Medicine: Engineering: Innovation:

 

 

A Method for Measuring the Flexibility of Blood Vessels

Using a Blood Pressure Meter

 

by Keiji Taniguchi1, Hiroshi Yamamoto2 , Ningfeng Zeng3, and Kengo Kashihara4

 

1 Honorary Professor of Fukui University, Fukui, 918-8186, Japan, and Xifan University of Technology, Xifan , China

2  CEO , Sakaimed.Co., Shinjiku,Tokyo,162-0801,Japan

3 Japanese Society of Anti-aging Medicine , Kobe City,  651-2122, Japan

4Kashihara Neurological Clinic, Fukui, Japan,

 

 

A simple method for measuring the flexibility of blood vessels in a human body is proposed. This method can measure the flexibility of blood vessels simply and economically. The correlation coefficient between our method and the baPWV method is more than -0.9.

 

Index Terms Flexibility of blood vessels

 

Introduction: In a blood pressure measurement, a blood vessel stopped the flow of blood by the cuff must be equivalently vibrated just like a spring motion by a pumping action of the heart. In this case, the transient temperature variation of an arterial systolic maximum value caused  by a heat stimulation may be able to use as an index which expresses a flexibility of  the blood vessel.

 

In this paper, the recent result updated for reference [1] is shown. The baPWV method (See Fig.4), which is used as a conventional method, is used for the calibration of our method.  Our experimental result shows that this proposed method has an excellent correlation with the baPWV method [2].

 

Consequently, our method can be used for measuring the flexibility of blood vessels simply and economically.

 

2.Method:

A. Relationship between Blood Pressure and Body Temperature

The relationships among the arterial systolic maximum value of blood pressure, the body temperature of the measured subject person, and the density of material flowing in the blood vessel (for example, uric acid crystals) can be expressed by the following equation:

                               (1)

 

Let us consider the case of small changes  and . The small change of the blood pressure can be expressed by the linear approximation as follows:

 

   (2)

 

In the above equation, if the diameter of the blood vessel is increased by the temperature variation (),

 

 takes the negative value.

 

From Eqs. (1) and  (2) , the following equation can be obtained: ,

where if  , then        (3)

 

 B. Body Temperature Variation

The small variation  of the body temperature can be given byas the function of time , where(minutes), is the initial value of time , and this value is counted as .

 

A rectangular-wave form expressed as a function of time is used as the heat stimulation source.  As an example, when a microwave oven of 600(watts)70(seconds) was used as the heat stimulation source,

about 50-water of 260(cc) for drinking can be obtained.

 

C. Analysis

(A) First of all, variables and functions in Equations (1) and (2) are substituted as follows:

 

, ,

 

, ,,

 

Consequently, the following equation can be obtained:

 

 ,       (4)

 

Where expresses the initial value of blood pressure counted as ,  is the sampling period, and this value is decided from the experimental considerations. For example, in this case is 2 (minutes), let us consider an example shown in table 1.

 

From this table, the following descriptions are obtained:

 

(mmHg),

 

,  and (mmHg).

 

These data were measured by using a blood pressure meter specified as: OMRON HEM-7230.

 

(B) Let us show the computation process using the samples measured previously.

 

From Equation (3), the values of  are (mmHg).  Using the values of shown above, the following parameter is calculated:

 

, .   (5)

 

.

 

 Where, .

 

The baPWV average value, which corresponds to  is 2339 (cm/sec). This result is shown using an arrow in Fig.1. In this figure, the measured subject persons 1, 5 and 6 are authors and 2, 3 and 4 are volunteers.

 

Table 1 Relationship among

 
 



0

115

 

 

2

113

-2

2

4

107

-6

8

6

110

+3

11

8

113

+3

14

10

108

-5

19

12

113

+5

24

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 


D. Evaluation Results

As a criterion of the evaluation of our method, the baPWV values are used. The relationship between  and baPWV is shown in Fig.1. Theoretically, the relationship between baPWV and R can be explained by Bernoullfs theorem added loss coefficient term. That is, the values of  baPWV and R are measured as the velocity and the pressure in the blood vessel, respectively.

 

The correlation coefficient between the baPWV method and our method is more than -0.9.  From this result, our method has excellent correlation with the baPWV method. This relation is shown by solid line in Fig.1. The equation of this line can be approximated as follows:

 

        (6).

 

E. Day-Time Series Variations

The relationship between R and daytime series variations between April 2, 2015 and April 15, 2015 is shown in Fig.2.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 


Figs 2 (a) and  (b) express the values of R for day time series variations, and a relation between baPWV and R, respectively.

 

 

F. R and Age Relations

A sky-blue line shown in Fig.3 expresses the relationship between  and Age. This figure is made using Reference [3], Fig.4, and Eq.(6).

 

 

 


In this figure, each zone expressed by the blue, pink, and yellow is the stiff blood vessel zone, slightly hard blood vessel zone, and flexible blood vessel zone, respectively.

 

3. Conclusion:

This method can be used to measure the flexibility of blood vessel in a human body simply and economically. The proposed method has excellent correlation with baPWV method.

 

The advantage of our method is that it can measure easily by using a blood pressure meter and a timer as measuring equipment. In an ageing society, this simple method will be able to play an important role for preventing metabolic syndrome in elder people.

 

 

 

 

4. Appendix

Fig.4 shows an example of the relationship between baPWV and age.





References:

[1] Keiji Taniguchi, Hiroshi Yamamoto, and  Ningfeng Zeng: Certificate of Patent, No.5518554, April 11, 2014

[2] Nikkei continuing medical education-1, p.1, Jan. 2006

[3] http://chuo.kcho.jp/0riginal/clinicallabo/lab-news-backnumber7.html

 

 



[ back to "Publications & Special Reports" ]
[ BWW Society Home Page ]