Development and clinical validation of passive shoulder exoskeleton with novel gravity compensation mechanism for stabilizing arm tremor of surgeons during minimally invasive surgery.

Introduction: During tasks like minimally invasive surgery (MIS), various factors can make working environment not be ergonomic, and those situations will accumulate fatigue in the surgeon's muscles which will inevitably lead to poor surgical performance. Therefore, there has been a need for technical solutions to solve this problem and one of the methods is exoskeleton robots.

Methods: We designed a passive shoulder exoskeleton whose workspace could be used for MIS to assist the surgeon's movements and performed computational and clinical validation.

Calibrating Low-Cost Smart Insole Sensors with Recurrent Neural Networks for Accurate Prediction of Center of Pressure.

This paper proposes a scheme for predicting ground reaction force (GRF) and center of pressure (CoP) using low-cost FSR sensors. GRF and CoP data are commonly collected from smart insoles to analyze the wearer's gait and diagnose balance issues. This approach can be utilized to improve a user's rehabilitation process and enable customized treatment plans for patients with specific diseases, making it a useful technology in many fields.

Ankle strategy assistance to improve gait stability using controllers based on in-shoe center of pressure in 2 degree-of-freedom powered ankle-foot orthoses: a clinical study.

Background: Although the ankle strategy is important for achieving frontal plane stability during one-leg stance, previously developed powered ankle-foot orthoses (PAFOs) did not involve ankle strategies because of hardware limitations. Weakness of movement in frontal plane is a factor that deteriorates gait stability and increases fall risk so it should not be overlooked in rehabilitation. Therefore, we used PAFO with subtalar joint for frontal plane movement and tried to confirm that the existence of it is important in balancing through clinical experiments.

The effects of operating height and the passage of time on the end-point performance of fine manipulative tasks that require high accuracy.

Sustained shoulder abduction, which results from an inappropriate worktable height or tool shape and long task hours, leads to an accumulation of muscle fatigue and subsequent work-related injuries in workers. It can be alleviated by controlling the table height or ergonomic tool design, but workers who are doing some types of work that require a discomfortable posture, such as minimally invasive surgery, cannot avoid these situations. Loads to the shoulder joint or muscles result in several problems, such as muscle fatigue, deterioration of proprioception or changing movement strategies of the central nervous system, and these are critical to work that requires a high accuracy of the upper extremities.

Policy Design for an Ankle-Foot Orthosis Using Simulated Physical Human-Robot Interaction via Deep Reinforcement Learning.

This paper presents a novel approach for designing a robotic orthosis controller considering physical human-robot interaction (pHRI). Computer simulation for this human-robot system can be advantageous in terms of time and cost due to the laborious nature of designing a robot controller that effectively assists humans with the appropriate magnitude and phase. Therefore, we propose a two-stage policy training framework based on deep reinforcement learning (deep RL) to design a robot controller using human-robot dynamic simulation.

Effects of the degree of freedom and assistance characteristics of powered ankle-foot orthoses on gait stability.

We studied the use of powered ankle-foot orthoses (PAFOs) and walking stability of the wearers, focusing on the ankle joint, which is known to play a critical role in gait stability. Recognizing that the subtalar joint is an important modulator of walking stability, we conducted the walking experiment on a treadmill by applying varying assistance techniques to the 2-degree-of-freedom (DOF) PAFO, which has the subtalar joint as the rotating axis, and the commonly used 1-DOF PAFO. The participants were 8 healthy men (mean±SD: height, 174.

Terrain Feature Estimation Method for a Lower Limb Exoskeleton Using Kinematic Analysis and Center of Pressure.

While controlling a lower limb exoskeleton providing walking assistance to wearers, the walking terrain is an important factor that should be considered for meeting performance and safety requirements. Therefore, we developed a method to estimate the slope and elevation using the contact points between the limb exoskeleton and ground. We used the center of pressure as a contact point on the ground and calculated the location of the contact points on the walking terrain based on kinematic analysis of the exoskeleton.

Design of a Pneumatic Actuated Ankle-Foot Orthosis which has Talocrural and Subtalar Joint.

As aging progresses, risk of falls in elderly people increases due to the decreasing the range of motion (RoM) of eversion and the weakening of the plantar flexor. Balance training is performed to reduce the risk of falls and powered ankle-foot orthosis (PAFO) can be utilized in this process. The elderly can conduct training on the narrow roads or on the rugged ground with assistance on rotation of eversion and propulsion by PAFO.

Design of an Artificial Neural Network Algorithm for a Low-Cost Insole Sensor to Estimate the Ground Reaction Force (GRF) and Calibrate the Center of Pressure (CoP).

As an alternative to high-cost shoe insole pressure sensors that measure the insole pressure distribution and calculate the center of pressure (CoP), researchers developed a foot sensor with FSR sensors on the bottom of the insole. However, the calculations for the center of pressure and ground reaction force (GRF) were not sufficiently accurate because of the fundamental limitations, fixed coordinates and narrow sensing areas, which cannot cover the whole insole. To address these issues, in this paper, we describe an algorithm of virtual forces and corresponding coordinates with an artificial neural network (ANN) for low-cost flexible insole pressure measurement sensors.

Development of a cardiorespiratory monitoring system based on pressure change of aircushion.

Heartbeat and respiration are fundamental vital signs used for estimation of patient's status. In this study, we have proposed a simple method to monitor the heartbeat and respiration based on displacements of human body which occur due to periodic heartbeat and breathing.

A design of RF stimulator which is similar to temperature distribution by moxibustion (preliminary study).

We developed a novel radio-frequency (RF) stimulator to mimic heat effects similar to the temperature distributions created by moxibustion in porcine tissue. Moxibustion is a traditional Oriental medicine technique using moxa, which is utilized not only to cure disease, but also to increase immunity. However, it may lead to undesired effects including severe pains, blisters, and burns because of the difficulty of controlling heat intensity during the process.

Novel algorithm for the hemiplegic gait evaluation using a single 3-axis accelerometer.

This paper suggests the novel algorithm for the estimating gait parameters of the hemiplegic patients using a 3-axis accelerometer. The signal processing for algorithm consists of a bandpass filter and a least square acceleration filter. To evaluate the performance of the algorithm, the correlation coefficients of the stride and the step time between the 3-axis accelerometer and the Vicon motion analysis system are compared.

Adaptive noise canceling of electrocardiogram artifacts in single channel electroencephalogram.

A new method for estimating and eliminating electrocardiogram (ECG) artifacts from single channel scalp electroencephalogram (EEG) is proposed. The proposed method consists of emphasis of QRS complex from EEG using least squares acceleration (LSA) filter, generation of synchronized pulse with R-peak and ECG artifacts estimation and elimination using adaptive filter. The performance of the proposed method was evaluated using simulated and real EEG recordings, we found that the ECG artifacts were successfully estimated and eliminated in comparison with the conventional multi-channel techniques, which are independent component analysis (ICA) and ensemble average (EA) method.

Results of Curative Radiotherapy Alone in Patients with Uterine Cervical Carcinomas.

Purpose: To evaluate the role of curative radiotherapy alone in the treatment of uterine cervical carcinomas, by a retrospective analysis with respects to survival and pelvic control, and to find any risk factors of failure.

Materials And Methods: Between Jan. 1990 and Dec.