Apoptosis in Postmortal Tissues of Goat Spinal Cords and Survival of Resident Neural Progenitors.

Growing demand for therapeutic tissue repair recurrently focusses scientists' attention on critical assessment of postmortal collection of live cells, especially stem cells. Our study aimed to assess the survival of neuronal progenitors in postmortal spinal cord and their differentiation potential. Postmortal samples of spinal cords were obtained from human-sized animals (goats) at 6, 12, 24, 36, and 54 h after slaughter. Samples were studied by immunohistology, differentiation assay, Western blot and flow cytometry for the presence and location of GD2-positive neural progenitors and their susceptibility to cell death. TUNEL staining of the goat spinal cord samples over 6-54 h postmortem revealed no difference in the number of positive cells per cross-section. Many TUNEL-positive cells were located in the gray commissure around the central canal of the spinal cord; no increase in TUNEL-positive cells was recorded in either posterior or anterior horns of the gray matter where many GD2-positive neural progenitors can be found. The active caspase 3 amount as measured by Western blot at the same intervals was moderately increasing over time. Neuronal cells were enriched by magnetic separation with antibodies against CD24; among them, the GD2-positive neural progenitor subpopulation did not overlap with apoptotic cells having high pan-caspase activity. Apoptotic cell death events are relatively rare in postmortal spinal cords and are not increased in areas of the neural progenitor cell's location, within measured postmortal intervals, or among the CD24/GD2-positive cells. Data from our study suggest postmortal spinal cords as a valuable source for harvesting highly viable allogenic neural progenitor cells.

Feasibility and safety study of wearable cyborg Hybrid Assistive Limb for pediatric patients with cerebral palsy and spinal cord disorders.

Introduction: The wearable cyborg Hybrid Assistive Limb (HAL) is the world's first cyborg-type wearable robotic device, and it assists the user's voluntary movements and facilitates muscle activities. However, since the minimum height required for using the HAL is 150 cm, a smaller HAL (2S size) has been newly developed for pediatric use. This study aimed to (1) examine the feasibility and safety of a protocol for treatments with HAL (2S size) in pediatric patients and (2) explore the optimal method for assessing the efficacy of HAL. Methods: This clinical study included seven pediatric patients with postural and motor function disorders, who received 8-12 sessions of smaller HAL (2S size) treatment. The primary outcome was the Gross Motor Function Measure-88 (GMFM-88). The secondary outcomes were GMFM-66, 10-m walk test, 2- and 6-min walking distances, Canadian Occupational Performance Measure (COPM), a post-treatment questionnaire, adverse events, and device failures. Statistical analyses were performed using the paired samples t-test or Wilcoxon signed-rank test. Results: All participants completed the study protocol with no serious adverse events. GMFM-88 improved from 65.51 ± 21.97 to 66.72 ± 22.28 (p = 0.07). The improvements in the secondary outcomes were as follows: GMFM-66, 53.63 ± 11.94 to 54.96 ± 12.31, p = 0.04; step length, 0.32 ± 0.16 to 0.34 ± 0.16, p = 0.25; 2-MWD, 59.1 ± 57.0 to 62.8 ± 63.3, p = 0.54; COPM performance score, 3.7 ± 2.0 to 5.3 ± 1.9, p = 0.06; COPM satisfaction score, 3.3 ± 2.1 to 5.1 ± 2.1, p = 0.04. Discussion: In this exploratory study, we applied a new size of wearable cyborg HAL (2S size), to children with central nervous system disorders. We evaluated its safety, feasibility, and identified an optimal assessment method for multiple treatments. All participants completed the protocol with no serious adverse events. This study suggested that the GMFM would be an optimal assessment tool for validation trials of HAL (2S size) treatment in pediatric patients with posture and motor function disorders.

Safety and Feasibility Study of the Medical Care Pit Walking Support System for Rehabilitation of Acute Stroke Patients.

