| abstract |
(57) [Abstract] [Objective] A specific wavelength light equivalent to the light absorption spectrum of venous blood is irradiated to a vein site together with a reference light, and the same is transmitted through a filter that transmits the specific wavelength light. The position, shape or state is identified by being visually recognized as dark. As a result, the detection of the vein site, such as when the injection needle is punctured into the subcutaneous vein, the determination of the same state, or the certainty and safety of the puncture action are dramatically improved. The light emitted from the light source for specific wavelength (1) is transmitted through the specific wavelength filter for light source (2) and combined with the light (3) of the reference light source, for example, a vein (6) in the upper arm (5). Is projected on a portion where the light is likely to exist, and the reflected light is visually observed through a specific wavelength filter (4). The latter filter (4) is held by the holding section (7). |