JP6345322B1 - Watch system - Google Patents

Abstract

There is provided a watching system using a watching bed equipped with a pin sensor for load measurement that can be easily used for an existing bed. A monitoring bed (10) having a load measuring pin sensor (70), a signal processing unit (100) for obtaining a biological signal by processing an output of the load measuring pin sensor (70), and a processing result of the signal processing unit (100). A display system (120) for displaying the signal, wherein the signal processing unit 100 is adapted to the biological amplifier (106) for amplifying the biological signal and the biological signal amplitude of the measurement target (8). A biological offset follow-up processing unit 110C that dynamically controls the offset and gain of the output of the biological amplifier (106). [Selection] Figure 9

Description

The present invention relates to a monitoring system, and in particular, in a patient bed or a bed for a healthy person (hereinafter collectively referred to as a bed) in a hospital or a care facility such as a care bed, a medical bed, an electric bed or a care lift, It is easy to measure the load at the required part of the bed, which is suitable for measuring the load and obtaining biological information such as weight, vibration and breathing, heartbeat, etc. about Protection system using a bed watching with a load measuring sensor using also readily available strain gauges be installed in retrofit on.

  In recent years, heels of elderly people with dementia and accidents of falling or falling around the bed have become social problems, and countermeasures are required. In addition, by monitoring the movement of a user who has been in the bed for a long period of time, such as an elderly person or a patient who has just been postoperatively, using bed load information, it is possible to more quickly in the event of an abnormal situation. It is expected to be able to respond appropriately.

  For this purpose, for example, in Patent Documents 1 to 3, a load detector is provided between the leg portion of the bed or between the leg portion and the floor to directly measure the load, or torque that indirectly measures the load to the lifting mechanism of the floor portion. It is described that a sensor is provided. Patent Documents 4 and 5 describe providing a load detector on the frame of the bed.

JP-A-2-280733 Japanese Patent No. 3093745 Japanese Patent No. 3322632 Japanese Patent No. 4818162 Japanese Patent No. 4551417 Japanese Patent No. 4857156

  On the other hand, recently, as described in Patent Document 6, an electric bed has been put into practical use. However, conventionally, there has not been a load measuring sensor that can be easily used in an existing bed.

The present invention, wherein those so has been made to solve the conventional problems, the Protection System using a bed watching with a load measuring sensor using readily available strain gauges in existing bedding The issue is to provide.

The present invention relates to a monitoring bed having a load measuring sensor using a strain gauge, a signal processing unit for processing the output of the load measuring sensor to simultaneously obtain a biological signal, a load and a center of gravity, and the signal processing. A display system for displaying a processing result of the unit, wherein the signal processing unit superimposes the load signal amplifying unit for amplifying the output of the load measuring sensor and the load signal. An analog biological offset tracking unit and a biological signal amplification unit for extracting a biological signal, and an A / D conversion unit that obtains a biological AD value by A / D converting the output of the biological signal amplification unit; become biological AD value is a value close to the center of the living full-scale range and amplitude to dynamically control the offset and gain of the load signal to be within a predetermined range, digital biological offset By including the following processing unit, it is obtained by solving the above problems.

Here, the signal processing unit, the output of a load measuring sensor, in addition to negative-phase output of the other of the load measuring sensor, respiration, can be made to cancel the noise on the biological signals including the heartbeat.

According to the present invention, for example, a load signal and a biological signal can be simultaneously acquired by a load measuring sensor (for example, a pin sensor) using a strain gauge inserted as a connecting pin in a connecting portion between a plurality of frames of a bed, for example, upper and lower frames. As a result, the load measuring sensor can be easily used for the existing bed, and the patient movement based on the biological signal corresponding to the slight change in the load detected by the load measuring sensor. Biometric information about breathing, heartbeat can be easily acquired.

Furthermore, by mounting the sensor the load measuring the bed, can be easily realized bed watching has a load measurement function.

  Furthermore, a watching system can be easily realized by using the watching bed.