Stroke rehabilitation with mechanical assistance improves outcomes by facilitating repetition and relieving the care burden of therapy staff. Here, we tested the Medical Care Pit (MCP) walking assistance training device in the rehabilitation of eight acute stroke patients (median age 60.7 ± 16.3 years) who had recently suffered ischemic (three) or hemorrhagic (five) stroke (14.1 ± 6.5 days). Patients received standard rehabilitation approximately 5 days per week (weekdays only), plus MCP therapy twice a week, totaling four MCP sessions over 2 weeks. Fugl-Meyer Assessment-Lower Extremities (FMA-LE), Functional Ambulation Category (FAC), and other gait-associated parameters were measured. Over the 10.5 ± 1.6 days of therapy, MCP qualitatively assisted in gait analysis and real-time patient feedback while independent walking scores significantly improved (FAC 2.2 ± 0.8 to 3.1 ± 1.3, p = 0.020). FMA-LE scores also slightly improved but not to significance (p = 0.106). Objective burden on patients, as measured by modified Borg scale, was significantly improved (2.7 ± 1.6 to 2.0 ± 1.6, p = 0.014). In terms of questionnaires, anxiety scores for the physical therapist regarding gait training and falling with MCP significantly decreased (3.8 ± 2.3 to 1.0 ± 1.6; p = 0.027 and 3.1 ± 2.2 to 0.8 ± 1.3; p = 0.045) from the first to fourth sessions. Taken together, MCP, in addition to the usual rehabilitation program, was effective in gait rehabilitation for independent walking and relieved burdens on the patients. Such walking support systems may be an important part of acute stroke rehabilitation.

Feasibility and Efficacy of the Newly Developed Robotic Hybrid Assistive Limb Shoulder Exercises in Patients with C5 Palsy during the Acute Postoperative Phase.

Background and Objectives: Although postoperative C5 palsy is a frequent complication of cervical spine surgery, no effective therapeutic rehabilitation approach has been established for postoperative C5 palsy. The purpose of this study was to find evidence confirming the effectiveness and feasibility of robotic Hybrid Assistive Limb (HAL) shoulder exercises for C5 palsy. Materials and Methods: In this before-after, uncontrolled case series clinical study, we performed a mean of 11.7 shoulder training sessions using a shoulder HAL immediately after the onset of C5 palsy in seven shoulders of six patients who developed postoperative C5 palsy and had difficulty raising their shoulder during the acute postoperative phase of cervical spine surgery. Shoulder HAL training was introduced as early as possible after evaluating the general condition of all inpatients who developed C5 palsy. Patients underwent shoulder abduction training using shoulder HAL on an inpatient and outpatient basis at 2-week or 1-month intervals. Adverse events associated with shoulder HAL training were investigated. The shoulder abduction angle and power without the shoulder HAL were evaluated before shoulder HAL usage, at every subsequent session, and upon completion of all sessions. Results: Severe adverse events due to shoulder HAL training were not reported. After completion of all shoulder HAL sessions, all patients showed improved shoulder elevation, while shoulder abduction angle and power improved over time. Conclusions: Shoulder elevation training with HAL in patients in the acute stage of postoperative C5 palsy has the potential to demonstrate improvement in shoulder joint function with a low risk of developing severe adverse events.

A possible contribution of the locus coeruleus to arousal enhancement with mild exercise: evidence from pupillometry and neuromelanin imaging.

Acute mild exercise has been observed to facilitate executive function and memory. A possible underlying mechanism of this is the upregulation of the ascending arousal system, including the catecholaminergic system originating from the locus coeruleus (LC). Prior work indicates that pupil diameter, as an indirect marker of the ascending arousal system, including the LC, increases even with very light-intensity exercise. However, it remains unclear whether the LC directly contributes to exercise-induced pupil-linked arousal. Here, we examined the involvement of the LC in the change in pupil dilation induced by very light-intensity exercise using pupillometry and neuromelanin imaging to assess the LC integrity. A sample of 21 young males performed 10 min of very light-intensity exercise, and we measured changes in the pupil diameters and psychological arousal levels induced by the exercise. Neuromelanin-weighted magnetic resonance imaging scans were also obtained. We observed that pupil diameter and psychological arousal levels increased during very light-intensity exercise, which is consistent with previous findings. Notably, the LC contrast, a marker of LC integrity, predicted the magnitude of pupil dilation and psychological arousal enhancement with exercise. These relationships suggest that the LC-catecholaminergic system is a potential a mechanism for pupil-linked arousal induced by very light-intensity exercise.

