US 5,790,729 A · Photoplethysmographic instrument having an integrated multimode optical coupler device

Abstract

The integrated multimode optical coupling apparatus comprises an N-to-M optical coupling arrangement that is simple to manufacture, minimizes optical losses and is significantly less expensive than the prior art arrangements of coupling optical signals. The preferred embodiment of the apparatus of the present invention comprises a substrate into which is formed a plurality of optical channels, each of which is joined at one end into a single output optical channel. This integrated optical coupler is formed by diffusing silver ions or other equivalent ions into the glass substrate in these defined areas to form channels of high optical refractive index in the body of the substrate. At one end of each of the optical channels that are formed in the substrate, the plurality of the optical channels are joined together in a volumetric region of the substrate wherein the individual channels merge into one unified common structure. The output optical channels are joined to this combiner to thereby carry the combined light output to the output terminals. One application of this apparatus is in the field of photoplethysmography, such as in a pulse oximeter instrument.

Claims10

Dependent claims

A passive optical coupler apparatus for interconnecting light beams output by a first plurality of light sources with at least one output optical device comprising:

a substrate;
an optical combiner formed in said substrate;
a plurality of optically transmissive input optical channels formed in said substrate, each of said input optical channels having a first end located at a surface of said substrate and a second end terminated in said optical combiner;
at least one optically transmissive output optical channel formed in said substrate, each of said output optical channels having a first end located at a surface of said substrate and a second end terminated in said optical combiner;
at least one output monitor optical channel having a first end located at a surface of said substrate and a second end terminated in said optical combiner for transmitting a predetermined proportion of light received by said optical combiner to said first end of said output monitor optical channel;
and
wherein said optical combiner optically interconnects said second ends of said plurality of input optical channels with said second ends of said at least one output optical channel and said second end of said output monitor optical channel to enable light beams transmitted by selected ones of said plurality of input optical channels to enter selected ones of said second ends of said at least one output optical channel and said second end of said output monitor optical channel for transmission to said first ends thereof.

4 more elements

A photoplethysmographic instrument which produces a plurality of beams of light for application to a subject under test, comprising:

a plurality of light sources, each of which is capable of generating a beam of light;
a probe for applying said generated beams of light to a subject under test;
passive optical coupler apparatus for interconnecting light beams output by said plurality of light sources with at least one probe optical transmission channel which transmits said beams of light to said probe, comprising:
a substrate;
an optical combiner formed in said substrate;
a plurality of optically transmissive input optical channels formed in said substrate, each of said input optical channels having a first end located at a surface of said substrate and a second end terminated in said optical combiner;
at least one optically transmissive output optical channel formed in said substrate, each of said output optical channels having a first end located at a surface of said substrate and a second end terminated in said optical combiner;
and
wherein said optical combiner optically interconnects said second ends of said plurality of input optical channels with said second ends of said at least one output optical channel to enable light beams transmitted by selected ones of said plurality of input optical channels to enter selected ones of said second ends of said at least one output optical channel for transmission to said first ends thereof for coupling to said probe optical transmission channel.

6 more elements

Dependencies are inferred from the claim text.

Photoplethysmographic instrument having an integrated multimode optical coupler device

Life of this patent

Photoplethysmographic instrument having an integrated multimode optical coupler device

Life of this patent

Abstract

Claims10