KR102129475B1 - Electrocardiograph Elastic-Textile Electrode Capable of Measuring Electrocardiograph Without Distortion Despite Change of Body Surface Area - Google Patents

Abstract

The present invention relates to an ECG electrode measuring ECG by being attached to a person to be measured. The ECG electrode is made of elastic fiber with electrical conductivity, and the ECG electrode may measure ECG even if a person to be measured moves freely since the ECG electrode may maintain a large contact area with a skin surface of the person to be measured when movement such as breathing or exercise of the person to be measured occurs. In particular, even when a body surface area changes according to the movement of the person to be measured, an ECG signal may be accurately measured without distortion since a change in resistance of flexible fiber with electrical conductivity is not large.

Description

Elastic Cardiograph Elastic-Textile Electrode Capable of Measuring Electrocardiograph Without Distortion Despite Change of Body Surface Area}

The present invention relates to an electrocardiogram electrode attached to a subject to measure electrocardiogram, and more specifically, to accurately measure the ECG signal without distortion despite a change in body surface area caused by movement such as breathing or exercise of the subject. It relates to an electrocardiogram electrode.

The electrical signals generated from the heart are transmitted to the entire heart along the electrical conduction system in the heart, and the electrical muscle signals constrict the cells that make up the heart and the heart beats.

Electrocardiograph (Electrocardiograph) is a graph showing the electrical activity status of the heart occurring during the cycle of the heartbeat, and is used to diagnose coronary artery disease such as angina pectoris or myocardial infarction, arrhythmia or electrolyte abnormality, or to check cardiac abnormalities during surgery Is becoming.

The electrocardiogram is measured by an electrical signal through an electrocardiogram electrode installed on the subject's skin, and is largely divided into a skin-insertable electrode inserted into the skin of the subject and a skin-attached electrode attached to the skin of the subject. Republic of Korea Patent Registration No. 10-1381424 discloses an electrocardiogram sensor with a skin equipped with an electrode, a wireless sensor module, and an antenna. Although such an implantable sensor has an advantage of measuring an accurate ECG signal, it is inserted by cutting the skin. There is also the burden of using human-friendly materials to prevent infection in the body.

Korean Patent Publication Nos. 2010-0039026, 2016-0092560, etc. are disclosed as skin-insertion-type sensors, and the ECG sensors of Patent Publication No. 2010-0039026 are annular and circular made of titanium (Ti) or copper (Cu). An electrode is attached to the subject's skin to measure the ECG signal. However, the electrode of the electrocardiogram sensor is made of metal and lacks flexibility, so it is difficult to adhere closely to the curved skin surface, and thus the reliability of the measured electrical signal is low.

And, the sensor of Patent Publication No. 2016-0092560 has an advantage of high flexibility compared to a metal electrode by using an electrode made of a conductive fiber, but when measuring an electrocardiogram, an ECG measured due to a change in body surface area when the subject breathes or moves. There is a problem that the signal is noisy.

That is, when the body surface area of the subject changes, the fiber electrode attached to the skin also stretches or contracts along the direction of the skin surface, and thus, a resistance change occurs due to a change in the cross-sectional area and length of the conductive fiber, thereby signaling the ECG signal measured. Distortion occurs.

In particular, the ECG signal to be measured is a micro signal that is only a microvolt (mV) level, and it is difficult to measure the reliable ECG because it is greatly affected by noise of a small size.

Republic of Korea Registered Patent Publication No. 10-1381424 (Invention name: Insertion type wireless ECG fabric electrode device) Republic of Korea Patent Publication No. 2010-0039026 (Name of invention: MEMS electrode module single point meter reading ECC measuring sensor and its manufacturing method) Republic of Korea Patent Publication No. 2016-0092560 (name of the invention: an electrocardiogram electrode-integrated blood pressure measuring device for arteriosclerosis measurement)

The present invention was devised to solve the above-mentioned problems of the prior art, and the object of the present invention is to freely expand and contract freely according to movements such as breathing or exercise of the subject, and accurately measure the ECG signal without distortion even when the body surface area changes accordingly. It is to provide an electrocardiogram electrode that can.

In order to solve the above technical problem, the present invention is woven with a warp and weft to form a contact surface that contacts the skin, and the warp or weft is an electrically conductive conductor coated with a conductive metal powder or a conductive polymer on the outer surface of a newly stretched screen. It provides an electrocardiogram fabric electrode, characterized in that made of a stretchable conductive yarn covered.

In addition, in the present invention, the electric conductor is covered with 500 to 1,200 twists on the outer surface of the screen.

In addition, in the present invention, the electrically conductive yarn is coated with silver (Ag) powder on 30-60 denier synthetic fibers.

In addition, the screening in the present invention is made of polyurethane fibers of 40 to 80 denier.

