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Falls and associated injuries are the most serious medical problem affecting the functional independence among both White non-Hispanics and Latino older adults. Studies have shown the effectiveness of Tai Chi exercise in reducing falls... more
Falls and associated injuries are the most serious medical problem affecting the functional independence among both White non-Hispanics and Latino older adults. Studies have shown the effectiveness of Tai Chi exercise in reducing falls but have primarily focused on White non-Hispanic older adults. There is limited research that examines the effectiveness of this exercise on balance among different racial/ethnic minority older adults. This study focused on the interrelationship between functional status (balance performance) and psychosocial status (depression) before and after a 12-week Tai Chi program among Latinos in a Midwestern metropolitan city. Results indicated that at baseline, prior to the start of the Tai Chi program, participants who were more depressed had poorer functional status. Participants who had higher depression at baseline, experienced greater improvement in functional status, following the 12-week Tai Chi exercise program, compared with those who had lower levels of depression.
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The ubiquitous nature of laparoscopic surgery and the decreased training time available for surgeons are driving an increased need for effective training systems to help surgeons learn different procedures. A cost-effective and... more
The ubiquitous nature of laparoscopic surgery and the decreased training time available for surgeons are driving an increased need for effective training systems to help surgeons learn different procedures. A cost-effective and user-friendly simulator has been designed to imitate specific training tasks for laparoscopic surgery in virtual environments via image processing and computer vision. The capability of using various actual surgical instruments suited for these specific procedures gives heightened fidelity to the simulator. Image processing via matlab software provides real-time mapping of the graspers in the workspace to the virtual reality (VR) environment (vizard software). Two different tasks (peg transfer and needle passing) were designed to evaluate trainees and compare their performance with characteristics of expert surgeons. Pilot testing of the system was carried out with 11 subjects to validate the similarity of this device with an existing surgical box trainer. Task completion time and muscle activity have been used as metrics for evaluation. The decrease in completion time for all subjects suggests similarity of skills transfer for both simulators. In addition, the p-value of muscle activity showed no significant differences for most muscles in the peg transfer task when using either the VR or physical analog environment and no significant differences for about half of the muscles in the needle passing task. Based on the results, the new proposed VR simulator appears to be a viable alternative to help trainees gain laparoscopic skills.
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This single-blinded, randomized controlled study investigated the effects of practicing Tai Chi on the postural control and cognitive performance of older women while dual tasking. Community-dwelling older women (n=31) were recruited from... more
This single-blinded, randomized controlled study investigated the effects of practicing Tai Chi on the postural control and cognitive performance of older women while dual tasking. Community-dwelling older women (n=31) were recruited from community centers. They were randomized to Tai Chi group (n=15, 12-form Yang style Tai Chi training) or a control group (n=16, general interest classes) for 16 weeks. Balance was tested in single leg stance after stepping down from a step, with and without a concurrent auditory response task (auditory Stroop test). Balance was measured by total sway path and sway area of subject's center of pressure (COP). The reaction time and the correctness of the auditory Stroop test were also measured. Tai Chi subjects made fewer errors in auditory Stroop test under dual-task condition after Tai Chi training (p=0.01). They also showed significant decreases in the COP path (p<0.05) and the COP area (p<0.05) in their postural control after training in ...
Research Interests: Psychology, Complementary and Alternative Medicine, Cognition, Plant Biology, Postural Control, and 14 moreMedicine, Physical Therapy, Older Adults, Humans, Stroop effect, Female, Aged, Randomized Controlled Trial, Tai Chi, Integrative and Complementary Medicine, Postural Balance, Dual Tasking, Task Performance and Analysis, and Pharmacology and pharmaceutical sciences
This study investigated how the ergonomic factors, such as hand dominance and postural selection, influenced on surgical performance regarding the changes of muscle activity. Twenty novices performed two virtual laparoscopic surgical... more
This study investigated how the ergonomic factors, such as hand dominance and postural selection, influenced on surgical performance regarding the changes of muscle activity. Twenty novices performed two virtual laparoscopic surgical training tasks and five target muscle activities were measured. Compared with using dominant hand, surgical skills performance using non-dominant hand increased muscle activities. Muscle fatigue is more likely induced in standing position than sitting position during practice. This study suggests an emerging need to focus on hand dominance during laparoscopic surgical training to address the impact of hand discrepancy on bimanual coordination. It is also important to pay attention on postural selection during training to reduce muscle fatigue, which possibly leads to injuries.
