Catheter malfunction determinations using physiologic pressure

• US 20080243074A1
• Filed: 03/30/2007
• Published: 10/02/2008
• Est. Priority Date: 03/30/2007
• Status: Active Grant

• Current Assignee: Medtronic Incorporated (Medtronic Plc)
• Original Assignee: Medtronic Incorporated (Medtronic Plc)
• Inventors: Miesel, Keith A., Coffey, Robert J.
• Granted Patent: US 8,323,244 B2
• Time in Patent Office: Days
• US Class Current: 604/111
• CPC Class Codes: A61M 2005/1726 the body parameters being measured at, or proximate to, the infusion site
• CPC Class Codes: A61M 2202/0464 Cerebrospinal fluid
• CPC Class Codes: A61M 5/14276 specially adapted for implantation
• CPC Class Codes: A61M 5/16859 Evaluation of pressure response, e.g. to an applied pulse

Abstract

Methods and systems for determining whether an implanted catheter used to deliver fluids to a selected internal delivery site is malfunctioning. The malfunctions may include that the infusion section of the catheter is not located at or has migrated away from the selected internal delivery site, is leaking, is blocked, etc. The determination is made by analyzing the pressure modulation of fluid within the catheter and determining whether the pressure of the fluid in the catheter is modulated by physiologic pressure changes experienced at the selected internal delivery site. The physiologic pressure modulations at the selected internal delivery site may be caused by, e.g., cardiac activity, respiration, changes in patient'"'"'s posture, etc.

Claims

1. A method of identifying the presence of a catheter malfunction in an implanted catheter, the method comprising:

measuring pressure of a fluid located within a lumen in a catheter implanted in a patient, wherein the lumen extends to an infusion section that is located at a selected internal delivery site in the patient;

developing a pressure modulation profile based on the measured pressure of the fluid in the lumen; and

comparing the pressure modulation profile to a selected pressure profile.

2. A method according to claim 1, wherein developing the pressure modulation profile is based on measuring the pressure of the fluid in the lumen when the fluid is stationary within the lumen.

3. A method according to claim 1, further comprising determining the existence of a catheter malfunction if the pressure modulation profile differs from the selected pressure profile.

4. A method according to claim 3, further comprising providing an alert to the patient and/or a third party after determining the existence of the catheter malfunction.

5. A method according to claim 3, further comprising terminating delivery of the fluid to the lumen after determining the existence of a catheter malfunction.

6. A method according to claim 1, wherein the selected pressure profile is based at least in part on patient respiration.

7. A method according to claim 1, wherein the selected internal delivery site is in a blood vessel of the patient.

8. A method according to claim 1, wherein the selected pressure profile is based at least in part on patient cardiac activity.

9. A method according to claim 1, wherein the selected internal delivery site is in the intrathecal space of the patient.

10. A method according to claim 9, wherein the selected pressure profile is based at least in part on changes in the pressure of the fluid as the patient moves between supine and upright postures.

11. A method according to claim 1, wherein the pressure modulation profile is developed based on pressure measurements obtained at only selected intervals.

12. A method according to claim 11, wherein the selected intervals are chosen based at least in part on the patient'"'"'s circadian rhythm.

13. A method according to claim 1, wherein the fluid in the lumen of the catheter comprises a therapeutic substance, and wherein the method further comprises delivering the therapeutic substance to the patient through the infusion section of the catheter.

14. A method according to claim 1, further comprising storing data representative of the pressure modulation profile in a data storage device before comparing the pressure modulation profile to a selected pressure profile.

15. A method of identifying the presence of a catheter malfunction in an implanted catheter, the method comprising:

measuring fluid pressure of a fluid located within a lumen in a catheter implanted in a patient, wherein the lumen extends to an infusion section that is located at a selected internal delivery site in the patient;

developing a pressure modulation profile based on the measured fluid pressure of the fluid in the lumen; and

determining if the pressure modulation profile includes pressure modulation caused by patient cardiac activity.

16. A method according to claim 15, wherein developing the pressure modulation profile is based on measuring the pressure of the fluid in the lumen when the fluid is stationary within the lumen.

17. A method according to claim 15, further comprising determining the existence of a catheter malfunction if the pressure modulation profile does not include pressure modulation caused by patient cardiac activity.

18. A method according to claim 17, further comprising providing an alert to the patient and/or a third party after determining the existence of the catheter malfunction.