The perspective view which looked at the example of the whole structure of the electric bed to which embodiment of the pin sensor of the example used by this invention is attached from diagonally upward. Similarly perspective view from below Similarly, an enlarged perspective view of the head side of the electric bed as seen from above Similarly, a drawing substitute photo showing the pin sensor mounting state of the embodiment The perspective view which shows the (A) structure of 1st Embodiment of a pin sensor, and (B) Sectional drawing which shows an attachment state Similarly, (A) a perspective view showing a configuration of the second embodiment, (B) a sectional view showing an attached state, and (C) a sectional view showing a cross section of a pin sensor and a pin sensor receiving portion on the stay side. The block diagram which shows the whole structure of the 1st Example of the monitoring system which employ | adopted 2nd Embodiment. The top view which shows the arrangement | positioning position to the bed of the pin sensor similarly used as a connection pin The figure which similarly shows the example of the signal change during (A) biological signal and (B) process Flow chart showing the procedure for processing biological signals The figure which shows the example where the noise was canceled similarly The top view which shows the example of the sample point of the load table similarly used by a gravity center position detection process The top view which similarly shows the example of a detection of the gravity center between two points The top view which similarly shows the example which detects the center-of-gravity position on a bed from the center of gravity between two points The figure which shows the whole structure of 2nd Example of the watching system which added the camera. The figure which shows an example of the monitor screen of 2nd Example Figure showing another example

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In addition, this invention is not limited by the content described in the following embodiment and an Example. In addition, the constituent elements in the embodiments and examples described below include those that can be easily assumed by those skilled in the art, those that are substantially the same, and those in the so-called equivalent range. Furthermore, the constituent elements disclosed in the embodiments and examples described below may be appropriately combined or may be appropriately selected and used.

The electric bed 10 to which the embodiment of the pin sensor of the example used in the present invention is attached mainly includes an upper frame 20 capable of moving up and down and a lower frame 50 containing moving wheels 52 as shown in FIGS. I have.

  On the upper frame 20, a back bottom 22, a waist bottom 24, a knee bottom 26, and a foot bottom 28 are provided in order from the patient's head to the foot.

  Cylindrical pipes (referred to as horizontal pipes) 30, 36, 54, 60 are provided in the lateral direction on the patient head side and the foot side of the upper frame 20 and the lower frame 50, respectively.

  The electric bed 10 is configured such that the upper frame 20 that supports the back bottom 22 and the like moves up and down by the movement of a pipe (referred to as an outer pipe) 92 (refer to FIG. 2) that constitutes a rod of the actuator. Thereby, the height of the upper frame 20 can be adjusted.

  Below the back bottom 22, waist bottom 24, knee bottom 26, and foot bottom 28, a back raising device (not shown) for raising the back bottom 22 and a knee raising device (not shown) for raising the knee bottom 26. Is omitted).

  The upper frame 20 and the lower frame 50 are respectively a right stay 32 and a left stay 34 fixed to both sides of the upper frame head side horizontal pipe 30, and a right stay 38 and a left side fixed to both sides of the upper frame foot side horizontal pipe 36. There are a stay 40, a right stay 56 and a left stay 58 fixed to both sides of the lower frame head side horizontal pipe 54, a right stay 62 and a left stay 64 fixed to both sides of the lower frame foot side horizontal pipe 60, and correspondingly. The stays 32 and 56, 34 and 58, 38 and 62, 40 and 64 are connected by connecting pins 71, 72, 73 and 74, respectively, as illustrated in the case of the stays 34 and 58 in FIG.

  In the first embodiment of the pin sensor, a pin sensor 70 as shown in FIG. 5 is used as the connecting pins 71 to 74.

