JP6535770B2 - Biological information monitoring system - Google Patents

Description

  The present invention relates to a biological information monitoring system that monitors biological information of a subject based on changes in the position of the center of gravity of the subject on a bed.

  Subject's biological information is one of the important information for knowing the physical condition of the patient and the care recipient in the medical or nursing care field. For example, the subject's respiratory status can be grasped, and it can be used for grasping symptoms such as sleep apnea syndrome and snoring and improvement of these symptoms.

  It has been proposed to place a load sensor under the legs of the bed and measure the breathing state of the subject based on the measurement value of the load sensor (Patent Document 1). Furthermore, a load detector may be disposed under the leg of the bed to determine the movement of the center of gravity of the test subject on the bed, and the respiratory movement and the heartbeat movement of the test subject based on the movement of the center of gravity. It is proposed (patent document 2).

Patent No. 4883380 Japanese Examined Patent Publication No. 61-24010

  In a medical site, it is desired to accurately grasp the position of the center of gravity of a subject on a bed, but the inventions described in Patent Documents 1 and 2 can not meet the needs of such a site.

  Then, an object of this invention is to provide the biometric information monitoring system which can grasp | ascertain the gravity center position of the test subject on a bed correctly.

According to a first aspect of the invention,
A biological information monitoring system for monitoring various biological information of a subject on a bed, comprising:
A plurality of load detectors provided under the bed or the legs of the bed for detecting the load of the subject and outputting it as a load signal;
A signal separation unit that separates components corresponding to each of a plurality of frequency bands from load signals output from each load detector;
There is provided a living body information monitoring system, comprising: a center of gravity position calculating unit that calculates a center of gravity of a subject based on the separated components.

  In the biological information monitoring system according to the first aspect, the plurality of frequency bands may include a frequency band of respiration and a frequency band of heartbeats.

  In the biological information monitoring system according to the first aspect, the center-of-gravity position calculation unit may calculate the center-of-gravity position based on a component corresponding to a frequency band of respiration.

  The living body information monitoring system according to the first aspect may further include a living body information analysis unit that analyzes the breathing state of the subject based on the temporal variation of the calculated barycentric position.

  According to the biological information monitoring system of the present invention, the position of the center of gravity of the subject on the bed can be accurately grasped.

FIG. 1 is a block diagram showing the configuration of a biological information monitoring system according to an embodiment of the present invention. FIG. 2 is an explanatory view showing the arrangement of the load detector with respect to the bed. FIG. 3 is a flowchart showing a gravity center locus calculation method according to an embodiment of the present invention. FIG. 4 is an explanatory view showing the arrangement of four load detection areas defined on the bed upper surface. FIG. 5 shows an example of a load signal from a load detector. FIG. 6 shows an example of the gravity center locus of the subject. FIG. 7 is a flowchart showing a method of calculating the position of the center of gravity of the subject based on the respiratory component or the heartbeat component separated from each load signal. FIG. 8 is a block diagram showing an overall configuration of a bed system according to a modification.

First Embodiment
A first embodiment of the present invention will be described with reference to FIGS. 1 to 7.

  As shown in FIG. 1, the biological information monitoring system (respiratory waveform drawing system, respiratory information acquisition system) 100 of the present embodiment performs observation and measurement in order to grasp the biological condition of the subject on the bed, and detects the load. The control unit 3 mainly includes a control unit 3, a storage unit 4, and a display unit 5. The load detection unit 1 and the control unit 3 are connected via the A / D conversion unit 2. Further, a notification unit 6 and an input unit 7 are connected to the control unit 3.

  The load detection unit 1 includes four load detectors 11, 12, 13, 14. Each of the load detectors 11, 12, 13, 14 is a load detector that detects a load using, for example, a beam type load cell. Such a load detector is described, for example, in Japanese Patent No. 4829020 and Japanese Patent No. 4002905. The load detectors 11, 12, 13 and 14 are connected to the A / D converter 2 by wires, respectively.

The four load detectors 11, 12, 13, 14 of the load detector 1 are disposed under the legs of the bed used by the subject. Specifically, as shown in FIG. 2, the load detectors 11, 12, 13, 14 are located under the casters C ₁ , C ₂ , C ₃ , C ₄ attached to the lower ends of the legs at the four corners of the bed BD. It is arranged respectively.

