Oculometric measures as a tool for assessment of clinical symptoms and severity of Parkinson's disease.

Abnormalities of oculometric measures (OM) are widely described in people with Parkinson's disease (PD). However, knowledge of correlations between abnormal OM, disease severity and clinical assessment in PD patients is still lacking. To evaluate these correlations, PD patients (215 patients, mean age 69 ± 9.1 years, 79 females) with severe (H&Y > 3) and mild to moderate (H&Y ≤ 2) disease, and 215 age-matched healthy subjects were enrolled. All patients were evaluated using MDS-UPDRS and an oculometric test using computer vision and deep learning algorithms. Comparisons of OM between groups and correlations between OM and MDS-UPDRS scores were calculated. Saccadic latency (ms) was prolonged in patients with severe compared with mild to moderate disease (pro-saccades: 267 ± 69 vs. 238 ± 53, p = 0.0011; anti-saccades: 386 ± 119 vs. 352 ± 106, p = 0.0393) and in patients with mild to moderate disease versus healthy subjects (pro-saccades: 238 ± 53 vs. 220 ± 45, p = 0.0003; anti-saccades: 352 ± 106 vs. 289 ± 71, p < 0.0001). Error rate (%) was higher among patients with severe (64.06 ± 23.08) versus mild to moderate disease (49.84 ± 24.81, p = 0.0001), and versus healthy subjects (49.84 ± 24.81 vs. 28.31 ± 21.72, p = 0.00001). Response accuracy (%) was lower for patients with severe (75.66 ± 13.11) versus mild to moderate disease (79.66 ± 13.56, p = 0.0462), and versus healthy subjects (79.66 ± 13.56 vs. 90.27 ± 8.79, p < 0.0001). Pro- and anti-saccadic latency, error rate and accuracy were correlated with MDS-UPDRS scores (r = 0.32, 0.28, 0.36 and -0.30, respectively, p < 0.0001) and similar correlations were found with its axial subscore (R = 0.38, 0.29, 0.44, and -0.30, respectively, p < 0.0001). Several OM were different in patients under levodopa treatment. OM worsened as PD severity increases, and were correlated with MDS-UPDRS scores. Using OM can be implemented for PD patients' assessment as a tool to follow disease progression.

Myoelectric Prosthesis Users Improve Performance Time and Accuracy Using Vibrotactile Feedback When Visual Feedback Is Disturbed.

OBJECTIVE: To evaluate the effects of adding vibrotactile feedback (VTF) in myoelectric prosthesis users during performance of a functional task when visual feedback is disturbed. DESIGN: A repeated-measures design with a counter-balanced order of 3 conditions. SETTING: Laboratory setting. PARTICIPANTS: Transradial amputees using a myoelectric prosthesis with normal or corrected eyesight (N=12, median age 65±13y). Exclusion criteria were orthopedic or neurologic problems. INTERVENTIONS: All participants performed the modified Box and Blocks Test, grasping and manipulating 16 blocks over a partition using their myoelectric prosthesis. This was performed 3 times: in full light, in a dark room without VTF, and in a dark room with VTF. MAIN OUTCOME MEASURES: Performance time, that is, the time needed to transfer 1 block, and accuracy during performance, measured by number of empty grips, empty transitions with no block and block drops from the hand. RESULTS: Significant differences were found in all outcome measures when VTF was added, with improved performance time (4.2 vs 5.3s) and a reduced number of grasping errors (3.0 vs 6.5 empty grips, 1.5 vs 4 empty transitions, 2.0 vs 4.5 block drops). CONCLUSIONS: Adding VTF to myoelectric prosthesis users has positive effects on performance time and accuracy when visual feedback is disturbed.

Evaluation of the effects of adding vibrotactile feedback to myoelectric prosthesis users on performance and visual attention in a dual-task paradigm.

