Sensors for catheter pumps
Sensors for catheter pumps are disclosed herein. The catheter pump can include a catheter assembly comprising a catheter and a cannula coupled to a distal portion of the catheter. The cannula can have a proximal port for permitting the flow of blood therethrough. The catheter assembly can include a sensor to be disposed near the proximal port. A processing unit can be programmed to process a signal detected by the sensor. The processing unit can comprise a computer-readable set of rules to evaluate the signal to determine a position of the cannula relative to an aortic valve of a patient.
1 . A catheter pump comprising:
a catheter body percutaneously insertable into a vasculature of a patient;
a cannula and impeller coupled to the catheter body and deliverable with the catheter body to a target location in the patient's body to perform a treatment procedure;
a sensor assembly comprising at least one sensor element positioned along a distal portion of the catheter body at a position proximally adjacent the impeller; and
a sheath disposed about the catheter body;
wherein the sensor assembly is selectively positionable relative to the sheath in a first position wherein the at least one sensor element is isolated from blood and anatomy in the vasculature and a second position wherein the at least one sensor element is exposed to blood in the vasculature for measuring a pressure of the blood at the target location.
2 . The catheter pump of claim 1 , wherein the sheath is slidable relative to the at least one sensor element to locate the sensor element in the first position or the second position.
3 . The catheter pump of claim 1 , wherein the cannula and impeller are expandable in a deployed configuration from the slidable sheath.
4 . The catheter pump of claim 1 , wherein the at least one sensor element is exposed through at least one window in the second position.
5 . The catheter pump of claim 4 , wherein the window is formed in the sheath wherein the at least one sensor element is disposed on a wall of the cannula.
6 . The catheter pump of claim 4 , wherein the window is formed in a central lumen of the catheter pump, and the at least one sensor element is disposed in a central lumen that extends distal to the impeller.
7 . The catheter pump of claim 1 , wherein the at least one sensor element is exposed within a left ventricle of the patient at the target location, and wherein the impeller is operable at a clinician adjustable speed and position relative to the left ventricle to pump blood through an aorta of the patient at a flow rate sufficient to support the patient at a maintained average pressure of less than about 15 mmHg in the left ventricle of the patient.
8 . The catheter pump of claim 7 , wherein the flow rate is at least about 2 liters per minute (Lpm) to about 6 Lpm.
9 . The catheter pump of claim 8 , wherein the flow rate is about 4 Lpm to about 6 Lpm.
10 . The catheter pump of claim 9 , wherein the flow rate is about 4 Lpm to about 5.5 Lpm.
11 . The catheter pump of claim 10 , wherein the flow rate is about 4.5 Lpm to about 5.5 Lpm.
12 . The catheter pump of claim 7 , wherein the maintained average pressure is between about 2 mmHg to about 15 mmHg.
13 . The catheter pump of claim 12 , wherein the maintained average pressure is between about 2 mmHg about 10 mmHg in the left ventricle of the patient.
14 . The catheter pump of claim 13 , wherein the maintained average pressure is between about 2 mmHg and about 8 mmHg.
15 . The catheter pump of claim 14 , wherein the maintained average pressure is between about 3 mmHg to about 6 mmHg.
16 . The catheter pump of claim 15 , wherein the maintained average pressure is between about 4 mmHg to about 5 mmHg.
17 . The catheter pump of claim 7 , wherein the impeller assembly is configured to be advanced past the aortic valve until at least one inlet of the cannula is distal the aortic valve by a distance in a range of about 0.5 cm to about 4 cm.
18 . The catheter pump of claim 17 , wherein the impeller assembly is configured to be advanced past the aortic valve until at least one inlet of the cannula is distal the aortic valve by a distance in a range of about 1.5 cm to about 3 cm.
19 . The catheter pump of claim 7 , wherein the impeller assembly is movable relative to the aortic valve of the patient to substantially smooth out spikes in a pressure signal from the pressure element.
20 . The catheter pump of claim 1 , wherein the at least one sensor element is exposed within a left ventricle of the patient at the target location, and wherein the impeller is operable at a clinician adjustable speed and position to pump blood through an aorta of the patient at a flow rate sufficient to support the patient at a maintained average pressure of about less than about 135% of a normal human average ventricular pressure.
21 . The catheter pump of claim 20 , wherein the maintained average pressure of about 105% to about 125% of the normal human average ventricular pressure.
22 . The catheter pump of claim 21 , wherein the catheter pump is configured to maintain an average pressure of about 105% to about 115% of the normal human average ventricular pressure.