feedback. MethodsTwelve healthy volunteers performed deep breathing exercises following audio instruction for three cycles, followed by audio instruction and real-time visual feedback for another three cycles. In the visual feedback system, we used a RealSense™ D415 camera to capture RGB and depth images for human pose-estimation with Google MediaPipe. Target-tracking regions were defined based on the relative position of detected joints. The processed depth information of the tracking regions was visualised on a screen as a motion bar to provide real-time visual feedback of breathing intensity. Pulmonary function was simultaneously recorded using spirometric measurements, and changes in pulmonary volume were derived from respiratory airflow signals. ResultsOur movement-tracking model showed a very strong correlation (r = 0.90 ± 0.05) between thoracic motion signals and spirometric volume, and a strong correlation (r = 0.73 ± 0.22) between abdominal signals and spirometric volume. Displacement of the chest wall was enhanced by RGB-D visual feedback (23 vs 20 mm, P = 0.034), and accompanied by an increased lung volume (2.58 vs 2.30 L, P = 0.003). ConclusionWe developed an easily implemented thoracoabdominal movement-tracking model and reported the positive impact of real-time RGB-D visual feedback on self-promoted external chest wall expansion, accompanied by increased internal lung volumes. This system can be extended to home-based PR.

Robotic system for nasopharyngeal swab sampling based on remote center of motion mechanism.

In this study, a robotic system is proposed for nasopharyngeal (NP) swab sampling with high safety and efficiency. Most existing swab-sampling robots have more than six degrees of freedom (DOFs). However, not all six DOFs are necessarily required for NP swab sampling. A high number of DOFs can cause safety problems, such as collisions between the robot and patient. We developed a new type of robot with four DOFs for NP swab sampling that consists of a two DOFs remote center of motion (RCM) mechanism, a two DOFs insertion mechanism, and a nostril support unit. With the nostril support unit, the robot no longer needs to adjust the insertion position of the swab. The proposed robot enables the insertion orientation and depth to be adjusted according to different postures or facial shapes of the subject. For intuitive and precise remote control of the robot, a dedicated master device for the RCM and a visual feedback system were developed. The effectiveness of the robotic system was demonstrated by repeatability, RCM accuracy, tracking accuracy, and in vitro phantom experiments. The average tracking error between the master device and the robot was less than 2mm. The contact force exerted on the swab prior to reaching the nasopharynx was less than 0.04 N, irrespective of the phantom's pose. This study confirmed that the RCM-based robotic system is effective and safe for NP swab sampling while using minimal DOFs.

‘Um, so like, is this how I speak?’: design implications for automated visual feedback systems on speech

ABSTRACT At a time when diverse forms of automated visual feedback systems on speech are introduced to the Human–Computer Interaction (HCI) community, our research investigates the possible design spaces and design implications to consider when creating them. We utilised a Wizard of Oz prototype that recognises fillers during speech and sends out real-time feedback in the form of a flickering screen and a post-report with graphic charts. We let 27 participants use this prototype and interviewed them about their general experience of using such systems. Based on thematic analysis, we propose eight design implications to consider when designing an automated visual feedback system on speech. Additionally, we discuss the possible future for automated visual feedback systems on speech where they collaborate with fields such as personal informatics (quantified self), self-determination theory (SDT) and motivation, and other socio-ethnic areas

Mobility Rehab visual feedback system for gait rehabilitation in older adults

BackgroundGait and balance impairments are among the main causes of falls in older adults. The feasibility and effectiveness of adding sensor-based feedback to physical therapy (PT) in an outpatient PT setting is unknown. We evaluated the feasibility and effectiveness of PT intervention combined with a therapist-assisted visual feedback system, called Mobility Rehab, (PT + MR) in older adults.MethodsTwenty-eight older adults with and without neurological diseases were assigned either PT + MR (n = 22) or PT alone (n = 6). Both groups performed 8 sessions (individualized) of 45 min long (30 min for gait training and 15 min for endurance, strength, and balance exercises) in an outpatient clinic. Mobility Rehab uses unobtrusive, inertial sensors on both wrists and feet, and at the sternum level with real-time algorithms to provide real-time feedback on five gait metrics (step duration, stride length, elevation at mid-swing, arm swing range-of-motion [ROM], and trunk coronal ROM), which are displayed on a tablet. The primary outcome was the Activities-specific Balance Confidence scale (ABC). The secondary outcome was gait speed measured with wearable inertial sensors during 2 min of walking.ResultsThere were no between-group differences at baseline for any variable (P > 0.05). Neither PT + MR nor PT alone showed significant changes on the ABC scores. PT + MR, but not PT alone, showed significant improvements in gait speed and arm swing ROM. The system was evaluated as ‘easy to use’ by the PT.ConclusionsOur preliminary results show that PT + MR improves gait speed in older adults with and without neurological diseases in an outpatient clinic.Clinical Trial Registrationwww.ClinicalTrials.gov, identifier: NCT03869879.