  The A / D conversion unit 2 includes an A / D converter that converts an analog signal from the load detection unit 1 into a digital signal, and is connected to the load detection unit 1 and the control unit 3 by wiring.

  The control unit 3 is a dedicated or general-purpose computer, in which a frequency analysis unit 31, a signal separation unit 32, a gravity center position calculation unit 33, and a biological information analysis unit 34 are constructed.

  The storage unit 4 is a storage device that stores data used in the biological information monitoring system 100, and can use, for example, a hard disk (magnetic disk). The display unit 5 is a monitor such as a liquid crystal monitor that displays the information output from the control unit 3 to the user of the biological information monitoring system 100.

  The notification unit 6 includes a device that visually or aurally performs predetermined notification based on the information from the control unit 3, for example, a speaker. The input unit 7 is an interface for performing predetermined input to the control unit 3 and may be a keyboard and a mouse.

  Such biological information monitoring system 100 can be used to detect and monitor various types of biological information including the breathing state of the subject on the bed. Acquisition and monitoring of various types of biological information are performed based on fluctuations in the position of the center of gravity of the subject on the bed.

  The operation | movement which calculates the gravity center position of the test subject on a bed using the biometric information monitoring system 100 is demonstrated. The calculation of the center of gravity of the subject using the biological information monitoring system 100 is, as shown in FIG. 3, a load detection step (S01) for detecting the load of the subject and temporal variation of the center of gravity of the subject based on the detected load. And a center of gravity locus calculation step (S02) for calculating (centroid center of gravity locus).

In the load detection step S01, the load of the subject S on the bed BD is detected using the load detectors 11, 12, 13, 14. The load detectors 11, 12, 13 and 14 are disposed under the casters C ₁ , C ₂ , C ₃ and C ₄ respectively as described above, so the load applied to the upper surface of the bed BD is four loads. Detectors 11, 12, 13, 14 are dispersedly detected. Specifically, as shown in FIG. 4, the rectangular upper surface of the bed BD is vertically and horizontally divided into two and equally divided into four rectangular regions I to IV.

  Thereby, the load applied to the region I where the lower left half of the subject S lying on the bed BD lies (is lying on the back) is mainly detected by the load detector 11, and the lower right half of the subject S in the same state The load applied to the region II in which is located is mainly detected by the load detector 12. Similarly, the load applied to the region III where the right upper body of the subject S lying on the bed BD is located is mainly detected by the load detector 13, and the region IV where the left upper body of the subject S in the same condition is located The load applied to is mainly detected by the load detector 14. When the subject S is not on the bed BD, the total of the outputs from the load detectors 11, 12, 13, 14 represents the weight of the bed alone, and when the subject S is on the bed BD, the load Since the total of the outputs from the detectors 11, 12, 13, 14 represents the weight of the bed alone and the weight of the subject S, by storing the weight of the bed alone in the storage unit 4, the subject S can The weight of the subject S can be measured when he / she comes to bed. If the weight of the bed is not uniform in the four regions, the difference is stored as the weight of the bed corresponding to the load detector. In addition, it is desirable to reflect in the bed weight a situation that brings about a weight other than the subject S during actual measurement, for example, that a duvet or luggage is placed.

  The load detectors 11, 12, 13 and 14 respectively detect loads (load changes) and output them to the A / D converter 2 as analog signals. The A / D conversion unit 2 converts an analog signal into a digital signal (hereinafter referred to as a “load signal”) with a sampling cycle of, for example, 5 milliseconds, and does not pass through the frequency analysis unit 31 or the signal separation unit 32. , And output to the gravity center position calculation unit 33.

An example of the load signal is shown in FIG. 5, the time _{t 10} ~ time _{t 14} load signal _{s 1} from the load detector 11, 12, 13, 14 output until (solid line), _{s 2} (dashed line), _{s 3} (dashed line) , S ₄ (two-dot chain line). The subject S is supposing to the central portion of the bed BD as shown in FIG. 4 during the period from time t ₁₀ to time t ₁₁ (period P ₁₁ ), and from time t ₁₁ to time t ₁₂ Period P ₁₂ ) moves to the side I of the bed BD and to the side IV of the bed BD, and during the period from time t ₁₂ to time t ₁₃ (period P ₁₃ ), slightly to the center side of the bed BD compared to period P ₁₂ It has been observed that it is moving and supposing on the central part of the bed BD from time t ₁₃ to time t ₁₄ (period P ₁₄ ).

