Patent Publication Number: US-2023148935-A1

Title: Contactless Electrocardiogram Measurement Device

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims priority to Korean Patent Application No. 10-2021-0107385, filed Aug. 13, 2021, the disclosure of which is hereby incorporated by reference in its entirety. 
     BACKGROUND OF THE INVENTION 
     Field of the Invention 
     The following disclosure relates to a contactless electrocardiogram measurement device, and more particularly, to a contactless electrocardiogram measurement device which can indirectly measure an electrocardiogram of an object person through a vibration sensor without direct contact with a body of the object person. 
     Description of Related Art 
     Currently, many people are complaining of a symptom such as fatigue or lethargy due to a phenomenon such as reduced sleep time or difficulty falling into deep sleep. In severe cases, this phenomenon may not only cause such a simple symptom, but also cause high blood pressure, obesity or diabetes, or lead to deteriorated health due to occurrence of a disease related to a cardiovascular system, nerves or brain. As a result, technologies are being developed or commercialized in which sleep of an object person is monitored to diagnose a sleep quality of the object person, respiratory status and cardiovascular function during sleep, sleep apnea or the like, and to diagnose and prevent a disease related to the sleep of the object person at an early stage. 
     A sleep monitor may be mounted on a wearable device, a mobile device or bedding, and measure the brain wave, electrocardiogram, exercise, sleep or the like of the object person. In this case, it is possible to diagnose and predict various sleep safety-related diseases such as sleep apnea, depression, stress, fibrosis, heart failure and arrhythmia through the electrocardiogram measurement. It is also possible to obtain data for distinguishing stable and deep sleep of the object person from unstable sleep of the object person through the electrocardiogram measurement. 
     Currently, Korean Patent Publication No. 10-2018-0015336 (entitled, “bed cable for electrocardiogram measurement” and published on Feb. 13, 2018) discloses technology of a bed cable for measuring the electrocardiogram for the sleep monitoring. Referring to  FIG.  1   , the bed cable for electrocardiogram measurement may include: a mat  1  which supports a measurement object person  0 ; a plurality of measurement electrodes  2  which receive a micro-current generated from the measurement object person  0  through the skin of the measurement object person  0 ; at least three connection terminals  3  which are positioned on a support surface of the mat  1  on which the measurement object person  0  is supported, and to which a measurement electrodes  2  are connected; at least two connection terminals  4  which are electrically connected to an electrocardiogram system “E”; and a connection circuit  5  which is positioned in the mat  1  and connects the connection terminal  3  and the connection terminal  4  with each other, wherein at least one of the plurality of measurement electrodes  2  provides the electrocardiogram system “E” connected to the connection terminal  4  with the micro-current generated in a process of depolarizing a heart muscle of the measurement object person  0 . 
     The electrocardiogram measurement technology as described above for sleep monitoring, which is currently disclosed, may have low accessibility. The reason is that the technology may be limited to only a specialized facility to provide this service as most of the bedding needs to be made separately so that the electrodes and terminals are embedded therein. In addition, the electrocardiogram measurement using the electrodes may require the electrodes or another device to be attached to the body of the object person, and may thus disturb the sleep of the object person and also affect a measurement result. 
     SUMMARY OF THE INVENTION 
     An exemplary embodiment of the present disclosure is directed to providing a contactless electrocardiogram measurement device which can indirectly measure an electrocardiogram of an object person through a vibration sensor without direct contact with a body of the object person, and measure vibration more precisely while reducing foreign body sensation felt by the object person. 
     In one general aspect, a contactless electrocardiogram measurement device includes a measurement unit disposed between a vibration medium and a support member to measure vibration generated from a body of an object person that is transmitted from the vibration medium, wherein the measurement unit includes a plate-shaped cover portion interposed between the vibration medium and the support member, and a vibration sensor for detecting the vibration generated in the cover portion, and the vibration sensor is embedded in the vibration medium or the support member. 
     In addition, the vibration medium and the support member may be a topper and a mattress, respectively. 
     In addition, the contactless electrocardiogram measurement device may further include a processor fixed on the support member and receiving data measured by the vibration sensor. 
     In addition, the contactless electrocardiogram measurement device may further include a case into which the vibration sensor is inserted and which has one side coupled to one surface of the cover portion, wherein the case has the one side open. 
     In addition, the cover portion may include a plate-shaped cover body having a diameter greater than its thickness and a first screw hole passing through both surfaces of the cover body, the case may include a second screw hole disposed in the one side thereof to face the first screw hole, and the cover body and the case may be screwed to each other. 
     In addition, a seating groove into which a cable is able to be inserted may be disposed in the one side of the case, and the cable may be wired to the vibration sensor. 
     In addition, the cover portion may have a disk shape, and both the surfaces of the cover portion may be in contact with the vibration medium and the support member, respectively. 
