Tensys Medical, Inc.

Ivac Medical Systems, Inc.

Vitalwave Corporation

Cardiac Profiles, Inc.

Other

Gregory I Voss

Robert Dwaine Butterfield

Russell D Hempstead

Stuart L Gallant

Manouchehr Goharlaee

Gregory J Martin

Alvis J Somerville

William H Markle

Warren B Craycroft

Bernhard B Sterling

Gail Dawn Baura

Stephen H O'Leary

Mark W Perona

James M Perry

Rankin A Clinton, Iii

Andrew R Lawrence

Casper W Barnes

Simon E Finburgh

Ronald S Conero

Ronald J Vidischak

Stephen R Hessel

Methods, associated algorithms, and systems for determining cardiac and/or cardiovascular performance from three measurements on a subject are presented, where two of the measurements are provided by plethysmographs and one measurement is provided by an electrocardiogram. The two plethysmographs are placed different distances from the subject's heart. Certain embodiments use the three measurements to calculate intermediate variables of a left ventricular ejection time and a pre-ejection period.

Method and system for determining cardiac performance

An improved method and apparatus for non-invasively assessing one or more hemodynamic parameters associated with the circulatory system of a living organism. In one aspect, the invention comprises a method of measuring a hemodynamic parameter (e.g., arterial blood pressure) by applanating or compressing portions of tissue proximate to the blood vessel of concern until a desired condition is achieved, and then measuring the hemodynamic parameter. Such applanation effectively mitigates transfer and other losses created by the tissue proximate to the blood vessel, thereby facilitating accurate and robust tonometric measurement. An algorithm adapted to maintain optimal levels of applanation is also described. Methods and apparatus for scaling such hemodynamic parameter measurements based on subject physiology, and providing treatment to the subject based on the measured parameters, are also disclosed.

Method and apparatus for non-invasively measuring hemodynamic parameters using parametrics

Improved methods and apparatus for non-invasively assessing one or more parameters associated with fluidic systems such as the circulatory system of a living organism, when such parameters are potentially affected by other concurrent events. In one exemplary embodiment, apparatus and methods for compensating for occlusive events (e.g., pressure cuff inflation) occurring ipsilateral to the location of parameter measurement are disclosed. Upon passive detection of signal degradation resulting from the event, the apparatus selectively enters a 'wait state' wherein further processing of the hemodynamic data is suspended until the degrading event subsides. This behavior mitigates any adverse effects the event might have on the accuracy of the representation of the measured hemodynamic parameter generated by the system. In another exemplary embodiment, the measured data is analyzed in order to classify the type of event (e.g., occlusive or other), such classification allowing the system to appropriately tailor its response to the event.

Method and apparatus for control of non-invasive parameter measurements

Improved methods and apparatus for non-invasively assessing one or more parameters associated with fluidic systems such as the circulatory system of a living organism. In a first aspect, an improved method of continuously measuring pressure from a compressible vessel is disclosed, wherein a substantially optimal level of compression for the vessel is achieved and maintained using perturbations (e.g., modulation) of the compression level of the vessel. In one exemplary embodiment, the modulation is conducted according to a pseudo-random binary sequence (PBRS). In a second aspect, an improved apparatus for determining the blood pressure of a living subject is disclosed, the apparatus generally comprising a pressure sensor and associated processor with a computer program defining a plurality of operating states related to the sensed pressure data. Methods for pressure waveform correction and reacquisition, as well as treatment using the present invention, are also disclosed.

Methods and apparatus for control of non-invasive parameter measurements

A method for determining a cardiac function, comprising (i) determining base anatomical characteristics associated with the subject, (ii) determining pulse delay to a first body site (PD) and a second body site (PD) as a function of the anatomical characteristics, wherein the distance via the arterial tree from the aortic valve to the first body site (PD) is different than the arterial tree distance from the aortic valve to the second body site (PD), (iii) determining pulse wave velocity between the first body site and the second body site (PWV), (iv) determining pulse wave velocity between the aortic valve and the first body site (PWV) as a function of PWV, and the anatomical characteristics; and (v) determining the pre-ejection period (PEP) as a function of PDand PWV.

Method for determining a cardiac function

Apparatus for control of non-invasive parameter measurements

Apparatus is disclosed for non-invasively monitoring a subject's blood pressure, in which a pressure sensor assembly that includes a pressure transducer is compressed against tissue overlying an artery, with sufficient force to compress the artery. A motor first servo control system optimizes the amount of artery compression, which occurs at a mean transmural pressure of about zero, by modulating one side of a lever arm compressing the assembly against the tissue, creating a pressure signal indicative of transmural pressure. Since different pressure effects are realized according to the amount of artery compression, an appropriate control signal can be produced that provides for a second motor to adjust the other side of the lever arm to provide the optimum compression of the assembly into the tissue overlying the artery. The apparatus is optimally positioned over an artery by including an ultrasonic blood flow sensor configured to sense the flow of blood under the pressure transducer.

Apparatus and method for non-invasively monitoring a subjects arterial blood pressure

Apparatus and method for non-invasively monitoring a subject's arterial blood pressure

Apparatus is disclosed for non-invasively monitoring a subject's blood pressure, in which a flexible diaphragm that encloses a fluid-filled chamber is compressed against tissue overlying an artery, with sufficient force to compress the artery. A first, relatively slow servo control system optimizes the amount of artery compression, which occurs at a mean transmural pressure of about zero, by modulating the volume of fluid within the chamber and noting the resulting effect on the pressure within the chamber. Since different pressure effects are realized according to the amount of artery compression, an appropriate control signal can be produced that provides the optimum mean diaphragm pressure. In addition, a second, relatively fast servo control system supplies the fluid to and from the chamber, so as to compensate for pressure variations within artery. This minimizes variations in the artery's effective diameter, whereby the pressure within the fluid-filled chamber closely follows the actual arterial pulse waveform.

Apparatus and method for non-invasively monitoring a subject's arterial

Growing community of inventors

Solana Beach, CA, United States of America

Gregory I Voss