Monitoring treatment of peripheral artery disease (PAD) using diffuse optical imaging

A diffuse optical imaging apparatus comprising:

• a substrate having a front face;
• a plurality of light sources mounted to the substrate and aimed in a forward direction with respect to the front face, wherein at least a portion of each of the plurality of light sources is disposed in front of the front face, and wherein each of the plurality of light sources has a different wavelength;
• a plurality of light detectors mounted to the substrate and aimed to detect light arriving from in front of the front face, wherein at least a portion of each of the plurality of light detectors is disposed in front of the front face;
• a pad shaped and dimensioned to sit in front of the front face, the pad having (a) a plurality of light source openings shaped and dimensioned to accommodate portions of each of the plurality of light sources that are disposed in front of the front face and (b) a plurality of light detector openings shaped and dimensioned to accommodate portions of each of the plurality of light detectors that are disposed in front of the front face, wherein the pad has a front surface shaped and dimensioned for contacting a person's skin;
• and
• a plurality of electrical conductors that (i) convey electrical signals that drive the plurality of light sources and (ii) convey electrical signals representative of the light detected by the plurality of light detectors.