Method and apparatus for detecting the onset and relative degree of atherosclerosis in humans

An apparatus for detecting the degree of atherosclerosis in an artery comprising:

• means for changing blood flow through an artery with the application of differing amounts of induced pressure thereat;
• means for sensing an arterial blood volume differential while said artery is placed under said differing amounts of induced pressure and generating representative data;
• means for relating said volume differential representative data to data representing said differing amounts of induced pressure;
• means, coupled to said means for relating, for correlating the volume differential-induced pressure relationship with one of a plurality of predetermined waveform shapes;
• and,
• means for generating one of a plurality of atherosclerosis indicator signals based upon the waveform correlation wherein each indicator signal indicates a different degree of atherosclerosis.

An apparatus for non-invasively detecting the relative degree of atherosclerosis in a patient comprising:

• means for changing blood flow through an artery by placing relatively discrete levels of pressure on a portion of said artery;
• means for non-invasively sensing blood volume as an impedance pulse in said artery at various induced pressure levels and generating an impedance pulse signal representative thereof, and obtaining a representative signal of a tissue impedance near said artery;
• means for calculating an arterial blood volume differential from said impedance pulse signal and the tissue impedance signal;
• means for sensing and calculating a blood pressure differential of the patient;
• means for obtaining a peak compliance value by determining a maximal ratio of the blood volume differential and blood pressure differential by repeatedly obtaining the arterial blood volume differential at different induced levels of arterial pressures;
• means for providing a target value related to at least one factor of factors from the group consisting of a chronological age of said patient, said representative signal of said tissue impedance, said target value being based upon a quantitative analysis of arteries possessing different degrees of atherosclerosis;
• means for determining and indicating the relative degree of atherosclerosis by comparing said target value with a patient specific value that is computed using a predetermined correlation incorporating said peak compliance value and at least one characteristic value from the group consisting of a detected systolic pressure, a detected diastolic pressure, an ascertained cholesterol level and the patient's chronological age, all obtained from said patient.

A non-invasive apparatus for detecting atherosclerosis of a patient comprising:

• means for changing blood flow through an artery with the application of discrete levels of induced pressure thereat;
• means for obtaining an arterial blood volume differential by non-invasively sensing pulsatile blood flow through said artery while said artery is placed under said discrete levels of induced pressure;
• means for sensing and calculating a pressure differential of the pulsatile blood flow passing through an arterial system that includes said artery;
• means for obtaining a peak compliance value by determining a maximal ratio of the blood volume differential and the pressure differential;
• means for providing a target value for said patient using a first predetermined correlation incorporating at least one from the group consisting of a patient's chronological age factor, a tissue factor characteristic of said patient, a diastolic pressure, a systolic pressure, and a cholesterol level, said first predetermined correlation derived from a quantitative analysis of arteries possessing different degrees of atherosclerosis:
• means for calculating and indicating the relative degree of atherosclerosis by comparing said target value with a patient specific value that is computed using a second predetermined correlation with said peak compliance value and at least one characteristic value from the group consisting of a detected systolic pressure, a detected diastolic pressure, an ascertained cholesterol level and the patient's chronological age, all obtained from said patient.

An apparatus for detecting the degree of atherosclerosis of a patient under study comprising:

• means for changing blood flow through an artery with the application of discrete levels of induced pressure thereat;
• means for obtaining an arterial blood volume differential from said artery while said artery is placed under said discrete levels of induced pressure;
• means for obtaining the patient's blood pressure differential from said artery while said artery is placed under said discrete levels of induced pressure;
• means for calculating a peak arterial compliance value by selecting the maximal ratio of said volume differential and said pressure differential;
• means for providing a target value for said patient using a first predetermined correlation incorporating at least one from the group consisting of a patient's chronological age factor, a patient's tissue factor, a diastolic pressure, a systolic pressure, and a cholesterol level, said first predetermined correlation derived from a quantitative analysis of arteries possessing different degrees of atherosclerosis;
• means for determining and indicating the relative degree of atherosclerosis by comparing said target value with a patient specific value from a second predetermined correlation incorporating said peak compliance value and at least one characteristic value from the group consisting of a detected systolic pressure, a detected diastolic pressure, an ascertained cholesterol level and the patient's chronological age, all obtained from said patient.