Devices and methods for measurement of Vena Cava dimensions, pressure and oxygen saturation
Catheter-based devices and methods for continuously monitoring vascular lumen dimensions, in particular in the inferior vena cava (IVC) for determining heart failure and/or fluid status of a patient. Related therapy systems and methods for integrated monitoring and therapy are also disclosed.
1. A catheter for monitoring a vascular lumen dimension, comprising:
an elongate catheter body having proximal and distal ends, the distal end configured for placement within a patient's vasculature;
a distal end region configured and dimensioned to engage a wall of the vascular lumen to maintain the position of the distal end region with respect to the vascular lumen wall; and
at least one detection element configured to detect lumen diameter at a monitoring location disposed in the distal end region of said catheter body;
wherein said catheter body and distal end region are configured for placement in the vena cava with an anchor element disposed in said distal end region configured to securely position the at least one detection element with respect to the vena cava wall; and
wherein the anchor element is disposed at a longitudinal distance from the at least one detection element sufficient to isolate the at least one detection element from distortions of the vessel caused by the anchoring element.
2. The catheter of claim 1 , wherein said detection element comprises an ultrasound transducer and the anchor element is further configured to contact the ultrasound transducer with the vena cava wall with the ultrasound transducer oriented substantially in the direction of the vena cava wall opposite said transducer.
3. The catheter of claim 1 , further characterized in that an anchor isolation structure is positioned in said longitudinal distance between the at least one detection element and the anchor element, wherein the anchor isolation structure comprises a member having sufficient stiffness to maintain the at least one detection element substantially in contact with the IVC wall.
4. The catheter of claim 1 , wherein the catheter distal end region is configured for placement in the inferior vena cava (IVC) in engagement with the IVC wall.
5. The catheter of claim 1 , wherein the distal end region is configured to naturally orient itself in a predictable orientation relative to the anterior-posterior axis of the vessel.
6. The catheter of claim 1 , wherein said detection element comprises an ultrasound transducer.
7. The catheter of claim 1 , wherein said distal end region comprises a biased, curved portion configured to engage the lumen wall at two spaced apart locations.
8. The catheter f claim 1 , further comprising a pressure sensing port disposed in the distal end region.
9. The catheter of claim 1 , further comprising an oxygen saturation sensing port disposed in the distal end region.
10. The catheter of claim 1 , further comprising one or more blood flow sensors.
11. The catheter of claim 1 , wherein said catheter body comprises at least one lumen configured for delivery or removal of fluid into or out of the vascular lumen.
12. The catheter of claim 1 , wherein said distal end region comprises positioning means configured to securely position the at least one detection element within the vascular lumen without affecting the natural dimensions and motion of the vascular lumen at the detecting location.
13. A catheter for monitoring a vascular lumen dimension, comprising:
an elongate catheter body having proximal and distal ends, the distal end configured for placement within a patient's vasculature;
a distal end region configured and dimensioned to engage a wall of the vascular lumen to maintain the position of the distal end region with respect to the vascular lumen wall;
at least one detection element configured to detect lumen diameter at a monitoring location disposed in the distal end region of said catheter body;
wherein said distal end region comprises a biased, curved portion configured to engage the lumen wall at two spaced apart locations; and
wherein said detection element comprises an ultrasound transducer disposed in said biased, curved portion at a location configured to be positioned in engagement with the lumen wall with said transducer positioned to direct a signal across the lumen and receive the reflection therefrom.
14. A catheter for monitoring a vascular lumen dimension, comprising:
an elongate catheter body having proximal and distal ends, the distal end configured for placement within a patient's vasculature;
a distal end region configured and dimensioned to engage a wall of the vascular lumen to maintain the position of the distal end region with respect to the vascular lumen wall;
at least one detection element configured to detect lumen diameter at a monitoring location disposed in the distal end region of said catheter body;
an oxygen saturation sensing port disposed in the distal end region; and a second oxygen saturation sensing port disposed in the catheter body proximal to the distal end region positioned to be located in the superior vena cava when the distal end region is positioned in the inferior vena cava.