Research Interests: Computer Science, Skeletal muscle biology, Medicine, Physical Medicine and Rehabilitation, Library and Information Studies, and 14 moreHumans, Computer Assisted Instruction, Female, Pubmed, Male, Adult, Public health systems and services research, Hand, Reproducibility of Results, Sitting, Postural Balance, Sensitivity and Specificity, Functional Laterality, and Psychomotor Performance
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The objective of this study was to compare three different surgical skills practice environments while performing a virtual laparoscopic surgical training task using a multi-degree of freedom joystick, a commercial manipulator or a... more
The objective of this study was to compare three different surgical skills practice environments while performing a virtual laparoscopic surgical training task using a multi-degree of freedom joystick, a commercial manipulator or a training box. Nine subjects performed a virtual peg transfer task and their upper extremity muscle effort and fatigue were measured. The results demonstrated a similar muscle effort and fatigue of the upper extremity among the three training environments. Subjects with medical backgrounds used significantly higher muscle effort when they performed the training task using the joystick than the manipulator, but used similar muscle effort between the joystick and the training box. This study suggests that the multi-degree of freedom joystick could provide more options to practice virtual laparoscopic surgical training tasks with muscle effort and fatigue similar to other traditional training boxes.
Research Interests: Computer Science, Medicine, Virtual Reality, Library and Information Studies, Humans, and 13 moreComputer Simulation, Female, Pubmed, Male, Electromyography, Computer User Interface Design, Adult, Public health systems and services research, Clinical Competence, Upper Extremity, Joystick, Equipment Design, and Laparoscopy
The objective of this study was to compare three different surgical skills practice environments while performing a virtual laparoscopic surgical training task using a multi-degree of freedom joystick, a commercial manipulator or a... more
The objective of this study was to compare three different surgical skills practice environments while performing a virtual laparoscopic surgical training task using a multi-degree of freedom joystick, a commercial manipulator or a training box. Nine subjects performed a virtual peg transfer task and their upper extremity muscle effort and fatigue were measured. The results demonstrated a similar muscle effort and fatigue of the upper extremity among the three training environments. Subjects with medical backgrounds used significantly higher muscle effort when they performed the training task using the joystick than the manipulator, but used similar muscle effort between the joystick and the training box. This study suggests that the multi-degree of freedom joystick could provide more options to practice virtual laparoscopic surgical training tasks with muscle effort and fatigue similar to other traditional training boxes.
Research Interests: Computer Science, Medicine, Virtual Reality, Library and Information Studies, Humans, and 13 moreComputer Simulation, Female, Pubmed, Male, Electromyography, Computer User Interface Design, Adult, Public health systems and services research, Clinical Competence, Upper Extremity, Joystick, Equipment Design, and Laparoscopy
Research Interests: Robotics, Computer Science, Medical Education, Treatment Outcome, Robotic Surgery, and 13 moreMedicine, da Vinci Robotic Surgical System, Humans, ROBOT, Graduate medical education, Clinical Sciences, Time Factors, Surgical Robot Market, Task Performance and Analysis, Biomechanical Phenomena, Medical, Motor activity, and Smoothness
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The objective of this study was to determine the muscle activities of upper extremities while performing fundamental surgical training tasks using a virtual simulator. Six subjects performed virtual cutting tasks and their muscle... more
The objective of this study was to determine the muscle activities of upper extremities while performing fundamental surgical training tasks using a virtual simulator. Six subjects performed virtual cutting tasks and their muscle activities of upper extremities were measured. The results demonstrated a significant increase in muscle activities in both proximal and distal upper extremities, which are the common areas of occurrence of injury after prolonged practice. This study suggests that the upper trapezius and the extensor digitorum are essential prime movers to perform surgical training tasks. These muscles should be monitored for performance assessment in future studies.
