Influence of Robot-Assisted Gait Training on Lower-Limb Muscle Activity in Patients With Stroke: Comparison With Conventional Gait Training.

OBJECTIVE: To measure muscle activity before and after robot-assisted gait training (RAGT) in patients with stroke and examine the differences in muscle activity changes compared with conventional gait training (CGT). METHODS: Thirty patients with stroke (RAGT group, n=17; CGT group, n=13) participated in the study. All patients underwent RAGT using a footpad locomotion interface or CGT for 20 minutes for a total of 20 sessions. Outcome measures were lower-limb muscle activity and gait speed. Measurements were performed before the start of the intervention and after the end of the 4-week intervention. RESULTS: The RAGT group showed increased muscle activity in the gastrocnemius, whereas the CGT group showed high muscle activity in the rectus femoris. In the terminal stance of the gait cycle, the gastrocnemius, the increase in muscle activity was significantly higher in the RAGT group than in the CGT group. CONCLUSION: The results suggest that RAGT with end-effector type is more effective than CGT to increase the gastrocnemius muscle activity.

Effect of gait rehabilitation with a footpad-type locomotion interface on gait ability in subacute stroke patients.

BACKGROUND: Gait rehabilitation using a footpad-type locomotion interface has been reported as effective in improving gait ability in chronic stroke patients. However, the effect on subacute stroke patients is unknown. OBJECTIVE: To compare the effect of gait rehabilitation using a footpad-type locomotion interface (Gait Training with Locomotion Interface group; GTLI group) with conventional gait rehabilitation (control group) in subacute stroke patients. METHODS: Twenty-one stroke patients (GTLI group: n = 13, control group: n = 8) participated in the study. All participants received gait rehabilitation using the footpad-type locomotion interface or conventional gait rehabilitation for 20 minutes x 20 sessions. Outcome measures were functional ambulation Category (FAC), gait speed, gait endurance and lower muscle strength. Measures were taken at baseline and 1, 2, 3 and 4 weeks. RESULT: The GTLI group significantly improved gait speed and gait endurance compared with the control group. However, FAC and lower limb muscle strength were not significantly different. CONCLUSIONS: The results suggest that gait rehabilitation using the footpad-type locomotion interface can improve gait ability better than conventional gait rehabilitation.

Streaming, Bouncing, and Rotation: The Polka Dance Stimulus.

When the objects in a typical stream-bounce stimulus are made to rotate on a circular trajectory, not two but four percepts can be observed: streaming, bouncing, clockwise rotation, and counterclockwise rotation, often with spontaneous reversals between them. When streaming or bouncing is perceived, the objects seem to move on individual, opposite trajectories. When rotation is perceived, however, the objects seem to move in unison on the same circular trajectory, as if constituting the edges of a virtual pane that pivots around its axis. We called this stimulus the Polka Dance stimulus. Experiments showed that with some viewing experience, the viewer can "hold" the rotation percepts. Yet even when doing so, a short sound at the objects' point of coincidence can induce a bouncing percept. Besides this fast percept switching from rotation to bouncing, an external stimulus might also induce slower rotation direction switches, from clockwise to counterclockwise, or vice versa.

Evaluation of the Perceptual Characteristics of a Force Induced by Asymmetric Vibrations.

This paper describes the perceptual characteristics of a sense of a force induced by asymmetric vibration using a vibration speaker-type non-grounded haptic interface. We confirm that the vibration speaker generates a perceived force that pulls or pushes a user's hand in a particular direction when an asymmetric amplitude signal that is generated by inverting a part of a sine wave is input. In this paper, to verify the system with respect to various factors of force perception caused by asymmetric vibration, we conducted six experiments and the following results were obtained. (1) The force vector can be controlled by reversing the asymmetric waves. (2) By investigating the physical characteristics of the vibration, asymmetric vibration was confirmed. (3) The presentation of vibration in the shear direction on the finger pad is effective. (4) The point of subjective equality of the perceived force can be controlled by up to 0.43 N by changing the amplitude voltage of the input signals. (5) The minimum stimulation time required for force perception is 66.7 ms. (6) When the vibration is continuously presented for 40 to 50 s, the perceived force decreases because of adaptation. Hence, we confirmed that we can control both the direction and magnitude of the reaction force by changing the input signal of the vibration speaker.

Encountered-Type Haptic Interface for Representation of Shape and Rigidity of 3D Virtual Objects.

