Low noise oximetry cable
The present disclosure includes a cable for a patient monitoring system. The cable can have a flexible and durable overall construction that enables the cable to withstand repeated winding and unwinding and prevent kinks from developing. The cable may include multiple bundles encased in inner jackets that reduce the amount of friction against other cable elements and allows the bundle to move more freely inside an outer jacket of the cable. The multiple bundles may include multiple wires or cords. The cable can include a flexible core that runs through the middle of the cable. The multiple bundles can be twisted, weaved, or untwisted around the core.
1. An oximetry system capable of acquiring signals indicative of one or more physiological parameters of a patient, the oximetry system comprising:
a noninvasive sensor comprising a detector configured to detect light attenuated by a body tissue of a patient and output a detector signal indicative of the light detected after attenuation by the body tissue;
a patient monitor configured to receive the detector signal and determine one or more physiological parameters for the patient from the detector signal; and
a cable comprising:
a core comprising a plurality of fibers;
a plurality of bundles comprising a first bundle and a second bundle, the first bundle comprising a first plurality of wires and an inner shield at least partially surrounding the first plurality of wires, the second bundle comprising a second plurality of wires, the inner shield being configured to provide electromagnetic interference protection;
an outer shield at least partially surrounding the first bundle and the second bundle and configured to provide electromagnetic interference protection; and
a jacket at least partially surrounding the outer shield, wherein no bundle of the plurality of bundles is concentric with the core.
2. The oximetry system of claim 1 , wherein the noninvasive sensor comprises a sensor housing configured to position an emitter and the detector proximate to the body tissue, and the one or more physiological parameters comprise an oxygen saturation and a pulse rate, the first bundle being configured to transmit the detector signal from the noninvasive sensor to the patient monitor.
3. The oximetry system of claim 1 , wherein the core is flexible and configured to reduce a tensile stress exerted on the cable and increase a durability of the cable.
4. The oximetry system of claim 3 , wherein the first bundle and the second bundle are twisted or weaved around the core.
5. The oximetry system of claim 1 , wherein the inner shield comprises a metal.
6. The oximetry system of claim 1 , wherein the cable comprises a third bundle at least partially surrounded by the outer shield, the third bundle comprising a third plurality of wires.
7. The oximetry system of claim 6 , wherein the first bundle, the second bundle, and the third bundle are twisted or weaved around the core.
8. The oximetry system of claim 1 , wherein the first bundle and the second bundle are not concentric with each other.
9. The oximetry system of claim 5 , wherein the metal comprises a copper or a silver.
10. The oximetry system of claim 1 , wherein the first bundle comprises a different number of wires than the second bundle.
11. The oximetry system of claim 1 , wherein the core comprises a plurality, of arcuate surfaces that contact the first bundle and the second bundle and limit an amount of contact between the first bundle and the second bundle.
12. The oximetry system of claim 11 , wherein the plurality of arcuate surfaces are formed at least partly by pressure from the first bundle and the second bundle on the core.
13. A cable for transmitting signals in an oximetry system, the cable comprising:
a plurality of bundles comprising a first bundle and a second bundle, the first bundle comprising a first plurality of wires and an inner shield at least partially surrounding the first plurality of wires, the second bundle comprising a second plurality of wires, the inner shield being configured to provide electromagnetic interference protection;
a core comprising a plurality of fibers and configured to reduce a tensile stress exerted on the cable and increase a durability of the cable; and
an outer shield at least partially surrounding the first bundle and the second bundle and configured to provide electromagnetic interference protection,
wherein no bundle of the plurality of bundles is concentric with the core.
14. The cable of claim 13 , wherein the first bundle and the second bundle are twisted or weaved around the core.
15. The cable of claim 13 , wherein the second bundle comprises a second shield at least partially surrounding the second plurality of wires, the second shield being configured to provide electromagnetic interference protection.
16. The cable of claim 13 , further comprising a third bundle disposed within a jacket along with the first bundle and the second bundle.
17. The cable of claim 13 , wherein the first bundle and the second bundle are not concentric with each other.
18. The cable of claim 13 , wherein the core defines a central axis for the cable.
19. The cable of claim 13 , wherein the first bundle comprises a different number of wires than the second bundle.
20. A method of manufacturing a cable for transmitting signals in an oximetry system, the method comprising:
assembling a first bundle comprising a first plurality of wires and an inner shield at least partially surrounding the first plurality of wires, the inner shield being configured to provide electromagnetic interference protection;
assembling a second bundle comprising a second plurality of wires; and
placing, within a jacket and an outer shield, the first bundle and the second bundle adjacent to a core so that the first bundle and the second bundle are not concentric with the core, the outer shield being configured to provide electromagnetic interference protection, the core comprising a plurality of fibers.
21. The method of claim 20 , further comprising twisting or weaving the first bundle and the second bundle around the core.
22. The method of claim 20 , wherein said placing comprises placing, within the jacket and the outer shield, a third bundle adjacent to the core, the third bundle comprising a third plurality of wires.
23. The method of claim 22 , further comprising twisting or weaving the first bundle, the second bundle, and the third bundle around the core.
24. The method of claim 20 , wherein said placing comprises placing the first bundle and the second bundle so that the first bundle and the second bundle are not concentric with each other.
25. The method of claim 20 , wherein said placing comprises placing the first bundle and the second bundle adjacent to the core so that the core defines a central axis for the cable.