     In addition, the vibration medium or the support member may have a cavity disposed in its surface in contact with the cover portion to embed the vibration sensor therein, and an area of the cavity may be smaller than an area of the cover portion. 
     In addition, wherein the case may be disposed at a diameter center of the cover portion. 
     In addition, the contactless electrocardiogram measurement device may further include a fixing member for fixing the vibration sensor into the case. 
     In addition, the cover portion may have hardness greater than that of the vibration medium. 
     In another general aspect, a method for calculating a contactless electrocardiogram signal by using the contactless electrocardiogram measurement device described above includes: calculating a first electrocardiogram signal of an object person by using the contactless electrocardiogram measurement device; measuring a second electrocardiogram signal of the object person by using a contact electrocardiogram including electrodes; analyzing a correlation between the first electrocardiogram signal and the second electrocardiogram signal; and correcting data by reflecting the analyzed correlation in a calculation formula of the first electrocardiogram signal. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG.  1    is a view showing a contact electrocardiogram measurement device according to the prior art. 
         FIG.  2    is a view showing a contactless electrocardiogram measurement device installed on a bed according to the present disclosure. 
         FIG.  3    is a perspective view showing a measurement unit disposed between a vibration medium and a support member according to the present disclosure. 
         FIG.  4    is a cross-sectional view showing an example in which the measurement unit is disposed between the vibration medium and the support member according to the present disclosure. 
         FIG.  5    is a perspective view of the measurement unit according to the present disclosure. 
         FIG.  6    is an exploded perspective view of the measurement unit according to the present disclosure. 
         FIGS.  7 A to  9 B  are views each comparing the measurement unit according to the present disclosure and a device having a different shape. 
         FIG.  10    is a cross-sectional view showing another example in which the measurement unit is disposed between the vibration medium and the support member according to the present disclosure. 
         FIG.  11    shows a table comparing actual measurement data and calculated data to which a method for calculating a contactless electrocardiogram signal according to the present disclosure is applied with each other. 
     
    
    
     DESCRIPTION OF THE INVENTION 
     Hereinafter, a contactless electrocardiogram measurement device according to the present disclosure is described in detail with reference to the accompanying drawings. The accompanying drawings are only provided by way of example in order to sufficiently transfer the spirit of the present disclosure to those skilled in the art. Therefore, the present disclosure is not limited to the accompanying drawings provided below, and may be implemented in another form. In addition, like reference numerals denote like elements throughout the specification. 
     Technical terms and scientific terms used in the specification have the general meanings understood by those skilled in the art to which the present disclosure pertains unless otherwise defined, and descriptions for the known function and configuration unnecessarily obscuring the gist of the present disclosure are omitted in the following description and the accompanying drawings. 
       FIGS.  2  to  4    are related to a contactless electrocardiogram measurement device according to the present disclosure:  FIG.  2    is a view showing a contactless electrocardiogram measurement device installed on a bed according to the present disclosure;  FIG.  3    is a perspective view showing a measurement unit disposed between a vibration medium and a support member according to the present disclosure; and  FIG.  4    is a cross-sectional view showing an example in which the measurement unit is disposed between the vibration medium and the support member according to the present disclosure. 
     Referring to  FIG.  2   , a contactless electrocardiogram measurement device  10  according to the present disclosure may be installed on a product such as a bed  20  including a vibration medium  21  and a support member  22 . In this case, the contactless electrocardiogram measurement device  10  can be installed in any of various product groups such as a vehicle seat and a floor mat when including the vibration medium  21  and the support member  22 . In the case of the bed  20 , the vibration medium  21  and the support member  22  may be a topper and a mattress, respectively, and the vibration medium  21  may be a product of any of various types supported by the support member  22  as well as the topper. In addition, the contactless electrocardiogram measurement device  10  may directly transmit a vibration signal to the outside by measuring vibration generated from an object person, or calculate an electrocardiogram signal from the vibration signal and transmit the same to the outside. In this case, the contactless electrocardiogram measurement device  10  may further include a wireless communication means to enable its data communication with a user terminal  30  such as a smartphone  31  or a personal computer (PC)  32 . 
     Referring to  FIG.  3   , the contactless electrocardiogram measurement device  10  may include a measurement unit  100  disposed between the vibration medium  21  and the support member  22 , and a processor  200  calculating the electrocardiogram signal by using the vibration signal measured by the measurement unit  100 . In this case, the measurement unit  100  and the processor  200  may perform data communication with each other by being connected to each other by wire through a cable C. Alternatively, the measurement unit  100  and the processor  200  may be wirelessly connected to each other by being equipped with a wireless communication means, respectively. Here, the measurement unit  100  may be disposed while being unexposed as the measurement unit is covered by the vibration medium  21 , and the processor  200  may be disposed while being exposed to be manipulated. For example, the processor  200  may be disposed on a side surface of the support member  22 . 
