Dermal punch device

Abstract

A dermal punch for extracting skin or tissue samples. The dermal punch has a blade having a pair of walls. Each wall is convex and opens towards each other. The walls are connected to each other at a pair of mating edges. Each wall has a cutting edge. In a preferred embodiment, the ratio of the minor axis to the major axis of the opening created by the walls is between 1 to 3 and 1 to 4, wherein the major axis extends through the mating edges. The cutting edge is formed of a plurality of teeth and the teeth have a sawtooth shape. The cutting edge has a projecting edge for each wall, and the projecting edge is concave. The cutting length is greater than twice the length of the projecting edge.

1 . A dermal punch comprising: 
 a handle;    a blade extending from the handle and having a pair of walls, each of the walls having an external convex surface and connected at a pair of mating edges to define a cavity having a major axis and a minor axis smaller than the major axis, the walls having a distal cutting edge.    
   
   
       2 . The dermal punch of claim 1 wherein the walls join each other at the mating edge at an angle between the range of 75° and 115°.  
   
   
       3 . The dermal punch of  claim 2  wherein the walls join each other at the mating edge at an angle between the range of 85° and 95°.  
   
   
       4 . The dermal punch of  claim 1  wherein the cutting edge further comprises a plurality of teeth and a ratio of the minor axis to the major axis is at least 1 to 2.  
   
   
       5 . The dermal punch of  claim 4  wherein the teeth have a sawtooth shape.  
   
   
       6 . The dermal punch of  claim 5  wherein the-teeth have a root angle of between 15° and 35° and a tip angle between 15° and 35°, the tooth having a minimum depth of 2 millimeters.  
   
   
       7 . The dermal punch of  claim 1  wherein the cutting edge has a projecting edge for each wall, and each projecting edge has an apex.  
   
   
       8 . The dermal punch of  claim 1  wherein the cutting length is greater than twice the length of the projecting edge.  
   
   
       9 . The dermal punch of  claim 1  wherein the cutting edge has a projecting edge that has a projection at the mating edge and at a center portion.  
   
   
       10 . The dermal punch of  claim 5  wherein the teeth have different lengths.  
   
   
       11 . A method of collecting a selected region of skin comprising the steps of: 
 providing a dermal punch having a blade including a pair of walls, each wall having a cutting edge;    positioning the cutting edge relative to the selected region of skin; and    puncturing the skin with the cutting edge on the dermal punch by pushing the dermal punch into the skin.    
   
   
       12 . The method of  claim 11  wherein the step of positioning includes placing an apex of each projecting edge in contact with the skin with the selected patch of skin interposed.  
   
   
       13 . The method of  claim 11  further comprising the step of removing the region of skin from a body by pulling the dermal punch in a motion perpendicular to the skin.  
   
   
       14 . The method of  claim 13  further comprising the step of closing the wound on the skin.  
   
   
       15 . The method of  claim 14  wherein the closing of the wound in the skin is done with an adhesive.  
   
   
       16 . The method of  claim 14  wherein the closing of the wound in the skin is done with a surgical staple.  
   
   
       17 . A dermal punch comprising: 
 a blade having a pair of walls, each wall being convex and forming a cavity having a major axis and a minor axis shorter than the major axis;    each wall having a cutting edge; and    a mechanism for moving each wall relative to each other.    
   
   
       18 . The dermal punch of  claim 17  wherein the mechanism of the walls are portably mounted to each other for moving the apex of each wall towards each other.  
   
   
       19 . The dermal punch of  claim 17  wherein the mechanism is a tweezers such that the walls move towards each other.  
   
   
       20 . The dermal punch of  claim 17  wherein the cutting edge is formed of a plurality of teeth.  
   
   
       21 . The dermal punch of  claim 20  wherein the tip of the tooth is located equidistant between the edges of the walls projecting the furthest.  
   
   
       22 . The dermal punch of  claim 21  wherein the tip of the teeth in proximity to the edge of the wall extends distal approximately the length of the apex tooth.  
   
   
       23 . The dermal punch of  claim 17  wherein the walls are connected to each other at a pair of mating edges, and a ratio of the minor axis to the major axis is between  1  to 3 and 1 to 4.  
   
   
       24 . The dermal punch of  claim 17  further comprising a device for applying medical glue.  
   
   
       25 . The dermal punch of  claim 17  further comprising a device for applying at least one staple to the incision.  
   
   
       26 . The dermal punch of  claim 20 , wherein the teeth have a sawtooth shape and each tooth has a root angle of between 15° and 35° and a tip angle between 15° and 350°, the tooth having a minimum depth of 2 millimeters.  
   
