JP6731435B2 - Biological signal detection module - Google Patents

Description

The present invention relates to a module for detecting biosignals of a patient (human or animal) such as electrocardiographic signals and bioimpedance signals.

Electrical Impedance Tomography (EIT) is an imaging technique based on applying an alternating electrical signal in the frequency range of 10 kHz to 2.5 MHz to the body surface of a patient. The device used for this purpose comprises a plurality of sensors (electrodes) arranged in contact with the skin, which sensors are coupled by electrical conductors to a processing unit which produces said alternating signal. The method of use comprises a plurality of steps, each step selecting a pair of electrodes to inject the signal and measuring the induced voltage detected at the non-selected electrodes. In subsequent steps, another pair of electrodes is selected to inject a signal and this sequence is continued until all electrodes of the device have been selected to complete the probe cycle. The induced voltage detected by the electrodes can be processed by a specific software to generate an image representing the ventilation and perfusion phenomenon in the living body of the subject.

In a research setting, it is acceptable for the electrodes to be individually placed around the patient's chest. However, this approach is difficult because the user must take care to maintain the proper alignment of the placement electrodes. To solve this problem, different solutions have already been described and developed for mounting the electrodes in a module that is easily applicable to the patient.

The impedance signal detected in each cycle includes signals originating from factors based on the normal functioning of the organism. Thus, for example, the signal detected by the electrodes in each measurement cycle is distorted under the influence of the electrical and mechanical signals produced by the activity of the heart. Therefore, this effect must be separated from the signal generated by mechanical ventilation in order to improve the analysis of each of these phenomena.

Therefore, the need to synchronize the acquisition of impedance signals in devices capable of delivering electrocardiogram (ECG) signals is well known, and the algorithm of the EIT device can identify when a heartbeat occurs. The effect of this activity can be separated from the ventilation activity. Alternatively, the device providing the ECG signal can also indicate not only when a heartbeat occurs, but also other instants involved in the cardiac cycle.

This integration with ECG devices can be achieved via different methods.

For example, according to the first method, the ECG device may be a different device than the EIT device, or (multi-parameter vital signs, common in intensive care, operating and emergency rooms). It may be part of a different device (such as a monitor).

In this case, there are drawbacks with integration. Since hospitals typically own different brands of equipment, integrating ECG equipment with EIT equipment requires coordination between different providers and their interests.

According to the second method, for example, the ECG device may be integrated into the EIT device. This solution is also well known and usually solves the problem of integration between different devices provided by different sources. The ECG acquisition circuit may be located on an electronic board that is independent of the EIT circuit, or may be integrated within the EIT circuit itself, sharing some use of electronic components.

This second method solves the main drawback of the first method, but with the major problem of having too many electrodes applied to the patient. In this case, the patient to whom the EIT device is attached must wear two sets of electrodes for ECG signal acquisition applied to his or her chest. In this case, the first set is intended for use by EIT devices and the second set is intended for use by ECG monitors, which may be part of a stand-alone device or a multi-parameter vital signs monitor.

Moreover, in addition to the severe discomfort experienced by the patient, another drawback resulting from this excess electrode is the difficulty of using the EIT device itself.

These sets of ECG acquisition electrodes typically include 3, 5 or 10 cables, which are aggregated in an intermediate coupling component, from which as a thick cable containing all the signals in the ECG device. Connect to the connector.

If the EIT device is a module of a multi-parameter vital signs monitor, the same challenges exist with worse problems. The reason is that in this case there is less freedom to position the EIT device to facilitate electrode application. Synchronization with the ECG acquisition module is facilitated if from the same manufacturer, but is usually done by sending to the EIT module identified cardiac events based solely on digital analysis of the electrocardiogram signal, Not appropriate. This is because it includes delays that are not necessarily uniform.

Apart from the previous examples, several documents reflecting the state of the art are worth mentioning.

In this regard, reference is made to document PI0704408-9. This document describes a modular belt with multiple electrodes intended for application around a part of the body of a patient or animal, but does not mention the addition of ECG electrodes to the same belt. ..

