US 2011/0257520 A1 · LEAK DETECTING APPARATUS

Abstract

A leak detecting apparatus is provided which can detect leak of a liquid injected through an injection needle into a blood vessel of a human body near its surface with high accuracy. The apparatus emits a light ray in a predetermined wavelength band containing a particular wavelength at which the reflectivity for the liquid is lower than the reflectivity for internal tissues of the human body, to the human body at a position thereof where the injection needle is inserted, and detects the light ray in the wavelength band reflected inside the human body. The apparatus measures the average intensity of the detected light ray in the wavelength band and the intensity of the detected light ray at the particular wavelength to determine an occurrence of leak when the ratio of the intensity at the particular wavelength to the measured average intensity in the wavelength band is lower than a predetermined reference value. Variations in human body or physical condition affect the whole of the wavelength band but have no effects on the relative relationships between the wavelength band and the particular wavelength. Thus, the leak of the liquid can be detected without being affected by variations in human body or physical condition.

Claims44

Dependent claims

A leak detecting apparatus which detects leak of a liquid injected through an injection needle into a blood vessel of a human body near a surface thereof, comprising:

at least one light ray emitting means for emitting a light ray containing a at least one first particular wavelength at which the reflectivity for the liquid is different from the reflectivity for internal tissues of the human body and at least one second particular wavelength at which the reflectivity for the liquid is lower or approximately equal to the reflectivity for the internal tissues of the human body, to the human body at a position thereof where the injection needle is inserted;
at least one light ray detecting means for detecting the light ray at the first particular wavelength and the light ray at the second particular wavelength which are reflected inside the human body;
first measuring means for measuring the intensity of the detected light ray at the first particular wavelength;
second measuring means for measuring the intensity of the detected light ray at the second particular wavelength;
ratio calculating means for calculating the ratio of the intensity at the first particular wavelength to the measured intensity at the second particular wavelength:
leak determining means for determining occurrence of leak when the calculated ratio is changed from a predetermined reference value;
and
leak alarming means for outputting and notifying a leak alarm when the occurrence of leak is determined.

5 more elements

A method for detecting a leak of a liquid injected through an injection needle into a blood vessel of a human body near a surface thereof, comprising:

emitting a light ray containing at least one first particular wavelength at which the reflectivity for the liquid is different from the reflectivity for internal tissues of the human body and at least one second particular wavelength at which the reflectivity for the liquid is lower or approximately equal to the reflectivity for the internal tissues of the human body, to the human body at a position thereof where the injection needle is inserted;
detecting the light ray at the first particular wavelength and the light ray at the second particular wavelength which are reflected inside the human body;
measuring the intensity of the detected light ray at the first particular wavelength:
measuring the intensity of the detected light ray at the second particular wavelength:
calculating the ratio of the intensity at the first particular wavelength to the measured intensity at the second particular wavelength;
determining occurrence of leak when the calculated ratio is changed from a predetermined reference value;
and
outputting and notifying a leak alarm when the occurrence of leak is determined.

5 more elements

Dependencies are inferred from the claim text.

Leak detecting apparatus

Life of this patent

Leak detecting apparatus

Life of this patent

Abstract

Claims44