Methods and Apparatuses for Assessment and Management of Hemodynamic Status

Abstract

Embodiments of the present invention provide reliable, convenient, and cost-effective methods and apparatuses to determine the hemodynamic status of the patent. The methods and apparatuses provide for the noninvasive determine of hemodynamic status by using systematic perturbations of venous return or trend observation over time. Embodiments do not require invasive pressure monitoring or the use of ventilator but instead can be an entirely noninvasive system.

We claim: 
     
         1 . An apparatus for determining the volume status of a patient, comprising:
 (a) a pulse contour measurement device;   (b) an airway resistance device comprising at least one flow-independent pressure valve allowing air flow after a pressure threshold has been satisfied;   (c) a processing system configured to determine a variation of time intervals within the pulse contours measured by the pulse contour measurement device;   (d) a volume status determination system configured to determine the volume status of the patient from the variation of time intervals.   
     
     
         2 . The apparatus of  claim 1 , further comprising a sensor configured to measure the presence of airflow through the airway resistance device, wherein the processing system is configured to determine the variation of time intervals measured during the presence of air flow through the airway resistance device. 
     
     
         3 . The apparatus of  claim 1 , further comprising a communication device configured to communicate with the patient. 
     
     
         4 . The apparatus of  claim 1 , wherein the pulse contour measurement device is a photoplethysmogram. 
     
     
         5 . The apparatus of  claim 1 , wherein the airway resistance device is configured to vary the pressure threshold. 
     
     
         6 . The apparatus of  claim 1 , further comprising an electrocardiogram measurement device, wherein the processing system is configured to determine the variation of time intervals between the pulse contours and the electrocardiogram. 
     
     
         7 . The apparatus of  claim 1 , further comprising an accelerometer measurement device. 
     
     
         8 . The apparatus of  claim 1 , wherein the pulse contour measurement device is configured to be worn around the wrist. 
     
     
         9 . The apparatus of  claim 1 , wherein the pulse contour measurement device is configured to be worn in a ring-like manner around a finger of the patient. 
     
     
         10 . The apparatus of  claim 1 , wherein the pulse contour measurement device is configured to be worn in or on an ear of the patient. 
     
     
         11 . The apparatus of  claim 1 , wherein the pulse contour measurement device is housed together with the airway resistance device.