   
       27 . The dermal punch of  claim 26  wherein the cutting edge has a projecting edge for each wall, and the projecting edge is concave.  
   
   
       28 . The dermal punch of  claim 27  wherein the cutting length is greater than twice the length of the projecting edge.  
   
   
       29 . The dermal punch of  claim 17  further comprising a mechanism for closing the wound.  
   
   
       30 . A dermal punch comprising: 
 a handle;    a blade extending from the handle and having a plurality of distally extending teeth surrounding an opening in which a tissue sample is inserted.    
   
   
       31 . The dermal punch of  claim 30  wherein the blade has a pair of walls that join each other at a mating edge at an angle between the range of 75° and 115°.  
   
   
       32 . The dermal punch of  claim 31  wherein the walls join each other at the mating edge at an angle between the range of 85° and 95°.  
   
   
       33 . The dermal punch of  claim 30  wherein the plurality of teeth define a cutting edge and a projecting edge.  
   
   
       34 . The dermal punch of  claim 30  wherein the teeth have a sawtooth shape.  
   
   
       35 . The dermal punch of  claim 30  wherein the teeth have a root angle of between 15° and 35° and a tip angle between 15° and 35°, the tooth having a minimum depth of 2 millimeters.  
   
   
       36 . The dermal punch of  claim 30  wherein the cutting edge has a projecting edge that is concave.  
   
   
       37 . The dermal punch of  claim 33  wherein the cutting edge has a length that is greater than twice a length of the projecting edge.  
   
   
       38 . The dermal punch of  claim 33  wherein the projecting edge has a projection at a mating edge and at a center portion.  
   
   
       39 . The dermal punch of  claim 30  wherein the teeth have different sizes.  
   
   
       40 . A method of collecting a selected region of skin comprising the steps of: 
 providing a dermal punch having a blade including a plurality of teeth defining a cutting edge;    positioning the cutting edge relative to the selected region of skin; and    puncturing the skin with the cutting edge on the dermal punch by pushing the dermal punch into the skin.    
   
   
       41 . The method of  claim 40  wherein the step of positioning includes placing an apex of each projecting edge in contact with the skin with the selected patch of skin interposed.  
   
   
       42 . The method of  claim 40  further comprising the step of removing the selected region of skin from a body by pulling the dermal punch in a motion perpendicular to the skin.  
   
   
       43 . The method of  claim 40  further comprising the step of closing a wound on the skin.  
   
   
       44 . The method of  claim 43  wherein the closing of the wound in the skin is done with an adhesive.  
   
   
       45 . The method of  claim 43  wherein the closing of the wound in the skin is done with a surgical staple.  
   
   
       46 . A dermal punch comprising: 
 a blade having a pair of walls, each wall being convex and forming a cavity having a major axis and a minor axis shorter than the major axis;    each wall having a plurality of teeth defining a cutting edge.    
   
   
       47 . The dermal punch of  claim 46  wherein the teeth define a convex projecting edge.  
   
   
       48 . The dermal punch of  claim 46  wherein the blade has 12 to 18 teeth on each wall.  
   
   
       49 . The dermal punch of  claim 46  wherein the plurality of teeth have different lengths to define a curved projecting edge.  
   
   
       50 . The dermal punch of  claim 46  wherein a tip of each tooth is located equidistant between the edges of the walls projecting the furthest.  
   
   
       51 . The dermal punch of  claim 50  wherein the tip of the teeth in proximity to the edge of the wall extends distal approximately the length of a tooth apex.  
   
   
       52 . The dermal punch of  claim 46  wherein the walls are connected to each other at a pair of mating edges, and a ratio of the minor axis to the major axis is between 1 to 3 and 1 to 4.  
   
   
       53 . The dermal punch of  claim 46  further comprising a device for applying medical glue.  
   
   
       54 . The dermal punch of  claim 46  further comprising a device for applying at least one staple to the incision.  
   
   
       55 . The dermal punch of  claim 46  wherein the teeth have a sawtooth shape and each tooth has a root angle of between 15° and 35° and a tip angle between 15° and 35°, the tooth having a minimum length of 2 millimeters.  
   
   
       56 . The dermal punch of  claim 46  wherein the cutting edge has a projecting edge for each wall, and the projecting edge is concave.  
   
   
       57 . The dermal punch of  claim 56  wherein the cutting length is greater than twice the length of the projecting edge.  
   
   
       58 . The dermal punch of  claim 46  further comprising a mechanism for closing the wound.  
   
   
       59 . The dermal punch of  claim 46  further comprising a kit including a plurality of blades having different sizes.  
   
   
       60 . The dermal punch of  claim 46  further comprising a handle, the blade being removable from the handle.