Abstract:
A releasable liner for a sensor device having adhesive and conductive gel portions includes a flexible sheet having a free end and a fixed end, and a portion of the flexible sheet that is releasably attached to the sensor device, wherein the flexible sheet is folded upon itself so that the fixed end is generally adjacent the free end. Exerting a pulling force on the free end releases the liner in a controlled manner to uncover the adhesive and conductive gel portions of the sensor device.

Description:
FIELD OF THE INVENTION 
       [0001]    This invention relates generally to a protective liner for a sensor device and, more specifically, to a protective liner that may be controllably and systematically removed from a sensor device. 
       BACKGROUND OF THE INVENTION 
       [0002]    Electrocardiogram (ECG) devices, using twelve (12) or more leads are known. Twelve-lead systems typically utilize individual leads that are connected to a patient, whereas ECG systems employing more than 12-leads are likely to be deployed in the form of an electrode vest, which is applied to the patient&#39;s torso. By way of example, one type of electrode vest is described in U.S. Pat. No. 6,055,448. 
         [0003]    Electrodes for sensing bioelectric data or signals from a patient, whether connected to individual leads or in a multi-electrode vest require a conductive coupling gel placed between each electrode and the patient&#39;s skin. The gel better enables signal transfer between the patient&#39;s body and the electrode. The electrodes may also have an adhesive section to allow the electrodes to stay connected to the patient&#39;s skin during an ECG test. In addition, or alternatively, the conductive gel may have adhesive properties to allow the electrodes to adhere to the patient. Both the gel and adhesive section of an electrode must be protected from the environment until such time that the electrode is to be placed onto the patient. Individual protective patches that cover individual electrodes are known. The protective patches are removed by a medical clinician immediately prior to applying the electrodes to a patient. Alternatively, a single protective sheet may cover all of the electrodes on a vest. The protective sheet is removed immediately prior to placing the vest on a patient. Electrode vests may be unwieldy and difficult to apply to the patient and removing the individual protective patches or the larger protective sheet further complicates the utilization of such vests, making it difficult to place the vest and accompanying electrodes on the patient without the electrodes sticking to other parts of the vest or at the wrong locations on the patient. 
       SUMMARY OF THE INVENTION 
       [0004]    According to an embodiment of the invention, a releasable liner for a sensor device having a plurality of electrodes includes a first strip portion configured to overlay and adhere to at least one of the plurality of electrodes, the first strip portion having a fixed end attached to the sensor device, and a second strip portion extending approximately parallel to the first strip portion and positioned adjacent thereto, the second strip portion having a free end movable relative to the fixed end of the first strip portion, the second strip portion coupled to the first strip portion such that a pulling force applied to the free end causes the first strip portion to separate from at least one of the plurality of electrodes. 
         [0005]    According to another embodiment of the invention, a releasable liner for a sensor device includes a flexible sheet having a free end and a fixed end, and a portion of the flexible sheet that is releasably attached to the sensor device, wherein the flexible sheet is folded upon itself so that the fixed end is generally adjacent the free end. The liner is released from the sensor device when pulling force is exerted on the free end. 
         [0006]    In accordance with yet another example of the invention, a sensor device for positioning on a human patient, includes a patient-facing surface with at least a portion of the patient-facing surface having an adhesive characteristic that may be removably attached to the patient&#39;s body and a protective liner folded upon itself and releasably affixed to the patient-facing surface of the sensor device. Exerting a pulling force on the liner causes the liner to release from the patient-facing surface of the sensor device. 
         [0007]    In accordance with still another embodiment of the invention, a method for placing a sensor device in contact with a patient&#39;s anatomy includes the steps of positioning the sensor device on the patient in a desired position and releasing a protective sheet between the patent and a portion of the sensor device such that the releasing step exposes the sensor device to the patient&#39;s anatomy. 
