Observational studyEuropean journal of pain (London, England)2026
Reliability and Validity of a Novel, Portable Thermal Grill Illusion Apparatus Using Two Graphene Probes: An Initial Psychophysical Validation Study.
Observational study in European journal of pain (London, England), 2026. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Not yet cited in PubMed.
What it found
Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.
The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.
The trial behind it
Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.
Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.
Who cites it
0 citing papers in PubMed.
No citing paper in PubMed yet.
Corrections and comments
PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.
Authors and funding
4 authors.
Funding
Abstract
backgroundThe thermal grill illusion (TGI) is a psychophysical phenomenon in which combined heat and cold stimulation evokes an illusory burning or painful heat sensation. Although TGI has potential for sensory assessment, conventional multi-probe apparatuses are often bulky and costly. This cross-sectional observational study conducted an initial psychophysical validation of a novel portable TGI device using two graphene probes.
methodsFifty-two healthy participants were evaluated using a novel 2-probe device and a previously used 8-probe apparatus. Concurrent validity and agreement were assessed using correlations, intraclass correlation coefficients (ICC), Bland-Altman analysis, and Bayesian equivalence testing for Visual Analogue Scale (VAS) ratings of heat, cold, pain, and discomfort. Sensory-quality profiles were compared using item-level Short Form McGill Pain Questionnaire-2 (SF-MPQ-2) descriptors. Within-session reliability and measurement precision were evaluated using ICC, standard error of measurement (SEM), and trial-averaging analyses across ten repeated trials.
resultsThe 2-probe device showed moderate-to-excellent correspondence with the 8-probe apparatus for VAS ratings. Pain and discomfort ratings were lower with the 2-probe device, but both devices commonly elicited hot-burning sensations. Repeated measurements with the 2-probe device showed improved reliability and reduced measurement error when multiple trials were averaged; averaging four trials provided high reliability for pain ratings.
conclusionThe portable 2-probe device showed feasible psychophysical performance for inducing and repeatedly assessing TGI sensations under experimental conditions. Further validation with formal control conditions and clinical populations is warranted. SIGNIFICANCE STATEMENT: This study provides initial psychophysical validation of a pocket-sized two-probe thermal grill illusion (TGI) device using graphene probes. The device showed moderate-to-excellent correspondence with an eight-probe apparatus, preserved a core hot-burning sensory quality, and improved reliability when multiple trials were averaged. These findings support its feasibility as a compact tool for standardized repeated assessment of TGI sensations under experimental conditions, warranting further validation with formal control conditions and clinical populations.
Indexed as
Identifiers
What OpenQuestion holds
Registered trials
Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.