Systems and methods for monitoring and evaluating neuromodulation therapy

Abstract

Systems and methods for informing and evaluating neuromodulation therapy are disclosed herein. A system configured in accordance with embodiments of the present technology can include, for example, a guidewire having a proximal portion, a distal portion configured to be positioned at a target site in a blood vessel of a human patient, and a sensing element positioned along the distal portion. The sensing element can be a pressure sensing element, a flow sensing element, an impedance sensing element, and/or a temperature sensing element. The system can further include a controller configured to obtain one or more measurements related to a physiological parameter of the patient via the sensing element. Based on the measurements, the controller can determine the physiological parameter and compare the parameter to a predetermined threshold. Based on the comparison, the controller and/or the operator can assess the likelihood of the patient benefiting from neuromodulation therapy.

I/We claim: 
     
         1 . A neuromodulation/evaluation system, comprising:
 a neuromodulation catheter comprising an elongated shaft defining a lumen therethrough, a proximal portion, and a distal portion, wherein the distal portion is configured to deliver therapeutic neuromodulation at a target site in a renal blood vessel of a human patient;   a guidewire configured to be slidably positioned within the lumen of the elongated shaft, the guidewire having a distal portion and a sensing element positioned along the distal portion, wherein the sensing element is configured to detect physiological measurements at the target site; and   a controller configured to be communicatively coupled to the sensing element, wherein the controller is further configured to—
 obtain the physiological measurements via the sensing element; 
 determine a physiological parameter based on the physiological measurements; 
 compare the physiological parameter to a predetermined threshold; and 
 based on the comparison, provide an indication to an operator regarding whether the patient has physiological characteristics indicative of a therapeutic response to renal neuromodulation therapy at the target site. 
   
     
     
         2 . The neuromodulation/evaluation system of  claim 1  wherein the sensing element comprises a pressure sensing element, a flow sensing element, an impedance sensing element, and/or a temperature sensing element. 
     
     
         3 . The neuromodulation/evaluation system of  claim 1  wherein the sensing element is configured to detect physiological measurements indicative of renal artery wave speed, and wherein the controller is configured to determine renal artery wave speed based on the physiological measurements. 
     
     
         4 . The neuromodulation/evaluation system of  claim 1  wherein:
 the sensing element is configured to detect physiological measurements at a first branch of the renal artery and at a second branch of the renal artery; and 
 the controller is configured to—
 determine a first physiological parameter based on the physiological measurements taken from the first branch, 
 determine a second physiological parameter based on the physiological measurements taken from the second branch, 
 compare the first physiological parameter to the second physiological parameter, and 
 based on the comparison, determine whether the first or second branch will be more receptive to renal neuromodulation therapy. 
 
 
     
     
         5 . The neuromodulation/evaluation system of  claim 1  wherein:
 the sensing element is configured to detect physiological measurements at a branch vessel of the renal artery and at the renal artery; and 
 the controller is configured to—
 determine a first physiological parameter based on the physiological measurements taken from the branch vessel, 
 determine a second physiological parameter based on the physiological measurements taken from the renal artery, 
 compare the first physiological parameter to the second physiological parameter, and 
 based on the comparison, determine whether the branch vessel or the renal artery will be more receptive to renal neuromodulation therapy. 
 
 
     
     
         6 . A system, comprising:
 a guidewire having a proximal portion, a distal portion configured to be positioned at a target site in a renal blood vessel of a human patient, and a sensing element positioned along the distal portion, wherein the sensing element is a pressure sensing element, a flow sensing element, an impedance sensing element, and/or a temperature sensing element;   a controller configured to be communicatively coupled to the sensing element, wherein the controller is further configured to—
 obtain one or more measurements related to a physiological parameter of the patient via the sensing element; 
 determine the physiological parameter based on the measurements; 
 compare the physiological parameter to a predetermined threshold; and 
 based on the comparison, provide an indication to an operator regarding the likelihood the patient will have a therapeutic response to renal neuromodulation therapy at the target site. 
   
     
     
         7 . The system of  claim 6  wherein the sensing element is one of a plurality of sensing elements positioned along the distal portion of the guidewire. 
     
     
         8 . The system of  claim 6  wherein the physiological parameter is renal wave speed, and wherein the sensing element is configured to take measurements used to determine renal wave speed. 
     
     
         9 . The system of  claim 6  wherein the physiological parameter is renal resistance, and wherein the sensing element is configured to take measurements used to determine renal resistance. 
     
     
         10 . The system of  claim 6  wherein the physiological parameter is mean blood pressure, and wherein the sensing element is configured to take measurements used to determine mean blood pressure. 
     
     
         11 . The system of  claim 6  wherein the physiological parameter is mean blood velocity, and wherein the sensing element is configured to take measurements used to determine mean blood velocity. 
     
     
         12 . The system of  claim 6  wherein the sensing element is configured to take measurements from a renal artery main vessel, a main bifurcation of the renal artery, and/or one or more renal branches distal of the main bifurcation of the renal artery. 
     
