Detecting needle entry into a port of an infusion device
Systems for detecting needle insertion into a port chamber of an implantable medical device include a pressure sensor. The system detects characteristic pressure profiles associated with needle insertion into the port chamber through a septum and may generate a sensory cue to a clinician that proper needle placement has been achieved. Methods for detecting needle insertion into a port chamber of an implantable medical device includes detecting characteristic pressure profiles associated with needle insertion into the port chamber through a septum.
1. A method for detecting insertion of a needle into a port chamber of an implantable infusion device, the device including a port assembly defining the port chamber, the port assembly having a septum disposed across the port chamber to fluidly seal the port chamber relative to an exterior of the device, the method comprising:
sensing, via a pressure sensor in fluid communication with the port chamber, a pressure change in the port chamber; and,
determining, via electronics operably coupled to the pressure sensor, whether the sensed pressure change is indicative of insertion of the needle through the septum into the port chamber prior to dispensing fluid into the port chamber.
2. The method of claim 1 , wherein determining whether the sensed pressure change is indicative of insertion of the needle through the septum into the port chamber comprises determining whether the sensed pressure change reflects a transient pressure increase in the chamber.
3. The method of claim 2 , wherein determining whether the sensed pressure change is indicative of insertion of the needle through the septum into the port chamber further comprises determining whether the pressure in the chamber returns, within 5 seconds, to a level substantially similar to that prior to the transient pressure increase.
4. The method of claim 2 , wherein determining whether the sensed pressure change is indicative of insertion of the needle through the septum into the port chamber further comprises determining whether the pressure in the chamber returns, within 2 seconds, to a level substantially similar to that prior to the transient pressure increase.
5. The method of claim 2 , wherein determining whether the sensed pressure change is indicative of insertion of the needle through the septum into the port chamber further comprises determining whether the pressure in the chamber returns, in a logarithmic decay profile over time, to a level substantially similar to that prior to the transient pressure increase.
6. The method of claim 1 , further comprising:
identifying a characteristic transient pressure pattern profile associated with insertion of the needle through the septum into the port chamber,
wherein determining whether the sensed pressure change is indicative of insertion of the needle through the septum into the port chamber comprises comparing the sensed pressure change to the characteristic transient pressure pattern profile.
7. The method of claim 1 , further comprising:
generating a sensory cue if the sensed pressure change is indicative of insertion of the needle through the septum into the port chamber.
8. The method of clam 7 , wherein generating the sensory cue comprises generating an audible cue.
9. The method of claim 7 , wherein generating the sensory cue comprises generating the sensory cue from a second device, the second device being in wireless communication with the infusion device.
10. The method of claim 9 , wherein generating the sensory cue from the second device comprises generating the cue from a programmer device.
11. A method comprising:
inserting a needle into a patient to access a port chamber defined by a port assembly of an infusion device implanted in the patient, the port chamber being accessible from an exterior of the infusion device through a septum disposed across the port chamber to fluidly seal the port chamber relative to the exterior of the infusion device;
sensing a pressure change in a port chamber;
determining whether the sensed pressure change is indicative of insertion of the needle through the septum into the port chamber prior to dispensing fluid into the port chamber; and
generating a sensory cue if the sensed pressure change is indicative of insertion of the needle through the septum into the port chamber.
12. The method of claim 11 , further comprising alerting the infusion device that a needle is to be inserted into the port chamber.
13. The method of claim 11 , further comprising (i) delivering fluid through the needle, and (ii) determining whether the sensed pressure change is indicative of fluid being injected into the chamber.
14. The method of claim 13 , further comprising generating a sensory cue if the sensed pressure change is not indicative of fluid being injected into the chamber.