BFB2 – BIOFEEDBACK
CATEGORYElectromedical Devices, Pro Line, Products
With Biofeedback (biological retroaction) we mean the chain by which a person perceives and modify an action to to make it conform to his will.
The BFB2 is a machine that detects, measures and presents the potentials due to the currents transmitted to the nerve fibers.
For this characteristic this BFB2 is an electromyographic biofeedback. In this brief introduction we will try to provide an explanation of the BFB2’s purpose. The magnitude which is detected by the machine is a potential difference.
The detection is performed normally via three surface electrodes positioned, two on the muscle belly of the stroke of which is to measure the difference in potential and a third reference one, placed normally equidistant between the two, to form an isosceles triangle.
The potential electric value, generating the current stimulation of a muscle, even if bigger than informative transmission signals (visual signs, cerebral signs, etc.), results to be a microvolt order (millionths of volt).
This very low value provides in the measure system an amplification chain of a very high level, which normally would amplify also surrounding signals (disturbing) revealed by the electrodes (such as, for instance, the noise due to the electric grid present in all the working environments and with a way higher value of the signal willing to measure).
We have 4 different systems to show the value of the potential revealed by the machine (graphic-numeric-luminous-acustic), that are distinguished by their precision, the immediate relevance from the user, the type of sensation given to the user and the type of attention required by the user.
The choice of a type of presentation is determined by the mean by which the BFB2 is used. In the graphic representation, each point of the function is revealed on the temporal axe every 0,5 mS (milliseconds), meaning a time extremely shorter than the muscle contraction. The reported signal, indeed, it is the electromyographic signal, which provides useful information on the system efficiency (mandatory for a medical investigation), without specifying though immediately the average course of the energy associated to the signal, the only one that allows us to control our action, considering its slowest variation.
To obtain all this it is needed to elaborate and show the electromyographic
signal, making it proportional to the energy used in the contraction. Considering some technical-practic reasons, we opted to set an average time and presentation with intervals at a minimum of 130 mS, up to a maximum of 500 mS. This way we can get a good compromise between the speed of representation and the level of information associated.
The numeral presentation is simply the numeric value expressed in uV (microvolts) of the result of the signal elaboration in the time interval selected. This kind of presentation, even if extremely punctual and precise, varying when the signal changes, can provide useful information only to the operator, and not to the patient.
The luminous presentation consists in the activation of a graphic bar composed of 10 levels. The progressive activation of each level is proportional to the value of the result of the elaboration of the signal, mediated on 100 mS. The value (expressed in uV) of activation of the first level and the increment, necessary from a level to another, are programmable.
The acoustic presentationis basically the possibility of discriminate the levels detected previously visually with the graphic bar, through ten different acoustic frequencies that are proportional to the value of the result of the elaboration of the signal mediated on 100 mS.