Patient Self-Monitoring of IVC Volume for Early Heart Failure Warning Signs

Abstract

Methods for patient self-monitoring of vascular lumen dimensions, in particular in the inferior vena cava (IVC) for determining heart failure status of a patient. Related therapy systems as well as monitoring and therapy methods are also disclosed.

What is claimed is: 
     
         1 . A method for patient self-monitoring of fluid volume using external ultrasound, comprising:
 storing a three-dimensional ultrasound map of the patient in a detection system, said three-dimensional map including a reference image slice representing a monitoring location in the patient's IVC;   positioning an ultrasound probe of the detection system on the patient, said positioning comprising—
 generating a two-dimensional image slice of the patient using the ultrasound probe, 
 comparing the generated two-dimensional image slice with the three-dimensional ultrasound map; 
 determining a position of the generated two-dimensional slice within the three-dimensional ultrasound map relative to the reference image slice based on said comparing, and 
 indicating to the patient at least one movement of the ultrasound probe to position the ultrasound probe at the monitoring location; and 
   moving the ultrasound probe in accordance with said at least one indicated movement to the monitoring location; and   measuring variation in IVC dimensions over time by imaging opposed walls of the IVC at the monitoring location with the ultrasound probe.   
     
     
         2 . The method of  claim 1 , wherein said positioning further comprises aligning the ultrasound probe with marks previously placed on the patient's skin. 
     
     
         3 . The method of  claim 2 , wherein said aligning comprises viewing the marks through alignment windows on the ultrasound probe. 
     
     
         4 . The method of  claim 1 , wherein the reference image slice includes opposed walls of the IVC at the monitoring location. 
     
     
         5 . The method of  claim 1 , further comprising the patient self-securing the ultrasound probe to his/her body at the monitoring location. 
     
     
         6 . The method of  claim 5 , wherein said securing comprises attaching the ultrasound probe to the patient with a strap around the patient's body. 
     
     
         7 . The method of  claim 1 , wherein said indicating to the patient comprises wireless communication of the ultrasound probe with a handheld device and delivery of directional prompts through a user interface of the handheld device. 
     
     
         8 . The method of  claim 7 , wherein the handheld device is a cell phone. 
     
     
         9 . A method for patient self-monitoring of fluid volume using external ultrasound, comprising:
 marking a monitoring location on the patient overlying the patient's IVC;   patient self-positioning an ultrasound emitter and receiver at the location marks;   generating, with an ultrasound system, an ultrasound image of the patient including the IVC;   automatically identifying the IVC within the ultrasound image;   automatically identifying anterior and posterior walls of the IVC in the ultrasound image; and   continuously or periodically measuring variation in IVC dimension over time.   
     
     
         10 . The method for patient self-monitoring of  claim 9 , wherein said patient self-positioning comprises the patient wearing a wearable detection system. 
     
     
         11 . The method for patient self-monitoring of  claim 10 , wherein the patient self-positioning further comprises placing windows of the wearable detection system over the location marks. 
     
     
         12 . The method for patient self-monitoring of  claim 9 , further comprising:
 storing a three-dimensional ultrasound map of the patient in the ultrasound system, said three-dimensional map including a reference image slice representing the monitoring location in the IVC;   comparing the generated ultrasound image with the three-dimensional ultrasound map; and   determine a position of the generated ultrasound image within the three-dimensional ultrasound map relative to the reference image slice.   
     
     
         13 . The method for patient self-monitoring of  claim 12 , further comprising:
 indicating to the patient at least one movement of the ultrasound emitter and receiver to the monitoring location.   
     
     
         14 . The method for patient self-monitoring of  claim 10 , further comprising the patient self-securing the ultrasound probe to the patient at the monitoring location. 
     
     
         15 . A computer-based method for patient self-monitoring of fluid volume using external ultrasound, comprising:
 storing a three-dimensional ultrasound map of the patient in a monitoring system memory, said three-dimensional map including a reference image slice representing a monitoring location in the IVC;   self-positioning a monitoring system ultrasound probe on the patient, said positioning comprising—
 generating a two-dimensional image slice of the patient with the ultrasound probe, 
 comparing the generated two-dimensional image slice with the three-dimensional ultrasound map in a monitoring system processor communicating with the monitoring system memory to determine a position of the generated two-dimensional slice within the three-dimensional ultrasound map relative to the reference image slice, 
 indicating to an operator through a user interface communicating with the monitoring system processor at least one movement of the ultrasound probe to align the generated two-dimensional image slice with the reference image slice, and 
 self-securing the ultrasound probe to the patient at a monitoring position corresponding to the generated two-dimensional image slice being aligned with the reference image slice; and 
   measuring variation in IVC dimensions over time by imaging opposed walls of the IVC at the monitoring location with the ultrasound probe while secured to the patient at the monitoring position.   
     
     
         16 . The method of  claim 15 , wherein said self-positioning further comprises aligning the ultrasound probe with marks previously placed on the patient's skin. 
     
     
         17 . The method of  claim 16 , wherein said aligning comprises viewing the marks through alignment windows on the ultrasound probe housing. 
     
     
         18 . The method of  claim 15 , wherein the reference image slice includes opposed walls of the IVC at the monitoring location. 
     
     
         19 . The method of  claim 15 , wherein said self-securing comprises attaching the ultrasound probe to the patient with a strap around the patient's body.