Kiyoshi Eguchi

Development of single leg version of HAL for hemiplegia

Our goal is to try to enhance the QoL of persons with hemiplegia by the mean of an active motion support system based on the HAL’s technology. The HAL (Hybrid Assistive Limb) in its standard version is an exoskeleton-based robot suit to support and enhance the human motor functions. The purpose of the research presented in this paper is the development of a new version of the HAL to be used as an assistive device providing walking motion support to persons with hemiplegia. It includes the realization of the single leg version of the HAL and the redesign of the original HAL’s Autonomous Controller to execute human-like walking motions in an autonomous way. Clinical trials were conducted in order to assess the effectiveness of the developed system. The first stage of the trials described in this paper involved the participation of one hemiplegic patient who has difficulties to flex his right knee. As a result, the knee flexion support for walking provided by the HAL appeared to improve the subject’s walking (longer stride and faster steps). The first evaluation of the system with one subject showed promising results for the future developments.

Feasibility of rehabilitation training with a newly developed wearable robot for patients with limited mobility

OBJECTIVE To investigate the feasibility of rehabilitation training with a new wearable robot. DESIGN Before-after clinical intervention. SETTING University hospital and private rehabilitation facilities. PARTICIPANTS A convenience sample of patients (N=38) with limited mobility. The underlying diseases were stroke (n=12), spinal cord injuries (n=8), musculoskeletal diseases (n=4), and other diseases (n=14). INTERVENTIONS The patients received 90-minute training with a wearable robot twice per week for 8 weeks (16 sessions). MAIN OUTCOME MEASURES Functional ambulation was assessed with the 10-m walk test (10MWT) and the Timed Up & Go (TUG) test, and balance ability was assessed with the Berg Balance Scale (BBS). Both assessments were performed at baseline and after rehabilitation. RESULTS Thirty-two patients completed 16 sessions of training with the wearable robot. The results of the 10MWT included significant improvements in gait speed, number of steps, and cadence. Although improvements were observed, as measured with the TUG test and BBS, the results were not statistically significant. No serious adverse events were observed during the training. CONCLUSIONS Eight weeks of rehabilitative training with the wearable robot (16 sessions of 90min) could be performed safely and effectively, even many years after the subjects received their diagnosis.

Voluntary motion support control of Robot Suit HAL triggered by bioelectrical signal for hemiplegia

Our goal is to enhance the quality of life of patients with hemiplegia by means of an active motion support system that assists the impaired motion such as to make it as close as possible to the motion of an able bodied person. We have developed the Robot Suit HAL (Hybrid Assistive Limb) to actively support and enhance the human motor functions. The purpose of the research presented in this paper is to propose the required control method to support voluntarily motion using a trigger based on patients bioelectrical signal. Clinical trials were conducted in order to investigate the effectiveness of the proposed control method. The first stage of the trials, described in this paper, involved the participation of one hemiplegic patient who is not able to bend his right knee. As a result, the motion support provided by the HAL moved the paralyzed knee joint according to his intention and improved the range of the subjects knee flexion. The first evaluation of the control method with one subject showed promising results for future trials to explore the effectiveness for a wide range of types of hemiplegia.

Restoration of Gait for Spinal Cord Injury Patients Using HAL With Intention Estimator for Preferable Swing Speed

This paper proposes a novel gait intention estimator for an exoskeleton-wearer who needs gait support owing to walking impairment. The gait intention estimator not only detects the intention related to the start of the swing leg based on the behavior of the center of ground reaction force (CoGRF), but also infers the swing speed depending on the walking velocity. The preliminary experiments categorized into two stages were performed on a mannequin equipped with the exoskeleton robot [Hybrid Assistive Limb: (HAL)] including the proposed estimator. The first experiment verified that the gait support system allowed the mannequin to walk properly and safely. In the second experiment, we confirmed the differences in gait characteristics attributed to the presence or absence of the proposed swing speed profile. As a feasibility study, we evaluated the walking capability of a severe spinal cord injury patient supported by the system during a 10-m walk test. The results showed that the system enabled the patient to accomplish a symmetrical walk from both spatial and temporal standpoints while adjusting the speed of the swing leg. Furthermore, the critical differences of gait between our system and a knee-ankle-foot orthosis were obtained from the CoGRF distribution and the walking time. Through the tests, we demonstrated the effectiveness and practical feasibility of the gait support algorithms.

Robot Assisted Physiotherapy to Support Rehabilitation of Facial Paralysis

We have been developing the Robot Mask with shape memory alloy based actuators that follows an approach of manipulating the skin through a minimally obtrusive wires, transparent strips and tapes based pulling mechanism to enhance the expressiveness of the face. For achieving natural looking facial expressions by taking the advantage of specific characteristics of the skin, the Robot Mask follows a human anatomy based criteria in selecting these manipulation points and directions. In this paper, we describe a case study of using the Robot Mask to assist physiotherapy of a hemifacial paralyzed patient. The significant differences in shape and size of the human head between different individuals demands proper customizations of the Robot Mask. This paper briefly describes the adjusting and customizing stages employed from the design level to the implementation level of the Robot Mask. We will also introduce a depth image sensor data based analysis, which can remotely evaluate dynamic characteristics of facial expressions in a continuous manner. We then investigate the effectiveness of the Robot Mask by analyzing the range sensor data. From the case study, we found that the Robot Mask could automate the physiotherapy tasks of rehabilitation of facial paralysis. We also verify that, while providing quick responses, the Robot Mask can reduce the asymmetry of a smiling face and manipulate the facial skin to formations similar to natural facial expressions.