In addition, the sheet resistance of the ECG fabric electrode contact surface of the present invention is 160 to 235 mΩ/sq. It is preferred.

In addition, the ECG fabric electrode of the present invention has a resistance change rate of less than 3% due to elongation in a warp or weft direction, which is an elastic conductive yarn, and a resistance change rate of less than 3% until 10% elongation.

The electrocardiogram electrode according to the present invention is made of elastic fibers having electrical conductivity, and can be freely stretched while maintaining a large contact area with the skin surface of the subject when movement such as breathing or movement of the subject is measured, so that the electrocardiogram can be moved freely even by the subject. Measurement is possible, and the ECG signal can be accurately measured without distortion because the resistance change of the stretchable fiber having electrical conductivity is not large even when the body surface area changes according to the movement of the subject.

1 is a plan view of an electrocardiogram fabric electrode according to the present invention.
2 is a side view showing a state in which the electrocardiogram fabric electrode according to the present invention is attached to the skin surface of the subject.
3 is a perspective view and a cross-sectional view of a stretchable conductive yarn used as a warp or weft of an electrocardiogram fabric electrode according to the present invention.
4 is an enlarged photograph of a part of the surface of the electrocardiogram fabric electrode according to the embodiment of the present invention.
5 is a view showing an experiment for measuring the sheet resistance of Examples and Comparative Examples according to the present invention.
6 is a view showing an experiment of stretching an example and a comparative example according to the present invention.
7 is a graph showing a resistance change rate measurement graph according to an elongation in an oblique direction in Examples and Comparative Examples.
8 is a graph showing a resistance change rate measurement graph according to elongation in the weft direction of Examples and Comparative Examples.
9 is a view showing an electrocardiogram graph measured using examples and comparative examples according to the present invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

This embodiment is provided to more fully explain the present invention to those of ordinary skill in the art, the shape of the elements in the drawings, the size of the elements, the spacing between the elements, etc. to emphasize a more clear description For this, it may be exaggerated or reduced.

In addition, when it is determined that the technical features of the present invention may unnecessarily obscure the technical features of the present invention, as a matter of ordinary skill in the art, such as known functions or known configurations, which are related in principle in describing the embodiments. The description will be omitted.

The term'fiber' in the present invention refers to a natural or artificial linear polymer object that can be bent long, thin, and soft, and the term'filament' is a long fiber and refers to a fiber drawn infinitely long in a spun state. .

In addition, the term'covering' in the present invention refers to a method of winding (covering) the surroundings of the core yarn with another thread, and the term'elongation (or expressed in elongation, tensile elongation)' is pulled off. It shows the ratio of the length increased until the original length (unit: %).

1 is a plan view of an electrocardiogram electrode 10 according to the present invention, and FIG. 2 is a side view showing a state in which the electrocardiogram electrode 10 according to the present invention is attached to the skin surface S of a subject. Referring to FIGS. 1 and 2, the electrocardiogram electrode 10 according to the present invention is in the form of a patch having a contact surface 11 in contact with a skin surface S of a subject, and the contact surface 11 is a curved skin surface S ) Is made of a fiber material with excellent flexibility to be in surface contact.

The ECG electrode 10, which is a fiber material, is woven into the warp 12 and the weft yarn 13 as shown in FIG. 1, and the warp yarn 12 and the weft yarn 13 are transmitted to transmit an electrical signal through the contact surface 11. ) Any one or more are formed of a stretchable conductive yarn to have electrical conductivity along with stretchability.

3 is a perspective view and a cross-sectional view of the stretchable conductor 20 used as the warp 12 or the weft yarn 13 of the present invention, the stretchable conductor 20 is around the central screening 21 and screening 21 It is formed of a covering yarn (22) wound in a spiral form, wherein the screening (21) is made of elastic fibers so that it can be freely stretched from the skin surface according to the movement of the subject. As the examination 21 of the stretchable conductive yarn 20 is made of a stretchable fiber, the ECG electrode 10 may be stretched in the arrangement direction of the stretchable conductive yarn 20 so that it can be stretched according to the breath or movement of the subject. have.

Here, the elastic fibers used as the screening 21 may include polyurethane (polyurethane), styrene-butadiene-styrene (SBS), styrene butadiene rubber (SBR), polydimethylsiloxane (PDMS) or silicone-based rubber materials. , Polyurethane fibers having high elasticity and low elastic modulus and high elastic recovery are preferred. In addition, the screening 21 is preferably formed with a fineness of 40 to 80 denier so that durability and elasticity can be expressed.

