RU2444988C1 - Electrode device for wearable ecg-monitor - Google Patents

Abstract

FIELD: medicine.

SUBSTANCE: invention relates to medical equipment, namely to devices of long-term ECG monitoring. Electrode device for wearable ECG-monitor contains system of on-skin electrodes and monitoring unit, electrically connected to each other and placed on pendant fixed on the body. System of on-skin electrodes consists of two matrices of pin electrodes, whose free butt end parts have salient spherical surface and are installed on belt part of pendant, tightly filling the body with possibility of providing "dry" galvanic contact with areas of chest anterior surface in conditions of patient's free movements. Each matrix consists of two groups, pin electrodes in each of them are galvanically connected to each other. One of the groups, which has larger area, is intended for ECG signal registration, the other, with smaller area, for connection to means of cophasal noise suppression. Butt end fixing parts of electrode pins are fixed on flexible dielectric padding, connected with pendant, made from elastic textile material.

EFFECT: invention makes it possible to increase reliability of galvanic contact between patient's body and system of "dry" electrodes and improve ratio signal/noise of ECG signal in process of long-term application.

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Description

The invention relates to medical equipment and can be used for continuous collection of information about the functional state of a person in studies by electrocardiography.

There are various designs of cutaneous electrodes in electrocardiographic (ECG) monitoring systems to ensure electrical contact with the patient’s body, while at the same time not causing discomfort in a wearable version. Thus, the invention (EP 1486164 (A1), FRANZ et al., December 15, 2004) describes a system of sensor electrodes for recording an electrocardiogram (ECG), which are located on a strap covering the patient’s chest. The electrodes are evenly spaced. In the invention (US 6205346 (B1), Akiva, 03.20.2001) a headset is described as an apron on the chest made of rubber-like material, with electrodes mounted and fixed to the shoulder with the forearm. This headset works on dry contact, and due to stretching, the electrodes are placed in the necessary areas. However, this headset is not suitable for prolonged wearing.

The invention (WO2006095279 (A1), THTJS et al., 09/14/2006) describes a monitoring system for home use. Dry electrodes are placed on the clothes for use with a monitoring system in order to monitor the physiological parameters of the patient. The main idea of the invention is to insert dry electrodes in those places of the garment where there is a natural layer of sweat (in the armpits) if the garment is worn, which, however, requires restrictions on the period of use.

In the application (WO 2007040878 (A1), WIJISIRIWARDANA et al., 04/12/2007) an electrode system for recording an ECG formed by elements of electrically conductive threads woven into a garment is described. Three electrodes can be used, one of which can be connected to a noise reduction system, and two can be used to record an ECG. Although it is indicated that such a system can function for monitoring with dry electrodes, it is not very suitable for widespread use due to the need for a snug fit of the electrodes to the body and, accordingly, individual manufacture.

Closest to patentable is the design of the electrode system of a wearable ECG monitor described in the application (EP 1946698 (A2), HUEBNER et al., 23.07.2008 - the closest analogue). It contains a design worn over the head, having front and rear backs connected to the sternum with a belt of textile material on which the wearable device of the monitor is fixed. Under the shoulder straps and on the waist part, electrodes are placed to record ECG signals, and the wires connecting the electrodes are held in the body of the straps. A number of structural elements are made of elastic material to compensate for body movements. However, when using multiple electrodes, it is unlikely to use dry electrodes and at the same time adjust the monitor yourself.

The present invention is directed to creating a patient-friendly electrode device for an ECG monitor, providing versatility of use, long-term monitoring of cardiac parameters in the conditions of natural patient movements.

The electrode device for a wearable ECG monitor contains a system of cutaneous electrodes and a monitoring unit, electrically connected to each other and placed on a suspension mounted on the body.

The device is characterized in that the system of cutaneous electrodes contains two arrays of pin electrodes, the end free parts of which have a convex spherical surface and are mounted on the waist part of the suspension, fitting the body with the possibility of providing “dry” galvanic contact with the areas of the anterior surface of the chest under natural patient movements . Each matrix consists of two groups, the pin electrodes in each of which are galvanically connected to each other, one of which - a larger area - is designed to remove the ECG signal, and the other - a smaller area - to connect to common mode interference suppression means, while the end fixing parts of the electrode pins are mounted on a flexible dielectric substrate associated with a suspension made of elastic textile material.

The device may be characterized in that the pin electrodes on a flexible dielectric substrate are placed with a period equal to 1.5-1.8 pin diameters, their height is 1.4-1.6 pin diameters, while the groups are placed with a gap of 3- 3.5 pin diameters.

The device can be characterized by the fact that each matrix in the group of the larger area contains 5 × 5 pins, in the group of the smaller area - 5 × 3 pins with the diameter of the pins - 2-3 mm, the distance between the pins - 1.5-2.5 mm, their height is 4.2-4.8 mm and the gap between the groups is 6-8 mm.

The device can also be characterized by the fact that the suspension includes shoulder straps associated with a belt and a back closure made of elastic bands interacting with the possibility of simple separation.

The device can be characterized, in addition, by the fact that the groups of electrodes of each matrix are connected to the monitoring unit by flexible conductors located on the waist part of the suspension.