Development of an assist controller with robot suit HAL for hemiplegic patients using motion data on the unaffected side.

Among several characteristics seen in gait of hemiplegic patients after stroke, symmetry is known to be an indicator of the degree of impairment of walking ability. This paper proposes a control method for a wearable type lower limb motion assist robot to realize spontaneous symmetric gait for these individuals. This control method stores the motion of the unaffected limb during swing and then provides motion support on the affected limb during the subsequent swing using the stored pattern to realize symmetric gait based on spontaneous limb swing. This method is implemented on the robot suit HAL (Hybrid Assistive Limbs). Clinical tests were conducted in order to assess the feasibility of the control method. Our case study involved participation of one chronic stroke patient who was not able to flex his right knee. As a result, the walking support for hemiplegic leg provided by the HAL improved the subjects gait symmetry. The feasibility study showed promising basis for the future clinical study.

Application of robot suit HAL to gait rehabilitation of stroke patients: a case study

We have developed the Robot Suit HAL (Hybrid Assistive Limb) to actively support and enhance human motor functions. The HAL provides physical support according to the wearers motion intention. In this paper, we present a case study of the application of the HAL to gait rehabilitation of a stroke patient. We applied the HAL to a male patient who suffered a stroke due to cerebral infarction three years previously. The patient was given walking training with the HAL twice a week for eight weeks. We evaluated his walking speed (10 m walking test) and balance ability (using a functional balance scale) before and after the 8-week rehabilitation with the HAL. The results show an improvement in the gait and balance ability of a patient with chronic paralysis after gait training with the HAL, which is a voluntarily controlled rehabilitation device.

Myoelectric Controlled Prosthetic Hand with Continuous Force-Feedback Mechanism

In this paper, we propose a novel method to support learning of grasping behavior with a myoelectric hand through the use of force-feedback. A force transfer mechanism is implemented in the developed prosthetic hand, which creates a force stimulus that is synchronized with opening and closing of the gripper. For a person with congenital forearm defects, learning how to operate a myoelectric prosthetic hand is quite difficult. The force-feedback is presented at the end of the forearm of the affected side to assist the process of creating a body image. Several experiments were conducted to confirm the ability to generate real-time feedback with the developed hand. An extensive study was carried out on a subject with a congenital forearm defect, and the ability to perceive the stimulus of pressing force applied at the end of the forearm of the affected side was confirmed.

Smartphone-Based Real-time Assessment of Swallowing Ability From the Swallowing Sound

Dysphagia can cause serious challenges to both physical and mental health. Aspiration due to dysphagia is a major health risk that could cause pneumonia and even death. The videofluoroscopic swallow study (VFSS), which is considered the gold standard for the diagnosis of dysphagia, is not widely available, expensive and causes exposure to radiation. The screening tests used for dysphagia need to be carried out by trained staff, and the evaluations are usually non-quantifiable. This paper investigates the development of the Swallowscope, a smartphone-based device and a feasible real-time swallowing sound-processing algorithm for the automatic screening, quantitative evaluation, and the visualisation of swallowing ability. The device can be used during activities of daily life with minimal intervention, making it potentially more capable of capturing aspirations and risky swallow patterns through the continuous monitoring. It also consists of a cloud-based system for the server-side analyzing and automatic sharing of the swallowing sound. The real-time algorithm we developed for the detection of dry and water swallows is based on a template matching approach. We analyzed the wavelet transformation-based spectral characteristics and the temporal characteristics of simultaneous synchronised VFSS and swallowing sound recordings of 25% barium mixed 3-ml water swallows of 70 subjects and the dry or saliva swallowing sound of 15 healthy subjects to establish the parameters of the template. With this algorithm, we achieved an overall detection accuracy of 79.3% (standard error: 4.2%) for the 92 water swallows; and a precision of 83.7% (range: 66.6%-100%) and a recall of 93.9% (range: 72.7%-100%) for the 71 episodes of dry swallows.

Exoskeletal meal assistance system (EMAS III) for progressive muscle dystrophy patient

This paper introduces a 4-DOFs exoskeletal meal assistance system (EMAS II) for progressive muscle dystrophy patient. It is generally better for the patient to use his/her hands by himself in daily life because active works maintain level of residual functions, health and initiative of him/her. The EMAS II that has a new joystick-type user interface device and three-DOFs on a shoulder part is enhanced for an easier operation and more comfortable support on eating, as the succeeding model of the previous system that has two-DOFs on a shoulder. In order to control the 4-DOFs system by the simple user interface device, the EMAS II simulates upper limb motion patterns of a healthy person. The motion patterns are modeled by extracting correlations between the height of a users wrist joint and that of the users elbow joint at the table. Moreover, the EMAS II automatically brings users hand up to his/her mouth or back to a table when he/she pushes a preset switch on the interface device. Therefore a user has only to control a position of his/her wrist to pick or scoop foods and then flip the switch to start automatic mode, while a height of the elbow joint is automatically controlled by the EMAS II itself. The results of experiments, where a healthy subject regarded as a muscle dystrophy patient eats a meal with EMAS II, show that the subject finished her meal in a natural way in 18 minutes 40 seconds which was within a recommended time of 30 minutes.