Inter-Device Concordance of Plantar Thermal Asymmetry Measurement (HIK-DM-2026)
ConditionDiabetes Mellitus
Trial statusRecruiting
Trial phaseNot listed
Trial typeObservational
Biological sexAll
Age18+
SponsorEduardo Luis Martín Javier
About this trial
This cross-sectional observational study measures the inter-device concordance between two infrared thermographic cameras, a low-cost model (HIKMICRO Mini2 V2) and a high-resolution model (HIKMICRO M60), when measuring plantar skin temperature in adults with diabetes mellitus. Each participant undergoes two consecutive thermographic acquisitions, always less than 10 seconds apart, from a fixed tripod at 75 cm, under standardized environmental conditions. The order of the two cameras is randomized 1:1 at participant level (sequence A: M60 then Mini2 V2; sequence B: Mini2 V2 then M60). The primary endpoint is the agreement between the two devices for contralateral thermal asymmetry (Delta T) in each of six pre-specified plantar regions of interest (ROIs), quantified by the intraclass correlation coefficient (ICC) for absolute agreement, with the consistency ICC for mean plantar temperature (Tmean) as an exploratory endpoint.
The study is strictly metrological. Neither camera is a medical device under Regulation (EU) 2017/745, no clinical decision is derived from the measurements, and the study does not evaluate the detection, diagnosis, screening or prevention of any disease. Neither device is designated as a diagnostic reference standard. Participants with diabetes mellitus are included solely because plantar thermal variability is greater in this population, which makes the inter-device comparison metrologically demanding.
Eligibility criteria
This trial does not accept healthy volunteersQualifiers
Age 18 years or older.
Confirmed diagnosis of type 1 or type 2 diabetes mellitus.
Preserved plantar skin integrity at the time of the test.
Voluntary signature of the informed consent after receiving detailed information about the study.
Disqualifiers
Active ulcers or open wounds in the plantar area, since exudation alters thermal emissivity.
Acute skin infection or extensive mycosis of the foot.
Previous partial amputation of the forefoot or midfoot that alters the anatomy of the regions of interest.
Severe peripheral arterial disease (Fontaine grade IV, critical ischemia) compromising tissue viability.
Trial population
Adults with type 1 or type 2 diabetes mellitus recruited from the active caseload of general podiatry and physiotherapy consultations. Participants with a disability who require support in decision making or in expressing consent may take part with the participation and signature of their legal representative or designated support person, in accordance with Spanish Law 8/2021 of 2 June.
Trial design
Design model
Cohort
Time perspective
Cross-sectional
Treatments tested in this trial
HIKMICRO® Mini2 V2
DeviceLow-cost infrared thermographic camera (256 x 192 pixels, NETD below 40 mK) used solely as a measuring instrument. It is not a medical device and no clinical decision is derived from its readings.
HIKMICRO® M60
DeviceHigh-resolution infrared thermographic camera (640 x 480 pixels, NETD below 35 mK) used as a technical comparator. It is not designated as a clinical or diagnostic reference standard.
Treatment groups
130 Participants
are divided into 1 treatment groupGroup A: Diabetes patients2 interventions
Trial outcomes
Primary outcomes
1
Intraclass correlation coefficient for absolute agreement, ICC(A,1), between the two cameras for contralateral thermal asymmetry (Delta T) in each of six pre-specified plantar regions of interest
Delta T is computed per region as the absolute difference in mean temperature between homologous regions of the right and left foot. One ICC(A,1) is reported for each of the six regions defined a priori (hallux, first, third and fifth metatarsal heads, midfoot and heel), with its 95 percent confidence interval, using the McGraw and Wong (1996) formulation, equivalent to ICC(2,1) of Shrout and Fleiss (1979), two-way random effects, single measurement. Each region contributes 130 paired measurements. The study hypothesis is ICC greater than or equal to 0.80, tested against a null of ICC0 = 0.65. Neither device is treated as a reference standard.
Time frame
Single measurement session (Day 1)Secondary outcomes
1
Cohen's Kappa for inter-device agreement in the binary classification of thermal asymmetry at the 2.2 degree Celsius cut-off, per region of interest
Overall agreement proportion and Kappa with 95 percent confidence interval for the dichotomous classification Delta T greater than or equal to 2.2 degrees Celsius versus below it, in each of the six regions. The cut-off is used as an operational category without clinical connotation, and neither device is designated as the diagnostic reference.
Time frame
Single measurement session (Day 1)2
Consistency intraclass correlation coefficient, ICC(C,1), between the two cameras for mean plantar temperature (Tmean)
McGraw and Wong (1996) consistency formulation, equivalent to ICC(3,1) of Shrout and Fleiss (1979), reported with its 95 percent confidence interval. Exploratory endpoint with a hypothesis of ICC greater than or equal to 0.75. It is not powered by an independent sample size calculation.
Time frame
Single measurement session (Day 1)3
Bland-Altman systematic bias and 95 percent limits of agreement between the two cameras for mean plantar temperature (Tmean) and for contralateral thermal asymmetry (Delta T)
Systematic bias and 95 percent limits of agreement computed across the six pre-specified plantar regions of interest, for both the mean plantar temperature and the contralateral thermal asymmetry. Neither device is treated as a reference standard.
Time frame
Single measurement session (Day 1)4
Influence of participant clinical variables on the magnitude of inter-device discordance
The absolute inter-device difference is analyzed against the presence of peripheral sensory neuropathy, body mass index and type of diabetes mellitus.
Time frame
Single measurement session (Day 1)Sponsors and contacts
Click on the lead sponsor to view all of their trials.
Eduardo Luis Martín Javier
Lead sponsor
Universidad Europea de Canarias
Sponsor institution
Source ClinicalTrials.gov