Integrated spring-activated ballistic insertion for drug infusion device
An infusion set has an integrated ballistic inserter that can insert a needle at a controlled high rate of speed to a depth to deliver content to the upper 3 mm of skin surface, and a skin securing, adhesive layer to secure the skin surface at the insertion site such that the inserter that can insert a needle without a risk of tenting of the skin surface. A driving spring of the ballistic inserter is captured within the ballistic inserter, and can be released by user operation, to insert a needle at such a controlled rate of speed.
1. An integrated inserter, comprising:
a body comprising a needle hub and needle;
a spring disposed in said body and configured to urge said needle hub and needle into a down position upon release, wherein said spring is configured to insert said needle into the skin at a controlled rate of speed; and
a release mechanism, configured to releasably secure at least one of said spring and said needle hub in an up position and to release at least one of said spring and said needle hub from said up position when pulled free from said body.
2. An integrated inserter as claimed in claim 1 , wherein said release mechanism comprises:
a tab extending from said body and having a first end comprising a detent for releasably securing at least one of said spring and said needle hub in an up position, and a second end comprising a user-graspable surface.
3. An integrated inserter as claimed in claim 1 , further comprising a tube set connector.
4. An integrated inserter as claimed in claim 1 , wherein said spring comprises a length of about 38 mm, and a rate of about 0.05 N/mm.
5. An integrated inserter as claimed in claim 1 , wherein in said up position, a length of said spring is about 6.5 mm, and a force F Up is represented by a following equation:
F Up= k.x= 0.05 N/mm×(38−6.5)mm=0.05 N/mm×31.5 mm
F Up=1.58 N.
6. An integrated inserter as claimed in claim 1 , wherein in a skin contacting position, a length of said spring is about 8 mm, and a force F Skin is represented by a following equation:
F Skin= k.x= 0.05 N/mm×(38−8)mm=0.05 N/mm×30 mm
F Skin=1.50 N.
7. An integrated inserter as claimed in claim 1 , wherein in said down position, a length of said spring is about 10.5 mm, and a force F Down is represented by a following equation:
F Down= k.x= 0.05 N/mm×(38−10.5)mm=0.05 N/mm×27.5 mm
F Down=1.38 N.
8. An integrated inserter as claimed in claim 1 , wherein in said up position, said needle is recessed from a skin surface about 1.5 mm, such that said needle is accelerated by said spring for a distance of 1.5 mm before said needle comes into contact with said skin surface, and a speed of said needle and needle hub, V, at said point where said needle contacts said skin surface is represented by a following equation:
Work Done=Change in Kinetic Energy
F×d= 1/2m×(V2−U2)
where u= 0 msec,
1/2(1.58 N+1.50 N)×1.5 mm−3 mm=1/2×4.1 g−3 g×V2
V=1.06 m/sec.
9. An integrated inserter as claimed in claim 1 , further comprising at least one adhesive layer disposed upon a surface of said body.
10. An integrated inserter, comprising:
a body comprising a needle hub and needle;
a release mechanism; and
a spring disposed in said body and configured to urge said needle hub and needle from an up position into a skin contacting position, and further into a down position when said release mechanism is pulled free from said body, wherein said spring is configured to insert said needle at a controlled rate of speed.
11. An integrated inserter as claimed in claim 10 , wherein said release mechanism is configured to releasably secure at least one of said spring and said needle hub in said up position and to release at least one of said spring and said needle hub from said up position when pulled free from said body, and wherein said release mechanism comprises a tab extending from said body and having a first end comprising a detent for releasably securing at least one of said spring and said needle hub in an up position, and a second end comprising a user-graspable surface.
12. An integrated inserter as claimed in claim 10 , further comprising a tube set connector.
13. An integrated inserter as claimed in claim 10 , wherein,
said needle comprises a stainless steel or plastic material, with a gauge of between 25 gauge and 36 gauge, and one of a single-bevel, tri-bevel or 5-bevel, and having a length between 1.0 mm and 10 mm, and
wherein said spring comprises a length of about 38 mm in a relaxed state, and has a rate of about 0.05 N/mm.
14. An integrated inserter as claimed in claim 10 , wherein in said up position, a length of said spring is about 6.5 mm, and a force F Up is represented by a following equation:
F Up= k.x= 0.05 N/mm×(38−6.5)mm=0.05 N/mm×31.5 mm
F Up=1.58 N.
15. An integrated inserter as claimed in claim 10 , wherein in a skin contacting position, a length of said spring is about 8 mm, and a force F Skin is represented by a following equation:
F Skin= k.x= 0.05 N/mm×(38−8)mm=0.05 N/mm×30 mm
F Skin=1.50 N.
16. An integrated inserter as claimed in claim 10 , wherein in said down position, a length of said spring is about 10.5 mm, and a force F Down is represented by a following equation:
F Down= k.x= 0.05 N/mm×(38−10.5)mm=0.05 N/mm×27.5 mm
F Down=1.38 N.
17. An integrated inserter as claimed in claim 10 , wherein in said up position, said needle is recessed from a skin surface about 1.5 mm, such that said needle is accelerated by said spring for a distance of 1.5 mm before said needle comes into contact with said skin surface, and a speed of said needle and needle hub, V, at said point where said needle contacts said skin surface is represented by a following equation:
Work Done=Change in Kinetic Energy
F×d= 1/2m×(V2−U2)
where u= 0 m/sec,
1/2(1.58 N+1.50 N)×1.5 mm−3 mm=1/2×4.1 g−3 g×V2
V=1.06 msec.
18. An integrated inserter, comprising:
a body comprising a needle hub and needle;
a release mechanism;
a spring disposed in said body and configured to urge said needle hub and needle from an up position into a skin contacting position and further into a down position when said release mechanism is pulled free from said body, wherein said spring is configured to insert said needle at a controlled rate of speed; and
a tube connector.
19. A method targeting a desired needle placement depth into an upper skin surface, comprising the steps of:
placing an integrated inserter upon an infusion site and releasing a stored energy device to move a needle of said integrated inserter into said infusion site when a release mechanism of said device is pulled free from a body of said device, wherein said needle is moved into said infusion site at a controlled rate of speed; and
using said stored energy device to hold said needle of said integrated inserter in said infusion site.
20. A method as claimed in claim 19 , wherein said stored energy device comprises a spring and in an up position, a length of said spring is about 6.5 mm, and a force F Up is represented by a following equation:
F Up= k.x= 0.05 N/mm×(38−6.5)mm=0.05 N/mm×31.5 mm
F Up=1.58 N.
21. A method as claimed in claim 20 , wherein in a skin contacting position, a length of said spring is about 8 mm, and a force F Skin is represented by a following equation:
F Skin= k.x= 0.05 N/mm×(38−8)mm=0.05 N/mm×30 mm
F Skin=1.50 N.
22. A method as claimed in claim 20 , wherein in a down position, a length of said spring is about 10.5 mm, and a force F Down is represented by a following equation:
F Down= k.x= 0.05 N/mm×(38−10.5)mm=0.05 N/mm×27.5 mm
F Down=1.38 N.
23. A method as claimed in claim 20 , wherein in said up position, said needle is recessed from a skin surface about 1.5 mm, such that said needle is accelerated by said spring for a distance of 1.5 mm before said needle comes into contact with said skin surface, and a speed of said needle and needle hub, V, at said point where said needle contacts said skin surface is represented by a following equation:
Work Done=Change in Kinetic Energy
F×d= 1/2m×(V2−U2)
where u= 0 msec,
1/2(1.58 N+1.50 N)×1.5 mm−3 mm=1/2×4.1 g−3 g×V2
V=1.06 m/sec.