The period P _11, the subject S so was supine in central as bed BD shown in FIG. 4, in the period P _11, the signal from the load detector 13 and 14 arranged on the head side of the subject S s _{3, s 4} are substantially equal, the signal _s 1 from the load detector 11, 12 arranged on the leg side of the subject S, _{s 2} are approximately equal.

The period _{P 12,} the subject S region of the bed BD I, because it was moved to the IV side, in this period _{P 12,} region I, the signal _s 1 from the load detector 11 and 14 arranged in IV, s ₄ indicates a large load value as compared to the period P ₁₁ , and the signals s ₂ and s ₃ from the load detectors 12 and 13 disposed in the regions II and III indicate small load values as compared to the period P ₁₁ There is.

The period _{P 13,} the subject S, so was slightly moves to the center side of the bed BD as compared to the period _{P 12,} in this period _{P 13,} region I, the load detector 11 and 14 arranged in IV The signals s ₁ and s ₄ indicate small load values compared to the period P ₁₂ , and the signals s ₂ and s ₃ from the load detectors 12 and 13 disposed in the regions II and III are larger than the period P ₁₂ It shows the load value.

The period _{P 14,} the subject S, so was supine in central same bed BD to the period _{P 11,} the signal _s 1 ~s ₄ during this period _{P 14,} the signals _s 1 ~s ₄ during the period _{P 11} Is the same as

In the gravity center locus calculation step S02, the gravity center position calculation unit 33 calculates the position G (X, Y) of the gravity center G of the subject S on the bed BD based on the load signals s _{1 to} s ₄ from the load detectors 11 to 14. Calculated at a predetermined cycle T (for example, equal to the above-mentioned sampling cycle 5 ms), the temporal variation (center of gravity locus GT) of the position of the center of gravity G of the subject S is determined. Here, (X, Y) indicates coordinates on the XY coordinate plane where X is taken in the longitudinal direction and Y is taken in the lateral direction with the central portion of the bed BD as the origin (FIG. 6).

The calculation of the position G (X, Y) of the gravity center G by the gravity center position calculation unit 31 is performed by the following calculation. That G (X, Y), respectively the coordinates of the load detector _{11,12,13,14 (X 11, Y 11)} , (X 12, Y 12), (X 13, Y 13), (X 14 , Y ₁₄ ) and load detection values of the load detectors ₁₁ , ₁₂ , ₁₃ and ₁₄ are respectively calculated by the following equations as W ₁₁ , W ₁₂ , W ₁₃ and W ₁₄ .

  The center-of-gravity position calculation unit 33 calculates the position G (X, Y) of the center of gravity G at a predetermined sampling period T based on Equation 1 and Equation 2 above, while the time of the position G (X, Y) of the center of gravity G Fluctuation, that is, the center of gravity locus GT is determined and stored in, for example, the storage unit 4.

An example of the gravity center locus GT calculated by the gravity center position calculation unit 33 is shown in FIG. 6 shows the position G (X _P11 , Y _P11 ) of the center of gravity G of the subject S on the bed BD at any time t ₁₁₀ , t ₁₂₀ and t ₁₃₀ in the period P ₁₁ , P ₁₂ and P _{13 of} FIG. , G (X _P12 , Y _P12 ), G (X _P13 , Y _P13 ), and the dashed-dotted arrows connecting these are from position G (X _P11 , Y _P11 ) to G (X _P13 , Y _P13 ) The gravity center locus GT of the gravity center G of the subject S who moves up to is shown.

  In the present embodiment, the biological information analysis unit 34 analyzes the presence / absence of the body motion of the subject S and the appearance thereof based on the gravity center locus GT of the subject S calculated as described above by the gravity center position calculation unit 33. Specifically, the biological information analysis unit 34 calculates the moving speed (moving amount per unit time) of the center of gravity G based on the change in the position of the center of gravity G of the subject S at each time stored in the storage unit 4 If the calculated speed exceeds a predetermined threshold, it is determined that the subject S is performing body movement. In addition, the body movement of the subject S includes body movement (large body movement) caused by relatively large movement of the subject S, such as turning over, etc., movement of the hand or foot, face, etc. It includes body movement (small body movement) caused by relatively small movement of the body without movement of the trunk.

