Microneedle device

A microneedle device comprising:

• a barrel having a proximal end and a distal end, the proximal end of the barrel being open, the distal end of the barrel being open, and a central channel extending through the barrel from the distal end of the barrel to the proximal end of the barrel, and the distal end of the barrel including a plurality of concave formations, and the barrel being rigid;
• and
• a plunger having a proximal end, a distal end, and a body between the distal end of the plunger and the proximal end of the plunger, the distal end of the plunger including a substantially planar surface, the body of the plunger being sized and shaped to fit within the central channel of the barrel and allow reciprocating linear motion of the plunger in the barrel;
• and
• a rod having a proximal end, a medical portion, a distal end, a proximal portion extending from the medial portion of the rod to the proximal end of the rod, and a distal portion extending from the medial portion to the distal end of the rod;
• the rod being movable linearly in reciprocating fashion relative to the proximal end of the barrel, reciprocating motion of the rod being between a retracted position and an extended position, and the distal end of the rod being coupled to the proximal end of the plunger, and reciprocating motion of the rod being between the retracted position and the extended position causing equal reciprocating motion of the plunger;
• and
• a biasing means coupled to the plunger, the biasing means urging the plunger, and the rod coupled to the proximal end of the plunger, towards the retracted position;
• and
• a plurality of needles attached to and extending from the distal end of the plunger, the plurality of needles being contained within the central channel of the barrel when the rod is in the retracted position, and the plurality of needles extending beyond the distal end of the barrel when the rod in the extended position;
• and
• the biasing means comprising a sleeve having a proximal end and a distal end, the proximal end of the sleeve being open, the distal end of the sleeve being open, a central channel extending through the sleeve from the proximal end of the sleeve to the distal end of the sleeve, the sleeve being elastic and stretchable from a relaxed length to a stretched length, and at the stretched length the sleeve exerting a tensile force, the tensile force urging return of the sleeve to the relaxed length, and the sleeve providing a fluid tight seal between the rod and the plunger.

A microneedle device comprising:

• a sleeve having a proximal end and a distal end, the proximal end of the sleeve being open, the distal end of the sleeve being open, a central channel extending through the sleeve from the proximal end of the sleeve to the distal end of the sleeve, the sleeve being elastic and stretchable from a relaxed length to a stretched length, and at the stretched length the sleeve exerting a tensile force, the tensile force urging return of the sleeve to the relaxed length, and the sleeve providing a fluid tight seal between the rod and the plunger;
• and
• a reciprocating rod having a proximal end, a medial portion, a distal end, a proximal portion extending from the medial portion of the reciprocating rod to the proximal end of the reciprocating rod, and a distal portion extending from the medial portion to the distal end of the reciprocating rod;
• the distal portion of the reciprocating rod extending through the central channel of the sleeve, and the reciprocating rod undergoing reciprocating motion relative to the proximal end of the sleeve, the reciprocating motion of the reciprocating rod being between a retracted position and an extended position;
• and
• a barrel having a proximal end and a distal end, the proximal end of the barrel being open, the distal end of the barrel being open, and a central channel extending through the barrel from the distal end of the barrel to the proximal end of the barrel, and the barrel being rigid;
• and
• a plunger having a proximal end, a distal end, and a body between the distal end of the plunger and the proximal end of the plunger, the distal end of the plunger including a substantially planar surface, the body of the plunger being sized and shaped to fit within the central channel of the barrel and allow reciprocating linear motion of the plunger in the barrel, and the distal end of the reciprocating rod being coupled to the proximal end of the plunger, and reciprocating motion of the reciprocating rod being between the retracted position and the extended position causing equal reciprocating motion of the plunger, and the distal end of the elastic sleeve being coupled to the proximal end of the plunger, and
• a plurality of needles attached to and extending from the distal end of the plunger, the plurality of needles being contained within the central channel of the barrel when the reciprocating rod is in the retracted position, and the plurality of needles extending beyond the distal end of the barrel when the reciprocating rod is in the extended position.