Extravasation detection apparatus and method based on optical sensing

Extravasation detection apparatus comprising:

• a support pad adapted for attachment to a body part of a patient in proximity to a site at which a fluid is to be injected into the patient;
• a plurality of light sources, mounted to said support pad, for radiating light into the body part;
• means for energizing said light sources in an encoded manner to radiate light into the body part in an encoded manner;
• a plurality of light detectors, mounted to said support pad, for:
• (a) individually detecting light transmitted from said light sources that is reflected, scattered, diffused, or otherwise emitted from the body part, and
• (b) individually developing light source/light detector pair signals representative of the light detected individually by said light detectors;
• means for supplying a plurality of individual light source/light detector pair baseline signals associated with each said light source/light detector pairs and developed prior to injection of the fluid into the body part;
• means for comparing the light source/light detector pair signals with the associated light source/light detector pair baseline signals;
• means for developing, from the comparisons of the light source/light detector pair signals with the associated light source/light detector pair baseline signals, new light source/light detector pair signals having an improved signal-to-noise ratio;
• means for supplying a model, dependent on the arrangement of said light sources and said light detectors on said support pad and developed prior to injection of the fluid into the body part for calculating extravasation volume;
• means for combining, according to the extravasation model, the new light source/light detector pair signals having an improved signal-to-noise ratio to determine the volume of extravasation;
• and
• means for comparing the determined volume of extravasation with a prescribed level of extravasation.

A method for detecting extravasation of a fluid applied to a patient comprising the steps of:

• attaching a support pad to a body part of a patient in proximity to a site which a fluid is to be injected into the patient;
• radiating, in an encoded manner into the body part at the site at which he fluid is injected into the patient, light from a plurality of light sources mounted to aid support pad;
• detecting light transmitted from said light sources that is reflected, scattered, diffused or otherwise emitted from the body part individually by a plurality of light detectors mounted to said support pad;
• developing a plurality of light source/light detector pair signals representative of the light detected individually by said light detectors for each of said light sources;
• developing, prior to injection of the fluid into the body part, a plurality of individual light source/light detector pair baseline signals associated with each said light source/light detector pairs and against which measurements made during injection of the fluid into the body part are compared;
• developing from comparisons of the light source/light detector pair signals with the light source/light detector pair baseline signals new light source/light detector pair signals having an improved signal-to-noise ratio;
• developing, prior to injection of the fluid into the body part, an extravasation model, dependent on the arrangement of said light sources and said light detectors on said support pad, for calculating extravasation volume from the new light source/light detector pair signals having an improved signal-to-noise ratio;
• combining, according to the extravasation model, the new light source/light detector pair signals having an improved signal-to-noise ratio to determine the volume of extravasation;
• and
• comparing the determined volume of extravasation with a prescribed level of extravasation.

Extravasation detection apparatus comprising:

• a support pad adapted for attachment to a body part of a patient in proximity to a site at which a fluid is to be injected into the patient;
• at least one light source, mounted to said support pad, for radiating light into the body part;
• means for energizing said light source in an encoded manner to radiate light into the body part in an encoded manner;
• a plurality of light detectors, mounted to said support pad, for:
• (a) individually detecting light transmitted from said light source that is reflected, scattered, diffused or otherwise emitted from the body part, and
• (b) individually developing light source/light detector pair signals representative of the light detected individually by said light detectors;
• means for developing, prior to injection of the fluid into the body part, a plurality of individual light source/light detector pair baseline signals associated with each light source/light detector pair and against which measurements made during injection of the fluid into the body part are compared;
• means for comparing the light source/light detector pair signals with the associated light source/light detector pair baseline signals;
• means for developing from the comparisons of the light source/light detector pair signals with the associated light source/light detector pair baseline signals new light source/light detector pair signals having an improved signal-to-noise ratio;
• means for developing, prior to injection of the fluid into the body part, a model, dependent on the arrangement of said light source and said light detectors on said support pad, for calculating extravasation volume from the new light source/light detector pair signals having an improved signal-to-noise ratio;
• means for combining, according to the extravasation model, the new light source/light detector signals having an improved signal-to-noise ratio to determine the volume of extravasation;
• and
• means for comparing the volume of extravasation with a prescribed level of extravasation.

Extravasation detection apparatus comprising:

• a support pad adapted for attachment to a body part of a patient in proximity to a site at which a fluid is to be injected into the patient;
• a plurality of light sources, mounted to said support pad, for radiating light into the body part;
• means for energizing said light sources in an encoded manner to radiate light into the body part in an encoded manner;
• at least one light detector, mounted to said support pad, for:
• (a) individually detecting light transmitted from said light sources that is reflected, scattered, diffused or otherwise emitted from the body part, and
• (b) individually developing light source/light detector pair signals representative of the light detected individually by said light detector;
• means for developing, prior to injection of the fluid into the body part, a plurality of individual light source/light detector pair baseline signals associated with each light source/light detector pair and against which measurements made during injection of the fluid into the body part are compared;
• means for comparing the light source/light detector pair signals with the associated light source/light detector pair baseline signals;
• means for developing from the comparisons of the light source/light detector pair signals with the associated light source/light detector pair baseline signals new light source/light detector pair signals having an improved signal-to-noise ratio;
• means for developing, prior to injection of the fluid into the body part, a model, dependent on the arrangement of said light sources and said light detector on said support pad, for calculating extravasation volume from the new light source/light detector pair signals having an improved signal-to-noise ratio;
• means for combining, according to the extravasation model, the new light source/light detector signals having an improved signal-to-noise ratio to determine the volume of extravasation;
• and
• means for comparing the volume of extravasation with a prescribed level of extravasation.