Gait improvement with wearable cyborg HAL trunk unit for parkinsonian patients: five case reports.

Cybernic treatment involves the generation of an interactive bio-feedback loop between an individual's nervous system and the worn cyborg Hybrid Assistive Limb (HAL); this treatment has been applied for several intractable neuromuscular disorders. Thus, it is of interest to determine its potential for parkinsonian patients. This study confirmed the feasibility of using a HAL trunk unit to improve parkinsonian gait disturbance. HAL establishes functional and physical synchronization with the wearer by providing lateral cyclic forces to the chest in the form of somatosensory and motor cues. To confirm the feasibility of its use for improving parkinsonian gait disturbances, we conducted experiments with three Parkinson's disease patients and two patients with progressive supranuclear palsy. During the experiments, the immediate effect of the intervention was assessed; all participants exhibited improvements in gait disturbance while wearing the HAL unit, and this improvement effect persisted without the HAL unit in two participants. Afterward, based on the assessment, we conducted a continuous intervention for one participant. In this intervention, the number of steps in the final experiment was significantly decreased compared with the initial state. These findings suggest that the proposed method is an option for treating parkinsonian patients to generate somatosensory and motor cues.

Effects of cardiac rehabilitation with motion assistance from a wearable cyborg hybrid assistive limb on patients with chronic heart failure: a randomized controlled trial with a one-year follow-up.

[Purpose] We have recently reported that using a wearable cyborg hybrid assistive limb improved the isometric knee extensor muscle strength of patients with chronic heart failure. Here, we investigated the long-term effects of a lumbar-type hybrid assistive limb for patients with chronic heart failure. [Participants and Methods] A total of 28 hospitalized patients with chronic heart failure (mean age, 73.1 ± 13.8 years) were randomly assigned to two groups: the hybrid assistive limb group or the control group, in which they performed a sit-to-stand exercise with or without the hybrid assistive limb, respectively. The cardiac rehabilitation therapy included this intervention, which was performed as many times as possible for 5-30 minutes per day for 6-10 days. Clinical assessments like lower-limb muscle strength, walking ability, etc., were measured before and after the intervention. Cardiac events were followed up for up to a year after discharge. [Results] No adverse events occurred during the study period in either group. In terms of long-term effects, the incidence of cardiac events was 23% and 45% in the hybrid assistive limb and the control groups, respectively. [Conclusion] Hybrid assistive limb-assisted exercise therapy may be a safe and feasible cardiac rehabilitation tool in patients with chronic heart failure. The lumbar-type wearable cyborg hybrid assistive limb may have a positive effect on heart failure prognosis by adding long-term exercise therapy.

Effect of cyborg-type robot Hybrid Assistive Limb on patients with severe walking disability in acute stroke: A randomized controlled study.

OBJECTIVES: To investigate whether early gait training using Hybrid Assistive Limb (HAL) is feasible and improves walking and independency compared with conventional physical therapy (CPT) in patients with severe walking disability after stroke. METHODS: We conducted a single-center, randomized controlled study. Patients with first-ever stroke who had severe walking disability were included. All patients started gait training within 10 days post-stroke onset. Twenty-four patients were randomly assigned into HAL or CPT groups. Outcome measures were collected at three time points, at baseline, completion of 20 sessions of gait training (second assessment), and 3 months after the initiation of gait training. The primary outcomes were changes in motor sub-scores of the Functional Independence Measure or Functional Ambulation Category at the completion of the second assessment from baseline. RESULTS: Twenty-two patients (median age, 68 years; 12 patients in the HAL group and 10 patients in the CPT group) completed the study. There were no significant differences in primary outcomes. Apathy scale, one of the secondary outcomes, showed a decreasing trend in the HAL group (mean change of -3.8, 95% CI -8.14 to 0.475), and a slight increasing trend in the CPT group (mean change of 1.2, 95% CI -2.66 to 5.06) at the second assessment. Patients in the HAL group experienced no adverse events. CONCLUSIONS: Early gait training in patients with severe walking disability after stroke using HAL was feasible. Walking ability and independency were not improved at the completion of 20 sessions of gait training.

