Systems and methods for anchoring medical devices
Some embodiments of a medical device anchor system include an anchor device that secures a medical instrument (such as a catheter or the like) in place relative to a skin penetration point using subcutaneous anchors. In some implementations, the anchor device can be installed using a technique in which the subcutaneous anchors undergo relatively little or no flexing when being inserted through the skin into the subcutaneous region between the skin and underlying muscle tissue which may be occupied by fatty tissue.
1. An anchor device for releasably securing to an external portion of a catheter while another portion of the catheter occupies a skin penetration point, the anchor device comprising:
first and second anchors each having a longitudinal shaft portion and a flexible subcutaneous tine configured to be deployed through the skin penetration point and into a subcutaneous region along an underside of a skin layer; and
a retainer base to releasably secure with the external portion of the catheter, the retainer base being in a folded condition about a longitudinal fold axis of the retainer base prior to deployment of the flexible subcutaneous tines through the skin penetration point such that the flexible subcutaneous tines are positioned generally adjacent to each other and oriented to extend in substantially the same direction, wherein the longitudinal shaft portion of the first anchor is positioned on an opposite side of the longitudinal fold axis from the longitudinal shaft portion of the second anchor, and wherein the longitudinal shaft portion of each of the first and second anchors extends distally in a longitudinal direction from a distalmost end of the retainer base,
wherein the retainer base is adjustable to a non-folded condition about the longitudinal fold axis of the retainer base after deployment of the flexible subcutaneous tines through the skin penetration point so that the flexible subcutaneous tines are in an anchored position in which the flexible subcutaneous tines extend generally away from one another.
2. The device of claim 1 , further comprising a mechanism that releasably retains the retainer base in the folded condition, wherein the retainer base is biased to return to the non-folded condition.
3. The device of claim 2 , the retainer base is adjustable to a non-folded condition about the longitudinal fold axis of the retainer base in response to releasing the mechanism from the retainer base so that retainer base is urged to the non-folded condition by a spring bias force.
4. The device of claim 1 , the retainer base includes a first body portion that is pivotably coupled to a second body portion about the longitudinal fold axis of the retainer base, the longitudinal fold axis of the retainer base being defined by an elastically flexible longitudinal folding region positioned between the first body portion and the second body portion.
5. The device of claim 4 , wherein the longitudinal shaft portion of each of the first and second anchors having a distal end portion that is coupled with a respective one of the flexible subcutaneous tines, the longitudinal shaft portion of the first anchor being mechanically coupled to the first body portion of the retainer base, and the longitudinal shaft portion of the second anchor being mechanically coupled to the second body portion of the retainer base.
6. The device of claim 4 , further comprising a cap that is releasably attachable to the retainer base so as to define a channel therebetween that is sized to retain the external portion of the catheter.
7. The device of claim 6 , wherein the retainer base and the cap each include a gripper member configured to frictionally engage the external portion of the catheter.
8. The device of claim 6 , wherein the cap includes: a first mounting structure to releasably attach to a first mating structure of the first body portion of the retainer base, and a second mounting structure to releasably attach to a second mating structure of the second body portion of the retainer base, the first and second mating structures being positioned on opposite sides of the longitudinal fold axis of the retainer base.
9. The device of claim 1 , wherein each of the flexible subcutaneous tines has longitudinal convexly curved portion extending toward a tip at a free end, the longitudinal convexly curved portion being configured to abut against the underside of the skin layer.
10. The device of claim 1 , wherein during the retainer base is in the folded condition about the longitudinal fold axis of the retainer base prior to deployment of the flexible subcutaneous tines through the skin penetration point such that the flexible subcutaneous tines are arranged in a side-by-side position so that tips of the flexible subcutaneous tines are simultaneously insertable through the skin penetration point while the skin penetration point is already occupied by the catheter.
11. The device of claim 1 , wherein the flexible subcutaneous tines are configured to be deployed through the skin penetration point while in a generally non-stressed and non-flexed shape.
12. The device of claim 11 , wherein the flexible subcutaneous tines are configured to have the same generally non-stressed and non-flexed shape after the subcutaneous tines are adjusted to the anchored position in the subcutaneous region.