On the other hand, document PI 0805365 is for applying transcutaneous electrical stimulation to a patient and/or for detecting an electrical signal of a patient, with the aim of providing a solution for both economics and easy application to the patient. The electrodes used will be described. However, this document also does not explain the intervention of the electrocardiogram electrode, and thus does not solve the problem of integration with the electrocardiogram device.

Document US 2006/0058600 describes electrodes attached to a modular belt that is longitudinally coupled by means of an instrument that allows an acquisition set with varying numbers of electrodes. However, this document does not mention the acquisition of electrocardiographic signals by this belt.

Document US 4,722,354 describes a deformable conductive knitted fabric impregnated with a conductive adhesive that adheres to the skin of a patient. The electrical contacts are provided by flexible multicore cables and the insulation of the cable ends is removed to allow separation of these conductors on the textile surface. On this set an insulating plastic plate is glued in order to avoid accidental electrical contact with the conductive parts of the electrodes.

Document US 4,736,752 describes that the conductive part of an electrode comprises a plurality of conductive paint traces coated on a flexible insulating base, such as a thin sheet of polyethylene.

The above-referenced references refer to structural aspects and electrodes of belt-shaped modules for detecting biological signals without solving the problems associated with current belts.

Finally, the document PI0801014-5 refers to the use of data, signals, events and information detected by different means and devices to improve the functionality of electrical impedance tomography. This document considers the case where an ECG device can be integrated into an EIT device, but does not solve the important practical problem of applying two sets of ECG electrodes.

Therefore, in order to solve the above-mentioned specific problems and other problems existing in the prior art, one of the objects of the present invention is to provide a biological signal detection module including a sensor dedicated to the detection of an electrical signal from the heart. is there. Note that these sensors are provided on the same surface as the module.

Another object of the present invention is to provide a biosignal detection module including a sensor for simultaneously detecting an electrocardiographic signal and a bioimpedance signal. Note that such a sensor is provided on the same side as the module.

Since the biological signal detection devices and methods, and the list set forth herein with respect to those issues, are exemplary and not exhaustive, the invention further provides, through particular features, Other problems of the prior art not mentioned in the specification can also be solved.

U.S. Patent Application Publication No. 2006/0058600 U.S. Pat. No. 4,722,354 U.S. Pat. No. 4,736,752 Brazilian Patent Application Publication No. PI0704408-9 Brazilian Patent Application Publication No. PI0805365 Brazilian Patent Application Publication No. PI0801014-5

In particular, in order to avoid the aforementioned drawbacks in the prior art, the present invention provides a biosignal detection module including at least one sensor for detecting an electrocardiographic signal and at least one sensor for detecting a bioimpedance signal. Mention.

In the same context, the invention also refers to a biosignal detection module comprising at least one sensor capable of simultaneously detecting an electrocardiographic signal and/or a bioimpedance signal.

Depending on additional or alternative embodiments of the invention, the following features and potential variations thereof may also be present, alone or in combination.

The electrocardiographic signal is an electrocardiogram signal.

The bioimpedance signal is the signal used for electrical impedance tomography.

Sensors for electrocardiographic signals and bioimpedance are electrodes.

The sensor for simultaneous detection is an electrode.

The module includes a first surface and a second surface, the first surface being opposite the second surface, the first surface being accessible to a living body.

At least one sensor for detecting an electrocardiographic signal and at least one sensor for detecting a bioimpedance signal are disposed on the first surface.

At least one simultaneous sensor is located on the first surface.

The module has an elongated shape. as well as

The module is formed from a flexible material.

The objectives, enhancements and advantages of the bio-signal detection module that represent the objectives of the present invention will be apparent to those skilled in the art from the following description with reference to the accompanying drawings in connection with specific embodiments. Since these drawings are schematic and are for the purpose of teaching only explaining the invention, their size and proportions may not correspond to reality. Furthermore, no limitations are imposed beyond the scope defined by the appended claims.

It is a perspective view showing a first embodiment of the present invention. It is a perspective view showing a second embodiment of the present invention.

