Method and apparatus for determining vascular health conditions

• US 8,551,008 B2
• Filed: 10/12/2007
• Issued: 10/08/2013
• Est. Priority Date: 08/23/2002
• Status: Expired due to Fees

• Current Assignee: Endothelix Co., Board of Regents of the University of Texas System (University of Texas System)
• Original Assignee: Endothelix Co.
• Inventors: Naghavi, Morteza, Kharalkar, Nachiket, O'Brien, Timothy J.
• Primary Examiner(s): TOWA, RENE T
• Application Number:
  US11/871,901
• Publication Number:
  US 20080255471A1
• Time in Patent Office: 2,188 Days
• Field of Search: 600/474, 600479-481, 600/485, 600490-492, 600/504, 600/549, 600/555, 600/561
• US Class Current: 600/504
• CPC Class Codes: A61B 2560/0242 adapted to measure environmental factors, e.g. temperature, pollution
• CPC Class Codes: A61B 5/0008 Temperature signals
• CPC Class Codes: A61B 5/01 Measuring temperature of body parts ; Diagnostic temperature sensing, e.g. for malignant or inflamed tissue clinical contact thermometers G01K13/20
• CPC Class Codes: A61B 5/02007 Evaluating blood vessel condition, e.g. elasticity, compliance
• CPC Class Codes: A61B 5/02416 using photoplethysmograph signals, e.g. generated by infrared radiation A61B5/14552 takes precedence
• CPC Class Codes: A61B 5/1455 using optical sensors, e.g. spectral photometrical oximeters
• CPC Class Codes: A61B 5/4035 Evaluating the autonomic nervous system
• CPC Class Codes: A61B 8/08 Detecting organic movements or changes, e.g. tumours, cysts, swellings A61B8/02 - A61B8/06 take precedence
• CPC Class Codes: A61B 8/488 involving Doppler signals

Abstract

The present invention relates to assessing and measuring vascular and endothelial function. A vasostimulant is provided to a patient to stimulate hemodynamic activity in a selected extremity and vascular function is assessed by monitoring a change in a blood flow, skin temperature and/or blood oxygen content at the selected extremity and assessing the patient'"'"'s vascular function based upon the monitoring.

Claims

1. A method for assessing arterial reactivity in a patient, comprising:

a) providing a vasodilating stimulant to a patient by creating an arterial occlusion at a body part of said patient using one or more pressure cuffs thereby stimulating arterial reactivity in a first region of said body part of said patient;

b) simultaneously monitoring a patient'"'"'s skin surface temperature at the first region and at a second control region before the arterial occlusion, during the arterial occlusion, and after the arterial occlusion is removed and until an equilibrium temperature is achieved using a temperature measurement device that does not substantially apply any one of thermal energy, positive pressure and negative pressure to the skin surface;

wherein said second control region and said first region are located at contralateral body parts; and

c) identifying a baseline temperature at the first region before the arterial occlusion;

d) identifying a peak temperature at the first region after the arterial occlusion; and

e) assessing arterial reactivity in said patient based on temperature changes at the second control region and a rebound temperature change related to said baseline temperature and said peak temperature at the first region.

2. The method of claim 1 for assessing arterial reactivity further comprising:

a) creating the arterial occlusion for a predetermined period of time; and

b) ceasing the occlusion after the predetermined period of time.

3. The method of claim 1, wherein providing a vasodilating stimulant comprises occluding blood flow to at least one of:

(i) a leg, (ii) ankle, (iii) toe, (iv) arm, (v) wrist, and (vi) a finger.

4. The method of claim 1, wherein said monitoring occurs from a time prior to the beginning of said compression until a time after the hemodynamic activity has reached equilibrium.

5. The method of claim 1, wherein the monitoring comprises measuring changes in temperature at one of the patient'"'"'s fingertips.

6. The method of claim 5, further comprising plotting the measured changes in temperature as a function of time.

7. A method for assessing arterial reactivity in a patient comprising:

a) measuring a first equilibrium skin temperature at a first region of a body part of said patient using a temperature measurement device that does not substantially apply any one of thermal energy, positive pressure, and negative pressure to said first region of the patient;

b) compressing arteries of said body part of the patient using a pressure cuff such that arterial blood flow in said first region of said body part is occluded;

c) simultaneously measuring skin temperature at the first region and at a second control region of said body part during cuff compression, after release of the cuff and until a second temperature equilibrium is achieved;

wherein the second control region does not undergo arterial blood flow occlusion said cuff compression;

d) identifying a peak temperature at the first region after release of the cuff; and

e) assessing the patient'"'"'s arterial reactivity based upon temperature changes at the second control region and a rebound temperature change related to said first equilibrium temperature and said peak temperature at the first region.

8. The method of claim 7, wherein said first region is a digit.

9. The method of claim 8, wherein the digit is a finger and the temperature is measured on a fingertip.

10. The method of claim 7, comprising occluding blood flow in at least one extremity for a predetermined period of time and ceasing compression after the predetermined period of time, wherein said first region consists of one or more of:

a leg, ankle, toe, arm, wrist, and a finger.

11. The method of claim 7, wherein the measuring is conducted from a time prior to the occluding blood flow with a compressing cuff until a time after a equilibrium temperature is reached after ceasing compression.

12. The method of claim 7, further comprising plotting the measured temperature as a function of time.

13. A method for determining a arterial reactivity status in a patient comprising:

a) initiating monitoring of skin surface temperature at a selected point of a selected region the patient until a first equilibrium temperature is reached using a temperature sensor that does not substantially change the skin temperature;

b) while continuing the monitoring, occluding arterial blood flow to the selected point for a predetermined period of time by providing a vasodilating stimulant using a pressure cuff and ceasing the occlusion after the predetermined period of time;

c) simultaneously with said monitoring and said occluding, monitoring skin surface temperature at a control point that does not undergo arterial flow occlusion until the skin surface temperature of the selected point has reached a second equilibrium after ceasing the occlusion;

d) identifying a peak temperature at the selected point after release of the cuff; and

e) assessing the patient'"'"'s arterial reactivity based upon temperature changes at the control point and a rebound temperature change related to said first equilibrium temperature and said peak temperature at the selected point.

14. The method of claim 13, further comprising plotting the monitored temperature as a function of time.

15. The method of claim 13, wherein the selected region is a finger and the temperature is measured at a point on the skin surface of a fingertip.

16. The method of claim 13, wherein the blood flow is occluded at one or more regions selected from the group consisting of:

a leg, ankle, toe, arm, wrist, and a finger.