Abstract:
An allergy skin test device is disclosed that causes less pain than commonly used devices that include multi-point sharp puncture heads. The allergy skin test device incorporates multiple dull pressure heads distributed amongst the sharp multi-point sharp puncture heads, each dull pressure head activating a neurological pain gate that reduces pain sensation typically caused by the neighboring multi-point head when it engages the skin.

Description:
FIELD OF THE INVENTION 
       [0001]    This invention relates generally to allergy skin test devices, and particularly to allergy skin test devices having sharp points. 
       BACKGROUND OF THE INVENTION 
       [0002]    Allergy skin testing is based on introducing allergens into the skin. There are numerous known devices for introducing allergens using a plurality of closely spaced sharp probes. The test often causes pain, resulting in patient reluctance to complete the test, and frequently interferes with the otherwise calm nature of a medical office. 
         [0003]    As a result of the felt pain, patients will sometimes react with loud expressions of pain. Children will actually sometimes cry and scream. These audible reactions can negatively affect the patients that follow, creating further difficulties with patient compliance. 
       SUMMARY OF THE INVENTION 
       [0004]    As recognized by the invention, introduction of dull pressure in the proximity of a sharp stimulus to the skin will tend to block perception of the normally resulting sharp pain sensation. This is an application of what is sometimes referred to as “neurological pain gate theory”. The device of the invention advantageously exploits this effect for the first time in the field of allergy testing by first applying dull pressure by means of dull pressure heads regularly interspersed among a regular array of sharp puncture heads. The dull pressure heads are slightly longer than the sharp ones, and consequently, they touch the skin before the sharp heads as the sharp heads are pressed into the skin. 
         [0005]    Each dull head is supported on a flexible member, and when the allergy skin test device of the invention is pressed into the skin, the flexible member is urged into a flexed condition so as to apply pressure of a magnitude sufficient to activate the “pain gate” effect in the pain receptors that would otherwise be activated by the sharp puncture head. The dull heads are flexible enough to apply sufficient pressure, while not interfering with the sharp puncture heads&#39; ability to puncture the skin and introduce the allergens. In clinical testing of the device, subjects reported significantly less pain when compared to devices that do not include the dull heads. 
         [0006]    A first general aspect of the invention is an allergy skin test device, where the device includes a plurality of sharp puncture heads, and a plurality dull pressure heads, the plurality of dull pressure heads being interspersed among the plurality of sharp puncture heads, at least one dull pressure head being cooperative with a sharp puncture head so as to promote a pain gate effect that reduces pain sensation caused by the sharp puncture head. 
         [0007]    In preferred embodiments, the plurality of sharp puncture heads is arranged as a regular array of sharp puncture heads. In further preferred embodiments, the regular array is one of: a square array, a rectangular array, a linear array, a polygonal array, an oval array, a circular array, an ellipsoidal array, a radially symmetric array. 
         [0008]    In other preferred embodiments, there is a dull pressure head for each sharp puncture head. 
         [0009]    In yet other preferred embodiments, the at least one dull pressure head is cooperative with the sharp puncture head by being positioned so as to be able to contact skin of a patient before the cooperative sharp puncture head contacts the skin of the patient when the device is used. 
         [0010]    In still other preferred embodiments, both the plurality of sharp puncture heads, and the plurality dull pressure heads, extend from a gripping element used to apply the allergy skin test device to the skin of the patient. In further preferred embodiments, the gripping element is one of: a linearly extended member, a central hub member, a curved extended member, a round member, an oval member, an ellipsoidal member. 
         [0011]    In preferred embodiments, each dull pressure head is supported by a flexible arm that is sufficiently resistant to bending so as to apply pressure via the dull pressure head sufficient to promote a pain gate effect that reduces pain sensation caused by the sharp puncture head when it contacts the skin of the patient after the dull pressure head contacts the skin of the patient when the device is used. 
         [0012]    In other preferred embodiments, each dull pressure head is supported by a compressible column that is sufficiently resistant to being compressed so as to apply pressure via the dull pressure head sufficient to promote a pain gate effect that reduces pain sensation caused by the sharp puncture head when it contacts the skin of the patient after the dull pressure head contacts the skin of the patient when the device is used. 
         [0013]    Another general aspect of the invention is an allergy skin test device having a regular array of sharp puncture heads; a corresponding regular array of dull pressure heads, each of the sharp puncture heads being cooperative with a dull pressure head so as to contact the skin before the corresponding sharp puncture head; and a gripping element used to apply the allergy skin test device to the skin of the patient, both the regular array of sharp puncture heads, and the corresponding regular array of dull pressure heads, extending from the gripping element. 
         [0014]    In preferred embodiments, each sharp puncture head is supported by a first flexible arm cooperative with the gripping element, each dull pressure head is supported by a second flexible arm cooperative with the gripping element, each second flexible arm is in nearest neighbor relationship with the first flexible arm, and the first flexible arm is of a different length than the second flexible arm. 
         [0015]    In other preferred embodiments, the second flexible arm is longer than the first flexible arm. 