Here, in the center-of-gravity locus calculation step S02, as shown in Equation 1 and Equation 2 above, the total loads W ₁₁ , W ₁₂ , W ₁₃ and W ₁₄ detected by the load detectors ₁₁ , ₁₂ , ₁₃ , ₁₄ are obtained. The center-of-gravity position G (X, Y) is calculated on the basis of this. For this reason, for example, when an object is placed at a position away from the subject S on the bed, the gravity center position G (X, Y) calculated by Equation 1 and Equation 2 above is placed on the bed. Due to the influence of the load of the object, the subject S may deviate from the actual position of the center of gravity. Therefore, in the present embodiment, components included in a specific frequency band are separated from each of the load signals s _{1 to} s ₄ output from the load detectors 11 to 14, and the gravity center position of the subject S based on the separated components is also It is calculated.

A process of separating the components included in the frequency band of respiration (about 0.2 Hz to about 0.33 Hz) from each of the load signals s _{1 to} s ₄ and calculating the gravity center position of the subject S based on the separated components Will be described with reference to the flowchart of FIG.

In the frequency analysis step S10, the frequency analysis unit 31 obtains a frequency spectrum by Fourier transform for each or at least one of the load signals s _{1 to} s ₄ output from the load detectors 11 to 14.

In the signal separation step S20, the signal separation unit 32 specifies, from the frequency spectrum obtained in the frequency analysis step S10, the peak frequency included in the frequency band of respiration (that is, the frequency of the respiration of the subject S). Then, the signal separation unit 32 separates components s _b1 to s _b4 (hereinafter referred to as “respiratory components”) corresponding to the identified peak frequencies from each of the load signals s _{1 to} s ₄ .

In the center-of-gravity position calculation step S30, the center-of-gravity position calculation unit 31 calculates the center-of-gravity position G _b of the subject S on the bed according to Equation 1 and Equation 2 based on the respiratory components s _{b1 to} s _b4 separated in the signal separation step S20. Calculate (X, Y).

In the biological information analysis step S40, the biological information analysis unit 34 calculates the gravity center position G (X, Y) calculated on the basis of the total load and the gravity center position G _b (X, X) calculated on the basis of the respiratory components s _{b1 to} s _b4 . Any one of Y) may be adopted. For example, after comparing the gravity center position G (X, Y) calculated based on the total load and the gravity center position G _b (X, Y) calculated based on the respiratory components s _{b1 to} s _b4 , It may be determined which one is adopted as the center of gravity position. Alternatively, the distance between the gravity center position G (X, Y) based on the total load and the gravity center position G _b (X, Y) based on the respiration component is calculated, and if the distance exceeds a predetermined range The information analysis unit 34 may adopt the gravity center position G _b (X, Y) based on the respiration component as the gravity center position of the subject S. Here, the predetermined range may be set appropriately in consideration of, for example, the size of the bed, the height of the subject S, the weight, and the like.

  The living body information analysis unit 34 analyzes various living body information of the subject S using the adopted center of gravity position.

  By the way, human respiration is performed by moving the thorax and the diaphragm to expand and contract the lungs. Here, when inhaling, that is, when the lungs expand, the diaphragm lowers, and the viscera also move downwards. On the other hand, at the time of exhalation, that is, when the lungs contract, the diaphragm rises upward, and the viscera also moves upward. The inventor of the present invention found through research that the center of gravity G vibrates substantially along the extension direction of the spine (body axis direction) along with this visceral movement (hereinafter referred to as "respiratory vibration". ).

  Therefore, when the center-of-gravity position vibrates in a specific direction, the biological information analysis unit 34 regards the specific direction as the direction of the body axis of the subject S, and the posture of the subject S on the bed (body axis is bed Whether parallel or inclined with respect to the longitudinal direction of The direction of respiratory vibration can be specified, for example, by specifying an extreme point from the trajectory of respiratory vibration and an extreme point appearing immediately before or after the extreme point, and finding an axis connecting the two.

