Visual journey: Kao develops non-invasive technique to study blood vessels and capillaries in deep skin tissue

The link between blood flow and skin health has been of interest to the firm’s Skin Care Research Laboratory.

The Japanese personal care firm has been advancing research by investigation of the various functions of this blood vessel network from the perspective of maintaining beautiful and healthy skin.

As previously reported​, Kao researchers found that the appearance youthful skin was linked to higher blood flow.

In their latest study, Kao has developed an approach to simultaneously visualise the activities of blood vessels and capillaries in deep skin tissues.

The study results were recently published in part in the journal, Skin Research and Technology.

The blood vessels in the deeper layer and capillaries in the surface layer of skin differ in regard to their major roles and actions, these differences, said Kao are considered to be closely linked with skin condition.

However, obtaining details of blood flow for different vessels at an identical site simultaneously is considered difficult as several different instruments are needed for acquiring information present in layers that vary in depth and have constant blood flow changes.

The company explained that vessels and capillaries in the deeper layers of the skin could be detected simultaneously in videomicroscopic vascular images by use of automatic visual extraction technology.

The technique is based on Kao’s previous research, which reported the development of an image-processing technology capable of specifically extracting and quantitatively measuring blood flow changes in skin capillaries

By using this technology, the team captured an image of skin and filtered it so only information of the capillaries remained.

Researchers found that it could visualise the blood flow using videomicroscopy by viewing the hemoglobin component image, which would demonstrate blood flow in the deeper layer.

They considered that by integrating the brightness values in the image, blood flow could be estimated.

“With this technique, it is now possible to simultaneously obtain capillary blood flow information as well as that in the entire skin area by examining a single image,” ​said Kao.

Evaluating with vascular image analysis technology ​

Using this technique, the researchers obtained the inner upper arm skin from six Japanese male and female subjects.

The results showed that when exposed to heat, the hemoglobin component level increased and blood flow throughout the skin was also increased, whereas nearly no changes were seen in the capillaries.

When exposed to carbonic acid, both the hemoglobin component throughout the skin and capillary blood flow volume were increased.

These results support previous findings indicating that heat and carbonic treatment have different characteristic actions on blood vessels.

“These findings indicate that this image analysis technology can provide simultaneous evaluation of blood flow information from different blood vessels using a single image,” said the firm.

According to Kao, the development of this non-invasive and simple technique of image analysis will allow researchers to simultaneously obtain blood flow information for both capillaries and vessels in the deeper layer of an identical site.

With this development, it makes it possible to extensively investigate the relationship of blood flow at various depths with skin condition, as well as the effects of various approaches to promote blood circulation.

The firm concluded: “In the future, Kao plans to further study blood flow changes brought about by ageing and environmental factors, and the effects of blood flow status on various skin conditions.”​

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Source: Skin Research and Technology​

https://doi.org/10.1111/srt.12850​​

Skin capillary extraction technique based on independent component analysis and Frangi filter using videomicroscopy​

Authors: Akihiko Oharazawa, et al.​