Injection apparatus and special needle for making an injection at a predetermined depth in the skin

1. An injection apparatus for making an injection at a predetermined depth in skin, comprising:

a skin positioning member for positioning a patch of skin within an area of skin to hold the patch of skin in a defined position;

an injection needle comprising a tip, at least one bevel and a heel together forming a point at a distal end thereof, and a shaft portion immediately proximal of said heel having a longitudinal axis, including a lumen extending along the longitudinal axis, wherein the at least one bevel is formed between said tip and said heel such that a lumen opening is defined from the tip to a proximal end of the lumen opening located distal of the heel;

and an injection needle movement guide proximate the injection needle to guide said injection needle for movement from a parking position above said skin positioning member to an injection position in which the distal end of the needle lies at a predetermined distance below said skin positioning member;

wherein:

a length of the lumen opening of the needle from the tip of the needle to the proximal end of the lumen opening is in a range from 5 to 15 times an outer diameter of the shaft of the needle and the length of the lumen opening of the needle is measured parallel to the longitudinal axis of the needle;

wherein at least a part of the point of the injection needle is formed substantially parallel to the longitudinal axis of the needle.

2. The injection apparatus according to claim 1 , further comprising a housing containing: the injection needle mounted for guided movement from a parked position to an operative position; a detachable marker unit mounted to said housing and so positioned that said needle passes therethrough to reach said operative position; and a securing member coupled to the marker unit to secure said marker unit at an injection site prior to the making of an injection, whereby said apparatus can in use be positioned at an injection site, said needle can be moved to said operative position to make an injection and said housing can be removed leaving said marker unit at the injection site to mark the position thereof.

3. The injection apparatus according to claim 2 , wherein said marker unit comprises a plate having an aperture therein through which the needle passes in use.

4. The injection apparatus according to claim 3 , wherein said aperture has a maximum dimension of 2 mm or less.

5. The injection apparatus according to claim 1 , wherein the tip of the injection needle is closer to the longitudinal axis of the shaft portion than is the outside of the shaft portion.

6. The injection apparatus according to claim 1 , in which the outer diameter of the shaft of the injection needle is between 0.5 mm to 1.5 mm.

7. The injection apparatus according to claim 1 , in which the outer diameter of the shaft of the injection needle is 1.1 mm.

8. The injection apparatus according to claim 1 , in which the length of the lumen opening of the injection needle is between 5.5 mm and 16.5 mm.

9. The injection apparatus according to claim 1 , in which at least a part of the point of the injection needle is in the form of a part-cylinder.

10. The injection apparatus according to claim 9 , in which the distance perpendicular to the longitudinal axis of the injection needle from the tip to the bevel face at the part-cylinder is at least 50% of the outer diameter of the shaft of the needle.

11. The injection apparatus according to claim 1 , wherein the distal end of the needle lies within the skin.

12. The injection apparatus according to claim 1 , wherein the length of the lumen opening of the needle is in a range from 8 to 12 times an outer diameter of the shaft of the needle.

13. The injection apparatus according to claim 9 , further comprising a second bevel, wherein the bevel and the second bevel are on opposite longitudinal ends of the part-cylinder and the bevel and the second bevel are formed at similar angles with respect to the longitudinal axis.

14. An injection apparatus for making an injection at a predetermined depth in skin comprising: a skin positioning member for positioning on a patch of skin within an area of skin to hold the patch of skin in a defined position, an injection needle comprising a point having a tip at a distal end thereof and a shaft portion immediately proximal to said point, the shaft portion having a longitudinal axis, and an injection needle movement guide proximate the injection needle to guide said injection needle for movement from a parking position above the skin beside said skin positioning member to slide beneath said skin positioning member to an injection position in which the distal end of the needle lies at a predetermined distance below said skin positioning member; wherein: the tip of the injection needle is closer to the longitudinal axis of the shaft portion than is an outside of the shaft portion;

wherein the tip of the injection needle is closer to the longitudinal axis of the shaft portion than is the outside of the shaft by bending the tip of the injection needle.