Vasocor, Inc.

Other

Jeffrey K Raines

John N Hoffman

Leon T Snyder

William Insull, Jr

The calibrated method for characterizing blood flow in a limb of a patient during reactive hyperemia utilizes a blood pressure cuff. The method establishes a predetermined, near diastolic, pressure in said blood pressure cuff during the reactive hyperemic episode, continually senses the pressure in the cuff and periodically changes the internal volume of said blood pressure cuff by a predetermined volumetric amount to calibrate the system. The resultant change in the pressure is a calibration pressure pulse and is used to calculates pulsatile blood volume through the blood vessel. A calibrated method for determining the condition of blood vessels and endothelium includes determining, for each calibration cycle, a respective peak value for the blood volume and comparing the peak blood volume values with peak blood volume values for healthy blood vessels and endothelium. The comparison preferably utilizes a waveform. The calibrated system for characterizing blood flow includes a computerized electronic and pneumatic system which inflates, for a predetermined pre-test time, the blood pressure cuff to a suprasystolic pressure and thereafter establishes the near diastolic pressure in the cuff during the ensuing reactive hyperemic episode. A sensor substantially continually senses the pressure and generates a pressure signal. A subsystem periodically changes the volume of said blood pressure cuff during a calibration cycle. A corrected and calibrated blood volume signal is calculated with the calibration pressure signal. A calibrated system for determining the condition of blood vessels and endothelium is also disclosed.

Calibrated measurement of blood vessels and endothelium after reactive

The integrated peripheral vascular diagnostic system electronically links a pulse volume recorder PVR, an ocular pneumoplethysmograph OPG, a photoplethysmograph PPG, an audio-frequency analyzer AA unit which characterizes blood flow with a sensitive microphone, and a doppler ultrasound unit. This diagnostic equipment generates data signals. These data signals are converted into digital data signals and are stored in a database. The diagnostic system includes a computer with a processor, a memory, a keypad input device, a display monitor, a printer and an interface for connecting these electronic components together along with an interface for the PVR, OPG, PPG, AA and doppler ultrasound. The diagnostic system further includes a report generator which generates, displays and prints a plurality of vascular diagnostic reports from the digital instrument data signals and the keypad entry data. The diagnostic system also includes, in a further embodiment, an audio playback device such that the technician, when preparing the vascular diagnostic report, can listen to analog versions of the digital instrument data signals. The method for electronically integrating the vascular diagnostic system includes electronically obtaining and converting the instrument data signals into digital data signals, inputting keypad entry data representing manually acquired vascular medical data from the patient, compiling the digital data and the keypad entry data into a database and generating, displaying and printing a plurality of vascular diagnostic reports.

Integrated, peripheral vascular diagnostic system and method therefor

Integrated peripheral vascular diagnostic system and method therefor

The method of calibrating includes selecting discrete levels of cuff pressure and placing the artery under study at those discrete levels of induced pressure with a closed pneumatic cuff system, substantially continually sensing cuff pressures at each discrete level and thereby sensing blood volume change through the artery, electronically determining when a certain number of representative blood volume change signals are substantially equivalent, changing the volume in the closed pneumatic system at each discrete cuff pressure by a predetermined volumetric amount after determining substantial equivalency, and, correcting the blood volume change signal based upon the signals detected during the volume change of the closed pneumatic cuff system. The calibration device includes, in one embodiment, a controllable pneumatic pump, a pressure sensor, a computerized device for determining when a representative number of blood volume change signals (based on the pressure sensor signals) are substantially similar and thereafter generating a calibration trigger signal. The calibration system also includes a device which changes the volume in the closed pneumatic system by a predetermined calibrated volumetric amount upon application of the calibration trigger signal. This volume changing device may be a reciprocating piston.

