A device for measuring respiratory status in real time and a method thereof

Abstract

The present application discloses a device for measuring respiratory status in real time and its measuring method, characterized in that, including a main unit and a cable, a cable pulley is provided in the main unit, one end of the cable is wound around the cable pulley and the other end is fixed, a spring is provided between the cable pulley and the central rotating shaft, the spring provides a tightening torque to keep the cable pulley in a taut state, and an angle sensor and a signal collector are also provided in the main unit; the cable pulley is set as an inelastic thin wire, is worn around the human chest or abdomen, and the human body breathes to bring about a change in the outline of the body, and the cable pulley rotates with the change in the outline of the body, the angle sensor measures the angle of rotation of the cable pulley, and the signal collector collects and measures the measurement signal. Using the device provided by the present application, the changes in the outline of the body brought about by breathing can be monitored, and it can be used for respiratory training and can also be used for respiratory monitoring in daily life.

Description

Technical Field

[0001] The present application relates to a device for measuring respiratory status in real time and a measurement method thereof, belonging to the field of medical measurement technology. Background Art

[0002] Currently, the primary method for measuring respiratory status is with a measuring tape. After taking a deep breath, hold your breath and measure your chest circumference once. After taking a deep breath, hold your breath and measure again. The difference between the two is the chest circumference difference. This method only measures the chest circumference difference, lacks real-time data, cannot reflect respiratory rate, and requires assistance from an outsider.

[0003] Some existing technologies have explored the use of piezoelectric components, such as PVDF film, either alone or in combination with other materials, to form a chest strap. This approach uses the pressure changes generated by the user's breathing to measure the voltage across the piezoelectric component to monitor breathing conditions. While this method is convenient, it suffers from numerous technical drawbacks. The first is the friction between the strap and the body, with each part of the strap bearing some pressure. Therefore, the pressure felt by the piezoelectric component may not fully correspond to the pressure generated by breathing, making it difficult to compare different measurements. A second issue is the physical change in body contour caused by breathing (a distance), which also does not fully correspond to the pressure (a force) exerted by the piezoelectric component. Furthermore, the cushioning provided by body fat and clothing results in poor data reproducibility. A third issue is the inherent consistency of the piezoelectric film itself and its relaxation over time, which can also make the data unreliable. Therefore, chest or abdominal straps using piezoelectric components are currently only conceptual and have yet to enter practical use. Summary of the Invention

[0004] The purpose of this application is to provide a device that can monitor the changes in body contour caused by breathing and thus determine the breathing condition, so as to provide guidance for breathing training.

[0005] In order to achieve the above-mentioned purpose, the technical solution of the present application is to provide a device for real-time measurement of respiratory conditions, including a main unit and a pull wire, a pull wire wheel is provided in the main unit, one end of the pull wire is wound around the pull wire wheel and the other end is fixed, a clockwork spring is provided between the pull wire wheel and the central rotating shaft, the clockwork spring provides a tightening torque to keep the pull wire in a taut state, and an angle sensor and a signal collector are also provided in the main unit; the pull wire is set as an inelastic thin wire, which is worn around the human chest or abdomen. The human body's breathing causes changes in body contour, and the pull wire drives the pull wire wheel to rotate as the body contour changes. The angle sensor measures the rotation angle of the pull wire wheel, and the signal collector collects the measurement signal.

[0006] Preferably, the angle sensor is configured as a rotary potentiometer, and the angle sensor is coaxially mounted with the wire pulling wheel.

[0007] Preferably, the host is further provided with a communication module, the communication module is connected to the monitoring terminal, and the data collected by the signal collector is transmitted to the monitoring terminal via the communication module; the monitoring terminal is set to be a computer, a mobile phone or a tablet computer.

[0008] Optionally, an elastic band is provided between the pull cord and the human body, the elastic band being configured as an elastic and retractable elastic band, with both ends of the elastic band being fixed to both sides of the main unit; the pull cord and the elastic band are configured as a double-layer wearable structure, thereby avoiding skin damage caused by using only the pull cord or inaccurate measurement caused by the pull cord getting stuck in the skin.