The technical result consists in increasing the reliability of galvanic contact between the patient’s body and the system of "dry" electrodes of the monitor, that is, a contact that does not use electrically conductive gels, by providing variability with a large number of contacts of the same type, which ensures a reduction in motion artifacts during prolonged use. An additional result is the possibility of self-putting on the electrode device.

The invention is illustrated in the drawings, where:

figure 1 presents a diagram of an electrode device;

figure 2 - General view of the electrode device;

figure 3, 4 - design of electrode arrays.

Figure 1 presents a General diagram of an electrode device. It contains a suspension 1 with a belt part, on which two matrixes of 2 electrodes are mounted, made with the possibility of providing “dry” contact with the body and fixing on the patient’s body. Each matrix 2 contains groups of 3, 4 and 5, 6 electrodes, which are connected by conductors to the monitoring unit 7.

Suspension 1 is made according to the type of bodice fixed on the patient’s body by means of shoulder straps 22 of adjustable length. On the waist part 23, which surrounds the body, on flexible substrates 24, matrices of 2 electrodes are installed, forming groups 3, 4 and 5, 6, which provide “dry” galvanic contact with the paralosal regions of the anterior surface of the chest. The electrodes 25 are pins, the end free parts 26 of which have a convex spherical surface, and the end fastening parts of the pins of the electrodes 25 are mounted on a flexible dielectric substrate 24 connected to the suspension 1 made of elastic textile material. Moreover, all the end fastening parts of the pins of the electrodes 25 within each group (2, 3, 4, 5) are galvanically connected to each other. Therefore, at every moment of time, with any movement of parts of the patient’s body, there is a rather high probability that at least one electrode 25 from the group of pins mounted on a flexible substrate 24 will provide galvanic contact with the patient’s body.

Conductors connecting each of the four groups of 3, 4, 5, 6 electrodes with the monitoring unit 7 are laid inside the waist part 23 to the pocket 27, where the unit 7 is located.

The pin electrodes 25 in each of the groups are galvanically connected to each other.

The pin electrodes 25 on the substrate 24 are placed with a period equal to 1.5-1.8 diameters of the pins, their height is 1.4-1.6 diameters of the pins, while groups 3 and 4, as well as 5 and 6 are placed with a gap, constituting 3-3.5 diameter pins.

Each of groups 3 and 5, which have a large area, is designed to take ECG signals. Groups 4 and 6, which have a smaller area, are designed to be connected to means for suppressing common mode interference.

Suspension 1 is made of elastic bands, has a back closure and straps 22 of adjustable length, interacting with the possibility of simple connection / disconnection.

Topology example. The pin electrodes 25 are placed on a flexible dielectric suspension 1 made of silicone rubber. The matrix has dimensions 46 × 26 mm, 40 pin electrodes are placed on it. For the topology shown in FIG. 3, T = 10 mm, t = 5 mm. The large group contains 5 × 5 = 25 pins, the smaller group contains 5 × 3 = 15 pins, the groups are separated by a gap of 7 mm. The diameter of the pins is 3 mm, the radius of curvature is 1.5 mm, the height of the protruding part is 4.5 mm.

Tests have shown the convenience of self-putting on the device, the reliability of ensuring galvanic contact between the patient’s body and the system of “dry” pin electrodes during prolonged wearing of the suspension, which improves the signal-to-noise ratio of the received ECG signal.

Claims (5)

1. An electrode device for a wearable ECG monitor containing a system of cutaneous electrodes and a monitoring unit, electrically connected to each other and placed on a suspension mounted on the body, characterized in that the system of cutaneous electrodes contains two arrays of pin electrodes, the end free parts of which have a convex spherical surface and mounted on the waist part of the suspension, fitting the body with the possibility of providing "dry" galvanic contact with the areas of the front surface of the chest in conditions of the patient’s natural movements, each matrix consisting of two groups, the pin electrodes in each of which are galvanically connected to each other, one of which - of a larger area - is designed to take an ECG signal, and the other - of a smaller area - to connect to common-mode suppression means interference, while the end fastening parts of the electrode pins are mounted on a flexible dielectric substrate associated with a suspension made of elastic textile material. 2. The device according to claim 1, characterized in that the pin electrodes on a flexible dielectric substrate are placed with a period equal to 1.5-1.8 diameter of the pins, their height is 1.4-1.6 diameter of the pins, while the groups are placed with a gap of 3-3.5 pin diameters. 3. The device according to claim 1 or 2, characterized in that each matrix in the group of a larger area contains 5 × 5 pins, in the group of a smaller area of 5 × 3 pins with a diameter of the pins 2-3 mm, the distance between the pins 1,5-2 5 mm, their height is 4.2-4.8 mm and the gap between the groups is 6-8 mm. 4. The device according to claim 1, characterized in that the suspension includes shoulder straps associated with a belt, and a back closure made of elastic bands, interacting with the possibility of simple separation. 5. The device according to claim 1, characterized in that the groups of electrodes of each matrix are connected to the monitoring unit by flexible conductors located on the waist part of the suspension.

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