Active optical oximeter probe adapter

• US 6,023,541 A
• Filed: 03/17/1998
• Issued: 02/08/2000
• Est. Priority Date: 12/20/1995
• Status: Expired due to Term

• Current Assignee: Nellcor Puritan Bennett Incorporated (Medtronic Plc)
• Original Assignee: Nellcor Puritan Bennett Incorporated (Medtronic Plc)
• Inventors: Venkatachalam, K. L., Merchant, Adnan I., Chew, Bradford B.
• Primary Examiner(s): Lee, John D.
• Application Number:
  US09/040,218
• Time in Patent Office: 693 Days
• Field of Search: 356/41, 385/15, 385/16, 385/20-22, 385/53, 385/75, 600/309, 600/310
• US Class Current: 385/20
• CPC Class Codes: A61B 2560/045 with a separable interface unit, e.g. for communication
• CPC Class Codes: A61B 2562/08 Sensors provided with means for identification, e.g. barcodes or memory chips
• CPC Class Codes: A61B 5/14551 for measuring blood gases
• CPC Class Codes: G01N 35/00732 Identification of carriers, materials or components in automatic analysers

Abstract

An adapter which actively connects a 2-lead oximeter probe or monitor to a 3-lead monitor or probe. This is done actively, with the alternating drive signals from the oximeter monitor providing a control signal for switching the adapter connections. The adapter connections are preferably made with diodes, transistors, or other active devices.

Claims

1. An adapter for enabling a first type of optical oximeter probe to be utilized with an oximeter monitor that provides probe signals for a second type of optical oximeter probe, said adapter comprising:

a set of M inputs corresponding to said second type of optical oximeter probe;

a set of N outputs, corresponding to said first type of optical oximeter probe, wherein M and N are different; and

a conversion circuit, coupled between said M inputs and said N outputs, for activating an appropriate one of said N outputs in response to the detection of a signal on at least one of said M inputs.

2. The adapter of claim 1 wherein said conversion circuit comprises opto isolator circuits for electrically isolating said M inputs from said N outputs.

3. The adapter of claim 1 wherein said conversion circuit includes a current source for driving said N outputs with a current limited to a value which will not cause excessive temperature rise on a patient'"'"'s skin surface when applied to an LED in said first type of optical oximeter probe.

4. The adapter of claim 1 further comprising:

a probe detector input;

an oximeter detector output; and

an opto isolator coupled between said probe detector input and said oximeter detector output.

5. The adapter of claim 1 further comprising:

a first opto isolator coupled to a red LED cathode input of said M inputs; and

a second opto isolator coupled to an IR LED cathode input of said M inputs.

6. The adapter of claim 5 further comprising:

a probe detector input;

an oximeter detector output; and

a third opto isolator coupled between said probe detector input and said oximeter detector output.

7. The adapter of claim 6 further comprising:

a disconnect circuit coupled to said first and third opto isolators.

8. The adapter of claim 1 wherein said conversion circuit includes:

a resistor in series with a common node input of said M inputs;

an amplifier coupled to said resistor;

an opto isolator coupled to an output of said amplifier; and

a current source circuit coupled to an output of said opto isolator.

9. An adapter for enabling a first type of optical oximeter probe to be utilized with an oximeter monitor that provides probe signals for a second type of optical oximeter probe, said adapter comprising:

a set of M inputs corresponding to said second type of optical oximeter probe;

a set of N outputs, corresponding to said first type of optical oximeter probe, wherein M and N are different; and

a conversion circuit, coupled between said M inputs and said N outputs, for activating an appropriate one of said N outputs in response to the detection of a signal on at least one of said M inputs, said conversion circuit including

a first opto isolator coupled to a common node of said M inputs,

a second opto isolator coupled to a red LED cathode input of said M inputs, and

a third opto isolator coupled to an IR LED cathode input of said M inputs;

a probe detector input;

an oximeter detector output; and

a fourth opto isolator coupled between said probe detector input and said oximeter detector output.

10. A dual use probe for use with a plurality of pulse oximeters, comprising:

a first light emitter having an emitter drive terminal and an emitter output terminal;

a second light emitter having an emitter drive terminal coupled to said emitter output terminal of said first light emitter and a first probe output terminal, and having an emitter output terminal coupled to said emitter drive terminal of said first light emitter and a second probe output terminal; and

a third light emitter having an emitter drive terminal coupled to said first probe output terminal and having an emitter output terminal coupled to a third probe output terminal.

11. A dual use probe for use with a plurality of pulse oximeters, comprising:

a first light emitting diode;

a second light emitting diode having an anode coupled to a cathode of said first light emitting diode and a first output terminal, and having a cathode coupled to an anode of said first light emitting diode and a second output terminal; and

a third light emitting diode having an anode coupled to said first output terminal and a cathode coupled to a third output terminal.

12. A pulse oximeter system comprising:

a probe having a plurality of light emitters;

a pulse oximeter monitor for providing drive power to said plurality of light emitters over at least one drive line; and

a diverting circuit, coupled to said drive line, configured to divert power from said drive line for performing a function not performed by said pulse oximeter monitor.

13. The pulse oximeter system of claim 12 wherein said diverting circuit comprises an adapter for connecting said pulse oximeter monitor to said probe, said probe having at least first and second light emitters, said adapter comprising:

a common terminal for connecting to a one of said probe and an oximeter which is a three terminal device, the other being a two terminal device;

at least a first light emitter drive terminal for connecting to said oximeter over said drive line for providing an activating signal for one of said light emitters; and

a switching circuit, responsive to said activating signal, for alternately connecting, coincident with the alternate activation of said light emitters, said common terminal to two different I/O terminals of the two terminal device.

14. The pulse oximeter system of claim 13 wherein said switching circuit includes at least one optically isolated switch.

15. The pulse oximeter system of claim 12 wherein said diverting circuit draws less than 20 percent of the power provided to said light emitters on said drive line.

16. The pulse oximeter system of claim 12 wherein said diverting circuit comprises a switching circuit.

17. The pulse oximeter system of claim 16 wherein said switching circuit includes at least one current limiting resistor.

18. The pulse oximeter system of claim 16 wherein said switching circuit includes at least one optically isolated switch.

19. The pulse oximeter system of claim 12 wherein said light emitters are LEDs, and further comprising a detector mounted in said probe, said LEDs generating light which is scattered by a patient'"'"'s tissue and detected by said detector to create signals provided to said pulse oximeter monitor for calculating arterial oxygen saturation.

20. A pulse oximeter system comprising:

a probe having a plurality of LEDs;

a pulse oximeter monitor for providing drive power to said plurality of LEDs over at least one drive line; and

a diverting circuit, coupled to said drive line, configured to divert power from said drive line for controlling a switching circuit, said switching circuit including at least one current limiting resistor, said diverting circuit drawing less than 20 percent of the power provided to said LEDs on said drive line; and

a detector mounted in said probe, said LEDs generating light which is scattered by a patient'"'"'s tissue and detected by said detector to create signals provided to said pulse oximeter monitor for calculating arterial oxygen saturation.