  In the first embodiment of the pin sensor 70 exemplifying the case of the connection pin 71 in FIG. 5, the two force point portions 80 and 82 where the load of the upper frame 20 acts via the stay 32, for example, and the stress of the lower frame 50, for example, A fulcrum part 84 that acts via a stay 56, sensing parts 81, 83 that connect the force point parts 80, 82 and the fulcrum part 84, a shaft part 86 and a head part 88, and the force point part 80, the fulcrum part 84. And a strain gauge 90 that converts the strain generated in the sensing part 83 between the fulcrum part 84 and the force point part 82 into an electrical signal.

  The force point portions 80 and 82 and the fulcrum portion 84 are cylindrical.

  The sensing parts 81 and 83 are long in the horizontal direction and have a horizontally long prismatic shape having a necessary thickness in the vertical direction so as to ensure the strength as a connecting pin.

  In the present embodiment, the pin shape of the existing bed is maintained and can be replaced.

  In addition, this shape is used in order to clearly separate the portion to which the load is applied from the portion to be distorted.

  The strain gauges 90 are affixed to the upper and lower surfaces of the sensing parts 81 and 83, for example, by a bending method, and the outputs of the four strain gauges 90 provided above and below across the fulcrum part 84 are connected in a bridge shape. By doing so, the distortion can be detected with high sensitivity. Here, the strain gauge can be one, two, and four. The accuracy increases as the number increases. In the present embodiment, the number is four, and a bridge circuit is configured by four strain gauges.

  A second embodiment of the pin sensor 70 is shown in FIG. In the present embodiment, the portions of the first embodiment that are in contact with the frame side (here, stays 32 and 56) of the force point portions 80 and 82 and the fulcrum portion 84 are formed in a spherical shape, and the force is captured by points. As a result, as illustrated in FIG. 6B, even if the stay (32) is displaced in the axial direction, the position in contact with the force application point (80, 82) is not substantially changed. Further, even if the stay (56) is displaced in the axial direction, the position in contact with the fulcrum (84) is not substantially changed. Therefore, the displacement of the pin sensor 70 and the frame (32, 56) does not affect the fulcrum / power point, and the variation in the load value due to the axial displacement is reduced.

  Furthermore, in the second embodiment, as shown in FIG. 6C (a cross-sectional view seen from the direction of arrow C in FIG. 6B), for example, the cross-section of the center fulcrum portion 84 of the pin sensor 70 is square. The pin sensor 70 is prevented from rotating by adopting a shape and the corresponding cross section of the pin sensor receiving portion on the frame side (stay 56) also having a corresponding rectangular shape.

  The sensing parts 81 and 83 of the second embodiment are vertically long and long in the vertical direction and have a required thickness in the horizontal direction, so as to ensure strength as a connecting pin.

  The strain gauges 90 of the present embodiment are of a shear type, and the outputs of a total of four strain gauges 90 that are affixed symmetrically at 45 ° diagonally to the front and rear side surfaces of the sensing parts 81 and 83 are connected in a bridge shape. Thereby, the shear strain generated from the load applied to the fulcrum portion 84 and the force point portions 80 and 82 can be detected with high sensitivity. Here, the strain gauge can be one, two, and four. The accuracy increases as the number increases. In the present embodiment, the number is four, and a bridge circuit is configured by four strain gauges.

  A configuration similar to that of the fulcrum part 84 of the second embodiment can be added to the fulcrum part 84 and the force point parts 80 and 82 of the first embodiment to prevent rotation of the pin sensor 70 of the first embodiment.

  The first embodiment can be a shearing method and the second embodiment can be a bending method.

  In this way, it is possible to detect the load applied to the connecting portion of the upper and lower frames of the bed casing. From now on, the vibration applied to the casing of the electric bed 10 due to the load applied to the portion and the change thereof ( Wave) and biological information including respiration and heartbeat can be detected. Therefore, it is possible to detect the breathing and heartbeat of a sleeping person in a non-contact manner simply by sleeping on the electric bed 10.

  The position where the pin sensor 70 is used is not limited to the positions of the connecting pins 71 to 74, and may be other four points where the total load of the bed is applied. Depending on the structure of the bed, the score is not limited to four.

