References / Physics and formulas

The induced stimulus tracks how fast the field changes

Established physics
What reaches tissue depends on how fast the field changes, not on how strong it gets at its peak. That rate of change is what the report measures. Slew rate, Peak dB/dt, and Stimulation Intensity all rest on it.
Where it appears in the report: Slew Rate, Peak dB/dt Analysis, Stimulation Intensity

The evidence

By Faraday's law, a changing magnetic field induces an electric field in nearby tissue, and that induced field scales with the rate of change (dB/dt). It's the coupling the foundational PEMF bone-repair work was built on. Rate of change is the primary driver here, not the only one, since field strength and waveform shape the response too.
A changing magnetic field induces a circulating electric fieldA schematic of Faradays law: a magnetic field changing through a loop induces a circulating electric field in the tissue. The faster the field changes, the stronger the induced electric field.Induced electric field (E)Changing field(dB/dt)A fasterchange in the fieldinduces a strongerelectric field.© 2026 Gauss Labs
A magnetic field that changes in time induces an electric field in the tissue it passes through. This is Faraday's law, and it is why the speed of the field change (the slew rate) matters more than the field's peak strength: a faster change induces a stronger electric field, which is what stimulates the body.

Primary sources

  • Bassett CAL, Pawluk RJ, Pilla AA. Augmentation of Bone Repair by Inductively Coupled Electromagnetic Fields. Science. 1974;184(4136):575-577. view