Research Interests: Computer Science, Skeletal muscle biology, Medicine, Virtual Reality, Library and Information Studies, and 11 moreHumans, Computer Simulation, Female, Pubmed, Nebraska, Male, Electromyography, Computer User Interface Design, Skeletal Muscle, Public health systems and services research, and Upper Extremity
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Multiple obstacle avoidance induces a higher potential of falls among older adults. This study attempted to add other important measurements by investigating the pressure-related gait parameters when stepping over multiple obstacles on a... more
Multiple obstacle avoidance induces a higher potential of falls among older adults. This study attempted to add other important measurements by investigating the pressure-related gait parameters when stepping over multiple obstacles on a portable pressure-sensing walkway. Twenty-six young and 26 older participants were recruited in this study. A portable pressure-sensing Zeno walkway and cyclogram intersection point analysis method was introduced to collect both spatial–temporal and pressure-related gait parameters. Older adults significantly reduced foot integrated pressure of the leading leg when stepping over the second obstacle compared with young adults (p = .0078). A significantly larger cyclogram intersection point shift in medial–lateral direction was found in older adults than in young adults (p = .024) when stepping over the second obstacle, especially in the lateral direction. The results of this study showed that a pressure-sensing walking combined with cyclogram intersection point method could detect foot pressure distribution differences caused by aging.
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Research Interests: Robotics, Computer Science, Motor Learning, Augmented Reality, Medicine, and 10 morePhysical Medicine and Rehabilitation, Computer assisted orthopaedic surgery, Continuing Medical Education, Humans, Young Adult, Feedback, Visual Feedback, Adult, Clinical Competence, and Task Performance and Analysis
Increased fall risk in older adults and clinical populations is linked with increased amount and altered temporal structure of step width variability. One approach to rehabilitation seeks to reduce fall risk in older adults by reducing... more
Increased fall risk in older adults and clinical populations is linked with increased amount and altered temporal structure of step width variability. One approach to rehabilitation seeks to reduce fall risk in older adults by reducing the amount of step width variability and restoring the temporal structure characteristic of healthy young adults. The success of such a program depends on our ability to modulate step width variability effectively. To this end, we investigated how manipulation of the visual walking space in a virtual environment could modulate the amount and temporal structure of step width variability. Nine healthy adults performed self-paced treadmill walking in a virtual alley in a fixed-width Control condition (1.91 m) and two conditions in which the alley’s width oscillated sinusoidally at 0.03 Hz: between 0.38 and 1.14 m and 0.38–2.67 m in Narrow and Wide conditions, respectively. The step width time series from each condition was evaluated using: (i) the standard deviation to identify changes in the amount of variability and (ii) the fractal scaling exponent estimated using detrended fluctuation analysis (DFA) to identify changes in the temporal structure of variability in terms of persistence in fluctuations. The Wide condition neither affected the standard deviation nor the fractal scaling exponent of step width time series. The Narrow condition did not affect the standard deviation of step width time series compared to the Control condition but significantly increased its fractal scaling exponent compared to the Control and Wide conditions, suggestive of more persistent fluctuations characteristic of a healthy gait. These results show that virtual reality based rehabilitative intervention can modulate step width variability to potentially reduce fall risk in older adults and clinical populations.
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Evaluation of the learning curve for robotic surgery has shown reduced errors and decreased task completion and training times compared with regular laparoscopic surgery. However, most training evaluations of robotic surgery have only... more
Evaluation of the learning curve for robotic surgery has shown reduced errors and decreased task completion and training times compared with regular laparoscopic surgery. However, most training evaluations of robotic surgery have only addressed short-term retention after the completion of training. Our goal was to investigate the amount of surgical skills retained after 3 months of training with the da Vinci™ Surgical System. Seven medical students without any surgical experience were recruited. Participants were trained with a 4-day training program of robotic surgical skills and underwent a series of retention tests at 1 day, 1 week, 1 month, and 3 months post-training. Data analysis included time to task completion, speed, distance traveled, and movement curvature by the instrument tip. Performance of the participants was graded using the modified Objective Structured Assessment of Technical Skills (OSATS) for robotic surgery. Participants filled out a survey after each training session by answering a set of questions. Time to task completion and the movement curvature was decreased from pre- to post-training and the performance was retained at all the corresponding retention periods: 1 day, 1 week, 1 month, and 3 months. The modified OSATS showed improvement from pre-test to post-test and this improvement was maintained during all the retention periods. Participants increased in self-confidence and mastery in performing robotic surgical tasks after training. Our novel comprehensive training program improved robot-assisted surgical performance and learning. All trainees retained their fundamental surgical skills for 3 months after receiving the training program.