  FIG. 7 shows an overall configuration of a first example of the watching system according to the present invention in which the second embodiment of the pin sensor is adopted.

  In this 1st Example, each pin sensor 71-74 is each arrange | positioned at the head side of the electric bed 10, and the right and left of the leg | foot side, as shown in FIG.

  Here, in order to obtain biological information such as respiration and heartbeat, for example, by using at least two diagonal sensors such as pin sensors 71 and 74 or 72 and 73, it is possible to detect biological signals in the entire bed. It becomes.

  Further, in order to obtain the load / center of gravity information, the load and the center of gravity can be detected with high accuracy by using all the pin sensors 71 to 74.

  The outputs of the pin sensors 71 to 74 are input to the load signal amplifying unit 102 of the signal processing unit 100 as shown in FIG. Of the pin sensor outputs amplified by the load signal amplifying unit 102, for example, the outputs of the pin sensors 71 and 74 are input to the biological offset follower 104. The output of the biological offset follower 104 is input to the biological signal amplifier 106. The output of the biological signal amplification unit 106 is converted into a digital signal by the biological A / D conversion units 108A and 108B, and then includes a biological signal including a respiration detection unit 110A, a heart rate detection unit 110B, and a biological offset follow-up processing unit 110C. Input to the detection unit 110.

  The change range of the biological signal with respect to the change range of the entire load value of the pin sensor output signal is very small as illustrated in FIG. Therefore, the biological offset tracking processing unit 110C performs tracking processing as shown in FIGS. 9B and 10 to find a biological signal.

  Specifically, first, in step 1100 of FIG. 10, the output signals of the pin sensors 71 and 74 are amplified by the load signal amplifying unit 102 and the biological signal amplifying unit 106.

  Next, in step 1110, the biological A / D converters 108A and 108B are input to acquire the biological AD value. A waveform obtained by arranging the signals acquired here in time series is a biological signal.

  First, a biological offset range setting process is performed on the biological signal.

  Specifically, the process proceeds to step 1120, and it is determined whether or not the biological signal is in the biological AD full scale.

  If the determination result is No, the process proceeds to step 1130, where the biological offset is greatly changed, and the biological AD value is adjusted to be closest to the center of the biological AD full scale range.

  When the determination result in step 1120 is Yes, the process proceeds to step 1140 to perform a biological offset rough adjustment process.

  Specifically, in step 1140, the living body offset is changed to a medium level more finely than the living body offset range process, and the living body AD value is adjusted to be a value close to the center of the living body AD full scale range.

  When the result of step 1150 is Yes, biological offset fine adjustment processing is performed.

  Specifically, in step 1160, the biosignal gain is set for fine adjustment, and the signal is amplified. In step 1170, the offset of the biological signal is finely adjusted so that the entire amplitude of the biological signal falls within the fine adjustment range from the fine adjustment upper limit to the fine adjustment lower limit.

  If it is determined in step 1180 that the entire amplitude of the biological signal is within the fine adjustment range from the fine adjustment upper limit to the fine adjustment lower limit, the process of finding the biological signal ends.

  On the other hand, the output signals of the four pin sensors 71 to 74 are amplified by the load signal amplifying unit 102 and then input to the A / D conversion units 112A, 112B, 112C, and 112D for A / D conversion. Get the load AD value.

The load value on the bed is detected according to the following flow.
First, 1. The load AD value immediately after turning on the power and immediately after resetting is set to 0 offset value.
Then, 2. The value obtained by subtracting the 0 offset value from the load AD value when a load is applied on the bed is multiplied by a sensitivity correction coefficient for correcting a difference in sensitivity for each pin sensor. This is the load value for each pin sensor.
Next, 3. By summing the load values for each pin sensor, the load value on the bed can be detected.

  The load value obtained in real time on the bed in this manner is input to the load / centroid detection unit 114 including the load / centroid table 114A, the load detection unit 114B, and the center of gravity detection unit 114C.