[0009] Alternatively, an elastic belt is provided between the pull line and the human body, and the elastic belt includes an elastic belt segment one and a fixed belt segment two. The elastic belt segment one is set as an elastic and stretchable elastic belt, and the fixed belt segment two is set as an inelastic and non-stretchable non-elastic belt, and the pull line is fixed on the fixed belt segment two.

[0010] Preferably, the elastic band is provided with spaced-apart pull-wire limiting sleeves, through which the pull wire passes.

[0011] The present application also provides a method for measuring respiratory status in real time, using the above-mentioned device for measuring respiratory status in real time, and the steps are as follows:

[0012] Step 1: Assume the maximum rotation angle between two sampling intervals is a. a is determined by the diameter of the wire pulley; the larger the diameter, the smaller a. In a reasonable design, a should not exceed 180 degrees, and preferably not exceed 90 degrees.

[0013] Step 2: Use variable n to record the current number of revolutions. When the device is first powered on, n is initialized to 0. n can be a positive integer, 0, or a negative integer.

[0014] Step 3: Use variable e to record the angle obtained by the angle sensor 5. The range of e is greater than or equal to 0 degrees and less than 360 degrees.

[0015] Step 4: The actual rotation angle of the cable pulley during operation is recorded as g: g = n * 360 + e. Multiplying g by a coefficient r gives the displacement l. The two are in a simple linear proportional relationship: l = r * g. r is determined by the cable pulley diameter. l is the device's final output: the change in cable length.

[0016] Step 5: Initial measurement, n is 0, continuous sampling to obtain a sequence of e, the x-th sampling result is recorded as ex; check the difference d = ex - ex - 1, and handle it according to the following situations:

[0017] When the absolute value of d is less than a, it is normal and no special treatment is required. Calculate g and l according to the formula in step 4.

[0018] When the absolute value of d is not less than a, but d is less than 0 and d+360 is less than a, then add 1 to n and calculate g and l;

[0019] When the absolute value of d is not less than a, but d is greater than 0 and 360-d is less than a, then subtract 1 from n and calculate g and l;

[0020] The rest of the cases are abnormal and will be handled as errors after the alarm is triggered;

[0021] Step 6: The device continues to operate and processes according to step 5. The obtained series of data are the real-time changes of the body contour during breathing.

[0022] The advantage of this application is that the device provided by this application can monitor the changes in body contour caused by breathing, and can be used for breathing training as well as breathing monitoring in daily life. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 Schematic diagram of a device for real-time measurement of respiratory status provided in an embodiment;

[0024] Figure 2 A schematic diagram of the internal structure of a host provided in an embodiment;

[0025] Figure 3 1 is a system block diagram of a device for measuring respiratory status in real time provided in an embodiment;

[0026] Figure 4 A schematic diagram of a host housing provided in an embodiment;

[0027] Figure 5 Schematic diagram of the wire pulling wheel structure provided in the embodiment, which also shows the wiring terminals for fixing the wire pulling wire. DETAILED DESCRIPTION

[0028] In order to make the present application more clear and easy to understand, preferred embodiments are described in detail below with reference to the accompanying drawings.

[0029] Example

[0030] This embodiment provides a device and method for measuring respiratory status in real time, the structure of which is as follows: Figure 1 、 Figure 2 As shown, the structural diagram is as follows Figure 3 As shown, it includes a main unit 1 and a cable 2. A cable pulley 3 is provided in the main unit 1. One end of the cable 2 is wound around the cable pulley 3. A spring 4 is provided between the cable pulley 3 and the central shaft. The spring 4 provides a tightening torque to keep the cable 2 in a taut state at all times. A power supply, an angle sensor 5 and a signal collector are also provided in the main unit 1.

[0031] The pull wire 2 is an inelastic thin wire that is worn around the chest or abdomen of the human body. One end of the pull wire 2 is wrapped around the pull wire wheel 3, and the other end is fixed to the shell of the main unit 1; there is no limit to the fixing method, and it can be in various forms such as binding, locking or Velcro; breathing causes changes in body contour, and the pull wire 2 drives the pull wire wheel 3 to rotate as the body contour changes.

[0032] The wire pulley 3 is a circular wheel with an edge around which the wire can be wound, and can rotate around a central axis set in the main unit; the wire pulley 3 can store and release the wire 2 by rotating; the wire pulley 3 is assembled with the spring 4 through a fastening structure.