Multimodal feedback systems for smart laser osteotomy: Depth control and tissue differentiation.

The study aimed to improve the safety and accuracy of laser osteotomy (bone surgery) by integrating optical feedback systems with an Er:YAG laser. Optical feedback consists of a real-time visual feedback system that monitors and controls the depth of laser-induced cuts and a tissue sensor differentiating tissue types based on their chemical composition. The developed multimodal feedback systems demonstrated the potential to enhance the safety and accuracy of laser surgery. The proposed method utilizes a laser-induced breakdown spectroscopy (LIBS) system and long-range Bessel-like beam optical coherence tomography (OCT) for tissue-specific laser surgery. The LIBS system detects tissue types by analyzing the plasma generated on the tissue by a nanosecond Nd:YAG laser, while OCT provides real-time monitoring and control of the laser-induced cut depth. The OCT system operates at a wavelength of 1288 ± 30 nm and has an A-scan rate of 104.17 kHz, enabling accurate depth control. Optical shutters are used to facilitate the integration of these multimodal feedback systems. The proposed system was tested on five specimens of pig femur bone to evaluate its functionality. Tissue differentiation and visual depth feedback were used to achieve high precision both on the surface and in-depth. The results showed successful real-time tissue differentiation and visualization without any visible thermal damage or carbonization. The accuracy of the tissue differentiation was evaluated, with a mean absolute error of 330.4 μm and a standard deviation of ±248.9 μm, indicating that bone ablation was typically stopped before reaching the bone marrow. The depth control of the laser cut had a mean accuracy of 65.9 μm with a standard deviation of ±45 μm, demonstrating the system's ability to achieve the pre-planned cutting depth. The integrated approach of combining an ablative laser, visual feedback (OCT), and tissue sensor (LIBS) has significant potential for enhancing minimally invasive surgery and warrants further investigation and development.

Deep Neural Network-Based Visual Feedback System for Nasopharyngeal Swab Sampling.

During the 2019 coronavirus disease pandemic, robotic-based systems for swab sampling were developed to reduce burdens on healthcare workers and their risk of infection. Teleoperated sampling systems are especially appreciated as they fundamentally prevent contact with suspected COVID-19 patients. However, the limited field of view of the installed cameras prevents the operator from recognizing the position and deformation of the swab inserted into the nasal cavity, which highly decreases the operating performance. To overcome this limitation, this study proposes a visual feedback system that monitors and reconstructs the shape of an NP swab using augmented reality (AR). The sampling device contained three load cells and measured the interaction force applied to the swab, while the shape information was captured using a motion-tracking program. These datasets were used to train a one-dimensional convolution neural network (1DCNN) model, which estimated the coordinates of three feature points of the swab in 2D X-Y plane. Based on these points, the virtual shape of the swab, reflecting the curvature of the actual one, was reconstructed and overlaid on the visual display. The accuracy of the 1DCNN model was evaluated on a 2D plane under ten different bending conditions. The results demonstrate that the x-values of the predicted points show errors of under 0.590 mm from P0, while those of P1 and P2 show a biased error of about -1.5 mm with constant standard deviations. For the y-values, the error of all feature points under positive bending is uniformly estimated with under 1 mm of difference, when the error under negative bending increases depending on the amount of deformation. Finally, experiments using a collaborative robot validate its ability to visualize the actual swab's position and deformation on the camera image of 2D and 3D phantoms.

Visual servoing-based pneumatic hair transplantation mechanism for robotic FUE surgery

Hair transplantation surgery is an effective solution for hair loss problems, among which follicle unit extraction (FUE) surgery is more widely used and favored. At present, most hair transplantation surgeries still rely heavily on manual operation by doctors and very few hair transplantation robots with complex structures have been introduced. This paper proposes a pneumatic hair transplantation mechanism for FUE surgery, equipped with a camera, capable of automatically performing both hair implantation and extraction with airflow. This pneumatic method eliminates the complex needle structure, has the function of temporarily storing the follicles inside the needle, thus facilitating the automation of transferring follicles from extraction to implantation. Then a visual feedback system is proposed to accurately position the follicles during the transplantation. The experimental results show that average distance deviation between the actual and target positions is 0.6128 mm and the average deviation of hair implantation depth is 1.7176 mm, which verify the feasibility of the proposed system.

Designing Effective Instructional Feedback Using a Diagnostic and Visualization System: Evidence from a High School Biology Class

Although instructional feedback plays an essential role in regulating learning and improving performance, few studies have systematically investigated the needs of teachers and students for instructional feedback systems or developed designs and experiments, especially at the high school level. To address this research need, the present study investigated the needs of selected students and teachers in a high school in Hubei Province, China, and designed and developed a diagnostic visual feedback system for an experimental study with 125 students from a 10th-grade biology class in the same high school. The results showed that this diagnostic visual feedback report improved student performance (ES = 0.37) and that functions such as misconception location, knowledge diagnosis, and knowledge alert were well received by students. These findings have multiple implications for facilitating the design and development of diagnostic visual feedback systems.

