SummaryBackgroundEven though progress has been made, the detection of melanoma still poses a challenge. In light of this situation, the Nevisense electrical impedance spectroscopy (EIS) system (SciBase AB, Stockholm, Sweden) was designed and shown to have the potential to be used as an adjunct diagnostic tool for melanoma detection.ObjectivesTo assess the effectiveness and safety of the Nevisense system in the distinction of benign lesions of the skin from melanoma with electrical impedance spectroscopy.MethodsThis multicentre, prospective, and blinded clinical study was conducted at five American and 17 European investigational sites. All eligible skin lesions in the study were examined with the EIS-based Nevisense system, photographed, removed by excisional biopsy and subjected to histopathological evaluation. A postprocedure clinical follow-up was conducted at 7 ± 3 days from the initial measurement. A total of 1951 patients with 2416 lesions were enrolled into the study; 1943 lesions were eligible and evaluable for the primary efficacy end point, including 265 melanomas – 112 in situ and 153 invasive melanomas with a median Breslow thickness of 0·57 mm [48 basal cell carcinomas (BCCs) and seven squamous cell carcinomas (SCCs)].ResultsThe observed sensitivity of Nevisense was 96·6% (256 of 265 melanomas) with an exact one-sided 95% lower confidence bound estimated at 94·2% and an observed specificity of 34·4%, and an exact two-sided 95% confidence bound estimated at 32·0–36·9%. The positive and negative predictive values of Nevisense were 21·1% and 98·2%, respectively. The observed sensitivity for nonmelanoma skin cancer was 100% (55 of 48 BCCs and seven SCCs) with an exact two-sided 95% confidence bound estimated at 93·5–100·0%.ConclusionsNevisense is an accurate and safe device to support clinicians in the detection of cutaneous melanoma.What's already known about this topic?Although progress has been made in the detection of melanoma it still poses a challenge.Electrical impedance spectroscopy (EIS) may potentially be used as a diagnostic aid for the detection of melanoma.What does this study add? In the largest international prospective study of its kind in melanoma detection, the EIS system Nevisense was shown to be both accurate and safe in the lesion cohort studied. In the absence of a perfect gold standard, the accuracy of a device should be compared with the consensus diagnosis from multiple experts.

The functional integrity and pathology of the skin is reflected in its electrical impedance spectra. Non-invasive electrical impedance measurements of intact skin are dominated by the high impedic stratum corneum in low frequencies and with increasing frequency gradually comes to be dominated by viable skin. Models of this multi-layered organ can increase our understanding of the actual physical properties/dimensions and facilitate better diagnostics in certain applications. Therefore, a mathematical model considering conservation of charge in the various layers of the skin and adjacent electrodes is derived and validated with experimental findings; the latter was carried out on 60 young female subjects. The impact of the stratum corneum thickness, inundation, solvent and cohort size on the electrical properties is studied. Both model parameters and experimental conditions were adjusted for calibration and subsequent validation of the model with measurements. It is found that both the model's thickness of the stratum corneum as well as experimental soaking conditions (both time and saline concentration) affect the fit between the model and measurements. It is concluded that it is essential that the electrical properties of the skin are presented in the context of the ion concentration (if a moisturizer is employed) as well as the soaking time. Further refinements should be made to determine even more accurate dielectrical properties of the stratum corneum and viable skin layers by accounting for the true skin thickness and the heterogeneity of the skin layers-this would be useful in applications where subtle alterations in the skin are of interest.

Background: Previous studies have shown statistically significant differences in electrical impedance between various cutaneous lesions. Electrical impedance spectroscopy (EIS) may therefore be able to aid clinicians in differentiating between benign and malignant skin lesions. Objectives: The aim of the study was to develop a classification algorithm to distinguish between melanoma and benign lesions of the skin with a sensitivity of at least 98% and a specificity approximately 20 per cent higher than the diagnostic accuracy of dermatologists. Patients/Methods: A total of 1300 lesions were collected in a multicentre, prospective, non-randomized clinical trial from 19 centres around Europe. All lesions were excised and subsequently evaluated independently by a panel of three expert dermatopathologists. From the data two classification algorithms were developed and verified. Results: For the first classification algorithm, approximately 40% of the data were used for calibration and 60% for testing. The observed sensitivity for melanoma was 98.1% (101/103), non-melanoma skin cancer 100% (25/25) and dysplastic nevus