     Referring to  FIG.  4   , the measurement unit  100  may include a plate-shaped cover portion  110  interposed between the vibration medium  21  and the support member  22 , and a sensor assembly  120  embedded in a cavity  22   a  of the support member  22 . In this case, the sensor assembly  120  may be disposed at the center of the cover portion  110 . Here, the cover portion  110  may have a diameter greater than a diameter of the cavity  22   a  of the support member  22 , and thus be disposed while having an upper surface and a lower surface in contact with a lower surface of the vibration medium  21  and an upper surface of the support member  22 , respectively. In addition, the cover portion  110  may have hardness greater than that of the vibration medium  21  to prevent the transmitted vibration from being attenuated. Accordingly, even if the vibration generated from a body of the object person is partially attenuated through the vibration medium  21 , the cover portion  110  can separately suppress the vibration from being attenuated and more precisely detect a peak signal. In this case, the cover portion  110  may have an upper or lower thickness smaller than a front, rear, left or right diameter, and have a plate shape so that the object person does not feel direct foreign body sensation even when lying on the vibration medium  21 . In addition, the sensor assembly  120  may be disposed in the cavity  22   a  of the support member  22 , such that the object person may not feel direct foreign body sensation even when lying on the vibration medium  21 . 
       FIGS.  5  and  6    are related to the contactless electrocardiogram measurement device according to the present disclosure:  FIG.  5    is a perspective view of the measurement unit; and  FIG.  6    is an exploded perspective view of the measurement unit. 
     Referring to  FIG.  5   , the measurement unit  100  according to the present disclosure may include the plate-shaped cover portion  110  and the sensor assembly  120  coupled to one surface of the cover portion  110 . The following description describes each component in more detail with reference to  FIG.  6   . 
     The cover portion  110  may include a plate-shaped cover body  111  having a front, rear, left or right diameter greater than its upper or lower thickness. In this case, the front, rear, left or right side of the cover body  111  may have any of various shapes such as a polygon or a circle, and the vibration can be transmitted more precisely over a large area when the cover body  111  has a disk shape. In this case, the cover portion  110  may further include a first screw hole  112  passing through the upper and lower surfaces of the cover body  111 , and the measurement unit  100  may further include a fastening member  130  passing through the first screw hole  112  and coupling the cover portion  110  and the sensor assembly  120  to each other. 
     The sensor assembly  120  may include a cylinder-shaped case  121  having a hollow inside and an open top, and a vibration sensor  122  disposed in the hollow inside of the case  121 . In addition, the vibration sensor  122  may measure the vibration signal transmitted through the cover body  111  and the case  121 , or may be directly coupled to the cover body  111  to measure the vibration signal. In this case, the sensor assembly  120  may further include a fixing member  123  for fixing the vibration sensor  122  into the case  121 . 
     The sensor assembly  120  may further include a seating groove  121   a  disposed in an upper surface of the case  121  to seat the cable C therein, and a second screw hole  121   b  disposed to face the first screw hole  112  and coupled with an end portion of the fastening member  130 . Here, the cable C may be disposed to pass through a side surface of the case  121 . Alternatively, as shown in  FIG.  6   , the upper surface of the case  121  and the lower surface of the cover body  111  may be in contact with each other and the case  121  may be partially recessed downward to insert the cable C thereinto. In addition, the case  121  may be disposed at the diameter center of the cover body  111  to transmit the vibration received in a larger area to the vibration sensor  122 . 
       FIGS.  7 A to  9 B  are views each comparing performance of the contactless electrocardiogram measurement device according to the present disclosure and that of a device having a different shape. 
       FIG.  7 A  is a perspective view of the measurement unit  100  according to the present disclosure, and  FIG.  7 B  shows the vibration signal measured using the measurement unit  100 , respectively. In addition,  FIGS.  8 A and  9 A  are perspective views of a steel use stainless (SUS) cantilever  400  and an artificial intelligence (AI) cantilever  500 , respectively, and  FIGS.  8 B and  9 B  show the vibration signal measured by the SUS cantilever  400  and the AI cantilever  500 , respectively. 
     Referring to  FIG.  7 A to  9 B , the SUS cantilever  400  or the AI cantilever  500  may include a sensor unit  420  or  520  disposed on one side of a diaphragm  410  or  510  to detect the vibration in order to improve a sleep quality of the object person. In this case, a main peak may be often lost and a noise level may be higher as compared to the measurement unit  100 , and distortion of the vibration signal may thus be relatively great. That is, the measurement unit  100  according to the present disclosure can significantly reduce the distortion of the vibration signal than the structure such as the SUS cantilever  400  or the AI cantilever  500 , and thus obtain a more accurate vibration signal which can generate the artificial electrocardiogram signal. 