The present invention will now be described with respect to its particular embodiments with reference to the accompanying drawings. In the following figures and description, similar parts are designated by the same reference numerals throughout the specification and the drawings. The figures are not necessarily drawn to scale. Certain features are represented in an enlarged or rather schematic manner, and some details of conventional components may not be presented in order to improve the clarity and conciseness of the present description. .. The invention is capable of different embodiments. While particular embodiments are shown in the drawings and described in detail, it is believed that they should constitute an exemplification of the principles of the invention, which has been shown and described herein. There is no intent to limit to them and they should be considered as exemplifying the principles of the invention. It should be understood that the different teachings of the embodiments described below may be utilized separately or in any suitable combination to achieve the same desired effect.

FIG. 1 shows a first embodiment of the present invention. According to this first embodiment, the module 1 is elongate and comprises two surfaces, the first surface 2 being configured to contact the body of a patient (human or animal) and the second surface 3 being a first surface. It exists on the opposite side of one surface 2. The shape of each one of the surfaces 2 and 3 can vary within the scope of the invention, and the substantially rectangular shape shown in Figure 1 may vary depending on the manner in which the invention is embodied. .. Thus, in alternative embodiments, for example, the first surface 2 may be a rounded corner or a rectangle having a flat surface with undulations along its contour.

Furthermore, to facilitate application to the body of a patient, whether human or animal, the module 1 is formed from a flexible material, for example a polymeric material with elastic properties. In addition, the module 1 may be formed as a belt that may incorporate the flexibility provided by the polymeric materials described above to facilitate patient application and significantly improve comfort.

Referring back to FIG. The module comprises at least one sensor intended to detect an electrocardiographic signal 4 and two types of sensors having at least one sensor for detecting a bioimpedance signal 5, these sensors 4 and 5 being It should be noted that is located on the first surface 2 of the module. It should therefore be noted that the sensors 4 and 5 are arranged in the same area, in other words on the same "footprint".

In particular, electrocardiographic signals are electrocardiogram (ECG) signals and bioimpedance signals are used for electrical impedance tomography (EIT). Furthermore, in a particular embodiment of the invention, the sensors for the electrocardiographic signal 4 and for the bioimpedance signal 5 are electrodes.

In particular, the module 1 may include from 8 to 32 sensors on the first surface 2 for detecting the bioimpedance signal 5. It is important to point out that the spare number of sensors for detecting the impedance signal 5 may vary depending on the embodiment of the invention. Further, the placement of these sensors 5 may include spacing and distribution patterns. That is, these sensors may or may not be arranged, and may have a predetermined distance between them.

Also, in particular, the module may include various numbers of sensors for detecting the electrocardiographic signal 4. In this case, the placement of these sensors 4 on the first surface of the module 1 may or may not be along a placement pattern. Therefore, these sensors 4 may be arranged at random positions at the discretion of the person who embodies the present invention.

Thus, in view of the layout and placement options described above, the present invention provides a sensor for detecting the electrocardiographic signal 4, between the sensors for detecting the impedance signal 5, or even in other areas of the first surface 2. It may be provided.

Therefore, the module 1 already includes a sensor for detecting the electrocardiographic signal 4 and the impedance signal 5 in its body (more precisely, on the first surface 2), so that an electrocardiographic signal such as an ECG signal. It is not necessary to add, couple or connect additional sensors for measuring

Furthermore, since the sensor for detecting the electrocardiographic signal 4 and the sensor for detecting the bioimpedance signal 5 may have various shapes, such a feature limits the scope of the invention. There is no. Thus, for example, such a sensor may exhibit a circle, an oval, a rectangle, an ellipse, etc., although other shapes are possible.

As shown in FIG. 1, each sensor 4 and 5 is associated with at least one electrical conductor 6, which converges towards an outlet 7 associated with the body of the module 1. At this stage, it is important to point out that the representation of the conductor 6 in FIG. 1 is for illustration purposes only and is schematic. In fact, such a conductor 6 is provided in the module 1.