[0033] In a possible implementation, the clockwork spring 4 is preferably a flat spiral spring, which has the function of generating a retracting tightening torque on the pulling wheel 3 when the pulling wire 2 on the pulling wheel 3 is pulled out. Because of the existence of this tightening torque, the pulling wire 2 can be kept taut at all times.

[0034] The mechanism formed by the cable 2, cable reel 3, and spring 4 converts changes in the cable's length outside the main unit 1 into the rotation angle of the cable reel 3. Because the cable 2 is constantly taut, changes in its length outside the main unit 1 perfectly align with changes in the body's contour caused by breathing; thus, changes in the body contour caused by breathing are converted into changes in the angle of the cable reel 3.

[0035] The angle sensor 5 is coaxially mounted with the cable pulley 3 and is used to measure the rotation angle of the cable pulley 3. In a possible implementation, the angle sensor 5 is preferably a rotary potentiometer that can rotate back and forth an unlimited number of times. This is because if the potentiometer can rotate back and forth an unlimited number of times, the size of the host can be greatly reduced. If the potentiometer can only rotate back and forth less than one circle, a cable pulley with a larger diameter is required to measure the entire range, and the host size will exceed the comfort level of the human body.

[0036] Specifically, the method for measuring the respiratory status in real time using the above device is as follows:

[0037] When the angle sensor rotates multiple times, it will inevitably cross the limit, meaning it will jump from 0 degrees to 360 degrees, or vice versa. Therefore, two design measures must be taken to address this issue. The first measure is a signal analysis algorithm that determines the angle sensor's rotation direction based on the previously sampled value queue. When the signal crosses the limit, it adds or subtracts 360 degrees based on the current rotation direction as the base value for subsequent data. The second measure is to ensure that the first measure can be implemented smoothly. This means that the sampling frequency must be fast enough so that during normal use, the angle sensor will not rotate more than 180 degrees between two samples, and preferably no more than 90 degrees.

[0038] Based on the rate of rapid breathing, the amplitude of body contour changes, and the circumference of the wire pulley, we can infer that the sampling interval should be at least 20 times per second, preferably 50 times per second, and even more preferably 100 times per second. This interval is limited by the circuit hardware capabilities and cannot be increased arbitrarily. 100 times per second can be achieved on economical embedded hardware.

[0039] The specific steps are as follows:

[0040] Step 1: Assume that the maximum rotation angle between two sampling intervals is a. a is determined by the diameter of the wire pulley; the larger the diameter, the smaller a. In a reasonable design, a should not exceed 180 degrees, and preferably not exceed 90 degrees.

[0041] Step 2: Use variable n to record the current number of revolutions. When the device is first powered on, n is initialized to 0. n can be a positive integer, 0, or a negative integer.

[0042] Step 3: Use variable e to record the angle obtained by the angle sensor 5. The range of e is greater than or equal to 0 degrees and less than 360 degrees.

[0043] Step 4: The actual rotation angle of the cable pulley during operation is recorded as g: g = n * 360 + e. Multiplying g by a coefficient r gives the displacement l. The two are in a simple linear proportional relationship: l = r * g. r is determined by the cable pulley diameter. l is the device's final output: the change in cable length.

[0044] Step 5: Initial measurement, n is 0, continuous sampling to obtain the sequence of e, the one obtained by the xth sampling is recorded as e x ; Check the difference d=e x -e x-1 , which are divided into the following situations:

[0045] When the absolute value of d is less than a, it is normal and no special treatment is required. Calculate g and l according to the formula in step 4.

[0046] When the absolute value of d is not less than a, but d is less than 0 and d+360 is less than a, then add 1 to n and calculate g and l;

[0047] When the absolute value of d is not less than a, but d is greater than 0 and 360-d is less than a, then subtract 1 from n and calculate g and l;

[0048] The rest of the cases are abnormal and will be handled as errors after the alarm is triggered;

[0049] Step 6: The device continues to operate and processes according to step 5. The obtained series of data are the real-time changes of the body contour during breathing.

