Cell Phone Radiation Exposure Limits and Engineering Solutions.

In the 1990s, the Institute of Electrical and Electronics Engineers (IEEE) restricted its risk assessment for human exposure to radiofrequency radiation (RFR) in seven ways: (1) Inappropriate focus on heat, ignoring sub-thermal effects. (2) Reliance on exposure experiments performed over very short times. (3) Overlooking time/amplitude characteristics of RFR signals. (4) Ignoring carcinogenicity, hypersensitivity, and other health conditions connected with RFR. (5) Measuring cellphone Specific Absorption Rates (SAR) at arbitrary distances from the head. (6) Averaging SAR doses at volumetric/mass scales irrelevant to health. (7) Using unrealistic simulations for cell phone SAR estimations. Low-cost software and hardware modifications are proposed here for cellular phone RFR exposure mitigation: (1) inhibiting RFR emissions in contact with the body, (2) use of antenna patterns reducing the Percent of Power absorbed in the Head (PPHead) and body and increasing the Percent of Power Radiated for communications (PPR), and (3) automated protocol-based reductions of the number of RFR emissions, their duration, or integrated dose. These inexpensive measures do not fundamentally alter cell phone functions or communications quality. A health threat is scientifically documented at many levels and acknowledged by industries. Yet mitigation of RFR exposures to users does not appear as a priority with most cell phone manufacturers.

Quadriceps mechano- and electromyographic time-frequency responses during muscular contractions to volitional exhaustion.

INTRODUCTION: Surface electromyography (SEMG) and mechanomyography (SMMG) responses of the quadriceps during muscular contractions to exhaustion were computed and analyzed by analysis of variance and polynomial regression analyses. METHODS: Participants performed maximum flexion-extension movements at 180°/s until volitional exhaustion, rested for 2 minutes, and then completed a second bout of movements until exhaustion. Torque and SEMG/SMMG median frequencies and amplitudes were examined at 9 points across repetitions completed. RESULTS: (1) Torque decreased precipitously; (2) SEMG amplitude displayed an initial increase, then a steady decrease, and SMMG amplitude showed a continuous decrease; and (3) SEMG and SMMG median frequencies displayed a continual decrease over repetitions completed. Fractional polynomial and quadratic models explained the fatigue process with the highest precision. CONCLUSIONS: Changes in electrical and mechanical properties of the quadriceps during fatigue reflect alterations in neuromuscular activation strategies and/or muscle wisdom. SEMG frequency modeled muscle fatigue more effectively than amplitude, whereas SMMG frequency and amplitude were equally effective.

Analysis of the charge exchange between the human body and ground: evaluation of "earthing" from an electrical perspective.

OBJECTIVE: The purpose of this study was to investigate "earthing" from an electrical perspective through measurement and analysis of the naturally occurring electron flow between the human body or a control and ground as this relates to the magnitude of the charge exchange, the relationship between the charge exchange and body functions (respiration and heart rate), and the detection of other information that might be contained in the charge exchange. METHODS: Sensitive, low-noise instrumentation was designed and fabricated to measure low-level current flow at low frequencies. This instrumentation was used to record current flow between human subjects or a control and ground, and these measurements were performed approximately 40 times under varied circumstances. The results of these measurements were analyzed to determine if information was contained in the current exchange. RESULTS: The currents flowing between the human body and ground were small (nanoamperes), and they correlated with subject motion. There did not appear to be any information contained in this exchange except for information about subject motion. CONCLUSIONS: This study showed that currents flow between the environment (earth) and a grounded human body; however, these currents are small (nanoamperes) and do not appear to contain information other than information about subject motion.

Wavelet analysis of quadriceps power spectra and amplitude under varying levels of contraction intensity and velocity.

INTRODUCTION: We investigated the effect of contraction intensity [100%, 75%, 50%, and 25% maximum voluntary contraction (MVC)] and movement velocity (50°, 100°, 200°, and 400°/s) on surface electromyography root mean square amplitude (SEMGRMS ) and median frequency (SEMGMDF ) of rectus femoris (RF), vastus lateralis (VL), and vastus medialis (VM). METHODS: SEMGs during knee extension were resolved into their respective frequencies using wavelet transformations. RESULTS: RF, VL, and VM muscles displayed increased SEMGMDF as contraction intensity increased from 25% to 50% MVC and from 75% to 100% MVC, and each muscle displayed its own unique frequency shifting patterns. The SEMGMDF was not influenced by movement velocity. SEMGRMS increased in all 3 muscles as contraction intensity increased and was influenced by movement velocity, with the highest values observed at 400° and 200°/s. CONCLUSIONS: We infer that increasing contraction intensity facilitates greater recruitment of fast-twitch muscle fibers, but there are differing responses in RF, VL, and VM muscles.

The transport of extremely low-frequency electrical signals through an acupuncture meridian compared to nonmeridian tissue.

OBJECTIVES: This study investigated the manner in which extremely low-frequency (ELF) electrical energy is transported through biologic tissues, focusing on the differences between an acupuncture meridian and nonmeridian tissues. DESIGN: Using inserted needles as the electrodes, the energy transport properties of the Large Intestine (LI) meridian were compared to a control channel that had the same length as the meridian channel and comprised similar soft tissue. SUBJECTS: Twenty (20) participants were tested at the University of New Hampshire, Durham, with ages ranging from 22 to 60 years old. INTERVENTION: A Gaussian pulse with spectral energy extending into the kilohertz range was launched using a low-impedance amplifier at the distal point on either the LI meridian or a nearby control channel. The signal launched was measured at the proximal point using a high-impedance instrumentation amplifier. The ground reference for both the launch and receiver locations was a needle inserted in the lower leg. After taking the Fast Fourier Transform, power spectral measurements were calculated, giving a single value representing power density of the measured potential in the 2-100-Hz range. RESULTS: A paired, two-sided signed rank test was performed. For the data pairs in this study, p = 0.035, indicating that they are dissimilar with a statistical significance. CONCLUSIONS: The ELF electric energy is transported somewhat more efficiently through the LI meridian compared to a nonmeridian control. The results were not dramatic, with some participants giving greater values on the control channel, but they were statistically significant.