Patent ID: 7230687

Claim:
A blood leak detector comprising: a light source projecting a beam along an optical path, wherein the beam has a wavelength in a range of about 800 to 930 nm; a light detector receiving the beam through an aperture having a diameter in a range of 30 to 60 thousands of an inch; a housing having a slot to receive a tubular liquid passage between the light source and light detector, and where said slot is transverse to the optical path the slot has a width narrower than the tubular liquid passage when uncompressed, wherein the slot is exposed to ambient light which illuminates the tubular liquid passage while the blood leak detector is sensing for blood in the liquid passage, and a bore in the housing aligned with the optical path and with the light detector such that light from the light source passes through the bore before entering the detector, wherein the ambient light is blocked by the housing from shining directly to an end of the bore facing the detector.