The outlet 7 may have a tubular shape and may be integrally formed with the main body of the module 1. Alternatively, a separate device attached to the module 1 may be configured. Furthermore, this outlet 7 may be provided as a single cable, ie the main cable (“relay cable”), which connects the conductors 6 of the various sensors 4 and 5 coupled to the body of the module 1. In addition, the outlet 7, constructed as a single cable, i.e. the main cable, may also include a connector (not shown) to which the conductors 6 of the module 1 can be connected to those shown below. That is, to monitor a patient situation using an impedance tomography (EIT) device, a device that integrates impedance tomography (EIT) and electrocardiogram (ECG) functions, or using the data detected by sensors 4 and 5. Is another device.

FIG. 2 shows a second embodiment of the present invention. The module 1 of the second embodiment of the invention has the same features as the first embodiment, except for the fact that it comprises at least one sensor 8 capable of simultaneously detecting an electrocardiographic signal and/or a bioimpedance signal. Therefore, in the second embodiment, the module 1 includes a general-purpose type sensor capable of detecting both an electrocardiographic signal and a bioimpedance signal.

The shape and arrangement of this simultaneous sensor 8 may also vary, so that a plurality of sensors 8 may or may not be arranged, as in the case of the sensors 4 and 5 of the first embodiment. Furthermore, this sensor 8 is also arranged on the first surface 2 of the module 1, ie in the same area or “footprint”, as already described with respect to the sensors 4 and 5 of the first embodiment of the invention. May be embodied as an electrode. Therefore, the module 1 already includes a sensor in its body (more precisely, on the first surface 2) for detecting an electrocardiographic signal and an impedance signal, and therefore for measuring an electrocardiographic signal such as an ECG signal. It is not necessary to add, couple or connect additional sensors in.

The exact number of simultaneous sensors 8 arranged on the first surface 2 of the module 1 may also be varied within the scope of the invention. As in the first embodiment, the module 1 of the second embodiment of the invention may include 8 to 32 simultaneous sensors 8.

Of course, these numbers represent examples of quantities and are not limiting or limiting with respect to the scope of the invention.

In addition, as in the first embodiment of the invention, each simultaneous sensor 8 is associated with at least one electrical conductor 6, as schematically shown in FIG. These conductors 6 also converge towards an outlet 7, which can be embodied as a single cable, the main cable (“relay cable”). This cable uses an impedance tomography (EIT) device, a device including impedance tomography (EIT) and electrocardiogram (ECG) functions, an electrocardiogram device, or a patient situation using data detected by the simultaneous sensor 8. Other devices for monitoring the are coupled.

Another difference worth pointing out with respect to the second embodiment of the invention is the fact that the device for receiving the signals detected by the simultaneous sensor 8 comprises means for identifying and separating the electrocardiographic and bioimpedance signals. It is in.

In particular, these means for identifying and separating the signals detected by the coincidence sensor 8 may include amplifiers and filters. Thus, for example, an amplifier with a high input impedance may be coupled to the main cable itself, or more precisely to the conductor 6. After passing through the amplifier, a high pass filter may be applied to eliminate the sensor offset.

The high pass filter may be first order with a 2 Hz cutoff frequency. A low pass filter may then be applied to remove the high frequencies from the power supply of the device and the high frequencies generated in the sensor scanning performed to generate the image. This low pass filter is of the 8th order and may have a gain of 150 and a cutoff frequency of 40 Hz. At the end of these amplification and filtering steps, an electrocardiographic signal is acquired.

As mentioned above, locating the sensor for detecting the electrocardiographic signal 4 and the sensor for detecting the bioimpedance signal 5 on the same side 2 (ie "footprint") of the module 1 is in accordance with the invention. Brings many benefits. One of these advantages may be the fact that no sensors need to be added or coupled to measure electrocardiographic signals, such as electrocardiographic signals. Therefore, the problem of the prior art of excess electrodes is eliminated.

Yet another advantage is towards the outlet 7 embodied as a single cable, the main cable (“relay cable”), which is directly attached to the body of the module 1 and is coupled to the patient monitoring device. , Related to the fact that the conductor 6 converges. One of the advantages may be mentioned that the patient and the medical staff are no longer obstructed by the large number of wires and cables. Recall that each prior art electrode has one wire or cable attached to it. Moreover, it is worth remembering that these wires and cables according to the prior art are placed on the hospital bed, on the patient or even between the bed and the device, in order to monitor the condition of the patient. Is. The present invention successfully solves this problem.

