F. Noveletto

Biorretroalimentação para treinamento do equilíbrio em hemiparéticos por acidente vascular encefálico: estudo preliminar

Since balance dysfunction is frequent among poststroke hemiparetic patients, balance training is a fundamental goal in their rehabilitation. The purpose of this study was to assess the effects of biofeedback balance training on an unstable computerized platform in six hemiparetic patients (three men and three women, mean age 56,2 years old). Subjects were assessed, before and after treatment, as to functional mobility (by the timed up-and-go test, TUGT), functional reach, health-related quality of life (by the Nottingham health profile), and as to equilibrium on the unstable platform. The training on an unstable computerized platform took place along 23, 30-minute sessions for 8 weeks. Results showed significant improvement (p<0.001) in standing balance, of 119.1% with feet apart, and of 79.6% with feet together; a 15% increase (p<0.001) in functional reach; a 25.6% improvement in TUGT (p<0.001); and a slight improvement in self-reported quality of life. The program brought thus significant improvements for the sample studied, suggesting that the biofeedback balance training as here proposed may be a valuable tool in the rehabilitation of stroke hemiparetic patients.

Serious game for rehabilitation of the lower limb of hemiparetics patients after stroke

Introduction/Background Hemiparesis is the classic clinical condition of stroke and is related to important locomotor limitations. The treatment strategies traditionally chosen are limited by the monotony, boredom and repetitiveness of the exercises. Serious games (SG) combine specific physical training with a higher attentional and motivational level, increasing adherence to treatment. The aim of this study was to verify the therapeutic effects of exercise program using a SG developed for evaluation and rehabilitation of hemiparetic patients after stroke. Material and method Non-Randomized Controlled Clinical Trial involving 24 patients (12 men) was conducted. Patients were divided into 2 groups. One group consisted in realize exercises with a SG mim-Pong (experimental, Fig. 1 ) and the other group a conventional physical therapy (control). Both groups completed the 20-session treatment protocol. The following variables evaluated were: muscle strength, motor control, motor impairment, spasticity, functional mobility and gait speed. Data were analyzed with descriptive statistics, paired Students t-test and effect size calculation. Results Patients did not differ in terms of sociodemographic characteristics at baseline. In the experimental group, significant improvements were observed for all variables ( Table 1 ). Large effect sizes were found for muscle strength of hamstrings, quadriceps femoris and hamstrings scores, Fugl-Meyer Assessment Scale and Modified Ashworth Scale. In the control group the improvements were lower than experimental group with small to moderate effect sizes. Significant differences were found only for game scores (QFS and HS) probably due to learning during the training phase conducted before assessment with the SG. Conclusion These results suggest that SG promote superior improvements to those obtained with conventional treatment of hemiparetic patients after stroke. This superiority is probably due to increased attention demand and motivation during interventions with SG.

Low-Cost Body Impedance Analyzer for Healthcare Applications

Bioimpedance has been widely used in many health areas. The ability of the human body cells , as the response for the alternate electric current flow, can provide valuable information about health status of the subject. This work presents a low-cost body impedance measuring system. The system is composed by the impedance meter AD5933, a four-electrode front-end circuit, a microcontroller sys tem and a computer system for processing, visualization and data sto- rage. The developed system calculates the resistance, reactance and phase angle (PA) from measured impedance spectra. Two subjects were assessed and the bioimpedance data was com- pared with data encountered in the literature. Predictive equations were used to calculate fat-free mass (FFM), fat mass percentage (%FM) and total body water (TBW). Preliminary results describe consistent with the reference values in the literature, indicating that the developed device is proper to body impedance measurement. The body impedance analyzer developed in this work was conducted according to the requirements of healthcare applications, such as portability and low cost. It can be concluded that the developed system can be used for body composition assessment over a wide aging range.

Biomedical Control Interface for a Physical Rehabilitation Serious Game

The main objective of rehabilitation is to improve the patient functional capacities. Most rehabilitation processes can take a long period of time, which may induce patients to drop out of the treatment. Therefore, it is important to use new strategies to motivate patients for continuing their rehabilitation. This work presents the development of a biomedical system to be used as a control interface for a serious game in physical rehabilitation. The biomedical system allows the use of an electromyography, dynamometer or an inertial sensors based on an accelerometer and a gyroscope. The game was developed inspired in a tennis videogame called Pong and was designed based on the PBL (Points, Badges and LeaderBoard) strategy and adapted to have special features for rehabilitation. The aim of the game is to control a racket by using either EMG, dynamometry or the inertial sensor signals. The game is calibrated and adjusted according to patient limitations. The game performs scoring based on an empirical approach. Preliminary tests showed that the system meets the hardware and software requirements for use in rehabilitation according to the medical compliance for this type of device. Results showed that the dynamometry, EMG and accelerometry signals can easily be used to control the game interface.

Low Cost Biofeedback System for Muscular Strength Analysis and Training

Muscular strength is a critical biological variable in order to perform any motor tasks associated with activities based on our daily life. Although advances in this area have been increased, it involves complex biomechanical and physiological mechanisms to be understand, which makes it still a challenge in his area. Diseases such as stroke (cerebrovascular accident - CVA) cause loss of muscle strength and affect severely the balance. This study aims to develop a low cost system for training and analysis of force in a biofeedback path. Both homemade hardware and software were implemented by consisting of an electromyography (EMG) system, a handgrip dynamometer and an inertial sensors based on accelerometer and gyroscope. EMG and muscular strength data were collected from a male volunteer of 44 years old. EMG data are compared to the medical literature. These preliminary tests showed that the system meets the hardware and software requirements for use in biofeedback according to the medical compliance for this type of device. Results from handgrip tests showed that the wrist angle is very important to determine correctly the muscular strength. The proposed system might be used to evaluate muscular strength in post-stroke patients.

Dynamometry as a Coadjuvant Analysis for the Characterization of Frailty Syndrome in the Elderly

Over the last decade, the scientific advances in health care have increased the life expectancy of the world population. Although the number of research in this area has increased, there are still some question marks about the frailty in the elderly to be addressed. The objective of this work is to develop a biomedical instrumentation to measure and to assess the muscle strength by force measurements. In order to obtain the force curve, both handgrip strength and the quadriceps muscle strength are analyzed in the Maximum Voluntary Isometric Contraction (MVIC) from dominant body side. Muscle strength is measured by one load cell coupled into a home-made device. The signal is conditioned by a microcon-troller and connected to a computer system for data visualiza-tion and storage. Both handgrip and quadriceps muscle strength are analyzed from two healthy volunteers. Prelimi-nary results of this pilot study indicate that the developed device meets the objectives of this work and that it can be used to enhance the assessment in the elderly with the frailty syn-drome.