How BioReg searches, screens and grades the studies in this library
What does a positive study actually prove about a device?
A positive PEMF study is not evidence for a specific device unless the signal parameters studied, frequency, intensity, waveform, and exposure duration, are reasonably comparable to what that device produces. PEMF research varies enormously across these parameters and results do not transfer between them automatically. A 2022 review in Wiener klinische Wochenschrift called for international consensus on uniform reporting of magnetic flux density precisely because study protocols cannot currently be compared reliably. Where a study in this library does not report those parameters, we say so.
What does each evidence grade mean?
Every record in the library carries one of the grades below. Grades describe the strength of the evidence for the intervention studied, not the performance of any BioReg product.
| Grade | Definition |
|---|---|
| A | Multiple high-quality RCTs or meta-analyses showing consistent, significant benefit |
| A- | At least one high-quality RCT or meta-analysis showing significant benefit, with limited independent replication |
| B+ | Multiple RCTs, or a meta-analysis, showing significant but modest or mixed effects |
| B | Controlled trial evidence with methodological limitations or small samples |
| B- | Preliminary controlled evidence, minimal replication |
| C+ | Mixed evidence. Some positive controlled trials, no consistent effect across studies |
| C | Weak or conflicting evidence |
| D | Controlled evidence showing no significant benefit |
| F | Preclinical only. Cell culture, tissue, or animal research with no human clinical evidence |
| Review | Narrative or systematic review, not independently graded |
| Ongoing Trial | Registered trial without published results |
No BioReg category currently holds an A grade. The strongest categories in this library sit at A-, which means at least one high-quality trial or meta-analysis with limited independent replication.
Which databases are searched?
- PubMed and MEDLINE, searched by intervention term and by condition term
- Cochrane Library, for systematic reviews and controlled trial registers
- ClinicalTrials.gov, for registered trials with and without published results
- ScienceDirect and publisher sites, to retrieve full text where PubMed indexes only an abstract
- Google Scholar, used only for citation chasing from studies already retrieved
What is included and what is excluded?
Inclusion
- Peer-reviewed human studies of pulsed electromagnetic field therapy, transcranial magnetic stimulation, heart rate variability biofeedback, neurofeedback or electrodermal biofeedback
- Systematic reviews and meta-analyses covering those interventions, labelled Review where they are not independently graded
- Registered trials without published results, labelled Ongoing Trial
- Preclinical mechanism papers, labelled F, where they are cited for mechanism rather than clinical effect
- Studies reporting no benefit or a failed primary endpoint, on the same terms as positive studies
Exclusion
- Manufacturer marketing material, white papers and case reports presented as trial evidence
- Uncontrolled testimonials, single-patient anecdotes and internal data that has not been peer reviewed
- Studies whose intervention is unrelated to the modalities listed above
- Retracted papers, and papers whose primary outcome cannot be identified from the published report
- Comparative intensity claims against named or unnamed competitor devices, which this library does not publish
Who performs the grading?
Grading is performed by Turul Sengul, founder of BioReg Technologies and a bioregulation technology specialist with more than two decades of work in PEMF device development and clinical implementation. Grades are assigned from the published report, not from an abstract alone where full text is available, and a grade is lowered whenever sample size, blinding or outcome reporting is weaker than the study title implies.
When was this library last reviewed?
Last reviewed 2026-08-27. The library currently holds 50 published records across 16 categories. Records are re-checked when a cited trial is updated, retracted or superseded by a larger analysis. Browse the full library.
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The graded library and the underlying clinical documentation.