         [0008]    These and other examples of the invention will be described in further detail below. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0009]    Preferred and alternative examples of the present invention are described in detail below with reference to the following drawings: 
           [0010]      FIG. 1  is an exploded perspective view showing a sensor device and protective liner according to an embodiment of the present invention in relation to the front of a patient&#39;s body; 
           [0011]      FIG. 2A  is a perspective view of the sensor device and protective liner of  FIG. 1  placed onto a patient; 
           [0012]      FIG. 2B  is a perspective view of the sensor device and liner of  FIG. 2A  showing portions of the liner at various states of removal; 
           [0013]      FIG. 2C  is a perspective view of the sensor device and liner of  FIG. 2A  showing the liner entirely removed; 
           [0014]      FIG. 3A  is a schematic view of a portion of the liner covering electrodes on a sensor device; 
           [0015]      FIG. 3B  is a schematic view of a portion of the liner partially removed to partially expose electrodes on the sensor device; 
           [0016]      FIG. 3C  is a schematic view of a portion of the liner more fully removed to expose electrodes but still attached to the sensor device; 
           [0017]      FIG. 4A  is a schematic side view of the sensor device and liner of  FIG. 3A ; 
           [0018]      FIG. 4B  is a schematic side view of the sensor device and liner of  FIG. 3B ; 
           [0019]      FIG. 4C  is a schematic side view of the sensor device and liner of  FIG. 3C ; and, 
           [0020]      FIG. 5  is an exploded perspective view showing various components of the liner. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
       [0021]    As previously discussed, conventional, single sheet protective liners for electrode vests used with electrocardiogram (ECG) devices are cumbersome and unwieldy to use, making the vest difficult to apply to a patient. Accordingly, there is a need for a releasable liner for such an electrode vest that may be easily and quickly removed from the electrodes in a controlled manner and which does not complicate the attachment of the vest or otherwise disturb the placement of the electrodes on the patient. 
         [0022]      FIG. 1  illustrates an ECG sensor device  100  according to an embodiment of the present invention. Sensor device  100  includes an electrode vest  110  and protective liner  120 . Vest  110  includes a plurality of sensors, or electrodes,  400  and conductive traces on a flexible dielectric membrane  130 . The electrodes  400  are positioned on a patient-facing surface of the vest  110 . For purposes of clarity,  FIG. 1  is an exploded perspective view of the sensor device  100  that shows the liner  120  separated from the vest  110 . However, it is to be understood that before the sensor device  100  is affixed to the patient  150 , the liner  120  is in contact with the patient-facing side of vest  110  and covers the electrodes  400 . In this way, the liner  120  protects the electrodes  400  until they are affixed to the patient  150 . 
         [0023]      FIGS. 2A-C  illustrate how the sensor device  100  may be attached to the patient  150  who is about to undergo a medical test, such as an ECG exam. In  FIG. 2A , sensor device  100  is positioned over the front torso of the patient  150 . The liner  120  is in contact with the patient-facing surface of the vest  110  and, as illustrated in  FIG. 2A , the liner  120  is between the patient&#39;s skin and the electrode vest  110 . Accordingly, the electrodes  400  in  FIG. 2A  are not in contact with the patient. 
         [0024]    Turning to  FIG. 2B , the sensor device  100  is shown partially attached to the patient  150 . Portions of the liner  120  near the top of the vest  110 , closest to the patient&#39;s head, have been removed from the vest  110  and the electrodes  400  in this area of the vest  110  are in contact with the patient&#39;s skin.  FIG. 2C  shows the remaining portions of liner  120  removed from the sensor device  100  and all of the electrodes  400  on the vest  110  are in contact with the patient  150 . As depicted in  FIG. 2C , the sensor device is now ready to be connected to a remote device, such as an ECG base unit  190 . The electrodes  400  are electrically coupled to the ECG base unit  190  through connector  180  and cable  185 . 
         [0025]    As will be more fully appreciated from the following discussion and with reference to ( FIG. 2C ), the vest  110  and electrodes  400  in one embodiment of the present invention are held in place on the patient by adhesive patches  200  and adhesive gel  220  on or in the general vicinity of the electrodes  400 . Conventional, conductive gel, such as Katecho KM10T or Covidien RG-63B, is suitable for coupling the electrodes to the patient and allowing electrical conductivity there between. Once the ECG or other medical test utilizing the sensor device  100  is completed, the vest  110  may be removed from the patient  150  by pulling the vest  110  away from the patient and, thus, peeling the electrodes  400  from the patient  150 . The vest  110  may then be discarded. 