       FIG.  10    is related to the contactless electrocardiogram measurement device according to the present disclosure, and is a cross-sectional view showing another example in which the measurement unit is disposed between the vibration medium and the support member according to the present disclosure. 
     Referring to  FIG.  10   , the measurement unit  100  may include the plate-shaped cover portion  110  interposed between the vibration medium  21  and the support member  22 , and the sensor assembly  120  embedded in a cavity  21   a  of the vibration medium  21 . In this case, the sensor assembly  120  may be disposed at the center of the cover portion  110 . Here, the cover portion  110  may have a diameter greater than a diameter of the cavity  21   a  of the vibration medium  21 , and thus be disposed while having the upper surface and the lower surface in contact with the lower surface of the vibration medium  21  and the upper surface of the support member  22 , respectively. In addition, the cover portion  110  may have hardness greater than that of the vibration medium  21  to prevent the transmitted vibration from being attenuated. Accordingly, even if the vibration generated from the body of the object person is partially attenuated through the vibration medium  21 , the cover portion  110  can separately suppress the vibration from being attenuated and more precisely detect the peak signal. In this case, the cover portion  110  may have the upper or lower thickness smaller than the front, rear, left or right diameter, and have the plate shape so that the object person does not feel the direct foreign body sensation even when lying on the vibration medium  21 . In addition, the sensor assembly  120  may also be disposed in the cavity  21   a  of the vibration medium  21 , such that the object person may not feel the direct foreign body sensation even when lying on the vibration medium  21 . 
       FIG.  11    is related to a method for calculating a contactless electrocardiogram signal by using a contactless electrocardiogram measurement device according to the present disclosure, and shows a table comparing actual measurement data and calculated data to which the method for calculating a contactless electrocardiogram signal according to the present disclosure is applied with each other. 
     Referring to  FIG.  11   , the method for calculating a contactless electrocardiogram signal according to the present disclosure includes: calculating a first electrocardiogram signal of an object person by using a contactless electrocardiogram measurement device; measuring a second electrocardiogram signal of the object person by using a contact electrocardiogram including electrodes; analyzing a correlation between the first electrocardiogram signal and the second electrocardiogram signal; and correcting data by reflecting the analyzed correlation in a calculation formula of the first electrocardiogram signal. That is, the contactless electrocardiogram measurement device may calculate the first electrocardiogram signal of the object person by using a vibration signal, and the time-synchronized contact electrocardiogram can measure the second electrocardiogram signal of the same object person to correct the calculation formula for calculating the first electrocardiogram signal by using the vibration signal. Here, the correlation between the first electrocardiogram signal and the second electrocardiogram signal may be trained using a deep learning algorithm, and the trained deep learning algorithm may be provided through a network or the like. A user provided with the trained deep learning algorithm may update algorithm of his/her contactless electrocardiogram measurement device in real time, thereby minimizing an error with actual measurement data. As shown in the table of  FIG.  11   , it can be seen that a case of user #3,to which the trained deep learning algorithm is reflected, has a lower error rate between the actual measurement data (or electrocardiogram (ECG)) and the calculated data (or prediction) and a higher peak detection rate as compared to a case of user #1, #2, #4 or #5. 
     As set forth above, the contactless electrocardiogram measurement device configured as described above according to the present disclosure may include the plate-shaped cover portion which is disposed between the vibration medium and the support member to more precisely measure the vibration generated from the object person, and the vibration sensor which is embedded in the vibration medium or the support member, thereby reducing the foreign body sensation felt by the object person. Accordingly, the contactless electrocardiogram measurement device according to the present disclosure may solve the conventional problems caused by the disturbed sleep of the object person, and may also be used in a place other than the specialized facility to be more widely used. 
     The contactless electrocardiogram measurement device according to the present disclosure may generate the electrocardiogram signal by using only the signal received from the vibration sensor without being attached to the body of the object person in sleep, and may thus derive the cardiovascular disease and precise health-related information of the object person by performing the high-quality sleep monitoring. 
     The contactless electrocardiogram measurement device according to the present disclosure may have higher reliability of the measurement result because the calculation formula is corrected using the data measured in the conventional electrocardiogram. 
     As described above, the present disclosure is described with reference to the specific matter such as the specific components, the specific exemplary embodiments and the drawings, which are provided only for assisting in the general understanding of the present disclosure. Therefore, the present disclosure is not limited to the exemplary embodiments. Various modifications and changes may be made by those skilled in the art to which the present disclosure pertains from this description. 
     Therefore, the spirit of the present disclosure should not be limited to the exemplary embodiments described above, and the claims and all of modifications equal or equivalent to the claims are intended to fall within the scope and spirit of the present disclosure.