Skin preparation device and biopotential sensor

Abstract

The skin preparation device and sensor of the present invention include an array of rigid tines. The tines serve to “self-prepare” the skin at each electrode site. These tines, when pressed against the skin, penetrate the stratum corneum, thereby reducing skin impedance and improving signal quality. A self-prepping device of the present invention is an optimized array of short non-conductive rigid tines in which the individual tines are created in a geometry that allows for a sharp point at the tip when molding, machining or etching is used as a method of fabrication. This non-conductive array with rigid penetrating structures may, therefore, be used in combination with a conductive medium, preferably an ionic conductive gel. In penetrating the stratum corneum, micro-conduits are created in the layers of the skin enabling the conductive medium to reach the low impedance layers and to transmit bioelectrical signals from the skin to the electrode surface. Such a self-prepping device can be readily mass produced using molding methods or possibly other manufacturing methods, thereby providing for a low cost means of achieving improved performance of the biopotential sensor. Additionally this invention includes the integration of this self-prepping device into a biopotential sensor comprising an array of one or more electrodes.

1 . A skin preparation device comprising:
 a base member in the shape of a ring;   an array of rigid tines contiguous with the base member, each tine having a sharp tip adapted to penetrate stratum corneum and to reduce skin impedence and each tine has a height between 0.020 inches to 0.040 inches from the base member; and   a component configured to deliver a conductive gel below the stratum corneum.   
     
     
         2 . The skin preparation device of  claim 1 , wherein the component configured to deliver the conductive gel comprises a gel storage container coupled to the base member. 
     
     
         3 . The skin preparation device of  claim 2  wherein the gel storage container is a burst container adapted to release the conductive gel when pressed upon. 
     
     
         4 . The skin preparation device of  claim 1  wherein the component configured to deliver the conductive gel comprises:
 a channel extending through the base member, wherein the channel is adapted to allow passage of the gel through the base member. 
 
     
     
         5 . (canceled) 
     
     
         6 . The skin preparation device of  claim 1  wherein the tines are molded with a plastic resin containing carbon nanotubes. 
     
     
         7 . A skin preparation device comprising:
 a base member;   an array of rigid tines contiguous with the base member, each tine having a sharp tip adapted to penetrate stratum corneum and to reduce skin impedence and each tine has a height between 0.020 inches to 0.040 inches from the base member;   a component configured to deliver a conductive gel below the stratum corneum; and   wherein the base member is formed of multiple stepped levels each level containing a portion of the array of rigid tines.   
     
     
         8 . The skin preparation device of  claim 7 , wherein the component configured to deliver the conductive gel comprises a gel storage container coupled to the base member. 
     
     
         9 . The skin preparation device of  claim 8  wherein the gel storage container is a burst container adapted to release the conductive gel when pressed upon. 
     
     
         10 . The skin preparation device of  claim 7  wherein the component configured to deliver the conductive gel comprises:
 a channel extending through the base member, wherein the channel is adapted to allow passage of gel through the base member. 
 
     
     
         11 . (canceled) 
     
     
         12 . The skin preparation device of  claim 7  wherein the tines are molded with a plastic resin containing carbon nanotubes. 
     
     
         13 . A skin preparation device comprising:
 a base member; and   an array of tines contiguous with the base member, each tine having a pyramidal shape wherein one side of the pyramid is concave.   
     
     
         14 . The skin preparation device of  claim 13  further comprising:
 a plurality of apertures extending through the base member, 
 wherein the concave side of the pyramidal tine is aligned with a sidewall of one of the plurality of apertures. 
 
     
     
         15 . The skin preparation device of  claim 14  wherein each aperture has the concave side of one tine aligned with the sidewall of the aperture. 
     
     
         16 . The skin preparation device of  claim 14  wherein each aperture has the concave side of two tines aligned with the sidewall of the aperture. 
     
     
         17 . The skin preparation device of  claim 16  wherein the pyramidal tines are equally spaced around the perimeter of the aperture. 
     
     
         18 . The skin preparation device of  claim 13  further comprising:
 a separate gel storage container coupled to the base member. 
 
     
     
         19 . The skin preparation device of  claim 13  wherein the gel storage container is a burst container adapted to release a gel when pressed upon. 
     
     
         20 . The skin preparation device of  claim 13  further comprising:
 a channel extending through the base member, wherein the channel is adapted to allow passage of gel through the base of the member. 
 
     
     
         21 . The skin preparation device of  claim 13  wherein the tines of the tine array are 0.010 inches to 0.080 inches in height from the base member. 
     
     
         22 . The skin preparation device of  claim 13  wherein the tines are molded with a plastic resin containing carbon nanotubes. 
     
     
         23 . A sensor system comprising:
 a flexible substrate;   a plurality of electrodes coupled to the flexible substrate;   an adhesive substrate adjacent to each of the electrodes and the flexible substrate; and   a preparation device comprising:
 a base member in the shape of a ring; 
 an array of rigid tines contiguous with the base member, each tine having a sharp tip adapted to penetrate stratum corneum and to reduce skin impedence and each tine has a height between 0.020 inches to 0.040 inches from the base member; and 
 a component configured to deliver a conductive gel below the stratum corneum. 
   
     
     
         24 . The sensor system of  claim 23  wherein each electrode is coupled to a plurality of preparation devices, the preparation devices are arranged such that upon application of pressure to the electrode the preparation devices angle to adjust to the surface to which the sensor system is applied. 
     
     
         25 . A sensor system comprising:
 a flexible substrate;   a plurality of electrodes coupled to the flexible substrate;   an adhesive substrate adjacent to each of the electrodes and the flexible substrate; and   a preparation device comprising:
 a base member; 
 an array of rigid tines contiguous with the base member, each tine having a sharp tip adapted to penetrate stratum corneum and to reduce skin impedence and each tine has a height between 0.020 inches to 0.040 inches from the base member; 
 a component configured to deliver a conductive gel below the outermost layer of the stratum corneum; and 
 wherein the base member is formed of multiple stepped levels each level containing a portion of the array of rigid tines. 
   
     
     
         26 . The sensor system of  claim 25  wherein each electrode is coupled to a plurality of preparation devices, the preparation devices are arranged such that upon application of pressure to the electrode the preparation devices angle to adjust to the surface to which the sensor system is applied. 
     
     
         27 . A sensor system comprising:
 a flexible substrate;   a plurality of electrodes coupled to the flexible substrate;   an adhesive substrate adjacent to each of the electrodes and the flexible substrate; and   a preparation device comprising:
 a base member; and 
 an array of tines contiguous with the base member, each tine having a pyramidal shape wherein one side of the pyramid is concave. 
   
     
     
         28 . The sensor system of  claim 27  wherein each electrode is coupled to a plurality of preparation devices, the preparation devices are arranged such that upon application of pressure to the electrode the preparation devices angle to adjust to the surface to which the sensor system is applied.