19. A method according to claim 17, wherein the fluid comprises a therapeutic substances, and wherein the method further comprises:

delivering the therapeutic substance to the patient through the infusion section of the catheter; and

terminating delivery of the therapeutic substance to the patient after determining the existence of a catheter malfunction.

20. A method according to claim 15, wherein the selected internal delivery site is in a blood vessel of the patient.

21. A method according to claim 15, wherein the selected internal delivery site is in the intrathecal space of the patient.

22. A method according to claim 15, wherein the pressure modulation profile is developed based on pressure measurements obtained at only selected intervals.

23. A method according to claim 22, wherein the selected intervals are chosen based at least in part on the patient'"'"'s circadian rhythm.

24. A method of identifying the presence of a catheter malfunction in an implanted catheter, the method comprising:

measuring fluid pressure of a fluid located within a lumen in a catheter implanted in a patient, wherein the lumen extends to an infusion section that is located at a selected internal delivery site in the patient;

developing a pressure modulation profile based on the measured fluid pressure of the fluid in the lumen; and

determining if the pressure modulation profile includes pressure modulation caused by patient respiration.

25. A method according to claim 24, wherein developing the pressure modulation profile is based on measuring the pressure of the fluid in the lumen when the fluid is stationary within the lumen.

26. A method according to claim 24, further comprising determining the existence of a catheter malfunction if the pressure modulation profile does not include pressure modulation caused by patient respiration.

27. A method according to claim 26, further comprising providing an alert to the patient and/or a third party after determining the existence of the catheter malfunction.

28. A method according to claim 26, wherein the fluid comprises a therapeutic substance, and wherein the method further comprises:

delivering the therapeutic substance to the patient through the infusion section of the catheter; and

terminating delivery of the therapeutic substance to the patient after determining the existence of a catheter malfunction.

29. A method according to claim 24, wherein the selected internal delivery site is in a blood vessel of the patient.

30. A method according to claim 24, wherein the selected internal delivery site is in the intrathecal space of the patient.

31. A method according to claim 24, wherein the pressure modulation profile is developed based on pressure measurements obtained at only selected intervals.

32. A method according to claim 30, wherein the selected intervals are chosen based at least in part on the patient'"'"'s circadian rhythm.

33. An implantable infusion system comprising:

a pump mechanism fluidly coupled to a reservoir to receive fluid contained within the reservoir;

a catheter comprising a delivery lumen fluidly coupled to the pump mechanism, wherein the delivery lumen extends to an implantable infusion section in the catheter;

a pressure sensor positioned to monitor fluid pressure within the delivery lumen of the catheter and provide a pressure signal representative of the fluid pressure; and

control electronics connected to receive the pressure signal from the pressure sensor, wherein the control electronics further;

develops a pressure modulation profile based on the fluid pressure measured in the delivery lumen; and

compares the pressure modulation profile to a selected pressure profile.

34. A system according to claim 33, wherein the pump mechanism, the reservoir, and the control electronics are contained within one or more implantable housings along with a power source.

35. An implantable infusion system comprising:

a pump mechanism fluidly coupled to a reservoir to receive fluid contained within the reservoir;

a catheter comprising a delivery lumen fluidly coupled to the pump mechanism, wherein the delivery lumen extends to an implantable infusion section in the catheter;

a pressure sensor positioned to monitor fluid pressure within the delivery lumen of the catheter and provide a pressure signal representative of the fluid pressure; and

control electronics connected to receive the pressure signal from the pressure sensor, wherein the control electronics further;

develops a pressure modulation profile based on the fluid pressure measured in the delivery lumen; and

determines if the pressure modulation profile includes pressure modulation caused by patient cardiac activity.

36. A system according to claim 35, wherein the pump mechanism, the reservoir, and the control electronics are contained within one or more implantable housings along with a power source.

37. An implantable infusion system comprising:

a pump mechanism fluidly coupled to a reservoir to receive fluid contained within the reservoir;

a catheter comprising a delivery lumen fluidly coupled to the pump mechanism, wherein the delivery lumen extends to an implantable infusion section in the catheter;

a pressure sensor positioned to monitor fluid pressure within the delivery lumen of the catheter and provide a pressure signal representative of the fluid pressure; and

control electronics connected to receive the pressure signal from the pressure sensor, wherein the control electronics further;

develops a pressure modulation profile based on the fluid pressure measured in the delivery lumen; and

determines if the pressure modulation profile includes pressure modulation caused by patient respiration.

38. A system according to claim 37, wherein the pump mechanism, the reservoir, and the control electronics are contained within one or more implantable housings along with a power source.