Non-Invasive Multiplexed Real-Time Threshold Detection of Cardiac, Renal, and Metabolic Biomarkers via Wrist-Worn Infrared Spectroscopy

ObjectTransdermal biosensors may provide an alternative to conventional blood-based biomarker measurement. Our purpose was to determine the binary correlation between transdermal (Infrasensor; RCE, Inc, Carlsbad, CA) and conventional blood-based measurements. MethodsThis was a secondary analysis from a previously published observational cardiac troponin I (cTnI) study performed to establish the upper reference level of cTnI, at 10 US hospitals. After obtaining informed consent, 2 cohorts of patients were enrolled: 1) those who completed a health assessment questionnaire and appeared healthy, and 2) those with a known elevated cTnI per the local hospital standard assay. All blood lab analyses were performed at the University of Maryland Medical Center, Baltimore, MD. Normal was defined as cTnI <53.48 ng/L (male) or 34.11 ng/L (female) using the Siemens Atellica IM assay (Siemens Medical Solutions, Mountain View, CA), NT-proBNP <450 pg/mL (>75 years) or <124 pg/mL (<75 years), creatinine >1.17 mg/dL (male) or >0.95 mg/dL (female), and HbA1c <6.4%. The Infrasensor was placed on the patients wrist for measurement and blood drawn for analysis at approximately the same time. ResultsOf 840 enrolled patients, the median (IQR) age was 46 (30,57), 416 (49.5%) were female, 10.36% Hispanic, 6.7% Asian, 12.9% African American, and 69.1% White. Elevated lab tests were 102 hscTnIs, 156 NTproBNPs, 37 HbA1Cs, and 163 creatinines. Significant binary correlations were found between all transdermal signals and the corresponding lab blood levels ConclusionInfrasensor transcutaneous measurement demonstrates similar results as that obtained from blood testing in the central laboratory. CapsuleThe Infrasensor (RCE, Inc, Carlsbad, CA, USA) is rapid point of care transcutaneous biomarker measurement device. This study evaluated its ability to provide qualitative results for troponin I, NTproBNP, creatinine, and HbA1c levels in 840 patients. Significant correlations were found between all transdermal signals and the corresponding binary lab blood levels.