Optical components for an I.V. flow detector

In a drop detector comprising:

• (1) emitter means for providing em. radiation;
• (2) receiver means for, upon the receipt of said across em. radiation, providing a characteristic electrical signal;
• (3) retaining means, coupled to said emitter means and said receiver means, for holding a drip chamber composed of a material with a specified index of refraction and general shape through which drops of a liquid pass;
• and
• (4) optical means, coupled to said retaining means, having a first portion for altering the path of said em. radiation from said emitter through a particular drip chamber held by said retaining means and a second portion for altering the path of said em. radiation from said particular chamber to said receiver means,
• the improvement wherein said optical means, after said em. radiation has passed through said particular chamber and reached said second portion of said optical means, collimates said em. radiation.

In a drop detector comprising:

• (1) emitter means for providing em. radiation;
• (2) receiver means for, upon the receipt of said em. radiation, providing a characteristic electrical signal;
• (3) retaining means, coupled to said emitter means and said receiver means, for holding a drip chamber composed of a material with a specified index of refraction and general shape through drops of a liquid pass;
• and
• (4) optical means, coupled to said retaining means, for, altering the path of said em. radiation from said emitter through a particular drip chamber held by said retaining means and to said receiver means,
• the improvement wherein said optical means alters the path of said em. radiation passing through said particular chamber in a fashion that said path is symmetric about a plane passing through the center of said particular chamber and lying perpendicular to said path.

In a drop detector comprising:

• (1) emitter means for providing em. radiation from a first single location;
• (2) receiver means for, upon the receipt of said em. radiation at a second single location, providing a characteristic electrical signal;
• (3) retaining means, coupled to said emitter means and said receiver means, for holding a drip chamber composed of a material with a specified index of refraction and general shape through which drops of a liquid pass;
• and
• (4) optical means, coupled to said retaining means, for altering the path of said em. radiation from said emitter through a particular drip chamber held by said retaining means and to said receiver means,
• the improvement wherein said optical means, prior to said em. radiation entering said particular chamber, expands the beam of said em. radiation from said first location to a width at least about equal to the interior dimension of said chamber, makes said beam substantially uniform within said interior of said particular chamber as it travels through said interior of said particular chamber, and after said em. radiation has exited said chamber, condenses a beam of said em. radiation of a width at least about equal to said interior dimension to said second location.

In a method of detecting drops through a drip chamber located in an area including:

• (1) passing em. radiation through said chamber in said area;
• (2) receiving at least a portion of said em. radiation after is gas been passed through said area;
• and
• (3) determining the magnitude of said portion of said em. radiation,
• the improvement comprising placing said em. radiation, prior to its passage through said chamber, in a direction that will result in said radiation being collimated as it travels in the interior of said chamber.

In a method of detecting drops through a drip chamber located in an area including:

• (1) passing em. radiation through said chamber in said area;
• (2) receiving at least a portion of said em. radiation after it has passed through said area;
• and
• (3) determining the magnitude of said portion of said em. radiation,
• the improvement comprising collimating said em. radiation after said radiation has passed through said chamber.

In a method of detecting drops through a drip chamber located in an area including:

• (1) passing em. radiation through said chamber in said area;
• (2) receiving at least a portion of said em. radiation after it has passed through said area;
• and
• (3) determining the magnitude of said portion of said em. radiation,
• the improvement comprising altering the path of said em. radiation in a fashion that said path is symmetrical about a plane passing through the center of said chamber and lying perpendicular to said path.

In a method of detecting drops through a drip chambered in an area including:

• (1) passing through said chamber in said area em. radiation from a first single location;
• (2) receiving at a second single location at least a portion of said em. radiation emanating from said first location;
• said
• (3) determining the magnitude of said portion of said em. radiation,
• the improvement comprising (a), prior to said em. radiation entering said particular chamber, expanding the beam of said em. radiation from said first location to a width at least about equal to the interior dimension of said chamber, [and ] (b)making said beam substantially uniform as it travels through said interior of said chamber, and (c) after said beam has exited said chamber, condensing a beam of a width at least about equal to said interior dimension to said second location.