  Further, the biological information analysis unit 34 plots the distance between the position where the center of gravity position at each time is projected on the body axis and the vibration center of respiratory vibration, with the direction of the body axis as the vertical axis and the time axis as the horizontal axis. Thus, the breathing waveform of the subject S is drawn. Then, the biological information analysis unit 34 determines the respiration rate of the subject S by counting the number of maximum values or minimum values appearing on the respiratory waveform. Furthermore, the tidal volume (respiration depth) in one breath of the subject S is calculated based on the amplitude of the barycentric position (that is, the amplitude of the respiratory vibration or the amplitude of the respiratory waveform).

Next, the components included in the frequency band of the heart beat (about 0.5 Hz to about 3.3 Hz, hereinafter referred to as “heart beat band”) are separated from each of the weight signals s _{1 to} s ₄ , and based on the separated components The process of calculating the barycentric position of the subject S will be described with reference to the flowchart of FIG. 7. Note that this process may be performed in parallel with the calculation of the gravity center position G _b (X, Y) based on the above-described respiration component, or may be performed alone.

In the frequency analysis step S10, the frequency analysis unit 31 obtains the frequency spectrum of the heart rate band by Fourier transform for each or at least one of the load signals s _{1 to} s ₄ output from the load detectors 11 to 14.

In the signal separation step S20, the signal separation unit 32 specifies the peak frequency (that is, the frequency of the heart rate of the subject S) included in the heart rate band from the frequency spectrum obtained in the frequency analysis step S10. Then, the signal separation unit 32, from each of the load signal _s 1 ~s _4, components _s h1 _{~s h4} corresponding to the peak frequencies identified (hereinafter, referred to as "heartbeat component".) To separate.

In the center-of-gravity position calculation step S30, the center-of-gravity position calculation unit 31 calculates the center of gravity G of the subject S on the bed according to Equation 1 and Equation 2 above based on the heartbeat components s _{h1 to} s _h4 separated in the signal separation step S20. , “The center of gravity G _h based on the heart rate component” is calculated.

The center of gravity G _h based on the heart rate component of the subject S on the bed calculated using the heart rate components s _{h1 to} s _h4 separated from the load signals s _{1 to} s ₄ has the following features.

(1) the center of gravity _{G h} based on heart rate component of the load signal _s 1 ~s _4, because it is calculated using only heartbeat component _s h1 _{~s h4} that vibrates in response to the heartbeat of the subject S, for example, The subject does not move when a load by a third person (such as a visitor) with a heartbeat different from that of the subject S or a load by an inanimate object (such as a bag) without a heartbeat is applied on the bed BD. Move only when S moves.

(2) The inventors of the present invention, observation of the trajectory of the movement of the center of gravity G _h based on the heartbeat component, the direction the center of gravity G _h based on the heartbeat component, which has a certain degree rotating body axis of the subject S counterclockwise It was found to be slightly oscillating along the. This vibration (hereinafter referred to as "heartbeat vibration") is considered to be caused by the heartbeat.

In the biological information analysis step S40, the biological information analysis unit 34 compares the gravity center position G (X, Y) calculated based on the total load with the position of the gravity center G _h based on the heart rate component. You may decide which one to use as This determination can be made in the same manner as described above for the center-of-gravity position G _b (X, Y) based on the respiratory component.

In addition, the living body information analysis unit 34 can also determine whether the subject S is present on the bed BD, that is, the presence determination, based on whether or not the gravity center G _h based on the heartbeat component is obtained. . In the case where the subject S does not exist on the bed BD, there is no component that fluctuates according to the heart rate of the subject S in each of the signal components s _{1 to} s ₄ of the load detectors 11 to 14. The components can not be separated, and the center of gravity G _h based on the heartbeat component can not be calculated. Therefore, presence or heartbeat component, it is possible to perform the bed determined based on the calculated whether the center of gravity G _h based on heartbeat components. The living body information analysis unit 34 may determine that the subject S is present, for example, when it is confirmed that the center of gravity G _h based on the calculated heart rate component is present on the bed BD. Alternatively, when it is confirmed that the center of gravity G _h based on the heartbeat component vibrates in a predetermined direction tilted with respect to the body axis of the subject S, it may be determined that the subject S is on the floor.

Biometric information analysis unit 34 further includes a vibration direction of the center of gravity G _h based on the heartbeat component, can also be determined, the direction of the body axis of the subject S, the heart rate from the vibration per minute of the center of gravity G _h based on heartbeat component You can also ask for

  The effects of the biological information monitoring system 100 of the present embodiment are summarized below.