OBJECTIVE: To evaluate the effects of adding vibrotactile feedback to myoelectric prosthesis users on the performance time and visual attention in a dual-task paradigm. DESIGN: A repeated-measures design with a counterbalanced order of two conditions. SETTING: Laboratory setting. SUBJECTS: Transradial amputees using a myoelectric prosthesis with normal or corrected eyesight ( N = 12, median age = 65 ± 13 years). Exclusion criteria were orthopedic or neurologic problems. INTERVENTIONS: Subjects performed grasping tasks with their prosthesis, while controlling a virtual car on a road with their intact hand. The dual task was performed twice: with and without vibrotactile feedback. MAIN MEASURES: Performance time of each of the grasping tasks and gaze behavior, measured by the number of times the subjects shifted their gaze toward their hand, the relative time they applied their attention to the screen, and percentage of error in the secondary task. RESULTS: The mean performance time was significantly shorter ( P = 0.024) when using vibrotactile feedback (93.2 ± 9.6 seconds) compared with the performance time measured when vibrotactile feedback was not available (107.8 ± 20.3 seconds). No significant differences were found between the two conditions in the number of times the gaze shifted from the screen to the hand, in the time the subjects applied their attention to the screen, and in the time the virtual car was off-road, as a percentage of the total game time (51.4 ± 15.7 and 50.2 ± 19.5, respectively). CONCLUSION: Adding vibrotactile feedback improved performance time during grasping in a dual-task paradigm. Prosthesis users may use vibrotactile feedback to perform better during daily tasks, when multiple cognitive demands are present.

Changes in saccadic intrusions over time as an objective biomarker to follow ALS disease progression.

Objective: Saccadic Intrusions (SIs) are abnormal eye movements during gaze fixation. Studies have indicated the clinical relevance of SIs, especially of square wave jerks (SWJ) in ALS. We used a software-based platform to extract SIs as a part of an interventional drug trial. The objective was to examine SIs' change over time as a potential biomarker of ALS disease progression. Methods: 28 ALS patients (61.95 ± 8.6 years) were assessed with the revised ALS Functional Rating Scale (ALSFRS-R) and with an oculometric test. Changes of SIs over time and correlations with ALSFRS-R and its bulbar subscale were calculated. A power calculation was conducted to understand the practical implications of results. Results: A significant increase of SWJ over trial duration was observed, with an increase in frequency (mean rise of 0.14 ± 0.28, p < 0.01), amplitude (0.001 ± 0.0016 degrees, p < 0.005), overall duration of SWJ (0.13 ± 0.25, in %, p < 0.01), and in their relative part out of all intrusions (0.18 ± 0.32, in %, p < 0.005). Negative correlations were found with the bulbar subscale (R=-0.43, -0.41, -0.39 and -0.47, respectively, p < 0.001). The required sample size for observing a 40% reduction in bulbar aspects when using the oculometric test (α = 0.05 and ß = 0.8), was found to be 150 patients per arm, compared with 200 patients using the bulbar subscale. Conclusions: Evaluation of saccadic intrusions during fixation was able to detect disease progression over time, correlated with ALSFRS-R bulbar subscale. Eye movements can potentially serve as an objective biomarker in ALS clinical trials and reduce the required sample size to show clinical effect of therapies.

Correlation between oculometric measures and clinical assessment in ALS patients participating in a phase IIb clinical drug trial.

Objective: Oculometric measures (OM) can be extracted from eye movements during presentation of visual stimuli. Studies have indicated the benefit of OM in assessment of neurological disorders, including Amyotrophic Lateral Sclerosis (ALS). We used a new software-based platform for the extraction of OM during patients' assessment. Our objective was to examine the correlation between OM and clinical assessment as a part of a clinical drug trial. Methods: 32 ALS patients (mean age 60.75 ± 10.36 years, 13 females), were assessed using a validated score (ALSFRS-R), and a novel software-based oculometric platform (NeuraLight, Israel) as a part of a clinical drug trial. Correlations of ALSFRS-R with OM were calculated and compared with matched healthy subjects' data (N = 129). Results: A moderate correlation was found between ALSFRS-R and corrective saccadic latency (R = 0.52, p = 0.002). Fixation time during smooth pursuit and peak velocity during pro-saccades were both worse in ALS patients versus healthy subjects (mean (SD)=0.34(0.06) vs. 0.3(0.07), p = 0.01, and 0.41(0.05) vs. 0.38(0.07), p = 0.04, respectively). Patients with bulbar symptoms (N = 14) had a decreased pro-saccade gain compared with patients without bulbar symptoms (mean (SD)=0.1 (0.04) vs. 0.93 (0.07), p = 0.01), and a larger error rate of anti-saccade movement (mean (SD)=0.42 (0.21) vs. 0.28 (0.16), p = 0.04). Conclusions: Oculometric measures correlated with the clinical assessment and were different from data of healthy subjects. Further studies are warranted to establish the role of oculometrics in the evaluation of patients with ALS and other neurodegenerative disorders, and its possible use in clinical trials.

