DEVICES WITH REDUCED WICKING VOLUME BETWEEN SENSORS AND SWEAT GLANDS
The disclosed invention provides a sweat sensing device configured with reduced volume between sweat sensors and sweat glands, which decreases the chronologically assured sampling interval. In one embodiment, a sweat sensing device placed on the skin for measuring a property of a sweat analyte includes one or more sweat sensors and a volume-reducing component. The volume-reducing component provides a volume-reduced pathway for sweat between the one or more sweat sensors and sweat glands when the device is positioned on the skin. The volume-reducing component may include a wicking material or other component that at least partially creates the volume-reduced pathway.
1 . A sweat sensing device providing a reduced wicking volume, the sweat sensing device comprising:
a wicking space;
one or more volume-reducing components, wherein each volume-reducing component of the one or more volume-reducing components includes one or more of the following: a wicking collector, a wicking pump, and a wicking coupler; and
one or more sensors for measuring a characteristic of an analyte in sweat.
2 . The device of claim 1 , wherein a sweat flow pathway has a volume that is less than a volume of the wicking space, and at least one of the one or more volume-reducing components has a wicking pressure that is greater than a wicking pressure of the wicking space.
3 . The device of claim 1 , wherein at least a portion of an area of the wicking collector is on or adjacent to skin, and the area of the wicking collector has a volume that is less than a volume of the wicking space.
4 . The device of claim 1 , wherein the wicking space contains no more than 50% sweat by volume.
5 . The device of claim 1 , wherein:
the wicking collector has a wicking pressure that is greater than or equal to that of the wicking pump;
the wicking coupler has a wicking pressure that is greater than or equal to that of the wicking pump;
the wicking has a wicking pressure that is greater than or equal to that of the wicking space; or
the wicking collector has a wicking pressure that is greater than that of the wicking space.
6 . The device of claim 1 , wherein the wicking coupler has a greater wicking pressure than a wicking pressure of the wicking pump, the wicking pump has greater wicking pressure than a wicking pressure of the wicking collector, and the wicking collector has greater wicking pressure than a wicking pressure of the wicking space.
7 . The device of claim 1 , wherein a volume of sweat as a percentage of a total volume of at least one of the wicking collector, the wicking pump, and the wicking coupler is less than 50%.
8 . The device of claim 1 , wherein the one or more sensors receive a centered flow of sweat.
9 . The device of claim 2 , wherein the wicking collector has a cross-sectional surface area that includes a first portion comprised of a wicking component, and a second portion comprised of an open space, wherein a cross-sectional surface area of the first portion comprises less than 50% of a cross-sectional surface area of the wicking collector.
10 . The device of claim 2 , wherein the wicking collector includes a network of wicking channels, and wherein the network of wicking channels are at least partially open to a skin surface.
11 . The device of claim 2 , wherein the wicking collector includes a network of wicking channels, and wherein the network of wicking channels are at least partially closed to a skin surface.
12 . The device of claim 2 , wherein the wicking collector includes a network of wicking channels, and wherein the network of wicking channels includes a plurality of redundant channels.
13 . The device of claim 2 , wherein a distance between adjacent wicking pathways is less than 500 μm.
14 . The device of claim 1 , wherein the wicking collector includes one or more unidirectional wicking channels.
15 . The device of claim 1 , wherein the one or more sensors include one or more of: a sensor protection material and a spacer material.
16 . The device of claim 1 , wherein the device includes one or more of the following: one or more sensor protection components; one or more spacer components; one or more evaporation prevention components
17 . The device of claim 1 , wherein the wicking collector includes at least one electrode.
18 . The device of claim 1 , wherein the device, given that the wicking collector receives an average sweat flow rate of ˜50 nL/min/cm 2 , is capable of one of the following chronologically assured sweat sampling intervals: <90 minutes; <45 minutes; <30 minutes; <15 minutes; <9 minutes; <5 minutes; <3 minutes; <2 minutes; <1 minute.
19 - 55 . (canceled)