Synergy resulting from the combination of sensors 4, 5 or 8 in the same face 2 (or “footprint”) of the module 1 with the converging of electrical conductors towards the outlet 7, which is embodied in the form of a single cable, ie the main cable. The effect is also worth mentioning. The practical features and ease of use resulting from the combination of these two factors make the module 1 clearly more advantageous and more inventive than the prior art.

In addition, it is worth pointing out that the second embodiment of the invention also offers advantages in terms of diversity. More precisely, the patient-monitoring device uses such electrodes 8 as electrocardiogram electrodes, impedance tomography electrodes, provided that the simultaneous sensor 8 is capable of simultaneously detecting electrocardiographic signals and/or bioimpedance signals. Or it can be configured to be usable as both. Consequently, a certain number of simultaneous sensors 8 may be configured to operate as electrocardiographic electrodes and another specific number may be configured to operate as impedance tomography electrodes.

Although the biomedical signal detection module of the present invention is particularly useful for detecting electrocardiographic and bioimpedance signals, the inventive module may be configured for other types of applications, and equivalent The scope of protection of the present invention including various modifications may be modified in the mode of implementation so as to be limited only by the content of the appended claims.

Claims (14)

A device for detecting a biological signal,
An elongated belt having a first surface configured to contact the body of a patient and a second surface opposite the first surface;
A plurality of sensors on the first surface , each sensor of the plurality of sensors configured to simultaneously detect an electrocardiographic signal and a bioimpedance signal;
A plurality of conductors connected to a plurality of sensors in an elongated belt, each conductor of the plurality of conductors being connected to one sensor of the plurality of sensors;
A single outlet with a single or main cable connected to at least one device formed integrally with the elongated belt and configured to identify and separate electrocardiographic and bioimpedance signals;
Each conductor converges toward the single outlet device. The device of claim 1, wherein the electrocardiographic signal is an electrocardiographic signal and the bioimpedance signal is a signal used for electrical impedance tomography. A plurality of sensors comprises a plurality of electrodes configured to detect an electrocardiographic signal and the bio-impedance signal at the same time, according to claim 1. Elongate belt is formed from a flexible material, according to claim 1. At least one device
A high pass filter configured to eliminate the sensor offset,
And a low-pass filter configured to obtain ECG signals to the exclusion of bioimpedance signal, apparatus according to claim 1. The apparatus of claim 5 , wherein the high pass filter has a cutoff frequency of 2 Hertz. 7. The device of claim 6 , wherein the low pass filter has a cutoff frequency of 40 Hertz. The apparatus of claim 5 , further comprising a first amplifier coupled between the at least one sensor and the high pass filter. The apparatus of claim 1, further comprising a patient monitoring device operably coupled to the plurality of sensors and configured to generate an image from the bioimpedance signal. The apparatus of claim 1, further comprising a patient monitoring device operably coupled to the plurality of sensors and configured to integrate both electrical impedance tomography and electrocardiographic functions. An elongated belt having a first surface configured to contact the body of a patient and a second surface opposite the first surface, and as a single or main cable disposed on the first surface and connecting to a patient monitoring device An electrocardiogram via a device with multiple electrodes connected to multiple electrical conductors that converge towards a single outlet and configured to simultaneously detect both electrocardiographic and bioimpedance signals. Simultaneously detecting an input signal including a signal and a bioimpedance signal,
Transmitting an electrocardiographic signal and a bioimpedance signal through one or more conductors;
Filtering the input signal to separate the electrocardiographic signal and the bioimpedance signal. 12. The method of claim 11 , wherein filtering comprises first applying a high pass filter to the input signal and then applying a low pass filter to the input signal. 13. The method of claim 12 , further comprising generating an image from the bioimpedance signal output by the high pass filter prior to the low pass filter. 13. The method of claim 12 , wherein the high pass filter has a cutoff frequency of 2 Hertz and the low pass filter has a cutoff frequency of 40 Hertz.

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