  At this time, the opposite phase of the output signals of the foot-side pin sensors 73 and 74 is added to the output signals of the head-side pin sensors 71 and 72 to cancel the external noise caused by the floor superimposed on the electric signal and the vibration of the air. Accuracy can be improved. Since biological vibrations are also present in the foot-side pin sensors 73 and 74, biological signals are also attenuated. However, the effect of attenuating external noise due to floor and air vibrations is high, so the S / N ratio is improved. In the example, as illustrated in FIG. 11, it was confirmed that the vibration noise was reduced by about 50%, but the biological signal was reduced by about 30%, and the S / N ratio was improved by 1.4 times or more.

  The on-bed center of gravity position detection in the load detection unit 114B can be performed, for example, as follows.

  Here, the center-of-gravity position is detected based on the ratio of the load value for each of the four pin sensors, using the load value on the bed for each pin sensor previously obtained.

First, based on the load value on the bed for each pin sensor and the load table as shown in Table 1, the center of gravity position between the two points for each of the following two combinations of the four pin sensors 71 to 74 is calculated. To detect.
-Two points on the right head sensor 71 and the left foot sensor 72-Two points on the right head sensor 71 and the right foot sensor 73-Two points on the left head sensor 72 and the left foot sensor 74-On the right foot sensor 73 and the left foot Two points on sensor 74

  For example, when calculating the position of the center of gravity from two points on the right head sensor 71 and the left head sensor 72, the following is performed.

  First, the ratio of the right head load and the left head load with respect to the total of the four loads is calculated. In order to calculate the load ratio, a load table as shown in Table 1 is used.

  Table 1 shows the ratio of the load applied to the four pin sensors when a load is applied at each sample point in FIG.

1A) The position of the center of gravity that may become the right head load ratio with respect to the total of four points on the bed is calculated by linear interpolation from the load table as illustrated in FIG. FIG. 13 shows an example of linear interpolation at a position where the right head load ratio is 10%.
1B) The position of the center of gravity which may become the left head load ratio with respect to the total of four points on the bed is calculated from the load table by linear interpolation. FIG. 13 shows an example of linear interpolation at a position where the left head load ratio is 10%.
1C) The intersection of a linear interpolation line with a right head load ratio of 10% and a linear interpolation line with a left head load ratio of 10% is calculated. This is the position of the center of gravity between the two points on the right head sensor 71 and the left head sensor 72 (see FIG. 13).

2) Next, the on-bed barycentric position is detected from “the barycentric position with respect to two points” in the four pin sensors 71 to 74. That is, the following four “centroid positions with respect to two points” are detected by the processing of 1).
-Two points on the right head sensor 71 and the left foot sensor 72-Two points on the right head sensor 71 and the right foot sensor 73-Two points on the left head sensor 72 and the left foot sensor 74-On the right foot sensor 73 and the left foot Two points on sensor 74

  Therefore, as illustrated in FIG. 14, the center of gravity position on the bed is detected from the intersection of these four “center positions of the two points”.

  The outputs of the load / center-of-gravity detection unit 114 and the biological signal detection unit 110 are input to a floor detection unit 116 including a floor detection unit 116A, a wake-up detection unit 116B, and a bed detection unit 116C. Is done.

  The output of the away floor detection unit 116 is input to the communication unit 118 and input to and displayed on the display unit 120 including the load display unit 120A, the center of gravity display unit 120B, the respiration rate display unit 120C, and the heart rate display unit 120D. The

  Next, with reference to FIG. 15, a second embodiment of the monitoring system with a monitor camera added will be described.

  As shown in FIG. 15, in addition to the first embodiment of the watching system similar to FIG. 7, this second embodiment further has a visual field from the foot side to the head side, for example, provided on the foot board of the electric bed 10. Directed monitor camera 200 and an image recognition unit 210 for recognizing human body parts (head 8A, torso 8B, hand 8C, foot 8D, etc.) of patient 8 as objects or parts.

