Low noise cable providing communication between electronic sensor components and patient monitor
A physiological measurement system can include a low noise patient cable that connects a monitor and a noninvasive optical sensor. The cable has a plurality of emitter wires configured to communicate a drive signal between the monitor and at least one emitter. The cable also has a plurality of detector wires configured to communicate a physiological signal between at least one detector responsive to the emitter and the monitor. The emitter and detector wires are orthogonally disposed so that crosstalk between the two functionally different wires is mitigated.
1. A low noise patient cable comprising:
a plurality of detector wires configured to communicate a physiological signal between a detector, which is responsive to energy received from an emitter, and a monitor;
a shield disposed over the plurality of detector wires; and
a plurality of emitter wires configured to communicate a drive signal between the monitor and at least one emitter, wherein the plurality of emitter wires are twisted in an opposing rotational direction relative to the plurality of detector wires about the shield, wherein an angle between the plurality of emitter wires and the plurality of detector wires is between about 60 degrees and about 90 degrees.
2. The low noise patient cable of claim 1 , further comprising a plurality of fiber filler wires.
3. The low noise patient cable of claim 2 , wherein the plurality of detector wires are tinsel wires.
4. The low noise patient cable of claim 2 , wherein the plurality of fiber filler wires are Kevlar wires.
5. The low noise patient cable of claim 2 , wherein the plurality of fiber filler wires are aramid wires.
6. The low noise patient cable of claim 2 , further comprising a second shield disposed over the plurality of emitter wires.
7. The low noise patient cable of claim 6 , further comprising a jacket disposed over the second shield.
8. A method of making a cable, the method comprising:
twisting in a first direction a plurality of inner core wires;
disposing a shield over the plurality of inner core wires;
twisting in a second direction a plurality of outer core wires around the shield, the second direction being opposite the first direction; and
disposing a jacket around the plurality of outer core wires, wherein an angle between the plurality of inner core wires and the plurality of outer core wires is between about 60 degrees and about 90 degrees.
9. The method of claim 8 , further comprising twisting a plurality of fiber filler wires with the plurality of inner core wires.
10. The method of claim 8 , further comprising disposing a second shield around the plurality of outer core wires.
11. The method of claim 8 , further comprising twisting a plurality of fiber filler wires with the plurality of inner core wires.
12. The method of claim 11 , wherein the plurality of fiber filler wires are aramid.
13. The method of claim 11 , wherein the plurality of fiber filler wires are Kevlar.
14. The method of claim 8 , wherein the inner and outer core wires are tinsel wires.
15. The method of claim 14 , wherein the tinsel wires are made from a silver copper alloy.
16. A low noise patient cable comprising:
a plurality of inner core wires twisted about a central axis of the cable in a first direction, the plurality of inner core wires being configured to communicate a first electrical signal;
a shield disposed over the plurality of inner core wires;
a plurality of outer core wires twisted about the central axis in a second direction, the second direction being opposite the first direction, wherein the plurality of outer core wires are configured to communicate a second electrical signal, wherein an angle between the second direction and the first direction is between about 60 degrees and about 90 degrees.
17. The low noise patient cable of claim 16 , wherein the plurality of inner core wires are tinsel wires.
18. The low noise patient cable of claim 17 , wherein the tinsel wires are a silver copper alloy.
19. The low noise patient cable of claim 16 , further comprising a plurality fiber filler wires twisted with the inner core wires.
20. The low noise patient cable of claim 16 , further comprising a second shield disposed over the plurality of outer core wires.
21. The low noise patient cable of claim 16 , further comprising a jacket disposed over the second shield.
22. A resilient patient cable comprising:
a plurality of detector wires configured to communicate a physiological signal between a detector and a monitor; and
a plurality of emitter wires separated by a shield from a plurality of the detector wires, said plurality emitter wires configured to communicate a drive signal between the monitor and at least one emitter, wherein the plurality of emitter wires are twisted in an opposing rotational direction relative to the plurality of detector wires,
wherein the cable does not electrically fail after being kinked more than 1,000 times, and wherein an angle between the plurality of emitter wires and the plurality of detector wires is about 60 degrees to about 90 degrees.
23. The resilient patient cable of claim 22 , wherein the cable is capable of withstanding more than 1,500 kinks with a high degree of reliability.
24. The resilient patient cable of claim 22 , wherein the cable can withstand, on average, more than 5,000 kinks before an electrical failure occurs.
25. The resilient patient cable of claim 22 , wherein the cable can withstand, on average, more than 10,000 kinks before an electrical failure occurs.
26. The resilient patient cable of claim 22 , wherein the cable can withstand, on average, more than 12,500 kinks before an electrical failure occurs.