Photoacoustic confocal dermoscope with a waterless coupling and impedance matching opto-sono probe.

Recently, intensive research on photoacoustic (PA) imaging has been conducted to accelerate the development of dermoscopy of the human skin. In this Letter, we first developed a PA dermoscope equipped with a waterless coupling and impedance matching opto-sono probe to achieve quantitative, high-resolution, and high-contrast imaging of the human skin. Compared with the commonly used liquid-coupled PA probes, the human-skin-adapted probe can facilitate implementation in the clinical setting. The noninvasive imaging experiments of epidermal and dermal structures in volunteers have been carried out to demonstrate the high imaging quality that can be obtained by using such an opto-sono probe for a PA dermoscope. The imaging results show the characteristic parameters of the skin, including pigment distribution and thickness, vascular diameter, and depth. The results confirm that the opto-sono probe can play an important role in the PA dermoscope for making clear the distribution of the pigment layer and blood vessels in the human skin.