Conductive human interfaces
A conductive human interface has a fabric layer with an interior surface and an exterior surface. A soft coating overlies the interior surface of the fabric layer. An electrode or sensor is included to connect with a residual limb. A conductive path connects the electrode or sensor with an electrical connector which, in turn connects with a prosthetic or other assistive device. The conductive path includes a conductor having a section overlying the fabric layer. The overlying section of the conductor can be cord of conductive thread. A nonconductive support thread can extend through the fabric layer from the exterior surface to the interior surface, and further around the conductor to secure the overlying section of the conductor to the fabric layer.
1. A conductive human interface, consisting of:
a fabric layer flexible substrate having an interior surface and an exterior surface;
a coating of a soft polymer applied in a gel state that covers the interior surface of the fabric layer, such that the interior surface forms a boundary with the soft coating;
an electrode or sensor configured to electrically connect with a residual limb, the electrode or sensor protruding away from the interior surface of the fabric layer through the soft coating;
a cord of conductive thread embedded within the soft coating that extends through and is spaced from the interior surface of the fabric layer, the cord of conductive thread connecting the electrode with an electrical connector; and
nonconductive support thread extending through the fabric layer from the exterior surface thereof to the interior surface to extend around the cord of conductive thread, the nonconductive support thread being dissoluble for removal from the interface by dissolving in a solvent, such that upon removal of the nonconductive support thread a space is created allowing for shifting of the cord of conductive thread in response to forces imparted from the residual limb.
2. The interface of claim 1 , wherein the cord of conductive thread is formed of filaments that are bundled, spun, or twisted together.
3. The interface of claim 2 wherein the filaments include filaments that are formed of electrically nonconductive material and are coated or embedded with electrically conductive elements.
4. The interface of claim 2 , wherein the filaments include filaments that are formed of electrically conductive material.
5. The interface of claim 4 , wherein the electrically conductive material includes stainless steel.
6. The interface of claim 1 , wherein the cord of conductive thread has a monofilament structure.
7. The interface of claim 6 , wherein the monofilament structure is a filament formed of stainless steel.
8. The interface of claim 1 , wherein the fabric layer is stretchable in a stretchable direction, and wherein the cord of conductive thread has an extendable length portion with a first end, a second end spaced from the first end at a linear distance in the stretchable direction, and a length greater than the linear distance, whereby the greater length enables the cord of conductive thread to elongate in the stretchable direction when the fabric layer stretches in the stretchable direction.
9. The interface of claim 8 , wherein the stretchable direction is a longitudinal direction in which the first end of the extendable length portion is a proximal end and the second end is a distal end.
10. The interface of claim 8 , wherein the extendable length portion of the cord of conductive thread has first segments reaching toward the second end in orientations toward one side of the stretchable direction and has second segments reaching toward the second end in orientations toward an opposite side of the stretchable direction.
11. The interface of claim 10 , wherein the first and second segments include segments that are linear and reach toward the second end in a zig-zag configuration with corners between adjacent segments.
12. The interface of claim 10 , wherein the first and second segments include segments that are arcuate and reach toward the second end in a serpentine configuration with turns between adjacent segments.
13. The interface of claim 1 , wherein the support thread is dissoluble in water.
14. The interface of claim 1 , wherein the cord of conductive thread is subdivided into an electrical conductor and an electrical connector configured to connect with a prosthetic or other assistive device, a sensor at least partially embedded in the soft coating and the electrical conductor is part of a conductive path electrically interconnecting the sensor with the electrical connector.
15. The interface of claim 1 , wherein the cord of conductive thread is stitched with an aspect ratio greater than 1.
16. The interface of claim 1 , wherein the cord of conductive thread comprises multiple plies.
17. The interface of claim 1 , wherein the cord of conductive thread has a linear resistance of less than about 10 Ω/in.
18. The interface of claim 1 , wherein the cord of conductive thread has a linear density of at least 2,000 yd/lb.
19. The conductive human interface of claim 1 , wherein the cord of conductive thread is flexible.