The signal separation unit 32 according to the present embodiment is included in, for example, a respiratory component included in a frequency band of respiration and a frequency band of heartbeats from each of the load signals s _{1 to} s ₄ output from the load detectors 11 to 14. Separate heart rate components. The center-of-gravity position calculator 33 according to the present embodiment not only calculates the center-of-gravity position G _b (X, Y) based on the respiratory component, but also the heart rate component, as well as the center-of-gravity position G (X, Y) calculated based on the total load. The barycentric positions G _h (X, Y) based on each are calculated. For this reason, the biological information analysis unit 34 analyzes various biological information of the subject S for the gravity center position G _b (X, Y) based on the respiration component and the gravity center position G _h (X, Y) based on the heart rate component. Can be used to The gravity center position G _b (X, Y) based on the respiratory component and the gravity center position G _h (X, Y) based on the heartbeat component are loaded on the bed BD with loads not derived from the subject S, such as luggage and visitors. In this case, since it does not change, the biological information of the subject S can be more accurately analyzed by using these.

For example, the biological information analysis unit 34 uses the gravity center position G _b (X, Y) based on the respiratory component to indicate the posture (body axis direction) of the subject S on the bed, the respiratory waveform, the respiratory rate, and the respiratory ventilation amount. Breathing status can be analyzed.

In addition, the living body information analysis unit 34 can determine the presence of the subject S based on the heartbeat component or the presence or absence of the center of gravity G _h based on the heartbeat component. Heart rate is different from breathing, and can not be stopped consciously, so by making a presence determination based on the heart rate component or the presence or absence of the center of gravity G _h based on the heart rate component, the subject S gets up and down more reliably. It can be judged.

  The living body information monitoring system 100 of the present embodiment obtains the living body information of the subject S using the load detectors 11 to 14 disposed under the legs of the bed BD. Therefore, it is not necessary to attach the measuring device to the body of the subject S, and the subject S does not feel uncomfortable or uncomfortable.

<Modification>
The following modification can also be adopted in the biological information monitoring system 100 according to the above embodiment.

  For example, the cycle of breathing differs depending on the sex, physical size, vital capacity, etc. of the subject S, and there are individual differences in the cycle of heartbeats. Therefore, when there are a plurality of subjects S on the bed BD, different peak frequencies appear by the number of subjects S in the frequency bands of respiration and / or heart beat in the frequency spectrum obtained in the frequency analysis step S10.

Therefore, when a plurality of peak frequencies appear in the frequency band of respiration and / or heartbeat, the signal separation unit 32 determines that there are a plurality of subjects S on the bed, and each of the load signals s _{1 to} s ₄ And the respiratory component and / or the cardiac component corresponding to each subject S may be separated. Then, the center-of-gravity position calculation unit 33 may calculate the center-of-gravity position of each subject S based on the respiration component and / or the heart rate component corresponding to each subject S. For example, when peaks appear in the frequency 11 and the frequency 22 in the frequency band of respiration, the signal separation unit 32 determines that there are two subjects S on the bed, and in the signal separation step S20, the load signal s ₁ from each ~s _4, the respiratory component corresponding to the frequency .nu.1, separating the respiratory component corresponding to the frequency .nu.2. Then, in the gravity center position calculation step S30, the gravity center position calculation unit 33 calculates the gravity center position G _b1 (X, Y) based on the respiration component corresponding to the peak frequency _{1 1} and the gravity center based on the respiration component corresponding to the peak frequency _{2 2} The position G _b2 (X, Y) is calculated.

According to the above modification, even if there are a plurality of subjects S on the bed, the center of gravity G _b based on the respiration of each subject S and the center of gravity G _h based on the heart beat can be determined individually. The gravity center position of S can be grasped | ascertained correctly.

In the biological information monitoring system 100 of the above embodiments, the biological information analyzer 34 increases the load applied to the bed BD predetermined value (for example, about 40 kg) or more, and the center of gravity G _h based on the heartbeat component or heart obtained If may be determined that the subject S is implanted in, a load applied to the bed BD is reduced by more than a predetermined value, and the center of gravity G _h based on the heartbeat component or heart in the subject S If not prompted to liftoff You may judge.