Prevention of coronavirus contamination from the environment using an air-cleaning closed system drug-transfer device.

Background: Closed system drug-transfer devices (CSTD) allow the reconstitution of hazardous drugs into infusion bags, while preserving the sterility of the product and preventing the escape of liquids and aerosols into the environment. Air-cleaning technology CSTD is based on an activated carbon filter and a membrane which enable maintaining the drug sterile by filtration of air entering the vial during pressure equalization. Objective: The study aimed to investigate if an air-cleaning CSTD can prevent liquid viral contamination by human coronavirus OC43 (HCoV-OC43). Methods: Chemfort™ CSTD with (intact) or without (control) a Toxi-Guard system was used to transfer liquids between an IV bag and an empty vial (a total of 5 liquid transfers) inside a sealed glove box contaminated by HCoV-OC43 aerosols. In addition, the vial adaptor was challenged by direct spray of HCoV-OC43 solution on the septum and filter areas. HCoV-OC43 RNA was extracted from samples of the transferred liquid and compared between the devices with or without a Toxi-Guard system. Results: Use of a CSTD with the Toxi-Guard system resulted in non-detectable cycle threshold (CT) values, indicative of no detectable HCoV-OC43RNA in the transferred liquid, even when the septa and filter areas were directly sprayed with HCoV-OC43 stock solution. In contrast, use of the CSTD with no Toxi-Guard system resulted in a detectable CT value of the transferred liquid. Conclusions: Using Chemfort CSTD with integral Toxi-Guard technology can prevent the introduction of microbial and airborne contaminants into the fluid path, thus potentially protecting patients from infection.

Functional electrical stimulation compared with ankle-foot orthosis in subacute post stroke patients with foot drop: A pilot study.

Background: The conventional treatment for foot drop includes an ankle-foot orthosis (AFO) or functional electrical stimulation (FES). Goal: To compare gait parameters in patients following a subacute post stroke with foot drop treated with AFO or FES. Method: Twenty one subacute patients with stroke with foot drop were fitted with FES (N = 10) or AFO (N = 11). Evaluations were performed at baseline, following 4 weeks and 12 weeks. Spatiotemporal gait parameters and symmetry, dynamic electromyography, 10-m walk test, 6-min walk test, timed up and go, functional ambulation classification, and perception of improvement in walking were measured. The gait analysis measures were collected without the assistive devices while the functional measures were collected with them. Results: Both groups showed improvement in all of the outcome measures, with no between-groups differences. The swing duration's and step length's symmetry indicated better gait symmetry in the FES group after 12 weeks (p = 0.037, effect size = -0.538 and p = 0.028 effect size = -0.568, respectively). The FES group perceived significant improvement in gait after 4 weeks, while subjects in the AFO group reported to perceive improvement only after 12 weeks. Conclusions: Our findings suggest that FES is at least as effective as traditional AFO and may be more so.

Evaluation of the effectiveness of a novel gait trainer in increasing the functionality of individuals with motor impairment: A case series.

Regaining the ability to independently ambulate following a physical disability can increase functional ability and participation of patients in daily life. Gait trainers are assistive devices that enable body support and provide safety during gait. However, most conventional gait trainers are pre-configured to a constant position, therefore not suitable for practicing sit-to-stand function, and require assistance from a caregiver in order to mount the device from a sitting position. We therefore evaluated the effectiveness of a dynamically-adjusting gait trainer, designed to provide independence and safety during gait and various activities, in both lab setting and at home in four subjects (one female, three males, ages 32-79 years) with limited ambulation. Spatiotemporal parameters and gait symmetry were recorded, as well as activity levels, actual use of device, and satisfaction. Although gait parameters and physical activity levels were not notably improved, and in one case were worsened, three subjects reported positive experience with the gait trainer. The new gait trainer may have advantages in supporting users with limited mobility during walking and various functions and decrease the risk for falls. A longer practice time and individual fitting process are recommended for better accommodation to the new possibilities.

