PULSE OXIMETRY SYSTEM WITH LOW NOISE CABLE HUB

• US 20110209915A1
• Filed: 10/14/2010
• Published: 09/01/2011
• Est. Priority Date: 10/15/2009
• Status: Active Grant

• Current Assignee: Masimo Corporation
• Original Assignee: Masimo Corporation
• Inventors: Fechter, Joel, Fetherson, Shaun, Al-Ali, Ammar, Telfort, Valery G., Smith, Robert A.
• Granted Patent: US 9,106,038 B2
• Time in Patent Office: Days
• US Class Current: 174/71.R
• CPC Class Codes: A61B 2560/045 with a separable interface unit, e.g. for communication
• CPC Class Codes: A61B 2562/222 Electrical cables or leads therefor, e.g. coaxial cables or ribbon cables
• CPC Class Codes: A61B 5/14551 for measuring blood gases
• CPC Class Codes: A61B 5/301 providing electrical separation, e.g. by using isolating transformers or optocouplers
• CPC Class Codes: A61B 5/7203 for noise prevention, reduction or removal
• CPC Class Codes: A61B 7/00 Instruments for auscultation
• CPC Class Codes: H01R 2201/12 for medicine and surgery
• CPC Class Codes: H01R 31/065 with built-in electric apparatus

Abstract

A pulse oximetry system for reducing the risk of electric shock to a medical patient can include physiological sensors, at least one of which has a light emitter that can impinge light on body tissue of a living patient and a detector responsive to the light after attenuation by the body tissue. The detector can generate a signal indicative of a physiological characteristic of the living patient. The pulse oximetry system may also include a splitter cable that can connect the physiological sensors to a physiological monitor. The splitter cable may have a plurality of cable sections each including one or more electrical conductors that can interface with one of the physiological sensors. One or more decoupling circuits may be disposed in the splitter cable, which can be in communication with selected ones of the electrical conductors. The one or more decoupling circuits can electrically decouple the physiological sensors.

Claims

1. A cable hub comprising:

a first signal conditioning circuit configured to receive first signals from a first physiological sensor;

a second signal conditioning circuit configured to receive second signals from a second physiological sensor;

decoupling circuitry configured to electrically decouple the first and second signal conditioning circuits;

a shield configured to electromagnetically shield the first signal conditioning circuit at least in part; and

a cable configured to physically couple conductors from the first and second signal conditioning circuits to a connector configured to be coupled to a physiological monitor.

2. The cable hub of claim 1, wherein the decoupling circuitry comprises one or more of the following:

an optocoupler and a transformer.

3. The cable hub of claim 1, wherein the shield is electrically connected to a first ground connection of the first signal conditioning circuit but not to a second ground connection of the second signal conditioning circuit, thereby preserving electrical decoupling between the first and second signal conditioning circuits.

4. The cable hub of claim 1, further comprising:

a second connector configured to receive a first sensor cable associated with the first physiological sensor, and

a third connector configured to receive a second sensor cable associated with the second physiological sensor.

5. The cable hub of claim 1, wherein the cable comprises separate ground conductors for the first and second signal conditioning circuits.

6. The cable hub of claim 1, wherein the cable comprises a coextruded cable configured to reduce triboelectric noise.

7. A cable assembly, the cable assembly comprising:

a hub assembly configured to receive first and second cables, the first and second cables configured to receive physiological signals from one or more physiological sensors, the hub assembly comprising;

first circuitry configured to be in communication with the first cable,

second circuitry configured to be in communication with the second cable, and

local shielding disposed about the first circuitry.

8. The cable assembly of claim 7, further comprising decoupling circuitry configured to electrically decouple the first and second cables.

9. The cable assembly of claim 8, wherein the local shielding is connected to a first ground connection of the first circuitry but not to a second ground connection of the second circuitry.

10. The cable assembly of claim 7, wherein the first circuitry comprises first signal conditioning circuitry.

11. The cable assembly of claim 10, wherein the second circuitry comprises second signal conditioning circuitry.

12. The cable assembly of claim 7, wherein the one or more physiological sensors comprises an optical sensor and an acoustic sensor.

13. The cable assembly of claim 7, further comprising second local shielding disposed about the second circuitry.

14. A cable assembly comprising:

a first cable connector configured to receive a first sensor cable in communication with a first physiological sensor;

a second cable connector configured to receive a second sensor cable in communication with a second physiological sensor;

a first circuit in communication with the first cable connector;

a second circuit in communication with the second cable connector; and

a shield disposed about the first circuit.

15. The cable assembly of claim 14, further comprising decoupling circuitry configured to electrically decouple the first and second circuits.

16. The cable assembly of claim 14, wherein the shield is connected to a common potential of the first circuit.

17. The cable assembly of claim 14, wherein the shield is configured to reduce crosstalk noise between the first and second circuits.

18. The cable assembly of claim 14, wherein the shield is configured to reduce noise received by the first circuit.

19. The cable assembly of claim 14, further comprising a first shielded cable portion connected to the first circuit, the first shielded cable portion at least partially surrounding first wires of the first circuit.

20. The cable assembly of claim 19, further comprising a second shielded cable portion connected to the second circuit, the second shielded cable portion at least partially surrounding second wires of the second circuit.

21. The cable assembly of claim 20, wherein the first and second shielding cable portions are part of an instrument cable configured to be connected to a patient monitor.