When there is an element (impact element) which strikes the bed BD at a predetermined cycle on the bed BD, the load signals s _{1 to} s ₄ from the load detectors 11 to 14 are the same at the predetermined cycle. A waveform of the phase appears. If the load component including the waveform is separated using the frequency analysis unit 31 and the signal separation unit 32, and the gravity center position is calculated by the gravity center position calculation unit 33, the gravity center position of the impact element can be calculated. .

  In the above embodiment, the load detectors 11, 12, 13, 14 are not limited to load sensors using beam type load cells, and for example, force sensors can also be used.

  In the above embodiment, the load detector is not limited to four. Bed BD may be provided with additional legs and more than four load detectors may be used. Alternatively, load detectors may be arranged on only three of the legs of the bed BD. Even in the case of three load detectors, the gravity center position G of the subject S on the bed BD can be detected if the load detectors are not arranged in a straight line.

In the above embodiment, the load detector 11, 12, 13 and 14 had been arranged under the bed casters _C 1 attached to the lower end of the leg of the _{BD, C 2, C 3,} C 4 It is not restricted to this. The load detectors 11, 12, 13, 14 may be respectively provided between the four legs of the bed BD and the floor plate of the bed BD, or the four legs of the bed BD may be divided up and down. For example, it may be provided between the upper leg and the lower leg. In addition, the load detectors 11, 12, 13, and 14 may be integrated with the bed BD, and a bed system BDS including the bed BD and the biological information monitoring system 100 according to the present embodiment may be configured (FIG. 8). In the present specification, the “load detector provided in the bed” refers to the load detector provided between the four legs of the bed BD and the floor plate of the bed BD as described above, the upper leg, and the like. It means a load detector provided between the lower leg.

  In the above embodiment, even if a signal amplification unit for amplifying the load signal from the load detection unit 1 and a filtering unit for removing noise from the load signal are provided between the load detection unit 1 and the A / D conversion unit 2 good.

  In the biological information monitoring system 100 according to the above-described embodiment, the display unit 5 is not limited to the display of information on the monitor so that the user can visually recognize. For example, the display unit 5 may be a printer that periodically prints and outputs the respiratory state (respiratory rate and respiratory ventilation), heart rate and physical condition of the subject S, or the blue lamp lights up or leaves the room while in the bed If it is inside, it may be displayed using a simple visual expression such as lighting of a red lamp. Alternatively, the display unit 5 may transmit the biological information of the subject S to the user by voice. Furthermore, the biological information monitoring system 100 may not have the display unit 5 but may have only an output terminal for outputting information. A monitor (display device) or the like for performing display is connected to the biological information monitoring system 100 via the output terminal.

  Although the notification unit 6 of the above embodiment performs notification in an auditory manner, the notification unit 6 may be configured to perform notification visually by blinking light or the like, and is configured to perform notification by vibration. It is also good. In addition, the biological information monitoring system 100 of the above embodiment may not have the notification unit 6.

  The present invention is not limited to the above embodiment as long as the features of the present invention are maintained, and other embodiments considered within the scope of the technical idea of the present invention are also included in the scope of the present invention. .

  According to the biological information monitoring system of the present invention, since the center of gravity of the subject can be determined more accurately, the user who is mainly a doctor provides data suitable for observation, which contributes to the improvement of medical quality. can do.

Reference Signs List 1 load detection unit 11, 12, 13, 14 load detector 2 A / D conversion unit 3 control unit 31 frequency analysis unit 32 signal separation unit 33 center of gravity calculation unit 34 biological information analysis unit 4 storage unit 5 display unit 6 notification unit 7 input unit 100 biological information monitoring system BD bed BDS bed system GT center of gravity locus S subject

Claims (3)

A biological information monitoring system for monitoring various biological information of a subject on a bed, comprising:
A plurality of load detectors provided under the bed or the legs of the bed for detecting the load of the subject and outputting it as a load signal;
A signal separation unit that separates components corresponding to the frequency band of respiration and the frequency band of heart rate from the load signal output from each load detector;
And a center-of-gravity position calculation unit that calculates the center-of-gravity position of the subject based on at least one of the separated components. The biological information monitoring system according to claim 1, wherein the center-of-gravity position calculation unit calculates the center-of-gravity position based on a component included in a frequency band of respiration. The living body information monitoring system according to claim 2, further comprising a living body information analysis unit that analyzes a breathing state of the subject based on the temporal change of the calculated barycentric position.

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