[0050] The host 1 is connected to the communication module via an internal signal collector, such as Bluetooth, to exchange data with the monitoring terminal, which displays the data, such as real-time curves, etc. The monitoring terminal can be a computer, a mobile phone, or a tablet computer.

[0051] The above measurement method and implementation algorithm can be run in the monitoring terminal or in the host computer. It is preferably run in the monitoring terminal because it can reduce the cost of the host computer, and the monitoring terminal usually has stronger data processing capabilities.

[0052] In a possible embodiment, an elastic band 6 is provided between the pull wire 2 and the human body. Multiple pull wire limiting sleeves 61 are spaced apart on the elastic band 6. The pull wire 2 passes through the pull wire limiting sleeves 61. The pull wire limiting sleeves 61 restrict the pull wire 2 to the elastic band 6 to prevent it from escaping. It should be noted that the elastic band 6 is provided to prevent the pull wire 2 from directly contacting the human body when the device is in use, thereby improving the user experience. The elastic band 6 and the pull wire limiting sleeves 61 are not required for measurement and are auxiliary components.

[0053] The elastic band 6 is a stretchable elastic band, with its ends fixed to the sides of the main unit 1. This allows the main unit 1 to be conveniently wrapped around the chest or abdomen, preventing it from moving up and down during breathing and preventing the user from feeling any breathing obstruction. The elastic band 6 also serves another important purpose: it prevents the cable 2 from rubbing against the body during movement, causing damage. The elastic band 6 adheres to the body, and the cable 2 forms a double-layered band structure outside the fixed band.

[0054] The wire limiting sleeve 61 is a wire limiting device, which is used to prevent the wire 2 from running outside the elastic belt 6 and limit the area of ​​the wire 2. The method is to install several fixed or movable rings on the elastic belt 6, and the wire 2 is placed in the ring and constrained by the ring.

[0055] In a possible embodiment, the elastic band 6 is configured as two sections, including an elastic band section 1 62 and a fixed band section 2 63. The elastic band section 1 62 is configured as an elastic and stretchable elastic band, and the fixed band section 2 63 is configured as an inelastic and non-stretchable non-elastic band. One end of the pull wire 2 is wound around the pull wheel 3 in the main unit 1, and the other end does not need to be fixed on the main unit 1, but only needs to be fixed on the fixed band section 2 63. With this implementation structure, the pull wire 2 does not need to be wound around the main unit, and only a part of the length is needed. This can solve the problem that the main unit 1 is too large due to the excessive length of the pull wire 2. With this structure, the difference is that the pull wire 2 is fixed to one end of the fixed band section 2 63, and the fixed band section 2 63 is connected to the main unit 1. The pull wire 2 and the elastic band section 1 62 do not need to be fixedly connected to the main unit.

[0056] The advantage of using the device provided in this application is that similar products currently on the market include sleep monitoring belts, which are strips of piezoelectric material used to monitor the presence and frequency of breathing during sleep. These products cannot detect changes in body contour caused by breathing and cannot be used for respiratory training. The device provided in this embodiment can monitor changes in body contour caused by breathing with an accuracy of millimeters. It is mainly used for respiratory training, but can also be used for respiratory monitoring in daily life.

[0057] In a possible embodiment, unlike the aforementioned wire limiting device which uses a wire limiting sleeve 61 to fix the wire and prevent it from moving out of the elastic band area (if it moves out, it may directly rub the skin), the wire limiting device can also be a long sleeve that completely hides the wire 2, which is more aesthetically pleasing. Alternatively, a double-layer elastic band or a tubular elastic band can be used to hide the wire 2 or the outer sleeve of the wire 2 inside; this structure is more user-friendly.

[0058] Real-time measurement of breathing status:

[0059] The measured body contour changes are plotted with time on the horizontal axis and contour change on the vertical axis. These points are then connected to form a curve. The curve is a series of peaks and valleys, each representing a single breath. The peak is when the contour is at its maximum, and the valley is when it is at its minimum. In practical use, in addition to the number of breaths, the following key values ​​need to be extracted from the graph: inhalation rate, inhalation depth, breath-holding time, and exhalation rate.

[0060] The inspiratory rate measures the ratio of the height reached in the first second of inspiration to the peak height, while the physiological indicator corresponds to the ratio of the inspiratory volume in the first second. If the ratio falls below a certain value, such as 70%, a warning prompt will be issued.

