Closed-system catheter assembly

1. A catheter insertion device comprising:

a housing;

a latch, coupled to and extending from said housing, said latch comprising an external portion configured to snap-fit with at least one corresponding feature on a catheter device housing of a catheter device for resiliently coupling said housing to said catheter device;

a needle for insertion into a patient, said needle coupled to a needle collet that is slidably disposed within said housing; and

a spring coupled to said needle collet, wherein said latch comprises a first position in which an internal portion of said latch prevents extension of said spring and a second position in which said internal portion releases said spring to extend such that said spring relaxes and thereby retracts said needle entirely into said housing, and wherein said latch is configured to be held in said first position by said catheter device housing and to be released to said second position when said latch resiliently decouples from said catheter device.

2. The catheter insertion device of claim 1 , further comprising:

a viewing chamber, wherein blood in said viewing chamber is able to be viewed through said housing.

3. The catheter insertion device of claim 2 , further comprising:

a hydrophobic filter disposed in said viewing chamber, wherein said hydrophobic filter allows air to vent and seals said blood in said viewing chamber.

4. The catheter insertion device of claim 1 ,

wherein said needle collet is axially slidably disposed in said housing, and wherein, when said latch is released to said second position, said spring urges said needle collet to slide within said housing away from said latch.

5. The catheter insertion device of claim 1 , wherein blood passes through said catheter device via said needle into a viewing chamber disposed in a needle collet.

6. The catheter insertion device of claim 1 , wherein said at least one corresponding feature on said catheter device housing comprises one or more external features of said catheter device.

7. The catheter insertions device of claim 1 , wherein said catheter insertion device is a closed system.

8. A catheter device comprising:

a housing comprising a chamber;

a seal disposed in said chamber, wherein said seal is configured to reseal when a needle of a catheter insertion device is withdrawn from said seal such that blood is sealed in said chamber; and

wherein said housing comprises at least one external feature configured to snap fit with a latch that extends from a catheter insertion device housing of said catheter insertion device to maintain said needle in a position in which said needle passes through said seal in a configuration in which said housing is resiliently coupled with said catheter insertion device by said latch.

9. The catheter of claim 8 , wherein said catheter device is a closed system.

10. The catheter of claim 8 , wherein said housing further comprises internal features configured to receive coupling features of an extension set to snap fit said housing with said extension set.

11. The catheter of claim 10 , wherein said seal comprises:

a silicone seal.

12. The catheter of claim 11 , wherein said seal is configured to be punctured by a cannula of said extension set such that said blood is able to exit said chamber into said extension set.

13. The catheter of claim 8 wherein said housing comprises:

a funnel proximate said seal.

14. The catheter of claim 8 , wherein said seal is disposed proximate a joint between a first section and a second section.

15. A catheter system comprising:

an insertion device comprising:

a housing;

a latch, coupled to and extending from said housing, said latch comprising an external portion;

a needle for insertion into a patient, said needle coupled to a needle collet that is slidably disposed within said housing; and

a spring coupled to said needle collet; and

a catheter device,

said catheter device comprising:

a housing comprising a chamber and at least one feature configured to snap fit with said external portion of said latch of said insertion device; and

a seal disposed in said chamber, wherein said seal is configured to reseal when said needle is withdrawn from said seal such that blood is sealed in said chamber,

wherein said latch comprises a first position in which an internal portion of said latch prevents extension of said spring and a second position in which said internal portion releases said spring to extend such that said spring relaxes and thereby retracts said needle entirely into said housing of said insertion device, and wherein said latch is configured to be held in said first position by said housing of said catheter device and to be released to said second position when said latch decouples from said catheter device.

16. The catheter system of claim 15 , wherein said spring is compressed when said catheter device is coupled to said insertion device and said latch is in said first position.

17. The catheter system of claim 15 , wherein said insertion device is configured such that blood passes through said catheter via said needle into a viewing chamber disposed in said needle collet.

18. The catheter system of claim 15 , wherein said seal is configured to be punctured by an extension set such that said blood is able to exit said chamber into said extension set.

19. The catheter system of claim 15 ,

wherein said needle collet is axially slidably disposed in said housing of said insertion device, and wherein, when said latch is released to said second position, said spring urges said needle collet to slide within said housing away from said late.