Visual-haptic feedback for ROV subsea navigation control

Subsea engineering operations, including subsea inspection, installation and maintenance, heavily rely on the seamless interaction between remotely operated vehicles (ROV) and human operators. Subsea ROV control has always been a great challenge to human operators due to the dynamics of the subsea environment such as uncertainty of turbulence, affected visibility and interference with subsea ecosystems. Compared to engineering work on the ground, subsea engineering tasks are usually finished in a limited vision field with drift and localization problems. However, the traditional ROV feedback system, the live video streaming, cannot provide direct and intuitive perceptions of remote ROV workspace as well as a clear indication of the workspace uncertainties. Therefore, this research proposes a Virtual Reality augmented visual feedback system with haptic simulators to generate immersive, intuitive and effective feedback for human operators. The system can generate visual and haptic feedback as indications of flow conditions based on sensory data. A human subject experiment was performed to verify the effectiveness of this system. The result indicated that this system could significantly assist human operators in precepting the flow conditions in the ROV workspace in a more immersive and intuitive way.

Effect of Visual Feedback on Behavioral Control and Functional Activity During Bilateral Hand Movement.

Previous researches state vision as a vital source of information for movement control and more precisely for accurate hand movement. Further, fine bimanual motor activity may be associated with various oscillatory activities within distinct brain areas and inter-hemispheric interactions. However, neural coordination among the distinct brain areas responsible to enhance motor accuracy is still not adequate. In the current study, we investigated task-dependent modulation by simultaneously measuring high time resolution electroencephalogram (EEG), electromyogram (EMG) and force along with bi-manual and unimanual motor tasks. The errors were controlled using visual feedback. To complete the unimanual tasks, the participant was asked to grip the strain gauge using the index finger and thumb of the right hand thereby exerting force on the connected visual feedback system. Whereas the bi-manual task involved finger abduction of the left index finger in two contractions along with visual feedback system and at the same time the right hand gripped using definite force on two conditions that whether visual feedback existed or not for the right hand. Primarily, the existence of visual feedback for the right hand significantly decreased brain network global and local efficiency in theta and alpha bands when compared with the elimination of visual feedback using twenty participants. Brain network activity in theta and alpha bands coordinates to facilitate fine hand movement. The findings may provide new neurological insight on virtual reality auxiliary equipment and participants with neurological disorders that cause movement errors requiring accurate motor training. The current study investigates task-dependent modulation by simultaneously measuring high time resolution electroencephalogram, electromyogram and force along with bi-manual and unimanual motor tasks. The findings show that visual feedback for right hand decreases the force root mean square error of right hand. Visual feedback for right hand decreases local and global efficiency of brain network in theta and alpha bands.

Development of a Visual Feedback System Using HMD for Kinesthetic Illusion Control Induced by Tendon Vibration Stimulation

Development of a Visual Feedback System Using HMD for Kinesthetic Illusion Control Induced by Tendon Vibration Stimulation

Development and Evaluation of a Portable Visual Feedback System for Vocal Training through Tube Phonation

Development and Evaluation of a Portable Visual Feedback System for Vocal Training through Tube Phonation

Modeling and identification of rate-dependent and asymmetric hysteresis of soft bending pneumatic actuator based on evolutionary firefly algorithm

Soft-bending pneumatic actuators (SBPA) have shown great potential in various applications owing to their intrinsic compliance. However, motion control is still challenging because of the complicated hysteresis of the elastic material and pneumatic system, which unlike the general hysteresis found in the rigid body mechanism, is rate-dependent and asymmetric. A precise hysteresis model is crucial for improving the performance of SBPA. This study proposed a rate-dependent modified generalized Prandtl–Ishlinskii (RMGPI) model for a vulcanized silicone rubber-based fast pneu-net soft bending pneumatic actuator (fp-SBPA) to describe complicated hysteresis characteristics. A visual feedback system obtained the bending angle in real time. With the increase in the number of operators, the identification of the proposed model parameters became more complicated and time-consuming; thus, an evolutionary firefly algorithm (EFA) was developed to improve identification efficiency. A series of experiments and comparison studies were conducted to verify the effectiveness of the proposed model and identification method.

Portable High-Speed Optical Gaze Controller with Vision Chip

It is important to miniaturize robot systems while maintaining advantages such as high responsiveness and functionality for human-machine interactions and for achieving integration with other robotic systems such as drones. In this research, we focused on the miniaturization of a high-speed visual feedback system, and developed a “portable saccade mirror,” which is a system that can realize active target tracking using 1000 Hz image capturing, processing, and feedback actuation with only 3 ms latency in a handheld device. By using a three-dimensionally-stacked vision chip, the proposed system achieved high speed, low latency, low power consumption and compact size, and therefore, can be considered as a good example of a miniaturized high-speed visual feedback system. In this study, we evaluated the performance of the proposed system in comparison with the conventional optical gaze controller, and demonstrated some applications, such as tracking field scope and panorama target scanning.