         [0016]    In still other preferred embodiments, the first flexible arm is longer than the second flexible arm. 
         [0017]    In yet other preferred embodiments, the second flexible arm is less flexible than the first flexible arm. 
         [0018]    In still yet other preferred embodiments, each dull pressure head rises higher than a nearest sharp puncture head such that when the allergy skin test is used at an angle within a range of working angles, each dull pressure head contacts skin before the nearest sharp puncture head. 
         [0019]    In other preferred embodiments, each sharp puncture head is supported by a first compressible column, the first compressible column being supported by the gripping element, each dull pressure head is supported by a second compressible column that is in nearest neighbor relationship with the first compressible column, the second compressible column being supported by the gripping element, and the first compressible column is shorter than the second compressible column. 
         [0020]    Another general aspect of the invention is an allergy skin test device including a sharp puncture head; a plurality of dull pressure heads, each dull pressure head being cooperative with the sharp puncture head so as to resiliently contact the skin before the sharp puncture head; and a gripping element for gripping the allergy skin test device, for supporting the sharp puncture head and the plurality of dull pressure heads, and for applying pressure to skin of a patient via the sharp puncture head and the plurality of dull pressure heads. 
         [0021]    In preferred embodiments, each of the dull pressure heads is supported by a flexible arm that can apply sufficient pressure to provide a pain gate effect when contacting skin of a patient, without interfering with puncturing of skin by the sharp puncture head when used to introduce allergens into the skin. 
         [0022]    In other preferred embodiments, each of the dull pressure heads is supported by a compressible column that applies sufficient pressure to provide a pain gate effect when contacting skin of a patient, without interfering with puncturing of skin by the sharp puncture head when used to introduce allergens into the skin. 
         [0023]    Another general aspect of the invention is an allergy skin test device that includes a first applicator supporting a plurality of dull pressure heads, and having a plurality of holes interspersed among the plurality of dull pressure heads; and a second applicator, cooperative with the first applicator, the second applicator supporting a plurality of sharp puncture heads, the plurality of sharp puncture heads being sized and positioned so as to be able to simultaneously move through the plurality of holes, the plurality of dull pressure heads of the second applicator being interspersed among a plurality of holes sized so as to allow passage therethrough of the plurality of sharp puncture heads, at least one dull pressure head being cooperative with a sharp puncture head so as to promote a pain gate effect that reduces pain sensation caused by the sharp puncture head. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWING 
         [0024]    The invention will be more fully understood from the following detailed description, in conjunction with the following figures, wherein: 
           [0025]      FIG. 1  is a perspective view of an allergy skin test device of the prior art; 
           [0026]      FIG. 2  is a perspective view of an allergy skin test device of the invention having two linear arrays of sharp puncture heads and two corresponding linear arrays of dull pressure heads; 
           [0027]      FIG. 3  is a perspective view of an allergy skin test device having a single sharp puncture head, plus a plurality of dull heads on a flexible arm in the proximity of the sharp head; 
           [0028]      FIG. 4  is a perspective view of an allergy skin test device having a circular array of sharp puncture heads, also having a corresponding circular array of dull heads, each dull head being in proximity to each sharp puncture head; 
           [0029]      FIG. 5  is a perspective view of an allergy skin test device of the invention having dull heads that are supported by arms that are shorter than the arms that support the sharp puncture heads; 
           [0030]      FIGS. 6A and 6B  are perspective views of an embodiment wherein both the sharp puncture heads and the dull pressure heads are each supported by compressible columns; and 
           [0031]      FIG. 7  is a perspective view of a two-part embodiment, having a dull head portion and a sharp puncture head portion 
       
    
    
     DETAILED DESCRIPTION 
       [0032]    With reference to  FIG. 1 , a known allergy skin test device  10  is shown. The device  10  has a plurality of sharp puncture heads  12 , each sharp puncture head  12  being supported on a support arm  14 . Each support arm  14  is attached or integral with a gripping element  16  that is used to hold the allergy skin test device  10  when applying the device to the skin of a patient for allergy testing. This is a common allergy skin testing scenario, with the attendant pain and distress for a significant number of patients, because the sharp puncture heads each have a plurality of sharp probes that must penetrate into the skin. Such penetration causes pain and occasionally even some bleeding. Even when the pain and the bleeding are minor and temporary, they still present a problem for the medical personnel who must administer such tests. The pain is more of an issue than the minor and sporadic bleeding, since the pain more often elicits loud patient reactions, particularly among the young patients, and often interferes with patient&#39;s willingness to return for further or follow up testing. 
         [0033]    With reference to  FIG. 2 , an allergy skin test device  20  of the invention is shown, having all the elements of the known device, as well as a plurality of dull heads  22  supported on flexible arms  24 . In this embodiment, the flexible arms  24  are longer than the corresponding arms  14  that support each corresponding sharp puncture head  12 . However, it&#39;s also possible that a dull head can be supported on a flexible arm that is shorter than the flexible arm that supports the corresponding sharp puncture head. 
