Method and system for determination of the pressure-volume...

A - Human Necessities – 61 – B

Patent

Rate now

  [ 0.00 ] – not rated yet Voters 0   Comments 0

Details

A61B 5/029 (2006.01) A61B 5/0205 (2006.01) A61B 5/021 (2006.01) A61B 8/06 (2006.01)

Patent

CA 2233984

The present invention measures cardiac power and power increase under stress, thus calculating contractile reserve (CR), the difference between cardiac peak power and cardiac power at rest by connecting a person to an electrocardiograph and determining the pressure-volume loop (PVL) of a patient's heart. While deflating an inflated cuff on the person's arm at a controlled rate, a series of data points from peak systolic to diastolic pressure is obtained, each point consisting of cuff pressure at penetration coupled with the time of its occurrence after the corresponding ORS complex; a curve-fitting procedure is applied to turn said data points into a pressure curve resembling the ascending limb of the aortic pressure wave. The end systolic pressure (ESP) is calculated using the expression ESP = DP + 2/3 (PSP - DP), where DP = diastolic pressure and PSP = peak systolic pressure. The volume at point ESP is calculated by integrating said flow curve throughout the ejection phase of the patient's heart.

On mesure le rendement cardiaque et l'augmentation du rendement en cas d'effort, afin de calculer la réserve contractile (CR) et la différence entre le rendement cardiaque de crête et le rendement au repos. A cet effet, on relie un sujet à un electrocardiographe et on détermine la boucle pression-volume (PVL) du coeur du sujet. On dégonfle un brassard gonflé sur le bras du sujet à une vitesse déterminée, afin d'obtenir une succession de points de données allant de la pression systolique de crête à la pression diastolique, chacun de ces points étant constitué de la pression au niveau du brassard à la pénétration, associée à l'instant auquel elle se produit à la suite du complexe QRS correspondant. On met en oeuvre une procédure d'ajustement de courbe afin de transformer lesdits points de données en courbe de pression ressemblant à la branche ascendante de l'onde de pression aortique. On calcule la pression systolique finale (ESP) à l'aide de l'expression ESP = DP + 2/3 (PSP - DP), dans laquelle DP représente la pression diastolique et PSP représente la pression systolique de crête. On calcule le volume au point ESP par intégration de cette courbe de débit dans la totalité de la phase d'éjection du coeur du sujet.

LandOfFree

Say what you really think

Search LandOfFree.com for Canadian inventors and patents. Rate them and share your experience with other people.

Rating

Method and system for determination of the pressure-volume... does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Method and system for determination of the pressure-volume..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method and system for determination of the pressure-volume... will most certainly appreciate the feedback.

Rate now

     

Profile ID: LFCA-PAI-O-1820281

  Search
All data on this website is collected from public sources. Our data reflects the most accurate information available at the time of publication.