Pulse Wave Velocity, Arterial Compliance, and Blood Pressure

Abstract

Disclosed are methods for determining physiological parameters of an individual including blood pressure, arterial compliance, flow velocity, and pressure wave velocity. A noninvasive method for determining the blood pressure of a patient is based on measurements of flow velocity, pulse wave velocity and arterial compliance. A noninvasive method for determining the arterial compliance of a patient is based on measurements of blood pressure, flow velocity, and pulse wave velocity.

What is claimed 
     
         1 . A method for determining a blood pressure of a subject, the method comprising:
 providing a value for pulse wave velocity within an arterial segment or segments of a subject;   providing a value for flow velocity within the arterial segment or segments of the subject;   providing a value for an arterial compliance parameter of the subject; and   applying a model of fluid-structure interaction incorporating conservation of mass and momentum for the fluid, and linear elasticity of the structure, to calculate blood pressure of the subject using the provided values.   
     
     
         2 . The method of  claim 1 , wherein the arterial compliance parameter comprises distensibility. 
     
     
         3 . The method of  claim 1 , wherein the model of fluid-structure interaction comprises the equation 
       
         
           
             
               
                 p 
                 = 
                 
                   
                     2 
                     ⁢ 
                     
                       ( 
                       
                         
                           ρ 
                           ⁢ 
                           
                             
                               D 
                               ⁡ 
                               ( 
                               
                                 PWV 
                                 - 
                                 u 
                               
                               ) 
                             
                             2 
                           
                         
                         - 
                         1 
                       
                       ) 
                     
                   
                   D 
                 
               
               , 
             
           
         
       
       where PWV is the pulse wave velocity, u is the flow velocity, ρ is the density of the fluid, and D is the arterial compliance parameter. 
     
     
         4 . The method of  claim 1 , wherein a peak pulse wave velocity is associated with a systolic pressure. 
     
     
         5 . The method of  claim 1 , wherein a minimum pulse wave velocity is associated with a diastolic pressure. 
     
     
         6 . The method of  claim 1 , wherein a peak flow velocity is associated with a systolic blood pressure. 
     
     
         7 . The method of  claim 1 , wherein a minimum flow velocity is associated with a diastolic blood pressure. 
     
     
         8 . A method for determining an arterial compliance parameter of a subject, the method comprising:
 providing a value for pulse wave velocity within an arterial segment or segments of a subject;   providing a value for flow velocity within the arterial segment or segments of the subject;   providing a value for blood pressure of the subject; and   applying a model of fluid-structure interaction incorporating conservation of mass and momentum for the fluid, and linear elasticity of the structure, to calculate an arterial compliance parameter of the subject using the provided values.   
     
     
         9 . The method of  claim 8 , wherein the arterial compliance parameter comprises distensibility. 
     
     
         10 . The method of  claim 8 , wherein the model of fluid-structure interaction comprises:
 populating any one of equations   
       
         
           
             
               
                 D 
                 = 
                 
                   
                     
                       
                         [ 
                         
                           
                             ρ 
                             * 
                             
                               PWV 
                               f 
                               2 
                             
                           
                           - 
                           
                             p 
                             2 
                           
                         
                         ] 
                       
                       
                         - 
                         1 
                       
                     
                     ⁢ 
                         
                     or 
                     ⁢ 
                         
                     D 
                   
                   = 
                   
                     
                       [ 
                       
                         
                           
                             ∑ 
                             
                               i 
                               = 
                               1 
                             
                             N 
                           
                           
                             
                               ( 
                               
                                 
                                   ρ 
                                   * 
                                   
                                     PWV 
                                     f 
                                     2 
                                   
                                 
                                 - 
                                 
                                   p 
                                   2 
                                 
                               
                               ) 
                             
                             i 
                           
                         
                         N 
                       
                       ] 
                     
                     
                       - 
                       1 
                     
                   
                 
               
               , 
             
           
         
         where PWV is the pulse wave velocity, u is the flow velocity, p is the density of the fluid, and p is the blood pressure. 
       
     
     
         11 . The method of  claim 8 , wherein a peak pulse wave velocity is associated with a systolic pressure. 
     
     
         12 . The method of  claim 8 , wherein a minimum pulse wave velocity is associated with a diastolic pressure. 
     
     
         13 . The method of  claim 8 , wherein a peak flow velocity is associated with a systolic blood pressure. 
     
     
         14 . The method of  claim 8 , wherein a minimum flow velocity is associated with a diastolic blood pressure. 
     
     
         15 . A method for determining an arterial compliance parameter of a subject under stationary conditions comprising:
 providing one of an arterial diameter or radius associated with a first pressure;   providing one of an arterial diameter or radius associated with a second pressure; and   calculating an arterial compliance parameter by finding the difference between the first pressure arterial radius and the second pressure arterial radius, dividing by the difference of the product of the first pressure and the first radius and the product of the second pressure and the second radius, and multiplying by two.