Methods and devices for the diagnosis and treatment of diabetes
Methods and devices for the diagnosis and treatment of diabetes are disclosed in which an analyte concentration within a peritoneal fluid of a human subject may be determined by implanting an analyte sensor apparatus in the subject where the apparatus may comprise a housing and a flexible sensing catheter which has a lumen with a plurality of apertures and an exterior surface with an analyte sensor affixed thereto. The catheter may comprise a proximal end attached to the housing and the remaining end may be positioned freely within the peritoneal space to contact peritoneal fluid where an analyte concentration in the peritoneal fluid may be sensed. The housing may be anchored at a subcutaneous site proximate the peritoneal space. The sensed analyte concentration may then be transduced into a transmittable electrical signal.
1. A method of determining an analyte concentration within a peritoneal fluid of a human subject, comprising:
implanting an analyte sensor apparatus in the subject, the apparatus comprising a flexible sensing catheter and a housing, the catheter comprising, a lumen with a plurality of apertures and an exterior surface with an analyte sensor affixed thereto, the catheter comprising a proximal end attached to the housing, wherein the implanting step comprises positioning the sensing catheter freely within the peritoneal space and anchoring the housing at a subcutaneous site proximate the peritoneal space;
contacting the analyte sensor with a peritoneal fluid sample outside the sensing catheter;
sensing an analyte concentration in peritoneal fluid sample; and
transducing the sensed analyte concentration into a transmittable electrical signal.
2. The method of claim 1 wherein implanting the analyte sensor apparatus at a subcutaneous site proximate the peritoneal space comprises anchoring the housing of apparatus using, tissue in-growth cuffs attached to the exterior surface of the catheter to a tissue site within the abdominal wall.
3. The method of claim 1 wherein positioning the sensing catheter freely within the peritoneal space comprises positioning the sensing, catheter within the true pelvis.
4. The method of claim 1 wherein said sensing catheter incorporates a band of fibrin deposition resistant. material to allow fibrous capsules to be swept off the catheter with a flush.
5. The method of claim 4 wherein the fibrin deposition resistant material comprises PTFE.
6. The method of claim 1 wherein sensing an analyte comprises sensing glucose.
7. The method of claim 6 wherein sensing glucose comprises sensing by at least one of an optical method and an enzyme-mediated approach.
8. The method of claim 1 wherein sensing an analyte comprises sensing any one or more of a pH, a gas, an electrolyte, a metabolic substrate, a metabolite, an enzyme, or a hormone.
9. The method of claim 1 wherein sensing an analyte relates to monitoring clinical parameters relevant to kidney function.
10. The method of claim 1 wherein sensing an analyte relates to monitoring clinical parameters relevant to hemorrhage or shock.
11. The method of claim 1 wherein sensing an analyte relates to monitoring clinical parameters relevant to diabetes.
12. The method of claim 1 wherein sensing an analyte relates to monitoring clinical parameters relevant to cardiac function.
13. The method of claim 1 wherein sensing an analyte relates to monitoring clinical parameters relevant to infection or sepsis.
14. The method of claim 1 further comprising flushing the sensor and the lumen of the sensing catheter with a fluid.
15. The method of claim 14 wherein flushing the sensor and the lumen of the sensing catheter with a fluid occurs intermittently.
16. The method of claim 14 wherein flushing the sensor and the lumen of the sensing catheter with a fluid occurs automatically.
17. The method of claim 14 wherein flushing the lumen comprises drawing the fluid from a reservoir associated with the analyte sensor apparatus.
18. The method of claim 17 wherein drawing the fluid into the lumen from the fluid layer of the peritoneal space comprises drawing fluid through a semi-permeable membrane portion of the sensing catheter.
19. The method of claim 17 wherein flushing the lumen comprises pumping fluid out of the lumen.
20. The method of claim 14 wherein said reservoir is filled with heparin, anti-fibrin compounds and/or saline.
21. The method of claim 14 wherein said reservoir is filled with insulin.
22. The method of claim 21 wherein the reservoir is refilled intermittently.
23. The method of claim 14 wherein flushing the lumen comprises drawing the fluid into the lumen from the fluid layer of the peritoneal space.
24. The method of claim 1 wherein said analyte sensor apparatus may be coupled with an insulin pump to provide automatic delivery of insulin based on the readings of said analyte sensor.
25. The method of claim 24 wherein said insulin is delivered directly to the pelvic region of the peritoneal cavity.
26. The method of claim 24 wherein separate refillable reservoirs may be employed for insulin and the flushing solution.
27. The method of claim 1 wherein said analyte sensor and/or insulin pump may be anchored in the preperitoneal space.
28. The method of claim 27 wherein said analyte sensor and/or insulin pump may be connected to one or more subcutaneous ports for wireless communication, recharging of the device via inductive coupling, refilling of insulin and/or refilling of flush solution.
29. A method of determining an analyte concentration within a peritoneal fluid of a human subject, comprising:
inserting a flexible sensing catheter into a peritoneum, the catheter comprising a lumen with a plurality of apertures and an exterior surface with an analyte sensor affixed thereto, the catheter comprising a proximal end attached to the housing, wherein inserting comprises positioning the sensing catheter freely within the peritoneal space, tunneling the proximate end through the subcutaneous space and attaching the proximal end to a sensing apparatus outside of the body;
contacting the analyte sensor with a peritoneal fluid sample outside the sensing catheter;
sensing an analyte concentration in peritoneal fluid sample; and
transducing the sensed analyte concentration into an electrical signal outside of the body.
30. The method of claim 29 wherein said flexible sensing catheter may have more than one lumen wherein one of the lumens is attached to a source of insulin for delivery of insulin into the peritoneal cavity.
31. The method of claim 30 wherein said source of insulin may be coupled to said flexible sensing catheter to provide automated delivery of insulin based on peritoneal glucose readings.
32. The method of claim 30 wherein said insulin is delivered directly to the pelvic region of the peritoneal cavity.
33. The method of claim 29 wherein said sensing catheter is intermittently flushed to prevent encapsulation.
34. The method of claim 29 wherein said sensing catheter is flushed with heparin, anti-fibrin compounds and/or saline.
35. The method of claim 29 wherein said sensing catheter is flushed with an insulin solution.