         [0034]    In either case, the dull head  22  is taller than the sharp puncture head  12 , and consequently, when the allergy skin test device of the invention is applied to the skin of a patient, each dull head  22  will press against the skin BEFORE the corresponding nearby sharp puncture head  12 . This results in pressure applied to the skin nearby where the sharp punctures occur, and this pressure effects a neural mechanism that results in substantially “gating” pain sensations caused by the penetration of the sharp elements of the sharp puncture head  12  into the skin. 
         [0035]    In our testing, we discovered that pain in the arm was effectively blocked when the dull head is within ¼ of an inch in lateral distance from the sharp head. 
         [0036]    As to the height difference between the sharp head and the dull head, it is important that the dull head is higher so as to apply perceivable pressure to the arm before the sharp head first touches the arm. In our tests,  11   b  of force applied over the surface area of a dull head of 1/16″ in diameter was not enough. 2-3 lb applied over the surface area (e.g., 1/16 sq inch) of the same dull head caused a desirable pain gating effect. For skin test devices made of standard material, and where the arms that support the dull heads are made from this standard material, the height of each dull head can be about ⅛ th  of an inch higher than the highest point of a respective sharp head. In general, the restoring force as provided by the supporting arms (or supporting compressible columns) must provide the 2-3 lbs of force over the dull head surface area needed to cause the desired pain-gating effect. 
         [0037]    An important aspect of the height difference is that the dull heads contact the skin before the sharp head(s), regardless of which attack angle is used, wherein the attack angle falls within a range of working angles. Alternatively, one can define the range of working angles as the range of angles that ensure that the dull heads contact the skin with enough pressure to ensure a pain-gating effect. For example, such a range of working angles can be all angles within about 30 degrees of a normal vector that is perpendicular to the skin surface to be tested. 
         [0038]    The inclusion a flexible arm or compressible column (as opposed to a substantially inflexible arm or substantially non-compressible column) is to ensure that while the dull head applies sufficient pressure, it does not preclude the sharp head from sufficiently penetrating the skin. 
         [0039]      FIG. 3  shows another preferred embodiment  30  having a single sharp puncture head  32 , plus one or more dull heads  34  (e.g., two, as shown), each on a flexible arm  36  in the proximity of the sharp head  32 . The flexible arms  36  can be grasped near and along with the supporting member  38  to apply the single sharp head  32  to the skin of a person to be tested for an allergen. 
         [0040]      FIG. 4  shows another preferred embodiment  40  having a circular array of sharp puncture heads, (e.g., five sharp puncture heads)  42  also having a corresponding circular array of dull heads  44 , each dull head  44  being in proximity to each respective sharp puncture head  42 . All of the sharp puncture heads  42  and the respective dull pressure heads  44  are supported by a support element  46 , which can include a grasping portion (not shown) that is used to grasp and control the entire embodiment  40  so as to facilitate application of the sharp puncture heads  42  and the dull pressure heads  44  of the embodiment  40  to the skin. 
         [0041]      FIG. 5  shows another preferred embodiment  50  where the dull heads  52  are supported on arms  54  shorter than the arms  56  that support the sharp puncture heads  58 . The key is that each dull head applies 2-3 lb of force over the dull head surface area (e.g., 1/16 sq inch) so as to provide the desired pain-gating effect. 
         [0042]      FIGS. 6A and 6B  show external and cutaway views, respectively, of an embodiment  60  wherein both the sharp puncture heads  62  and the dull pressure heads  64  are each supported by compressible columns  66 ,  67 . Note that each compressible column  66  includes a compressible element  68  that stores compression potential energy when the compressible columns  66  are pressed towards the surface of skin to be tested. In this embodiment, compressible element  68  of each dull pressure head  64  applies 2-3 lb of force over the dull head surface area (e.g., 1/16 sq inch) so as to provide the desired pain-gating effect. Also, each sharp head  62  is supported on a compressible column  67  that provides sufficient pressure to enable the sharp head probes to penetrate the skin effectively. 
         [0043]      FIG. 7  shows a two-part embodiment, having a dull head portion  70  and a sharp puncture head portion  72 . The dull head portion  70  includes a plurality of dull pressure heads  74  supported on a support element  75 , which supports a plurality of compressible columns  76  for each dull pressure head  74 . 
         [0044]    The sharp puncture head portion  72  includes support element  77  that supports a plurality of sharp puncture heads  78 , each puncture head being supported on either a compressible or non-compressible column. 
         [0045]    To use this embodiment, the dull head portion  70  is first pressed via support element  75  against the skin of a person to be tested. The sharp puncture head portion  72  can then be grasped via the support element  77 . 
         [0046]    While dull pressure is thereby applied using the dull head portion  70 , the sharp puncture head portion  72  is pressed via support element  77  against the skin such that each sharp puncture head  78  contacts the skin via a corresponding hole  79 . 
         [0047]    Other modifications and implementations will occur to those skilled in the art without departing from the spirit and the scope of the invention as claimed. Accordingly, the above description is not intended to limit the invention, except as indicated in the following claims.