     
         13 . The system of  claim 6  wherein the controller is further configured to, based on the physiological parameter, indicate which portions of the blood vessel are more susceptible to neuromodulation therapy. 
     
     
         14 . The system of  claim 6  wherein the controller is further configured to, based on the physiological parameter, indicate which portions of the blood vessel are less susceptible to neuromodulation therapy. 
     
     
         15 . The system of  claim 6 , further comprising a neuromodulation catheter, and wherein the neuromodulation catheter comprises:
 an elongated shaft defining a lumen therethrough, the elongated shaft having a proximal portion and a distal portion, wherein the distal portion is configured to be positioned at the target site; and   a plurality of electrodes spaced along the distal portion of the shaft.   
     
     
         16 . The system of  claim 15  wherein:
 the guidewire is configured to be slidably positioned within the lumen of the elongated shaft; and 
 the controller is configured to be communicatively coupled to the electrodes, wherein the controller is further configured to—
 apply a first stimulus at and/or proximate to the target site within the blood vessel; 
 detect, via at least one of the electrodes, vessel impedance resulting from the first stimulus to determine a baseline impedance; 
 deliver neuromodulation energy to the target site within the blood vessel of the human patient via the distal portion of the shaft; 
 apply a second stimulus at and/or proximate to the target site within the blood vessel after delivering the neuromodulation energy; 
 detect, via at least one of the electrodes, vessel impedance resulting from the second stimulus to determine a post-neuromodulation impedance; and 
 assess efficacy of the neuromodulation based at least in part on a comparison of the baseline impedance and the post-neuromodulation impedance. 
 
 
     
     
         17 . The system of  claim 15  wherein the lumen is a first lumen, and wherein the neuromodulation catheter further comprises a second lumen extending along the shaft and configured to deliver a pharmacological agent at and/or proximate to the target site to provide the first and second stimuli. 
     
     
         18 . The system of  claim 15  wherein the distal portion of the shaft is configured to transform into a spiral shape such that at least one of the electrodes is configured contact an interior wall of the blood vessel, and wherein at least one of the electrodes is configured to deliver the neuromodulation energy. 
     
     
         19 . A method for evaluating patients for neuromodulation therapy, the method comprising:
 delivering a distal portion of a guidewire to a target site within a renal blood vessel of a human patient, wherein the distal portion of the guidewire includes a sensing element;   obtaining, via the sensing element, a baseline measurement related to a physiological parameter of the patient;   determining the physiological parameter based on the baseline measurement;   comparing the physiological parameter to a predetermined threshold; and   indicating, based on the comparison, whether the patient will have a therapeutic response to renal neuromodulation therapy.   
     
     
         20 . The method of  claim 19  wherein determining the physiological parameter comprises determining renal wave speed and/or renal resistance. 
     
     
         21 . The method of  claim 19  wherein determining the physiological parameter comprises determining mean blood pressure and/or mean blood velocity. 
     
     
         22 . The method of  claim 19  wherein:
 obtaining the baseline measurements comprises—
 obtaining physiological measurements from a branch vessel of the renal blood vessel, 
 obtaining physiological measurements from the renal blood vessel; 
 
 determining the physiological parameter comprises—
 determining a first physiological parameter based on physiological measurements taken from the branch vessel, and 
 determining a second physiological parameter based on physiological measurements taken from the renal blood vessel; 
 
 comparing the physiological parameter comprises—
 comparing the first physiological parameter to the second physiological parameter; and 
 
 indicating comprises—
 determining whether the branch vessel or the renal blood vessel will be more receptive to renal neuromodulation therapy. 
 
 
     
     
         23 . The method of  claim 19  wherein:
 obtaining the baseline measurements comprises—
 obtaining physiological measurements from a first branch vessel of the renal blood vessel, 
 obtaining physiological measurements from a second branch vessel of the renal blood vessel; 
 
 determining the physiological parameter comprises—
 determining a first physiological parameter based on physiological measurements taken from the first branch vessel, and 
 determining a second physiological parameter based on physiological measurements taken from the second branch vessel; 
 
 comparing the physiological parameter comprises—
 comparing the first physiological parameter to the second physiological parameter; and 
 
 indicating comprises—
 determining whether the first branch vessel or the second branch vessel will be more receptive to renal neuromodulation therapy. 
 
 
     
     
         24 . The method of  claim 19  wherein:
 obtaining the baseline measurements comprises measuring pressure and velocity within the renal blood vessel; and 
 determining the physiological parameter comprises determining renal wave speed using the following: 
 
       
         
           
             
               c 
               = 
               
                 
                   1 
                   ρ 
                 
                  
                 
                   
                     
                       ∑ 
                       
                         dP 
                         2 
                       
                     
                     
                       ∑ 
                       
                         dU 
                         2 
                       
                     
                   
                 
               
             
           
         
         
           wherein P is pressure, U is velocity, and ρ is density of blood. 
         
       
     
     
         25 . The method of  claim 19 , further comprising:
 advancing a neuromodulation catheter over the guidewire to the target site; and   applying renal neuromodulation therapy with the neuromodulation catheter.