Fig 1.
Schematic diagram of an optical sensor with a pressurization mechanism.
Fig 2.
Cross-sectional image of the optical sensor with a pressurization mechanism.
Fig 3.
Photo absorption coefficient of oxyhemoglobin and deoxyhemoglobin.
Fig 4.
Photograph of the sensing system.
Fig 5.
Time chart of pressure applied to the skin surface using the optical sensor with a pressurization mechanism.
In section A, the absorption of light by the dermal tissue is estimated. In section B1-B3, blood reflow characteristics of the peripheral blood vessels are recorded by changing P2.
Fig 6.
An index of blood reflow characteristic ΔCHb.
Fig 7.
Hemoglobin concentration CHb measured using the proposed method.
Figs (a) and (b) are CHb which are observed for two healthy volunteers. Figs (c) and (d) are CHb which were observed in two scleroderma patients.
Fig 8.
ΔCHb measured in four healthy volunteers and four scleroderma patients.
Fig 9.
ΔCHb measured in 26 healthy volunteers and 26 scleroderma patients.
(a):P2 = 88mmHg, (b):P2 = 64mmHg, (c):P2 = 40mmHg, and (d):P2 = 28mmHg.
Fig 10.
ΔCHb measured in healthy volunteers aged 65 to 75 years old (N = 10) and scleroderma patients aged 65 to 75 years old (N = 10).
(a):P2 = 88mmHg, (b):P2 = 64mmHg, (c):P2 = 40mmHg, and (d):P2 = 28mmHg.