Calibration of segmental blood volume changes in arteries and veins for

The method of calibrating the volume plethysmograph designed to detect atherosclerosis includes selecting discrete levels of cuff pressure and placing the artery under study at those discrete levels of induced pressure with a closed pneumatic cuff system, substantially continually sensing cuff pressures at each discrete level and thereby sensing blood volume change through the artery, electronically determining when a certain number of representative blood volume change signals are substantially equivalent, changing the volume in the closed pneumatic system at each discrete cuff pressure by a predetermined volumetric amount after determining substantial equivalency, electronically generating a calibration signal or factor at each discrete cuff pressure based upon changed blood volume change signal and, correcting the blood volume change representative signal based upon the calibration signal or factor at each discrete level of pressure. The calibration device includes, in one embodiment, a controllable pneumatic pump, a pressure sensor, a computerized device for determining when a representative number of blood volume change signals (based on the pressure sensor signals) are substantially similar and thereafter generating a calibration trigger signal. The calibration system also includes a device which changes the volume in the closed pneumatic system by a predetermined calibrated amount in the presence of the calibration trigger signal. This volume changing device may be a series of valves coupled by a chamber having a known volumetric size, a positive displacement pump driven by a stepper motor or a reciprocating piston.

Calibration of segmental blood volume changes in arteries and veins

The method of calibrating includes selecting discrete levels of cuff pressure and placing the artery or vein under study under discrete levels of induced pressure with a closed pneumatic system contained by the pressure cuff, substantially continually sensing cuff pressures at each discrete level and thereby sensing blood volume change through the artery, electronically determining when a certain number of representative time-based blood volume change signals are substantially equivalent, changing the volume in the closed pneumatic system at each discrete cuff pressure by a pre-determined volumetric amount after determining substantial equivalency, electronically generating a calibration signal at each discrete cuff pressure based upon the calibrated volume change and, correcting the blood volume representative signal based upon the calibration signal at each discrete level of pressure. The calibration device includes, in one embodiment, a controllable pneumatic pump, a pressure sensor, a computerized device for determining when a representative number of blood volume change signals (based on the pressure sensor signals) are substantially similar and thereafter generating a calibration signal. The calibration system also includes a device which changes the volume in the closed pneumatic system by a predetermined calibrated amount in the presence of the calibration trigger signal. This volume changing device may be a series of valves coupled by a chamber having a known volumetric size or a positive displacement pump driven by a stepper motor. The calibration system also includes a computerized device for correcting representative blood volume change signals based on the pressure signals at each discrete level of cuff pressure as corrected by the calibration signals represented by detected pressure signals obtained substantially simultaneously with the change of the volume at each discrete level of cuff pressure.

Calibration of segmental blood volume charges in arteries and veins for

The method of calibrating includes selecting discrete levels of cuff pressure and placing the artery or vein under study under discrete levels of induced pressure with a closed pneumatic system contained by the pressure cuff, substantially continually sensing cuff pressures at each discrete level and thereby sensing blood volume change through the artery, electronically determining when a certain number of representative time-based blood volume change signals are substantially equivalent, changing the volume in the closed pneumatic system at each discrete cuff pressure by a pre-determined volumetric amount after determining substantial equivalency, electronically generating a calibration signal at each discrete cuff pressure based upon the calibrated volume change and, correcting the blood volume representative signal based upon the calibration signal at each discrete level of pressure. The calibration device includes, in one embodiment, a controllable pneumatic pump, a pressure sensor, a computerized device for determining when a representative number of blood volume change signals (based on the pressure sensor signals) are substantially similar and thereafter generating a calibration signal. The calibration system also includes a device which changes the volume in the closed pneumatic system by a pre-determined calibrated amount in the presence of the calibration trigger signal. This volume changing device may be a series of valves coupled by a chamber having a known volumetric size or a positive displacement pump driven by a stepper motor. The calibration system also includes a computerized device for correcting representative blood volume change signals based on the pressure signals at each discrete level of cuff pressure as corrected by the calibration signals represented by detected pressure signals obtained substantially simultaneously with the change of the volume at each discrete level of cuff pressure.

Growing community of inventors

Miami, FL, United States of America

Jeffrey K Raines