Applying Incongruent Visual-Tactile Stimuli during Object Transfer with Vibro-Tactile Feedback.

The application of incongruent sensory signals that involves disrupted tactile feedback is rarely explored, specifically with the presence of vibrotactile feedback (VTF). This protocol aims to test the effect of VTF on the response to incongruent visual-tactile stimuli. The tactile feedback is acquired by grasping a block and moving it across a partition. The visual feedback is a real-time virtual presentation of the moving block, acquired using a motion capture system. The congruent feedback is the reliable presentation of the movement of the block, so that the subject feels that the block is grasped and see it move along with the path of the hand. The incongruent feedback appears as the movement of the block diverts from the actual movement path, so that it seems to drop from the hand when it is actually still held by the subject, thereby contradicting the tactile feedback. Twenty subjects (age 30.2 ± 16.3) repeated 16 block transfers, while their hand was hidden. These were repeated with VTF and without VTF (total of 32 block transfers). Incongruent stimuli were presented randomly twice within the 16 repetitions in each condition (with and without VTF). Each subject was asked to rate the difficulty level of performing the task with and without the VTF. There were no statistically significant differences in the length of the hand paths and durations between transfers recorded with congruent and incongruent visual-tactile signals - with and without the VTF. The perceived difficulty level of performing the task with the VTF significantly correlated with the normalized path length of the block with VTF (r = 0.675, p = 0.002). This setup is used to quantify the additive or reductive value of VTF during motor function that involves incongruent visual-tactile stimuli. Possible applications are prosthetics design, smart sport-wear, or any other garments that incorporate VTF.

Adding vibrotactile feedback to a myoelectric-controlled hand improves performance when online visual feedback is disturbed.

We investigated whether adding vibrotactile feedback to a myoelectric-controlled hand, when visual feedback is disturbed, can improve performance during a functional test. For this purpose, able-bodied subjects, activating a myoelectric-controlled hand attached to their right hand performed the modified Box & Blocks test, grasping and manipulating wooden blocks over a partition. This was performed in 3 conditions, using a repeated-measures design: in full light, in a dark room where visual feedback was disturbed and no auditory feedback - one time with the addition of tactile feedback provided during object grasping and manipulation, and one time without any tactile feedback. The average time needed to transfer one block was measured, and an infrared camera was used to give information on the number of grasping errors during performance of the test. Our results show that when vibrotactile feedback was provided, performance time was reduced significantly, compared with when no vibrotactile feedback was available. Furthermore, the accuracy of grasping and manipulation was improved, reflected by significantly fewer errors during test performance. In conclusion, adding vibrotactile feedback to a myoelectric-controlled hand has positive effects on functional performance when visual feedback is disturbed. This may have applications to current myoelectric-controlled hands, as adding tactile feedback may help prosthesis users to improve their functional ability during daily life activities in different environments, particularly when limited visual feedback is available or desirable.

Visuomotor behaviors and performance in a dual-task paradigm with and without vibrotactile feedback when using a myoelectric controlled hand.

Prosthesis users allocate visual attention to their prosthetic hand while performing activities of daily living (ADLs), due to absence of sensory feedback. Dual-task assignments present competition for visual attention and may affect the performance of ADLs. Vibrotactile feedback (VTF) is a frequently-used method to provide prosthesis users with tactile feedback. However, the effect of adding VTF on visual attention and performance in a motor dual-task paradigm has not been investigated. Our aim was to compare visual attention and performance during ADLs in a motor dual-task paradigm when using binary VTF and without using VTF. Forty-three able-bodied subjects (age 26 ± 6.6 years) had a myoelectric-controlled hand attached to their right hand. The dual task comprised of a computer game played with the left hand, while manipulating objects with the artificial hand. This was performed with and without VTF in a counter-balanced order of two conditions. An eye-tracker monitored visual attention, while time to complete each task and the time the virtual car went off-road were recorded. No significant differences were found in visual attention or in performance time between the two conditions. Further examination of adding VTF to prosthesis users is recommended, with disrupted visual feedback and basic grasping tasks.