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Research Interests: Psychology, Perception, Biomechanics, Motor Learning, Motion perception, and 15 moreMedicine, Physical Medicine and Rehabilitation, Gait, Humans, Female, Male, Electromyography, Computer User Interface Design, Self Concept, Adult, Cadence, Motor Behavior, Muscle Activity, Extremities, and photic stimulation
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Background Women surgeons may experience more ergonomic challenges while performing surgery. We aimed to assess ergonomics between men and women surgeons. Methods Laparoscopic surgeons from a single institution were enrolled. Demographics... more
Background Women surgeons may experience more ergonomic challenges while performing surgery. We aimed to assess ergonomics between men and women surgeons. Methods Laparoscopic surgeons from a single institution were enrolled. Demographics and intraoperative data were collected. Muscle groups were evaluated objectively using surface electromyography (EMG; TrignoTM, Delsys, Inc., Natick, MA), and comprised upper trapezius (UT), anterior deltoid, flexor carpi radialis (FCR), and extensor digitorum (ED). Comparisons were made between women (W) and men (M) for each muscle group, assessing maximal voluntary contraction (MVC) and median frequency (MDF). The Piper Fatigue Scale-12 (PFS-12) was used to assess self-perceived fatigue. Statistical analyses were performed using SPSS v26.0, α = 0.05. Results 18 surgeries were recorded (W:8, M:10). Women had higher activation of UT (32% vs 23%, p < 0.001), FCR (33% vs 16%, p < 0.001), and ED (13% vs 10%, p < 0.001), and increased effort of ED (90.4 ± 18.13 Hz vs 99.1 ± 17.82 Hz). Comparisons were made between W and M for each muscle group, assessing MVC and MDF. Conclusions After controlling for surgeon’s height and duration of surgery, an increase in muscle activation was seen for women laparoscopic surgeons. Since poor ergonomics could be a major cause of work-related injuries, we must understand differences in ergonomics between men and women and evaluate which factors impact these variations.
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This study aimed to investigate the effect of plantar vibrations on obstacle negotiation. Nineteen healthy young adults were randomly instructed to step over an obstacle without, with sub-, or with supra-threshold vibration via three... more
This study aimed to investigate the effect of plantar vibrations on obstacle negotiation. Nineteen healthy young adults were randomly instructed to step over an obstacle without, with sub-, or with supra-threshold vibration via three vibrotactile tactors. The spatial-temporal gait parameters, the lower extremity joint angles, the foot integrated pressure, and the foot integrated area were recorded. Results indicated that sub-threshold and supra-threshold vibration increased the toe clearance of both leading leg and trailing legs. Additionally, the vibrations also increased the foot integrate pressure and the hip angels during toe clearance on both sides. These findings were devoted to the further understanding of the processes underlying motor control when plantar sensation was manipulated. These observations could further be used for developing a rehabilitation protocol for patients who suffered the loss or deterioration of the somatosensory system.
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Feasibility and effectiveness of minimally invasive surgery have made the use of robotic surgical system a rising prevalence with a wide range of applications. However, as a remarkable result, how to adroitly and precisely manipulate the... more
Feasibility and effectiveness of minimally invasive surgery have made the use of robotic surgical system a rising prevalence with a wide range of applications. However, as a remarkable result, how to adroitly and precisely manipulate the sophisticated robotic surgery instruments is of fundamental importance to new surgeons. In order to provide the robotic surgical skill training for surgeons, we designed