The covering yarn 22 is a portion that is in contact with the measured skin surface S to form a contact surface 11, and is wound around the screen 21 to form a number of irregularities on the surface of the stretchable conductive yarn 20, thereby forming a skin surface. It forms a large contact area with (S). The covering yarn 22 is preferably formed with a fineness of 30 to 60 denier so that the frictional strength does not deteriorate while it is fine to form a contact area with a wider skin. As described above, as the covering yarn 22 made of fineness is formed on the surface of the electrocardiogram electrode 10, the shape of the electrocardiogram electrode 10 is in contact with a large area of the skin while flexibly changing its shape along the skin surface that is bent even in the movement of the subject. It can accurately measure the electrical signal generated from the skin surface (S).

Here, the covering yarn 22 is formed of an electrically conductive yarn coated with metal nanoparticles or a conductive polymer on the surface to have electrical conductivity. The electrically conductive yarn can be used without limitation as long as it is a fiber capable of conducting electricity. As an electrical conductor, materials such as polyester, polyethylene terephthalate, polyethylenenaphthalate, polyethylene, nylon, and acryl can be used alone or in combination. And preferably, can be used including nylon. As the metal nanoparticles, gold (Au), silver (Ag), copper (Cu), nickel (Ni), etc. can be used. As the conductive polymer, carbon black, carbon nanotubes (CNT), silver nanowires, polyurethane Etc. can be used.

As described above, the stretchable conductive yarn 20 made of the covering yarn 22 having electrical conductivity around the stretchable examination 21 may be used as either the warp 12 or the weft yarn 13, but the warp yarn 12 and the weft yarn may be used. (13) All of them may be used as the stretchable conductor 20. When both the warp 12 and the weft yarn 13 are used as the stretchable conducting yarn 20, it is possible to stretch in various directions as it is possible to stretch in the warp direction 12 and the weft yarn 13, and also the warp 12 Of course, the conductive metal or polymer coated on the weft yarn 13 is in contact with the skin to form a wide electrical contact area with the skin surface S of the object to be measured, thereby accurately measuring the bioelectrical signal of a fine size.

In particular, the stretchable conductor 20 of the present invention, the screening 21 is stretched only in accordance with movements such as breathing or exercise of the subject, and the covering yarn 22 covered around the screening 21 has a load due to stretching. Changes in the cross-sectional area and length of the covering yarn 22 are hardly generated due to no external force. Therefore, since there is little resistance change even when the body surface area changes due to the breathing or movement of the subject, the ECG signal can be accurately measured without affecting noise.

Here, the stretchable conductive yarn 20 is preferably covered with 500 to 1,200 twists (TM) around the judging 21. If the number of twists of the covering yarns 22 is less than 500, the warp yarns 12 and the weft yarns 13 When stretching, the spacing between neighboring covering yarns 22 is widened to decrease the electrical contact area, and when the number of twists exceeds 1,200, excessive stress is concentrated on the surface of the covering yarns 22, so that the metal powder or conductive polymer detaches from the surface. There is a problem.

As the covering yarn 22 made of fine fineness of 30 to 60 denier is covered on the outer surface of the screening 21 with 500 to 1,200 twists, the electrical contact area with the skin is maximized by the finely formed surface irregularities, thereby making it fine. Not only can the bioelectric signal of size be accurately measured, but even when the examination 21 is stretched, the covering yarn 22 is not subjected to a load or external force, and thus an accurate ECG signal can be measured without affecting noise.

In the ekg electrode 10 of the present invention, the sheet resistance of the contact surface may be maintained at a low resistance value of 200 to 250 mΩ/sq. during elongation or contraction. In the ECG electrode 10 of the present invention, the inclined 12 or the weft yarn 13, which is the stretchable conductive yarn 20, may be woven into plain weave, twill weave, runner weave, or change tissues thereof.

Examples and comparative examples of the present invention made as described above will be described below.

<Example 1>

The outer surface of the 50 denier polyurethane yarn was coated with 40 denier/12 filament nylon yarn coated with silver (Ag) nanopowder with a twist number of 1,000 to prepare a stretchable conductive yarn having a fineness of 100 denier. After weaving the stretched conductive yarn in a plain weave with warp and weft yarns, a length of 20 cm and a width of 5 cm were cut to prepare a strip-shaped ECG fabric electrode. 4 is an enlarged photograph of a part of the surface of the electrocardiogram fabric electrode manufactured as described above.

<Example 2>

A 40-denier/12-filament nylon yarn coated with silver (Ag) nano-powder was woven into a weft yarn as a weft yarn and stretched 20 cm in width and 5 cm in width to prepare a strip-shaped ECG fabric electrode.

<Comparative Example>

After weaving the warp and weft in plain weave with a silver (Ag) nano-powder coated 40 denier/12-filament nylon yarn, a length of 20 cm and a width of 5 cm were cut to prepare a strip-shaped ECG fabric electrode.

The resistance changes according to the sheet resistance and elongation of Examples 1 and 2 and Comparative Examples prepared as described above were measured as follows.

