Biomedical Engineering Reference
In-Depth Information
skin
medical
device
Near-
infrared
light
(a)
LED,LD
photodiode
LED,LD
photodiode
controller
Near-
infrared
light
medical
device
monitor
(b)
photodiode
LED,LD
Fig. 1.20.
A schematic diagram of near-infrared power/information transmission.
Power transmission (
a
) and information transmission (
b
)
laser diode,
light-emitting diode
skin
photo
diode
0.2
1.0
0.6
1.4
wavelength [
μ
m]
Fig. 1.21.
The transmittance of human skin and the spectral sensitivity of Si photo-
diodes. The wavelength range of near-infrared laser diodes and light-emitting diodes
is also shown
