Method and apparatus for diode laser pulse oximetry using fiber optical cables

• US 6,026,312 A
• Filed: 06/23/1997
• Issued: 02/15/2000
• Est. Priority Date: 07/21/1995
• Status: Expired due to Term

• Current Assignee: RIC INVESTMENTS LLC (Koninklijke Philips N.V.)
• Original Assignee: Respironics Incorporated (Koninklijke Philips N.V.)
• Inventors: Shemwell, David M., Ryan, George R.
• Primary Examiner(s): Dvorak, Linda C. M.
• Assistant Examiner(s): YARNELL, BRYAN KEITH
• Application Number:
  US08/876,181
• Time in Patent Office: 967 Days
• Field of Search: 600/310, 600/314-317, 600/322-324, 600/326, 600/328, 600/334, 600/473, 600/476
• US Class Current: 600/310
• CPC Class Codes: A61B 2562/228 Sensors with optical connectors
• CPC Class Codes: A61B 5/14552 Details of sensors specially adapted therefor
• CPC Class Codes: A61B 5/6826 Finger
• CPC Class Codes: A61B 5/6838 Clamps or clips

Abstract

A method and apparatus for transferring two frequencies of electromagnetic energy to and from a portion of a living body for the purpose of blood oxygen saturation measurements. The two frequencies of electromagnetic energy are transferred to the portion of the living body through a single optical fiber cable (which could be a bundle) to a coupler and then through a short section of optical cable to an optical element adjacent to the portion of the living body. After the two frequencies of electromagnetic energy are transmitted through the portion of the living body they are received by another optical element and transported away from the portion of the living body to a coupler through a short section of optical cable where they may be converted to electrical signals. Alternatively, the two frequencies of electromagnetic energy are carried away from the coupler. The signals from the coupler (whether they are electromagnetic signals or electrical signals) are directed to a measurement instrument, which through an adapter may be a conventional measurement instrument known in the prior art or a measurement instrument specifically designed for use with the signals produced at the coupler.

Claims

1. An apparatus for transmitting laser light through a portion of a living body, comprising:

a first source of laser light having a first frequency;

a second source of laser light having a second frequency;

a first fiber optic conduit to conduct said laser light having said first and second frequencies from said first and second sources to a vicinity of the portion of the living body, said first conduit having a main portion to receive said laser light from said first and second sources and a distal portion to conduct said laser light from the main portion of the first conduit to the vicinity of the portion of the living body;

a detection system to receive first and second signals which correspond to said first and second frequencies of laser light after said laser light has transmitted through said portion of the living body, said detection system having a distal portion to receive said first and second signals and a main portion to conduct said first and second signals to a measurement system that interprets said first and second signals; and

at least one coupler to removably connect said main portion to said distal portion of said first conduit at a location remote from said first and second sources and closer to the portion of the living body than it is to said first and second sources, and to removably connect said main portion to said distal portion of said detection system at a location remote from said measurement system and closer to the portion of the living body than it is to said measurement system,

wherein said distal portion of said detection system converts said transmitted laser light to first and second electrical signals.

2. A method for transmitting laser light through a portion of a living body, comprising the steps of:

a) providing a first source of laser light having a first frequency;

b) providing a second source of laser light having a second frequency;

c) providing a first fiber optic conduit to conduct said laser light having said first and second frequencies from said first and second sources to the vicinity of the portion of the living body, said first conduit having a main portion to receive said laser light from said first and second sources and a distal portion to conduct said laser light from the main portion of the first conduit to the vicinity of the portion of the living body;

d) providing a detection system to receive first and second signals which correspond to said first and second signals frequencies of laser light after said laser light has transmitted through a portion of the living body, said detection system having a distal portion to receive said first and second signals and a main portion to conduct said first and second signals to a measurement system that interprets said first and second signals;

e) removably interconnecting said main portion with said distal portion of said first conduit at a location remote from said first and second sources and closer to said portion of the living body than it is to said first and second sources; and

f) removably interconnecting said main portion with said distal portion of said detection system at a location remote from said measurement system and closer to the portion of the living body than it is to said measurement system,

wherein step d) further includes converting said transmitted laser light to first and second electrical signals within said distal portion of the detection system.

3. An apparatus for use in a pulse oximetry system, said apparatus comprising:

(a) a first laser light source for emitting laser light having a first frequency;

(b) a second laser light source for emitting laser light having a second frequency;

(c) a detector means for receiving light information and converting the received light information to electrical signals; and

(d) an optical system for receiving and transmitting laser light from said first and second light sources through a portion of a living body and for receiving and transmitting light which has passed through said portion of said living body to said detector means, said optical system comprising;

(i) a permanent section comprising;

a first fiber optic cable having a proximal end for receiving the laser light received from said first and second light sources;

a second fiber optic cable having a proximal end for transmitting said light information to said detector means; and

a connector means for connection with distal ends of said first and second fiber optic cables; and

(ii) a disposable section for directing light through said portion of said living body and receiving light which has passed through said portion of said living body and comprising a probe including;

a third fiber optic cable having a proximal end for detachable connection to said connector means to receive and conduct the laser light transmitted by said first fiber optic cable to a vicinity of said portion of said living body to be transmitted through said portion of said living body;

a fourth fiber optic cable having a proximal end for detachable connection to said connection means to receive and conduct light which has transmitted through said portion of said living body to said second fiber optic cable; and

a terminal element comprising a substrate and a first optical element for receiving light from a distal end of said third fiber optic cable to direct light onto and through said portion of said living body and a second optical element for receiving light which has passed through said portion of said living body and transmitting the light to a distal end of said fourth fiber optic cable;

said first and second optical elements being mounted on said substrate,

wherein when said first, second, third and fourth fiber optic cables are connected to said connection means, said connection means is located closer to said distal ends of said third and fourth fiber optic cables than to said proximal ends of said first and second fiber optic cables.

4. An optical system for use in a pulse oximetry system, said pulse oximetry system employing a first laser light source for emitting laser light having a first frequency, a second laser light source for emitting laser light having a second frequency and a detector means for receiving light information and converting the received light information to electrical signals, said optical system for receiving and transmitting laser light from said first and second light sources through a portion of a living body and for receiving and transmitting light which has passed through said portion of said living body to said detector means, said optical system comprising:

(a) a permanent section comprising;

a first fiber optic cable having a proximal end for receiving the laser light from said first and second light sources;

a second fiber optic cable having a proximal end for transmitting said light information to said detector means; and

a connector means for connection with distal ends of said first and second fiber optic cables; and

(b) a disposable section for directing light through said portion of said living body and receiving light which has passed through said portion of said living body and comprising a probe including;

a third fiber optic cable having a proximal end for detachable connection to said connector means to receive and conduct the laser light transmitted by said first fiber optic cable to a vicinity of said portion of said living body to be transmitted through said portion of said living body;

a fourth fiber optic cable having a proximal end for detachable connection to said connection means to receive and conduct light which has transmitted through said portion of said living body to said second fiber optic cable; and

a terminal element comprising a substrate and a first optical element for receiving light from a distal end of said third fiber optic cable to direct light onto and through said portion of said living body and a second optical element for receiving light which has passed through said portion of said living body and transmitting the light to a distal end of said fourth fiber optic cable, said first and second optical elements being mounted on said substrate,

wherein when said first, second, third and fourth fiber optic cables are connected to said connection means, said connection means is located closer to said distal ends of said third and fourth fiber optic cables than to said proximal ends of said first and second fiber optic cables.