This paper describes the development of an encountered-type haptic interface that can generate the physical characteristics, such as shape and rigidity, of three-dimensional (3D) virtual objects using an array of newly developed non-expandable balloons. To alter the rigidity of each non-expandable balloon, the volume of air in it is controlled through a linear actuator and a pressure sensor based on Hooke's law. Furthermore, to change the volume of each balloon, its exposed surface area is controlled by using another linear actuator with a trumpet-shaped tube. A position control mechanism is constructed to display virtual objects using the balloons. The 3D position of each balloon is controlled using a flexible tube and a string. The performance of the system is tested and the results confirm the effectiveness of the proposed principle and interface.

Optic nerve input-dependent regulation of neural stem cell proliferation in the optic tectum of adult zebrafish.

Adult neurogenesis attracts broad attention as a possible cure for neurological disorders. However, its regulatory mechanism is still unclear. Therefore, they have been studying the cell proliferation mechanisms of neural stem cells (NSCs) using zebrafish, which have high regenerative potential in the adult brain. The presence of neuroepithelial-type NSCs in the optic tectum of adult zebrafish has been previously reported. In the present study, it was first confirmed that NSCs in the optic tectum decrease or increase in proportion to projection of the optic nerves from the retina. At 4 days after optic nerve crush (ONC), BrdU-positive cells decreased in the optic tectum's operation side. In contrast, at 3 weeks after ONC, BrdU-positive cells increased in the optic tectum's operation side. To study the regulatory mechanisms, they focused on the BDNF/TrkB system as a regulatory factor in the ONC model. It was found that bdnf was mainly expressed in the periventricular gray zone (PGZ) of the optic tectum by using in situ hybridization. Interestingly, expression level of bdnf significantly decreased in the optic tectum at 4 days after ONC, and its expression level tended to increase at 3 weeks after ONC. They conducted rescue experiments using a TrkB agonist and confirmed that decrease of NSC proliferation in the optic tectum by ONC was rescued by TrkB signal activation, suggesting stimuli-dependent regulation of NSC proliferation in the optic tectum of adult zebrafish. © 2016 Wiley Periodicals, Inc. Develop Neurobiol 77: 419-437, 2017.

Novel 3-dimensional virtual hepatectomy simulation combined with real-time deformation.

AIM: To develop a novel 3-dimensional (3D) virtual hepatectomy simulation software, Liversim, to visualize the real-time deformation of the liver. METHODS: We developed a novel real-time virtual hepatectomy simulation software program called Liversim. The software provides 4 basic functions: viewing 3D models from arbitrary directions, changing the colors and opacities of the models, deforming the models based on user interaction, and incising the liver parenchyma and intrahepatic vessels based on user operations. From April 2010 through 2013, 99 patients underwent virtual hepatectomies that used the conventional software program SYNAPSE VINCENT preoperatively. Between April 2012 and October 2013, 11 patients received virtual hepatectomies using the novel software program Liversim; these hepatectomies were performed both preoperatively and at the same that the actual hepatectomy was performed in an operating room. The perioperative outcomes were analyzed between the patients for whom SYNAPSE VINCENT was used and those for whom Liversim was used. Furthermore, medical students and surgical residents were asked to complete questionnaires regarding the new software. RESULTS: There were no obvious discrepancies (i.e., the emergence of branches in the portal vein or hepatic vein or the depth and direction of the resection line) between our simulation and the actual surgery during the resection process. The median operating time was 304 min (range, 110 to 846) in the VINCENT group and 397 min (range, 232 to 497) in the Liversim group (P = 0.30). The median amount of intraoperative bleeding was 510 mL (range, 18 to 5120) in the VINCENT group and 470 mL (range, 130 to 1600) in the Liversim group (P = 0.44). The median postoperative stay was 12 d (range, 6 to 100) in the VINCENT group and 13 d (range, 9 to 21) in the Liversim group (P = 0.36). There were no significant differences in the preoperative outcomes between the two groups. Liversim was not found to be clinically inferior to SYNAPSE VINCENT. Both students and surgical residents reported that the Liversim image was almost the same as the actual hepatectomy. CONCLUSION: Virtual hepatectomy with real-time deformation of the liver using Liversim is useful for the safe performance of hepatectomies and for surgical education.

Development of a portable gait rehabilitation system for home-visit rehabilitation.

