The Johnson Noise in Biological Matter

Abstract

Can a very low intensity signal overcome a disturbance, the power density of which is much higher than the signal one, and yield some observable effects? The Johnson noise seems to be a disturbance so high as to cause a negative answer to that question, when one studies the effects on the cell level due to the external ELF fields generated by electric power lines (Adair, 1990, 1991). About this subject, we show that the masking effect due to the Johnson noise, known as “Adair’s constraint” and still present in the scientific debate, can be significantly weakened. The values provided by the Johnson noise formula, that is an approximate expression, can be affected by a significant deviation with respect to the correct ones, depending on the frequency and the kind of the cells, human or not human, that one is dealing with. We will give some examples. Eventually, we remark that the so-called Zhadin effect, although born and studied in a different context, could be viewed as an experimental test that gives an affirmative answer to the initial question, when the signal is an extremely weak electromagnetic field and the disturbance is a Johnson noise.

Natural ELF fields in the atmosphere and in living organisms

“…Unfortunately, a physical mechanism explaining these findings is still absent. The main obstacle in uncovering the physical explanation is the extremely weak amplitude of the magnetic fields used in the experiments, with an energy much lower than the surrounding noise factors and characteristic energy scales, such as the thermal fluctuations of the charged particles and the resulting Johnson-Nyquist noise (known in the literature as the 'kT problem'), the electrical noise (magnetic fields produced by the brain for example are of the same order of the SR field (~ pT) while fields produced by cardiomyocyte excitation is two orders of magnitude higher (~100pT)) and chemical energy required for biological processes (Adair, 1991;Binhi, et al, 2007;Scalia et al, 2012). A detailed description of electric and magnetic field strengths and noise levels can be found in Adair (1991).…”

Time Evolution of the Skin–Electrode Interface Impedance under Different Skin Treatments

“…In the majority of these devices, the recording interface is an electrode placed in direct contact with the skin to allow for transduction of biopotentials from the body to the acquisition and processing systems. Achieving a low-impedance interface between the electrode and the skin is vital to transduce signals with high fidelity, as too high of an impedance increases the thermal noise of the electrodes, thus degrading their signal-to-noise ratio (SNR) [ 5 , 6 , 7 ]. A low SNR may, in turn, prevent clean recording of muscle activation during electromyography (EMG) studies [ 8 ], or may cause morphological changes in electrocardiogram (ECG) signatures that can complicate interpretation [ 9 ].…”

Air Ionization and Its Effects on the Health—An Outline of a Research Project

“…They have been recently republished in a review [26]; the methods of measurements, models and correlations with human health have been republished in another review that collects a number of papers [27]. Now, in the present project, the analysis of a possibly different behavior, at sea level and at altitude, could be performed recurring to the two already mentioned devices-"Ions meter" and APEC 300-realized in the framework of the researches led by the Section BEM of C.I.R.P.S.…”