Pulsed red and near-infrared light (PBM) – Physics, biology and resonant frequencies

Pulsed light, biological resonance frequencies and tissue-specific interactions
Integrated subject report based on optical physics, biophysics, photobiology and resonance medicine

Introduction
Pulsed light in the red and near-infrared spectrum (PBM - Photobiomodulation) has been documented for several decades to have profound biological effects. When light is pulsed at specific frequencies, it can interact with the body's own electromagnetic resonances - from whole-body level (brain oscillations, heart rhythm, Schumann resonance) to molecular level (DNA vibrations, enzyme activities, water structures). Two main principles are behind it: optical penetration – how wavelength, pulse frequency, peak power and pulse width modulation affect how deeply photons reach into biological tissue, and resonant interaction – how light or field modulation at specific frequencies can trigger resonance in biological systems and thus enhance signal transduction.

The physics behind pulsed light and tissue penetration
Red light in the range 600–700 nm is suitable for skin, mucous membranes and blood vessels close to the surface with a typical penetration of 1–5 mm. Near-infrared light (700–1100 nm) is minimally absorbed in water and hemoglobin and can penetrate several centimeters into tissues such as muscle, joints and brain. Mid-infrared light (1100 nm–20 μm) is absorbed more strongly in water and mainly produces thermal effects in the surface. The THz range (0.1–10 THz) has high water absorption, but can also interact with molecular vibrations in DNA and proteins. Pulsing has several functions: high peak power combined with low average results in less surface heating and deeper penetration, low frequency pulsing below 100 Hz can entrain neurological rhythms and affect biorhythms, intermediate frequency from 100 Hz to 10 kHz can modulate reactive oxygen species and promote tissue repair, high frequency above 10 kHz can produce subcellular effects, while the GHz–THz range has theoretical relevance for resonances in water and DNA.

Biological resonance frequencies and target structures
Ultralow frequencies below 1 Hz are associated with brain waves, vascular waves and respiratory rhythms, and can affect HRV and blood pressure regulation. Low frequencies from 1 to 30 Hz cover, among other things, the Schumann resonance of 7.83 Hz, which is associated with cell repair and immune modulation, as well as 10 Hz, which corresponds to alpha rhythms in the brain and is linked to focus, neurorehabilitation and wound healing. The beta range around 20 Hz can affect nerve conduction and alertness. Intermediate frequencies include 40 Hz gamma waves that have strong evidence for neuroplasticity and amyloid clearance, while 100 Hz is linked to pain reduction and deeper tissue penetration. High frequencies from 1 kHz to MHz include, among other things, 8 kHz with a documented anti-inflammatory and wound-healing effect, as well as piezoelectric effects in collagen around 20–50 kHz. In the GHz–THz range there are hypothetical links to DNA torsion, protein folding and water structures.

Resonance measures in biological systems
Skin and keratinocytes respond to resonances at 7.83 and 10 Hz. Cortical brain areas are sensitive to 10 Hz and 40 Hz. The heart can be affected by rhythms in the range 0.1–1 Hz and 10 Hz. Mitochondria show responses at 10 Hz, 40 Hz and 1 kHz, while collagen structures can have piezoelectric responses at 20–50 kHz. DNA and water show theoretical or weaker evidence for resonances in the THz range.

 

Biological frequency ranges and effects

Ultra low frequencies (below 1 Hz)

• 0.1 Hz: Resonance with deep brain waves (delta) and vascular waves. Linked to deep relaxation and blood pressure regulation.

• 0.3 Hz: Baroreceptor response. Contributes to the stabilization of blood pressure.

• 0.5 Hz: Important for respiration and cardiac variability (HRV). Strong evidence for optimization of the autonomic nervous system.

Low frequencies (1–30 Hz)

• 1.96 Hz: Vestibular resonance, relevant to the organs of balance.

• 2.28 Hz (Nogier A): Associated with cell vitality and central gray matter.

• 4.56 Hz (Nogier B): Effects on metabolism and mood, including antidepressant effects.

• 7.83 Hz (Schumann resonance): Strong evidence for cell repair, stress reduction and immune modulation.

• 10 Hz: Coincides with the brain's alpha rhythms. Used to improve focus, stimulate wound healing and support neurorehabilitation.

• 20 Hz: Beta waves in the brain. Associated with alertness, alertness and nerve conduction.

Intermediate frequencies (30 Hz – 1 kHz)

• 40 Hz (gamma frequency): Strong evidence for neuroplasticity, cognitive support and amyloid clearance in the brain.

• 72.96 Hz (Nogier F): Indications for effects on joints and bones, as well as intellectual stimulation.

• 100 Hz: Well documented for deeper tissue penetration and effective pain reduction.

• 300 Hz: More limited documentation, possible stimulation of stem cells' bioenergetics.

• 1 kHz: Moderate evidence for support of nerve healing and modulation of oxidative stress.

High frequencies (1 kHz – MHz)

• 8 kHz: Strong evidence for wound healing and anti-inflammatory effects.

• 20–50 kHz: Indications of piezoelectric effects in collagen and bone. Weak to moderate evidence.

• 100 kHz – 1 MHz: Hypotheses of intracellular signaling and membrane resonance. The evidence is currently weak.

GHz–THz range

• 0.1–3 THz: Theoretical links to hydrogen bonds in water, DNA torsional modes and protein folding.

• 2.4 THz: Proposed resonance in the DNA phosphate backbone.

• 5–10 THz: Putative links to lipid membrane dynamics.
  The evidence in the GHz–THz range is weak to moderate, mainly based on laboratory studies and theoretical models.