This paper describes the development of a gait rehabilitation system with a locomotion interface (LI) for home-visit rehabilitation. For this purpose, the LI should be compact, small, and easy to move. The LI has two 2 degree-of-freedom (DOF) manipulators with footpads to move each foot along a trajectory. When the user stands on the footpads, the system can move his or her feet while the body remains stationary. The footpads can have various trajectories, which are prerecordings of the movements of healthy individuals walking on plane surfaces or slopes. The homes of stroke patients may have not only flat surfaces but also some slopes and staircases. The quadriceps femoris muscle is important for walking up and down slopes and staircases, and the eccentric and concentric contractions of this muscle are, in particular, difficult to train under normal circumstances. Therefore, we developed a graded-walking program for the system used in this study. Using this system, the user can undergo gait rehabilitation in their home, during visits by a physical therapist. An evaluation of the results of tests showed that the vastus medialis muscles of all the subjects were stimulated more than by walking on real slopes.

Effects of gait rehabilitation with a footpad-type locomotion interface in patients with chronic post-stroke hemiparesis: a pilot study.

OBJECTIVE: We developed a footpad-type locomotion interface called the GaitMaster. The purpose of this pilot study was to examine the effects of gait rehabilitation using the GaitMaster in chronic stroke patients. DESIGN: Randomized cross-over design. SETTING: An outpatient department. SUBJECTS: Twelve patients with chronic post-stroke hemiparesis. INTERVENTION: In group A, patients underwent an 'intervention phase' followed by a 'non-intervention phase', whereas in group B, patients underwent the non-intervention phase first, followed by the intervention phase. In the four- or six-week intervention phase, participants underwent twelve 20-minute sessions of gait rehabilitation using the GaitMaster4. MAIN OUTCOME MEASURES: We measured gait speed and timed up-and-go test. RESULTS: No differences between the two groups were observed in the baseline clinical data. For the combined groups A and B, the maximum gait and timed up-and-go test speeds improved significantly only in the intervention phase (P = 0.0001 and P = 0.003, respectively). The percentages of improvement from baseline at the end of GaitMaster training were 16.6% for the maximum gait speed and 8.3% for the timed up-and-go test. The effect size for GaitMaster4 training was 0.58 on the maximum gait speed and 0.43 on the timed up-and-go test. CONCLUSIONS: This pilot study showed that gait rehabilitation using the GaitMaster4 was a feasible training method for chronic stroke patients. Calculation of the sample size indicated that a sample size of 38 participants would be adequate to test a null hypothesis of nil benefit additional to routine rehabilitation for chronic stroke patients in a future randomized controlled trial.

Heat denaturation increases the sensitivity of the cytomegalovirus loop-mediated isothermal amplification method.

A new protocol for CMV LAMP with an additional heat denaturation step was developed. While the sensitivity of the original CMV LAMP method was 500 copies/tube, sensitivity was increased by up to 100 copies/tube by additional heat denaturation. CMV DNA was detected in 103 of 350 samples (29.4%) by the original CMV LAMP procedure and 148 of 350 samples (42.3%) by the new CMV LAMP protocol. When the pp65 antigenemia assay was used as the standard method, the sensitivity, specificity, PPV, and NPV of the new protocol were 92.9%, 77.7%, 62.2%, and 96.5%, respectively.

[A study of otitis externa associated with Malassezia].

Malassezia-positive smears can be recognized from otitis externa, however, there are few references in the literature to the relation between Malassezia and otitis externa. Therefore, the bacterial and clinical characteristics of 72 cases (63 patients) with otitis externa were investigated at the Department of Otorhinolaryngology, Takinomiya General Hospital to analyze this. Thirty-seven cases were bacterial otitis externa, 20 cases were fungal otitis externa, and 15 cases were etiological agents unknown in this study. The causative organisms in fungal otitis externa were the genera Aspergillus (10 cases), Malassezia (5) and Candida (5), respectively. We suspected that 5 cases were caused by Malassezia because Malassezia cell counts were greater than 10 per field (x 400), and a large number of Malassezia were isolated from all cases. In these cases, many squamous epithelial cells were observed by direct examination, and cells from the middle or basal layer of the ear canal were also recognized in three cases. Therefore, accelerated turnover of epidermal cells of the ear canal was suggested. The main symptoms were itching and fullness in the ear, with observations of redness and erosion in objective deterioration, and we felt that these conditions were similar to seborrheic dermatitis (SD). In addition, these five cases were confirmed as fungus-related otitis externa by their improvement with antifungal agents.