System for measuring and analyzing vasodilatation index

• US 20040254485A1
• Filed: 05/07/2004
• Published: 12/16/2004
• Est. Priority Date: 05/21/2003
• Status: Active Grant

• Current Assignee: Hsien-Tsai Wu
• Original Assignee: Hsien-Tsai Wu
• Inventors: Wu, Hsien-Tsai, Chen, Yung-Kang, Chi, Chih-Kai
• Granted Patent: US 7,077,809 B2
• Time in Patent Office: Days
• US Class Current: 600/490
• CPC Class Codes: A61B 5/06 Devices, other than using radiation, for detecting or locating foreign bodies for removing same A61B17/50 ; determining position of probes within or on the body of the patient
• CPC Class Codes: A61B 5/7203 for noise prevention, reduction or removal
• CPC Class Codes: A61B 5/7275 Determining trends in physiological measurement data; Predicting development of a medical condition based on physiological measurements, e.g. determining a risk factor
• CPC Class Codes: G16H 50/20 for computer-aided diagnosis, e.g. based on medical expert systems
• CPC Class Codes: G16H 50/30 for calculating health indices; for individual health risk assessment

Abstract

In a vasodilatation index measuring and analyzing system, a measuring unit includes a measuring device for measuring standard and comparative pulses of a digit of a subject in relaxed and comparative states, respectively. An external pressure is applied to a limb part of the subject to occlude blood flow to the digit following measurement of the standard pulse. The comparative pulse is measured upon release of the external pressure. A pre-processing unit is coupled to the measuring unit for filtering noise from and digitizing the standard and comparative pulses obtained by the measuring device. An analyzing unit is coupled to the pre-processing unit for calculating standard and comparative pulse areas of at least one cycle of the standard and comparative pulses processed by the pre-processing unit, respectively, and for subsequently calculating a pre-defined index related to a difference between the standard and comparative pulse areas.

Claims

1. A vasodilatation index measuring and analyzing system, comprising:

a measuring unit including a first measuring device for measuring a standard pulse and a comparative pulse of a first digit of a subject in a relaxed state and a comparative state, respectively, wherein an external pressure is applied to a limb part of the subject to occlude flow of blood to the first digit following measurement of the standard pulse of the first digit, the comparative pulse of the first digit being measured upon release of the external pressure;

a pre-processing unit, coupled to said measuring unit, for filtering noise from and digitizing the standard and comparative pulses obtained by said first measuring device; and

an analyzing unit, coupled to said pre-processing unit, for calculating standard and comparative pulse areas of at least one cycle of the standard and comparative pulses processed by said pre-processing unit, respectively, and for subsequently calculating a pre-defined index related to a difference between the standard and comparative pulse areas.

2. The vasodilatation index measuring and analyzing system according to claim 1, wherein said first measuring device measures the standard and comparative pulses of the first digit by emitting and receiving an optical signal through the first digit.

3. The vasodilatation index measuring and analyzing system according to claim 2, wherein the optical signal is infrared light.

4. The vasodilatation index measuring and analyzing system according to claim 1, wherein said analyzing unit calculates the pre-defined index according to the following equation:

[(comparative pulse area−

standard pulse area)/standard pulse area]×

100%.

5. The vasodilatation index measuring and analyzing system according to claim 1, wherein said measuring unit further includes a second measuring device for measuring a standard pulse and a comparative pulse of a second digit of the subject simultaneous with measuring operation of said first measuring device, said pre-processing unit filtering noise from and digitizing the standard and comparative pulses obtained by said second measuring device, said analyzing unit being further operable to perform a calculation based on the following equation:

distance between the first digit and the second digit/(a time difference between corresponding positions on pulse waveforms of the first and second digits obtained respectively by said first and second measuring devices).

6. The vasodilatation index measuring and analyzing system according to claim 5, wherein the corresponding positions on the respective waveforms are pacemaker positions.

7. The vasodilatation index measuring and analyzing system according to claim 5, wherein the corresponding positions on the respective waveforms are peak positions.