         [0026]    As previously discussed, liner  120  is left attached to the vest  110  until the electrodes  400  are to be attached to the patient  150 , thus preserving the cleanliness and integrity of the adhesive patches  200  and electrode gel  220 . 
         [0027]    As illustrated in  FIGS. 2A-C , and more fully described below, liner  120  provides a quick and simple way to attach the electrode vest  110  in the proper position on the patient  150 . Once the sensor device  100  is properly oriented on the patient ( FIG. 2A ), portions of the protective liner  120  are removed to allow the medical personnel to attach the vest  110  and electrodes  400  to the patient  150  in a controlled manner. 
         [0028]      FIG. 2B  shows the vest  110  partially affixed to the patient  150 . Preferably, the clinician removes some or all of patches  310  and affixes the associated adhesive patches and gel  200 ,  220  to the patient  150  to hold the vest  110  in the proper orientation. Starting near the top of the sensor device  100 , closest to the patient&#39;s head, portions of the liner  120 , illustrated as a series of strips, are removed and the corresponding portions of the vest  110  and electrodes  400  are pressed into place onto the patient&#39;s skin by the medical clinician. Continuing to work down the vest  110 , away from the patient&#39;s head, the medical personnel removes the strips of the liner  120  and affix the vest  110  and the uncovered electrodes  440  to the patient  150 . Once the liner  120  is completely removed, that is, once all of the strips have been removed ( FIG. 2C ), the vest  110  may then be connected to the remote equipment, such as the ECG base unit  190  to begin the desired medical test. After the test is completed, the medical personnel may remove the vest  110  from the patient  150  and discard it in an appropriate and conventional manner. 
         [0029]    In one embodiment, as briefly discussed above, liner  120  includes a number of releasable, protective strips  300  ( FIG. 1 ). The liner  120  may also include additional, releasable patches  310  positioned on extensions of the vest  110  that may cover electrodes  400  and/or adhesive patches  410  for securing the vest  110  to the patient  150 . When medical personnel apply the vest  110  to the patient  150 , the patches  310  near the patient&#39;s head may be removed first to allow the medical technician to place the vest  110  on the patient  150  and hold it in proper orientation. Similarly, the patches  310  near the bottom of the vest  110 , farthest away from the patient&#39;s head, may be removed next to further secure the vest  110  and electrodes  400  to the patient  150 . The patches  310  may be removed in this or a different order relative to each other and the liner strips  300  as preferred by the medical technician. 
         [0030]      FIGS. 3A-C  show one of the protective liner strips  300  during various stages of release from the vest  110 .  FIGS. 4A-C  are schematic side views of the liner strip  300  in the various stages of removal illustrated in corresponding  FIGS. 3A-C , and further illustrate the release of the liner strip  300  from the vest  110 .  FIGS. 3A-C  illustrate the liner strip  300  as viewed from the patient&#39;s side of the vest  110  while  FIGS. 4A-4C  illustrate corresponding side elevational views of the liner strip  300 . 
         [0031]    In  FIG. 3A , the liner strip  300  is placed on the vest  110  covering rows of electrodes  400 . The liner strip  300  includes a fixed end  320  releasably attached to the vest  110  by a fastening device  330 , which may take the form of, but is not limited to, adhesive tape, wax, hook and loop fasteners, magnets, etc. The liner strip  300  further includes a free end  340  that passes through a retainer  350  located distally from the fixed end  320  and then passes through a guide  360  located proximate the free end  340 , thus forming an open loop as best shown in  FIG. 4A . As illustrated in  FIGS. 3A-C  and as discussed with reference to  FIG. 5 , retainer  350  and guide  360  are attached to vest  110 . 
         [0032]    Referring specifically to  FIG. 4A , liner strip  300  is positioned between electrodes  400  and the patient&#39;s skin  155 . The liner strip  300  is attached at its fixed end  320  to dielectric membrane  130  by the fastening device  330  and passes through the retainer  350 . As previously discussed, the liner strip  300  is folded back on itself after passing through retainer  350  and may pass through a slot  365  in guide  360  so that free end  340  is looped back to the general proximity of, and even extending past, the fixed end  320 . 