Postoperative Acute-Phase Gait Training Using Hybrid Assistive Limb Improves Gait Ataxia in a Patient with Intradural Spinal Cord Compression Due to Spinal Tumors.

Sensory ataxia due to posterior cord syndrome is a relevant, disabling condition in nontraumatic spinal cord dysfunction. Ataxic gait is a common symptom of sensory ataxia that restricts activities of daily living. A 70-year-old woman with severe sensory disturbance was diagnosed with intradural extramedullary spinal cord tumors found in the thoracic spine region (T8). Surgical management of the tumors was performed. The patient received gait training 20 days after surgery (postoperative acute phase) using a hybrid assistive limb (HAL). HAL is a wearable exoskeleton cyborg that provides real-time assistance to an individual for walking and limb movements through actuators mounted on the bilateral hip and knee joints. Walking ability was assessed using the 10 m walking test, which included evaluating walking speed, step length, and cadence in every session. To evaluate the immediate effects of HAL training, walking speed and step length were measured before and after the training in each session. During the 10 m walking test, gait kinematics and lower muscle activity were recorded using a motion capture system and wireless surface electromyography before the first session and after completion of all HAL sessions. After the HAL training sessions, improvement in the patient's gait performance was observed in the gait joint angles and muscle activity of the lower limb. After 10 training sessions, we observed the following changes from baseline: walking speed (from 0.16 m/s to 0.3 m/s), step length (from 0.19 m to 0.37 m), and cadence (from 50.9 steps/min to 49.1 steps/min). The average standard deviations of the knee (from right, 7.31; left, 6.75; to right, 2.93; p < 0.01, left, 2.63; p < 0.01) and ankle joints (from right, 6.98; left, 5.40; to right, 2.39; p < 0.01, left, 2.18; p < 0.01) were significantly decreased. Additionally, walking speed and step length improved immediately after completing all the HAL training sessions. This suggests that HAL gait training might be a suitable physical rehabilitation program for patients with sensory ataxia causing dysfunctional movement of the lower limb.

Alteration of muscle activity during voluntary rehabilitation training with single-joint Hybrid Assistive Limb (HAL) in patients with shoulder elevation dysfunction from cervical origin.

Shoulder elevation, defined here as arm raising, being essential for activities of daily living, dysfunctions represent a substantial burden in patients' lives. Owing to the complexity of the shoulder joint, the tightly coordinated muscular activity is a fundamental component, and neuromuscular impairments have devastating effects. A single-joint shoulder type version of the Hybrid Assistive Limb (HAL) allowing motion assistance based on the intention of the user via myoelectric activation has recently been developed, and its safety was demonstrated for shoulder rehabilitation. Yet, little is known about the physiological effects of the device. This study aims to monitor the changes in muscle activity and motion during shoulder HAL rehabilitation in several patients suffering from shoulder elevation dysfunction from cervical radicular origin. 8 patients (6 males, 2 females, mean age 62.4 ± 9.3 years old) with weakness of the deltoid muscle resulting from a damage to the C5 nerve root underwent HAL-assisted rehabilitation. We combined surface electromyography and three-dimensional motion capture to record muscular activity and kinematics. All participants showed functional recovery, with improvements in their Manual Muscle Testing (MMT) scores and range of motion (ROM). During training, HAL decreased the activity of deltoid and trapezius, significantly more for the latter, as well as the coactivation of both muscles. We also report a reduction of the characteristic shrugging compensatory motion which is an obstacle to functional recovery. This reduction was notably demonstrated by a stronger reliance on the deltoid rather than the trapezius, indicating a muscle coordination tending toward a pattern similar to healthy individuals. Altogether, the results of the evaluation of motion and muscular changes hint toward a functional recovery in acute, and chronic shoulder impairments from cervical radicular origin following shoulder HAL rehabilitation training and provide information on the physiological effect of the device.