<Experiment 1: Measurement of sheet resistance>

As shown in Figure 5, the resistance of each of Examples 1 and 2 and Comparative Example 30 were connected to each other, and sheet resistances of Examples 1 and 2 and Comparative Examples were measured. The measured results are shown in Table 1 below.

division Example 1 Example 2 Comparative example Sheet resistance (mΩ/sq) 235 160 142

As shown in Table 1 above, the resistance value of Example 1 is 235 mΩ/sq, the resistance value of Example 2 is 160 mΩ/sq, respectively, and it is measured to be 142 mΩ/sq of Comparative Example 1, respectively. The resistance values were 93 mΩ/sq and 18 mΩ/sq, respectively, higher than Comparative Example 1, but the difference was slight. This difference in resistance value is compared to that of the electric conduction yarns of Examples 1 and 2 as the covering yarns, and it is assumed that the comparative example is due to the difference of ordinary yarns.

<Experiment 2: Measurement of resistance change rate according to elongation>

As shown in Figure 6, after fixing both sides of Examples 1 and 2 and Comparative Examples with clamps 40, stretched to 2%, 4%, 6%, 8%, and 10% along the warp and weft directions, respectively. The resistance change rate before and after extension was measured, and the measured results are shown in Tables 2 and 7 and 8 below.

<Storage change rate according to the elongation in the slope direction> Category/Elongation 2% 4% 6% 8% 10% Example 1 0.3% 0.8% 1.5% 2.0% 2.4% Example 2 0.6% 1.0% 1.7% 2.2% 2.5% Comparative example 3% 7% 13% 23% 38%

<Storage change rate according to elongation in weft direction> Category/Elongation 2% 4% 6% 8% 10% Example 1 0.6% 1.5% 2.2% 2.4% 2.8% Example 2 2.5% 6.4% 10% 15.8% 25% Comparative example 3% 7% 12% 18% 28%

As shown in Table 2 and FIG. 7, in the case of elongation in the oblique direction, Example 1 and 2 had a very low resistance change rate of 0.5% to 2.8%, whereas the Comparative Example had a significant resistance change of 3% to 27%. And, as shown in Table 3 and Figure 8, Example 1 in the elongation in the weft direction is very low, as in the oblique direction elongation, the change rate of resistance is 0.6% to 2.8%, whereas in Example 2, the rate of change of resistance is 2.5% to 25 %, the comparative example had a high resistance change rate of 4% to 28%.

Therefore, in Example 1, the rate of resistance change was very low in both the inclined and weft directions, but in Example 2, the elasticity change rate was low in the inclined direction elongation, but the resistance change rate was high in the elongation in the weft direction. It was confirmed that the comparative example has a high resistance change rate in both the oblique and the weft directions.

<Experiment 3: ECG measurement>

ECG was measured using Example 1 and Comparative Example 2. As shown in FIG. 9, ECG measurement was performed by attaching Example 1 and Comparative Example 2 to which a connection terminal connected to the ECG measuring device was attached to the chest of a 28-year-old adult male.

Referring to FIG. 9, when the subject was stopped and rotated left and right, there was no difference in the measured ECG waveform. However, when the movement was severe, such as walking or running in place, it was confirmed that Example 1 measured a stable electrocardiogram waveform even in the extreme movement of the subject, whereas in the case of the comparative example, a rapid electrocardiogram waveform was measured. The ECG waveform of the comparative example is presumed to be the reason that the electrode resistance value changes due to the external force generated according to the subject's intense movement.

As described above, since the resistance change of the elastic fiber having electrical conductivity is not large even when the body surface area changes according to the movement of the subject of the present invention, it is possible to measure the electrocardiogram with high psychological reliability without distortion of the ECG signal.

The present invention described above is not limited to the described embodiments, and it is obvious to those skilled in the art that various modifications and modifications can be made without departing from the spirit and scope of the present invention. Therefore, such modifications or modifications will have to belong to the claims of the present invention.

10: ECG electrode 11: contact surface
12: slope 13: weft
20: flexible evangelist 21: judging
22: covering yarn 30: ohmmeter
40: clamp

Claims (7)

An electrode that measures ECG by contacting the skin surface of the subject
It is woven with a warp and weft to form a contact surface that comes into contact with the skin. The ECG fabric electrode, characterized in that the rate of change of resistance is less than 3% until 10% elongation in the warp or weft direction, which is the stretchable conductive yarn. delete According to claim 1,
The electroconductive yarn is an electrocardiogram fabric electrode, characterized in that silver (Ag) powder is coated on 30-60 denier synthetic fibers. According to claim 3,
The examination is an electrocardiogram electrode characterized in that it is made of polyurethane fibers of 40 to 80 denier. According to claim 4,
The electrocardiogram fabric electrode has a sheet resistance of 160 to 235 mΩ/sq. delete delete

Images