         [0033]    Turning to  FIGS. 3B and 4B , free end  340  has been pulled away from the fixed end  320 . As oriented in  FIGS. 3B and 4B , free end  340  has moved to the left. This motion is accomplished by the medical technician pulling on free in  340 . As the free end  340  is pulled, the liner strip  300  disengages from the retainer  350 . The material properties and mechanical design of the retainer  350  allow it to give way and release the strip  300  when a sufficient pulling force is applied to end  340 . As end  340  is pulled, the strip  300  pulls away from retainer  350  and sequentially and controllably releases from, and exposes, electrodes  400 . As the strip  300  continues to be pulled, eventually, all electrodes  400  previously covered by strip  300  are uncovered and exposed to the patient  150  ( FIGS. 3C and 4C ). Continued pulling by medical personnel causes the liner strip  300  to eventually release completely from vest  110 . As discussed above, and with reference to  FIG. 2B , a medical technician may apply pressure to the vest  110  in the area of the exposed electrodes  400  so that they better adhere to the patient  150 . 
         [0034]    As the free end  340  of liner strip  300  is pulled, arms  351  of retainer  350  flex and release the liner strip  300  ( FIG. 3B ). As the medical personnel continues to pull the liner strip  300 , the strip releases from, and uncovers electrodes  400 . The uncovered electrodes  400  may be pressed into contact with the patient&#39;s skin  155 . In  FIG. 3C , the liner strip  300  has been pulled sufficiently far to uncover all previously covered electrodes  400 , but is still attached to the vest  110  at its fixed end  320  by tape  330 . Continued pulling of strip  300  releases the end  320  from the vest  110 . The tape may either remain on the vest  110  or on the liner strip  300 . All electrodes  400  previously covered by strip  300  are now uncovered and are in contact with the patient  150 . 
         [0035]      FIG. 5  illustrates one embodiment of a liner strip  300 . In this embodiment, retainer  350  and guide  360  are elements affixed to vest  110  ( FIGS. 1 and 2A ) by adhesive strips  375 . Alternatively, the retainer  350  and guide  360  may be attached to the vest  110  by other means, including but not limited to gluing or sonic welding. In the embodiment illustrated in  FIG. 5 , free end  340  has an arrowhead shape and is attached to the liner strip  300  by adhesive  380 . Free end  340  may have other shapes and may be attached to the liner strip  300  by other means, such as gluing or sonic welding. Further, end  340  may be formed as an integral part of liner strip  300 . One benefit of the arrowhead shape of end  340  is that the width of end  340  is larger than the width of slot  365  in guide  360  through which the liner strip  300  passes. This geometry prevents the free end  340  of liner strip  300  from unintentionally pulling back through the guide  360 . It is further understood that retainer  350  and guide  360  may be formed as part of, and integral with, vest  110 . For example, the retainer  350  and guide  360  may be laser cut into the dielectric substrate  130  of vest  110 . 
         [0036]    Preferably, a surface  315  ( FIG. 5 ) of liner strip  300  has sufficiently low adhesive properties that allow it to release from the adhesive gel on the electrodes  400  when an appropriate pulling force is applied to free end  340 . For example, silicone coated polyester release liner materials may offer these properties. Also preferably, the opposite surface  325  of liner strip  300  has sufficiently low coefficient of friction properties to allow it to slide easily against itself when a pulling force is applied to free end  340  (also  FIG. 5 ). 
         [0037]    While the preferred embodiment of the invention has been illustrated and described, as noted above, many changes can be made without departing from the spirit and scope of the invention. For example, the protective liner may be shaped other than as a series of strips and there may be more than one guide element along the liner strip. The characteristics of the protective liner material may be such that there is no need for a retainer or guide. For example, the liner may be stiff enough to hold its place on the vest without the need for a retainer. By way of further example, the length of the liner strip may be short enough that a guide is not required. Accordingly, the scope of the invention is not limited by the disclosure of the preferred embodiment. Instead, the invention should be determined entirely by reference to the claims that follow.