Ankle dorsiflexion training with a newly developed Hybrid Assistive Limb for a patient with foot drop caused by common peroneal nerve palsy: a case report.

[Purpose] An ankle disorder (foot drop) caused by common peroneal nerve palsy or cerebrovascular accident (stroke) interferes with patients' ability to walk and hinders in activities of daily living. A new robotic ankle, the Hybrid Assistive Limb, has been developed for the treatment of foot drop caused by common peroneal nerve palsy or sequelae of stroke. The purpose in this study was to report and examine the efficacy and feasibility of a case who was treated with voluntary ankle dorsiflexion training with the ankle Hybrid Assistive Limb. [Participant and Method] A 60-year-old man with foot drop due to peroneal nerve palsy that occurred without a contributory cause was treated via ankle dorsiflexion training with the use of a new robotic ankle, the "Ankle Hybrid Assistive Limb". [Results] Following total ankle rehabilitation training with the Ankle Hybrid Assistive Limb, improvements in ankle dorsiflexor strength, gait, and sensory function of the lower leg and foot were observed. [Conclusion] The newly developed ankle Hybrid Assistive Limb could be an effective training tool for foot drop caused by common peroneal nerve palsy.

Biofeedback Physical Therapy With the Hybrid Assistive Limb (HAL) Lumbar Type for Chronic Low Back Pain: A Pilot Study.

Objective There are many treatments for chronic low back pain, including various medications, exercise therapy, orthotics, and surgery, but no treatment is definitive. We hypothesized that biofeedback therapy using the hybrid assistive limb (HAL) lumbar type would have some immediate effects on chronic low back pain. The purpose of this pilot study was to assess whether immediate changes in low back pain and hip flexibility and any other adverse events would occur following the HAL biofeedback physical therapy. Methods This was a single-center, pilot, prospective, single-arm study of outpatient biofeedback physical therapy using the HAL lumbar type for patients with chronic low back pain. Patients underwent a 10-minute biofeedback physical therapy (lumbar flexion-extension, sit-to-stand, and squat) with the HAL lumbar type (in one session). The visual analog scale (VAS) score of low back pain during lumbar flexion, extension, lateral bending, and rotation was evaluated. The finger-to-floor distance (FFD), straight leg raising test (SLR), and the Thomas test were measured to assess hip flexibility. Results All 35 participants (14 men and 21 women) (100%) conducted a biofeedback HAL therapy session using the HAL lumbar type. No participant had deterioration of low back pain. No adverse events occurred. After the biofeedback therapy using the HAL lumbar type, SLR demonstrated a significant positive change with large effect size and sufficient power. Lumbar VAS during lumbar flexion and extension and FFD showed a significant positive change with medium effect size and adequate power. Conclusions Biofeedback therapy using the HAL lumbar type is an option for intervention in chronic low back pain.

Early Postoperative Rehabilitation Using the Hybrid Assistive Limb (HAL) Lumbar Type in Patients With Hip Fracture: A Pilot Study.

OBJECTIVE: To extend life expectancy after surgery, patients with hip fractures need to improve their mobility quickly through postoperative rehabilitation. Voluntary hip joint motion supported by the hybrid assistive limb (HAL) lumbar type, an exoskeleton robot suit characterized by its ability to detect the wearer's intentions through the bioelectrical signals and assist hip extension motions at an optimal timing, may be effective to improve mobility in patients with hip joint dysfunction after surgery. We aimed to introduce rehabilitation using the HAL lumbar type in the early period after hip fracture surgery. METHODS: Patients who underwent internal fixation for hip fracture at a single institution were prospectively enrolled. They received early postoperative rehabilitation (forward and backward bending of the lumbar spine, pelvic tilt forward and backward, standing up, and squatting) using the HAL lumbar type (six times a week for 15 min per session). Five-times-sit-to-stand (FTSS) and timed-up-and-go (TUG) tests were conducted at baseline before HAL rehabilitation (pre-HAL) and after the HAL rehabilitation (post-HAL) intervention. RESULTS: We enrolled 14 patients (one man, 13 women) in this study. There were no adverse events, and all patients were able to complete the entire rehabilitation program. Post-HAL FTSS showed significant improvement compared with pre-HAL and had a large effect size of 1.81 (95% CI = 0.93 to 2.66) and sufficient power. CONCLUSIONS: Robotic rehabilitation with HAL lumbar type could be introduced without adverse events, even in the early postoperative period following surgery for hip fracture. Further study is needed to develop an appropriate rehabilitation protocol using the HAL lumbar type.

