Blood and interstitial fluid sampling device

Abstract

A device and method for lancing a patient, virtually simultaneously producing and collecting a small fluid sample from a body. The device comprises a blood collection system including a lancing needle, drive mechanism, kneading or vibration mechanism, optional suction system, and sample ejection mechanism. The device is preferably sized to be hand-held in one hand and operable with one hand. The device can optionally contain integral testing or analysis component for receiving the sample and providing testing or analysis indication or readout for the user. In one configuration, the lancing needle may be withdrawn very slightly from the point of maximum penetration to create an opening in which blood can pool before being suctioned through to device.

1 . An apparatus for obtaining a sample of body fluid, comprising:
 a skin piercing member; and   a drive mechanism connected to the skin piercing member;   wherein the drive mechanism is adapted to extend the skin piercing member to a point of maximum penetration beneath a skin surface and withdraw the skin piercing member from the point of maximum penetration while maintaining the skin piercing member beneath the skin surface to create an opening in which body fluid can pool.   
     
     
         2 . The apparatus of  claim 1 , further comprising:
 a double stop system, wherein a first stop defines the point of maximum penetration and a second stop defines the point where the skin piercing member creates the opening in which body fluid can pool.   
     
     
         3 . The apparatus of  claim 1 , wherein the skin piercing member includes a fluid passage, the apparatus further comprising:
 a suction mechanism adapted to create suction to draw body fluid through the fluid passage.   
     
     
         4 . The apparatus of  claim 1 , further comprising:
 a sample collection chamber connected to the drive mechanism, wherein the drive mechanism is reusable and the sample collection chamber is disposable.   
     
     
         5 . The apparatus of  claim 1 , wherein the skin piercing member is disposable and the drive mechanism is reusable. 
     
     
         6 . The apparatus of  claim 1 , wherein the point of maximum penetration is at a depth of 0.3 to 0.6 millimeters below the skin surface. 
     
     
         7 . The apparatus of  claim 1 , further comprising:
 a penetration depth adjustment mechanism adapted to adjust the depth to which the skin piercing member penetrates beneath the skin surface.   
     
     
         8 . The apparatus of  claim 1 , further comprising:
 a needle guard connected to the drive mechanism, the needle guard adapted to contact the skin surface and inhibit the skin piercing member from contacting the skin while the skin piercing member is in a retracted position.   
     
     
         9 . A method, comprising:
 extending a skin piercing member of a fluid sampling device to a point of maximum penetration beneath a skin surface with a drive mechanism; and   withdrawing the skin piercing member from the point of maximum penetration with the drive mechanism while maintaining the skin piercing member beneath the skin surface and forming an opening between the skin piercing member and the skin in which body fluid can pool.   
     
     
         10 . The method of  claim 9 , further comprising:
 moving fluid from the opening between the skin piercing member and the skin through a passage in the skin piercing member.   
     
     
         11 . The method of  claim 9 , further comprising:
 forming a vacuum; and   drawing fluid from the opening between the skin piercing member and the skin using the vacuum.   
     
     
         12 . The method of  claim 9 , further comprising:
 moving fluid from the opening between the skin piercing member and the skin to a sample collection chamber connected to the drive mechanism.   
     
     
         13 . The method of  claim 9 , wherein said extending results in the skin piercing member reaching a maximum depth of 0.3 to 0.6 millimeters below the skin surface. 
     
     
         14 . The method of  claim 9 , further comprising:
 limiting the point of maximum penetration beneath the skin surface to a value that can be adjusted.   
     
     
         15 . The method of  claim 9 , wherein said extending includes extending the skin piercing member beyond a needle guard, the needle guard being adapted to contact the skin surface. 
     
     
         16 . An apparatus, comprising:
 a reusable fluid sampling device including a drive mechanism; and   a disposable member detachably mounted to the drive mechanism and adapted to be replaced after use, the disposable member including a skin piercing member with a fluid passageway, the skin piercing member being adapted to penetrate a skin surface;   wherein the drive mechanism extends the skin piercing member to a point of maximum penetration beneath the skin surface and, while maintaining the skin piercing member in the wound, pulls the skin piercing member back to permit body fluid accumulation; and   wherein the fluid passageway is adapted to draw fluid from the accumulated body fluid.   
     
     
         17 . The apparatus of  claim 17 , wherein the point of maximum penetration is at a depth of 0.3 to 0.6 millimeters below the skin surface. 
     
     
         18 . The apparatus of  claim 17 , wherein the reusable fluid sampling device includes a suction mechanism in communication with the fluid passageway, the suction mechanism adapted to draw accumulated body fluid through the fluid passageway. 
     
     
         19 . The apparatus of  claim 19 , wherein the suction mechanism includes a syringe with a plunger. 
     
     
         20 . The apparatus of  claim 19 , further comprising:
 a penetration depth adjustment mechanism adapted to adjust the depth to which the skin piercing member penetrates beneath the skin surface.