Prevention of coronavirus contamination from the environment using an air-cleaning closed system drug-transfer device

Background: Closed system drug-transfer devices (CSTD) allow the reconstitution of hazardous drugs into infusion bags, while preserving the sterility of the product and preventing the escape of liquids and aerosols into the environment. Air-cleaning technology CSTD is based on an activated carbon filter and a membrane which enable maintaining the drug sterile by filtration of air entering the vial during pressure equalization. Objective: The study aimed to investigate if an air-cleaning CSTD can prevent liquid viral contamination by human coronavirus OC43 (HCoV-OC43). Methods: ChemfortTM CSTD with (intact) or without (control) a Toxi-Guard system was used to transfer liquids between an IV bag and an empty vial (a total of 5 liquid transfers) inside a sealed glove box contaminated by HCoV-OC43 aerosols. In addition, the vial adaptor was challenged by direct spray of HCoV-OC43 solution on the septum and filter areas. HCoV-OC43 RNA was extracted from samples of the transferred liquid and compared between the devices with or without a Toxi-Guard system. Results: Use of a CSTD with the Toxi-Guard system resulted in non-detectable cycle threshold (CT) values, indicative of no detectable HCoV-OC43RNA in the transferred liquid, even when the septa and filter areas were directly sprayed with HCoV-OC43 stock solution. In contrast, use of the CSTD with no Toxi-Guard system resulted in a detectable CT value of the transferred liquid. Conclusions: Using Chemfort CSTD with integral Toxi-Guard technology can prevent the introduction of microbial and airborne contaminants into the fluid path, thus potentially protecting patients from infection (AU)

Prevention of Genu Recurvatum in Poststroke Patients Using a Hinged Soft Knee Orthosis.

OBJECTIVE: To evaluate the effect of a hinged soft knee orthosis on the gait pattern and symmetry of poststroke patients with chronic symptoms and knee hyperextension. DESIGN: An 8-week prospective, randomized, controlled study. SETTING: Outpatient clinic of a Department of Physical Medicine and Rehabilitation in an academic medical center. SUBJECTS: We recruited adult subjects (N = 31) at a minimum of 3 months after their first stroke. All subjects were able to ambulate independently before their stroke and walked independently with or without a walking aid at the time of recruitment. Subjects also had paresis of leg muscles and/or a spasticity pattern resulting in knee hyperextension. INTERVENTIONS: Each subject was tested 3 times, 4 weeks apart. Two tests were performed without the hinged soft knee orthosis, and the third examination was performed with the knee orthosis, after the subject ambulated with it for 4 weeks. OUTCOME MEASURES: Spatiotemporal gait parameters and symmetry and paretic knee angle and muscle activation patterns measured with and without the orthosis. In addition, the Berg Balance Scale, 6-Minute Walk Test, 10-Meter Walk Test (10MWT), and Timed Up and Go test were administered. RESULTS: The orthosis successfully prevented the paretic knee from hyperextending, and greater knee flexion was achieved during the swing phase. The results of the Berg Balance Scale, 6-Minute Walk Test, 10MWT, and Timed Up and Go Test significantly improved. Although no significant differences were found in spatiotemporal parameters and gait symmetry, 67.7% of the subjects increased their gait velocity by more than 0.1 m/s calculated from the 10MWT, which is considered a clinically meaningful difference on short-distance walks. The muscle activity patterns did not change while using the orthosis when comparing activation time and peak root mean square values. CONCLUSIONS: Use of a hinged soft knee orthosis to prevent genu recurvatum after stroke may be considered a viable option to alleviate excessive stress from the posterior soft tissues of the paretic knee and to prevent falls by restoring balance and confidence in the patient and by increasing swing knee flexion.