Development of a New Ankle Joint Hybrid Assistive Limb.

Foot and ankle disabilities (foot drop) due to common peroneal nerve palsy and stroke negatively affect patients' ambulation and activities of daily living. We developed a novel robotics ankle hybrid assistive limb (HAL) for patients with foot drop due to common peroneal nerve palsy or stroke. The ankle HAL is a wearable exoskeleton-type robot that is used to train plantar and dorsiflexion and for voluntary assistive training of the ankle joint of patients with palsy using an actuator, which is placed on the lateral side of the ankle joint and detects bioelectrical signals from the tibialis anterior (TA) and gastrocnemius muscles. Voluntary ankle dorsiflexion training using the new ankle HAL was implemented in a patient with foot drop due to peroneal nerve palsy after lumbar surgery. The time required for ankle HAL training (from wearing to the end of training) was approximately 30 min per session. The muscle activities of the TA on the right were lower than those on the left before and after ankle HAL training. The electromyographic wave of muscle activities of the TA on the right was slightly clearer than that before ankle HAL training in the resting position immediately after ankle dorsiflexion. Voluntary ankle dorsiflexion training using the novel robotics ankle HAL was safe and had no adverse effect in a patient with foot drop due to peroneal nerve palsy.

Immediate effects of hybrid assistive limb gait training on lower limb function in a chronic myelopathy patient with postoperative late neurological deterioration.

OBJECTIVE: The Hybrid Assistive Limb (HAL) has recently been used to treat movement disorders. Although studies have shown its effectiveness for chronic myelopathy, the immediate effects of HAL gait training on lower limb function have not been clarified. We conducted HAL gait training and examined its immediate effects on a 69-year-old man with re-deterioration of myelopathy in the chronic phase after surgery for compression myelopathy. The HAL intervention was performed every 4 weeks for 10 total sessions. Immediately before and after each session, we analyzed the patient's walking ability using the 10-m walk test. In the 4th HAL session, the gastrocnemius muscle activity was measured bilaterally using a synchronized motion capture-electromyogram system. RESULTS: The training effects became steady after the 2nd session. In sessions 2-10, the step length increased from 0.56 to 0.63 m (mean: 0.031 m) immediately after HAL training. The motion capture-electromyogram analyses showed that considerable amounts of gastrocnemius muscle activity were detected during the stance and swing phases before HAL training. During and immediately after HAL training, gastrocnemius activity during the swing phase was diminished. HAL gait training has an immediate effect for inducing a normal gait pattern with less spasticity in those with chronic myelopathy.

Functional magnetic resonance imaging of brain activity during hybrid assistive limb intervention in a chronic spinal cord injury patient with C4 quadriplegia.

Hybrid assistive limb (HAL) is a wearable robot, which has recently been used for the treatment of patients with movement disorders including spinal cord injury (SCI). Although several studies have indicated the effectiveness of HAL for SCI patients, changes in brain activity during the HAL intervention have not yet been fully characterized. A 19-year-old man with a chronic SCI resulting in complete C4 quadriplegia underwent five weeks of HAL training for a total of ten sessions. We evaluated his brain activity using task-induced functional MRI (fMRI) after the fourth, sixth and tenth HAL sessions. We also assessed the spasticity of this patient using the modified Ashworth scale (mAs). As controls for the task-induced fMRI, we examined the brain activity in two healthy subjects. The fMRI findings indicated an increased response to a motor imagery task in the patient's cerebral cortex compared to controls. In addition, the activation pattern in his cortex changed during the five weeks of HAL intervention. We observed increased cerebral lateralization in his primary motor cortex. We also found that the laterality index calculated for the precentral gyrus had a significant negative correlation with the total mAs score over the course of the HAL treatment. Our results indicate that the cerebral cortex of the present SCI patient was hyperactive during the imagery task, and the cortical activation was reduced with progression of the HAL treatment.

