Brazilian clinical engineering regulations: health equipment management and conditions for professional exercise

Abstract Introduction In Brazil, professionals, scientific community, and members of regulatory bodies have not yet achieved a consensus regarding who can legally perform the professional duties of a clinical engineer. We aim at clarifying this aspect, based on a detailed analysis of the pertinent regulations. Methods We acted on three fronts: (i) reviewing the current legislation regarding the clinical engineering exercise; (ii) visiting hospitals and working as trainee to understand how this exercise is implemented on Brazil's Federal District; (iii) one of the authors participated in virtual discussion groups of clinical engineering professionals, monitoring collective understanding of regulations, checking consistency of proper knowledge, and acting as an active opinion leader in the subject among peers. Results We try to make a formal definition of clinical engineer and indicate their characteristic activities. We propose a synthesis of the regulation regarding healthcare products' integrity protection and health technology management, identifying the engineering activities necessary to achieve those legal requirements. We analyze the legal constraints and conditions to exert engineering, indicating the necessary professionals' attributions and the way to obtain them. Finally, we provide a brief analysis of the technical requirements presented by the Brazilian Consumer Protection Code and of the 15.943 Brazilian Standard (NBR). Discussion We conclude that, despite the lack of consensus about the Clinical Engineering activity, there exists in Brazil a Clinical Engineering regulation, but it is spread in complex laws and normative resolutions, defining compulsory responsibilities and attributions, as well as conditions and prerequisites for role performance.

Motor unit action potential conduction velocity estimated from surface electromyographic signals using image processing techniques.

In surface electromyography (surface EMG, or S-EMG), conduction velocity (CV) refers to the velocity at which the motor unit action potentials (MUAPs) propagate along the muscle fibers, during contractions. The CV is related to the type and diameter of the muscle fibers, ion concentration, pH, and firing rate of the motor units (MUs). The CV can be used in the evaluation of contractile properties of MUs, and of muscle fatigue. The most popular methods for CV estimation are those based on maximum likelihood estimation (MLE). This work proposes an algorithm for estimating CV from S-EMG signals, using digital image processing techniques. The proposed approach is demonstrated and evaluated, using both simulated and experimentally-acquired multichannel S-EMG signals. We show that the proposed algorithm is as precise and accurate as the MLE method in typical conditions of noise and CV. The proposed method is not susceptible to errors associated with MUAP propagation direction or inadequate initialization parameters, which are common with the MLE algorithm. Image processing -based approaches may be useful in S-EMG analysis to extract different physiological parameters from multichannel S-EMG signals. Other new methods based on image processing could also be developed to help solving other tasks in EMG analysis, such as estimation of the CV for individual MUs, localization and tracking of innervation zones, and study of MU recruitment strategies.

Spatially distributed surface electromyography signal simulator.

Electromyographic signals are of great importance to current biomedical research society since they may be used in several ways as, for example, in the diagnosis of neuromuscular diseases, the control of active prosthetic limbs as well as the test and validation of medical equipment.

Electromyographic study in 5 muscles during an isometric fatiguing protocol.

In this study, 12 healthy men aging 22.8 ± 2.2 years old were submitted to a protocol of isometric resistance to fatigue contemplating elbow flexion on three different angles: 45°, 90° and 135°. The objective was to study electromyographic median frequency (MDF) in the following muscles: i) Biceps Brachialis Long Head (BBL), Brachioradialis (BRD), Flexor Digitorum Superficialis (FDS), Triceps Brachialis Long Head (TBL), and Extensor Digitorum (ED). It was verified that, for all muscles, including the muscles that act in opposition to the contraction, fatigue presence was verified by the decrease of MDF value.

On the behavior of surface electromyographic variables during the menstrual cycle.

The goal of this work is to study the behavior of electromyographic variables during the menstrual cycle. Ten female volunteers (24.0 ± 2.8 years of age) performed fatiguing isometric contractions, and electromyographic signals were measured on the biceps brachii in four phases of the menstrual cycle. Adaptations of classical algorithms were used for the estimation of the root mean square (RMS) value, absolute rectified value (ARV), mean frequency (MNF), median frequency (MDF), and conduction velocity (CV). The CV estimator had a higher (p = 0.002) rate of decrease at the end of the follicular phase and at the end of the luteal phase. The MDF (p = 0.002) and MNF (p = 0.004) estimators had a higher rate of decrease at the beginning of the follicular phase and at the end of the luteal phase. No significant differences between phases of the menstrual cycle were detected with the ARV and RMS estimators (p > 0.05). These results suggest that the behavior of the muscles in women presents different characteristics during different phases of the menstrual cycle. In particular, women were more susceptible to fatigue at the end of the luteal phase.

Evaluation of a mobile electrode for electrical stimulation of the perineal muscle.

This work evaluates the effectiveness of a new type of electrode for functional electrical stimulation of the perineal muscle in women. The new electrode is shaped like a pen, with an active stimulation electrode located on its tip. The goals of the study are to (i) demonstrate that stimulation using the new device results in increased muscle strength; and (ii) compare the performance of the new device with that of a traditional (fixed) electrode. Eight women were evaluated, following a blind study protocol. The preliminary results suggest that stimulation with the new electrode achieves better results than stimulation with traditional electrodes, as higher increases in strength were observed in the group that used the mobile electrode.

Gender differences in muscle fatigue of the biceps brachii and influences of female menstrual cycle in electromyography variables.

Several studies report gender differences in response to fatigue. Most results suggest that females have higher muscle endurance than males. Possible explanations lie on differences in muscle mass, substrate utilization, muscle morphology and neuromuscular activation. One relevant aspect not always considered is the hormonal fluctuations during the female menstrual cycle. The present work observed eighteen healthy and untrained adults (eight males, 26.9 +/- 4.0 yr and ten females, 24.0 +/- 2.8 yr) performing fatiguing isometric contractions to evaluate both the influence of menstrual cycle and gender differences in fatigability. Surface electromyographic signals were recorded from the biceps brachii using a linear electrode array of eight electrodes during 90 seconds at 40% of maximal voluntary contraction. Root mean square (RMS), mean frequency (MNF) the conduction velocity (CV) values were estimated using windows of 0.5 seconds. Female subjects showed overall lower fatigability, demonstrated by the lower mean CV decrease (1.494) compared to males (1.787). However, in periods of high decreases in hormones concentrations in females (the end of both the follicular and luteal phases), higher CV decreases were observed (1.921 and 2.183). These results indicate the need of considering the effects of hormonal fluctuations in females when observing gender effects on muscle fatigue.