As visual stimuli for exercise and cognitive rehabilitation of biomechanics, virtual reality (VR) and augmented reality (AR) devices have getting popularity. In the process of developing the relevant content for VR and AR, there has been a problem that only a specific platform must be supported or multiple programs must be used. Recently, the Unity 3D platform has been developed for the convenience of game development for VR or AR environments that potentially solve these problems. Unity 3D’s game engine and animation can easily implement a moving avatar as visual stimuli, and the speed of the avatars can be checked in real-time. Therefore, we developed a moving avatar as the visual stimuli using Unity 3D and conducted pilot experiments with four healthy subjects by performing the knee extension and ankle dorsiflexion tasks with and without visual stimuli. The number of movements was counted to check the feasibility of the effectiveness using visual stimuli using Unity 3D. The results showed that the number of movements was higher when the visual stimuli were presented compared to that without the visual stimuli in both ankle dorsiflexion and knee extension. Our findings and approach can be a basis for further developing rehabilitation training protocols using various visual stimuli with Unity 3D.

A numerical approach is one of feasible ways to discover the biomechanics of hallux valgus deformity with various osteotomy and fixation strategies. In the present study, two types of finite element models for analyzing the biomechanical performances of hallux valgus treatment with plate fixations were developed including the single first metatarsal bone model and the musculoskeletal lower extremity model. There are four types of plate fixations that were used to correct the deformity of hallux valgus. The strengths and limitations of both the single first metatarsal bone model and the musculoskeletal lower extremity model were evaluated and discussed. The results revealed that the single metatarsal bone models can be used to quickly predict the biomechanical performances of different hallux valgus treatments. Additionally, the musculoskeletal lower extremity models can be used to predict the biomechanical performances of different hallux valgus treatments under a physiological loading. The plate fixations with the insertion of all locking screws revealed better osteotomy fixation stability and lower risk of the implant failure compared to the other fixations. Additionally, the plate fixations with the insertion of six bone screws had lower risk of the metatarsal bone failure compared to the plate fixations with the insertion of four bone screws. The six holes plate with the insertion of six locking screws was the best treatment among the four treatment strategies. The numerical models and simulation techniques developed in the present study can provide useful information for understanding the biomechanics of hallux valgus treatments.

Although it has been reported that blood brain barrier (BBB) disruption following head impact can lead to increased vascular permeability and subsequent brain injury, the influence of pressure loading on BBB dysfunction is not fully understood. In this study, we exposed in vitro BBB models to impulsive pressure to mimic changes in intracranial pressure during head impact. Barrier function was examined by measuring transendothelial electrical resistance (TEER). Four models were used: an endothelial monolayer of rat brain capillaries (E00 model), a co-culture model of endothelial cells and pericytes (EP0 model), a co-culture model of endothelial cells and astrocytes (EA0 model), and a triple co-culture model of endothelial cells, pericytes, and astrocytes (EPA model). Immediately after loading, the E00 model showed a 13% decrease in TEER, the EP0 model showed an 8% decrease, the EA0 model showed a 40% decrease, and the EPA model showed a 33% decrease. At 2 days post-loading, TEER values in the EPA model remained decreased and the expression of claudin-5 and ZO-1 was significantly decreased, whereas GFAP expression was significantly increased. In conclusion, increased endothelial paracellular permeability induced by exposure to impulsive pressure is associated with astrocyte activation and decreased tight junction protein expression in vitro.

Hand prostheses by upper limb amputees are primarily dependent on visual feedback owing to the loss of sensory function in their hand. Although previous researches have been conducted on the restoration of the sensory function of amputees and on the development of electronic skin and gloves for sensory feedback, the realization to apply the research results to commercial hand prostheses is still difficult. In this study, we designed and developed a hand prosthesis cover including a sensory recognitive function which closely mimics human hand skin and, resulting into a multi-degree-of-freedom (DOF) myoelectric hand prosthesis. The proposed cover was made of flexible silicon to mimic the human hand skin, which can measure a grip force of less than 50 N using a tactile sensing module. The tactile sensing module was developed using a force-sensitive resistor sensor, and solid silicone vacuum compression molding by embedding the sensor and wires inside the cover was introduced for the fabrication process. A developed finger module for multi-DOF myoelectric hand prostheses by imitating the anatomical structure and motion mechanism of a human finger was compared the performance of the developed cover with that of a commercial cover on the developed finger module of the myoelectric hand prosthesis. The metacarpophalangeal joint range of motion of the finger module with the proposed cover with a 1.5 mm thickness was measured from 0° to 60° and the flexion angular velocity was recorded as a value of 60°/710 ms, which are similar to those of the commercial cover. From the experiments, we found that the hand gestures and grip motions seem to be similar with the proposed and commercial covers. From the experiment, we can suggest that the developed cover with sensory recognition can be directly applied to multi-DOF myoelectric hand prostheses. Also, with a fast and simple commercialized process, widely usage for amputees with the developed hand prosthesis cover will be available.

The purpose of this study was to develop quantitative parameters using range of motion (ROM) of shanks, thighs and knees to evaluate the effect of deep brain stimulation (DBS) on gait performance and freezing of gait (FOG) of patients with advanced Parkinson’s disease (PD). Three patients with FOG due to advanced Parkinson’s disease who has received DBS were recruited. The recruited subjects were instructed to walk on a 100-meter path in three conditions: 60 Hz DBS (60 Hz), 130 Hz DBS (130 Hz) and no DBS (Off). Five inertial measurement unit sensors were attached to subjects’ sacrum, bilateral shanks and thighs respectively. Quantified parameters included (1) spatial parameters: shanks, thighs and knees ROM; (2) temporal parameters: stride time, stance time duration and double support time percentage; (3) FOG severity: the percentage of FOG duration during path walking. Three subjects’ ROM of right shank significantly increased in 60 Hz,130 Hz and Off order. Compared to 130 Hz, right shank ROM of subjects S1, S2 and S3 significantly increased 13.2%, 99.6% and 6.1% in 60 Hz, respectively. In temporal parameters results, only double support time percentage was significantly different between 60 Hz and 130 Hz in all three subjects. When compared to 130 Hz, the double support time percentage of S1 and S2 significantly decreased 6.3% and 18.4% in 60 Hz, and that of S3 significantly increased 4.4%. ROM of right shank and FOG severity were highly correlated (R2 = 0.71). Shank ROM could represent subjects’ gait performance under different stimulation conditions. Shank ROM could be treated as a reference for clinicians to evaluate gait performance and severity of FOG immediately when DBS frequency is adjusted. This study demonstrated the potential of using objective parameters to optimize the DBS through assessing the gait performance changes in the clinic.