Staged treatment protocol for gait with hybrid assistive limb in the acute phase of patients with stroke.

Hybrid Assistive Limb (HAL) is a wearable human assistant cyborg-type robot that helps lower-leg movement based on bioelectrical signals detected from the voluntary movement of the person wearing it. In this study, we developed a novel staged HAL treatment protocol for patients with acute stroke. The Regain Program for Gait with HAL (RPG-HAL) was formulated in four steps, based on the severity of limb paralysis. Twenty-one patients with acute stroke received a combination treatment of RPG-HAL and conventional rehabilitation. The feasibility and safety of RPG-HAL were evaluated based on changes in physical function and activities of daily living (ADL). RPG-HAL yielded improvement in gait speed, cadence, step length, and functional ambulation category (FAC). The effect size was >0.8 in all measurements. FAC (1.90) and Barthel Index (BI) (1.92) exhibited the highest scores. Twelve out of 14 patients with FAC 0 before RPG-HAL reached the upper FAC. Thus, earlier intervention using RPG-HAL as improving physical function, ADL, and gait ability in patients with stroke.

Influence of the perfusion bioreactor on Stratified and Distributed approaches for multilayered tissue engineering on biodegradable scaffolds.

Despite wide use and approval of poly lactic-coglycolic acid (PLGA) for surgical applications, there have been very few studies on tissue constructions that mimic physiological multilayer structures by combining PLGA scaffolds with tissue engineering. In our study, we developed a bioreactor system to maintain, and to train two types of three-layered vascular-like structures. Then we examined how the perfusion conditions and different tissue engineering approaches affected the formation of the layered structure and degradation of the PLGA scaffolds. In the proposed Distributed Method, the cells were seeded layer by layer on a single scaffold, using spheroids bigger than scaffold fiber gaps and we achieved the higher cell density compared with the Stratified Method where we stacked three PLGA sheets seeded with individual vascular cell types. At the histological level, scaffold degradation was more prominent in the bioreactor compared to the same time interval in vivo. In addition, the faster flow accelerated the decomposition of PLGA fibers. Moreover, bioreactor perfusion culture at lower flow rates could balance cell adhesion and survival, improve the cell density and promote self-organization of multilayer structure with desirable rate of PLGA scaffolds degradation.

Basic study of epileptic seizure detection using a single-channel frontal EEG and a pre-trained ResNet.

Epilepsy is a neurological disorder that causes sudden seizures due to abnormal excitation of neurons in the brain. Approximately 30 % of patients cannot control their seizures using medication. In addition, since seizures can occur anywhere and at any time, caregivers must always be with the patient. Various researchers have developed seizure detection methods using multichannel EEG to improve the quality of life of patients and caregivers. However, the large size of the measurement device impedes transportation. We believe that a portable measurement device with a small number of channels is suitable for detecting seizures in daily life. Therefore, we need a system that can detect seizures using a small number of channels. The purpose of this research is to develop a seizure detection algorithm using a single-channel frontal EEG and to confirm its basic performance. We used EEG signals from a single electrode position (Fp1-F7, Fp2-F8), which is a bipolar derivation of the frontal region. We segmented the EEG using a 2 s sliding window with 50 % overlap and converted the segments into images. After preprocessing, we fine-tuned ResNet18, pre-trained on ImageNet, and developed an ensemble classification method. In the experiments with 10 epileptic patients (3 - 19 years old) registered in the CHB-MIT scalp EEG database, the results showed that the average sensitivity was 88.73 %, the average specificity was 98.98 %, and the average detection latency time was 7.39 s. In conclusion, the developed algorithm was validated as sufficiently accurate to detect epileptic seizures.Clinical Relevance- This establishes an image recognition algorithm that can detect epileptic seizures using a single- channel frontal EEG.