Non-invasive Imaging for In-vivo Quantification of Skin Composition and Structure

The clinical investigation aims to evaluate the potential value of an investigational medical device (IMD) based on a technology called SFDI, Spatial Frequency Domain Imaging. This is a non-invasive contactless technology for in-vivo measurement of the structure and molecular composition of the skin and its embedded blood volume. The technology is a promising tool for diagnostic support of pathology to the microcirculation, like in peripheral arterial disease and diabetes, but also for general cardiovascular disease risk assessment.

The IMD can measure the concentration of deoxy- and oxyhemoglobin, melanin and water, as well as structural properties in skin tissue, at two imaging depths.

The study participants mainly consist of a prospective primary care population, that undergo an investigation (including SFDI assessment) at a primary care visit. Other assessment data collected during the visit (including medical history, blood pressure, blood values, ankle-brachial index) is retrieved from the participant's medical journal. An extended examination (including SFDI assessment with addition of a 3-minute post-occlusive hyperemia (PORH) test and vascular assessment using the reference system Perimed Periflux 6000) will be offered to participants based on increased risk of cardiovascular disease in the primary care population, or for separately invited subjects with increased cardiovascular risk, known diabetes or as healthy controls. Repeated yearly measurements may be performed in subjects who are interested in doing so.

A subset of participants will undergo a multi-modal investigation which includes combining data from the current study with contactless laser vibrometry data from the investigation "Cardio Alpha" (CIV ID: CIV-22-08-040426). The hypothesis is that cardiovascular disease (CVD) risk assessment may be improved through a multi-modal approach, combining data on both macro- and microcirculatory function.

Another subset of participants will undergo a diabetic feet assessment protocol, including an SFDI assessment of the soles of the feet and assessment using reference methods for macro-and microcirculation, and a foot neuropathy assessment.

A third subset of participants will undergo a skin cancer assessment protocol, including SFDI assessment of a suspected lesion on the skin.

• Association between peak oxygen saturation measured by spatial frequency domain imaging (SFDI) on the palm and forearm and cardiovascular risk factors. [Срок оценки: Typically 3-6 months from enrolment. If 1-year follow-up, then 1 year and 3-6 months from enrolment.]
• Correlation between oxygenation on sole of the foot and tissue ischemia level [Срок оценки: Same day as enrolment.]
• Correlation between oxygenation on sole of the foot and neuropathy [Срок оценки: Same day as enrolment.]
• Correlation between water concentration on sole of the foot and tissue ischemia level [Срок оценки: Same day as enrolment.]
• Correlation between water concentration on sole of the foot and neuropathy [Срок оценки: Same day as enrolment.]
• Difference in oxygenation/ hemoglobin gradient between lesion and surrounding tissue [Срок оценки: At follow-up, within 3 months of enrolment.]