  The arrangement position of the monitor camera 200 is not limited to the footboard, and may be another position where the entire view of the bed can be taken.

  According to the second embodiment, in addition to the center of gravity detection result of the first embodiment, the object and parts of the patient 8 are recognized from the image of the monitor camera 200, and more accurate watching is performed according to the recognition result. be able to. That is, a highly reliable determination can be made by combining the two-dimensional image obtained by the monitor camera 200 and the bed information.

  For example, as shown in FIG. 16, when it is detected by the pin sensors 71 to 74 that the center of gravity is located at the end of the electric bed 10, and the patient image 8 is detected as being in the end sitting position as a result of the camera image recognition, it is watched as it is. Continue.

  On the other hand, as shown in FIG. 17, when it is determined that the patient 8 is sleeping, it is determined that there is a risk of falling or the like and a necessary action is taken such as generating an alarm.

  Thus, a highly reliable determination can be made by combining the two-dimensional image obtained by the monitor camera 200 and the bed information.

  Also, for example, video data can be recorded only when an event such as getting out of bed or falling or falling occurs.

  Furthermore, dangerous behavior can be predicted by converting information on a living body, a load, a center of gravity, and human behavior in real time and performing machine learning.

  The arrangement position and direction of the monitor camera 200 are not limited to the example of FIG.

  In the above embodiment, the present invention is applied to an electric bed, but the application target of the present invention is not limited to this, and a non-electric care bed, a medical bed, a care lift, and a healthy person It can also be applied to beds.

  The object to which the pin sensor is attached is not limited to an existing bed, and can be used by attaching it to a new bed from the beginning.

  The relationship between the frames is not limited to the upper and lower sides.

8 ... Patient 10 ... Electric bed 20 ... Upper frame 30, 36, 54, 60 ... Horizontal pipe 32, 34, 38, 40, 56, 58, 62, 64 ... Stay 50 ... Lower frame 70 ... Pin sensors 71-74 ... Connection Pins 80, 82 ... Power point portion 81, 83 ... Sensitive portion 84 ... Supporting point portion 86 ... Shaft portion 90 ... Strain gauge 100 ... Signal processing unit 102 ... Signal amplification unit for load 104 ... Biological offset follow-up unit 106 ... Signal amplification for biological matter 108A, 108B ... A / D conversion unit for living body 110 ... Biological signal detection unit 110A ... Respiration detection unit 110B ... Heart rate detection unit 110C ... Biological offset follow-up processing unit 112A, 112B, 112C, 112D ... A / D conversion unit for load 114 ... Load / gravity center detection unit 114A ... Load / gravity center table 114B ... Load detection unit 114C ... Center of gravity detection unit 116 ... Staying floor Exiting part 116A ... Bed detection part 116B ... Waking up detection part 116C ... Bed leaving detection part 118 ... Communication part 120 ... Display part 120A ... Load display part 120B ... Center of gravity display part 120C ... Respiration rate display part 120D ... Heart rate display part 200 ... Monitor camera 210 ... Image recognition unit

Claims (2)

A watching bed with a load measuring sensor using a strain gauge;
A signal processing unit for processing the output of the load measuring sensor to simultaneously obtain a biological signal, a load and a position of the center of gravity;
Display means for displaying the processing result of the signal processing unit;
A monitoring system with
The signal processing unit amplifies the output of the load measurement sensor, a load signal amplifying unit , an analog biometric offset follow-up unit and a biomedical signal for extracting a biometric signal superimposed on the load signal An amplification unit, an A / D conversion unit that obtains a biological AD value by A / D converting the output of the biological signal amplification unit, and the biological AD value is a value close to the center of the biological full-scale range, and the amplitude And a digital biological offset follow-up processing unit that dynamically controls the offset and gain of the load signal so that is within a predetermined range. The signal processing unit is configured so as to cancel a noise with respect to a biological signal including respiration and heartbeat by adding a phase opposite to an output of another load measuring sensor to an output of a certain load measuring sensor. The watching system according to claim 1.