[0061] The inspiratory depth is the peak height, and the corresponding physiological indicator is vital capacity. If it is lower than the height that the corresponding gender can reach, a warning will be issued.

[0062] The breath-holding time is the peak duration. If it is lower than the value that can be achieved for the corresponding age, a warning will be issued.

[0063] The exhalation rate determines the ratio of the height descended in the first second to the total height at the start of exhalation. This physiological indicator corresponds to the ratio of the exhaled volume in the first second. If it falls below a certain ratio, such as 60%, a warning is issued.

[0064] This process can be very effective in training patients, allowing them to gradually reach target levels and improve their respiratory conditions through visualization and warnings. Doctors can also monitor their patients' actual respiratory conditions through data.

[0065] It should be noted that the angle sensor has a linear region, which is generally less than 360 degrees, such as 320 degrees. In this linear region, the angle can be obtained through a proportional relationship. But outside this region, that is, in the nonlinear region, if the proportional relationship is continued to be used to obtain the angle, there will be a certain error. In implementations with high precision requirements, a calibration algorithm is required. A table lookup method can be used to process the nonlinear region. That is, the relationship between the measured value and the angle of the angle sensor in the nonlinear region is measured in advance. This nonlinear table is then written into the host. When the host finds that the range of the resistance value is in the nonlinear region, the angle value is obtained by looking up the table instead of by calculation. Through a series of designs and algorithms, the technical solution of the present application can achieve millimeter-level accuracy even in the nonlinear measurement area.

Claims

1. A method for measuring respiratory status in real time, characterized in that: The following device is used for measurement, including a main unit (1) and a cable (2), wherein a cable pulley (3) is provided in the main unit (1), one end of the cable pulley (2) is wound around the cable pulley (3) and the other end is fixed, a spring spring (4) is provided between the cable pulley (3) and the central rotating shaft, and the spring spring (4) provides a tightening torque to keep the cable pulley (2) in a taut state, and an angle sensor (5) and a signal collector are also provided in the main unit (1); the cable pulley (2) is set as an inelastic thin wire, which is worn around the chest or abdomen of the human body; the body contour changes due to human breathing, and the cable pulley (2) drives the cable pulley (3) to rotate with the change of the body contour, the angle sensor (5) measures the rotation angle of the cable pulley (3), and the signal collector collects the measurement signal, and the steps are as follows: Step 1: Assume that the maximum rotation angle between two sampling intervals is a; Step 2: Use variable n to record the current number of revolutions. Step 3: Use variable e to record the angle obtained by the angle sensor 5. The range of e is greater than or equal to 0 degrees and less than 360 degrees. Step 4: The actual rotation angle of the wire drawing wheel obtained during the operation of the equipment is recorded as g: g = n × 360 + e; the wire drawing displacement l: l = r × g, where r is determined by the diameter of the wire drawing wheel; Step 5: Initial measurement, n is 0, continuous sampling to obtain the sequence of e, the one obtained by the xth sampling is recorded as e x ; Check the difference d = e x -e x-1 , which are divided into the following situations: When the absolute value of d is less than a, it is normal and no special treatment is required. Calculate g and l according to the formula in step 4. When the absolute value of d is not less than a, but d is less than 0 and d+360 is less than a, then add 1 to n and calculate g and l; When the absolute value of d is not less than a, but d is greater than 0 and 360-d is less than a, then subtract 1 from n and calculate g and l; The rest of the cases are abnormal and will be handled as errors after the alarm is triggered; Step 6: The device continues to operate and processes according to step 5. The obtained series of data are the real-time changes of the body contour during breathing.

2. The method for measuring respiratory status in real time according to claim 1, wherein: The angle sensor (5) is configured as a rotary potentiometer, and the angle sensor (5) is coaxially mounted with the wire pulling wheel (3).

3. The method for measuring respiratory status in real time according to claim 1, wherein: The host (1) is further provided with a communication module, which is connected to a monitoring terminal. The signal collector collects data and transmits it to the monitoring terminal via the communication module. The monitoring terminal is configured as a computer, a mobile phone or a tablet computer.

4. The method for measuring respiratory status in real time according to claim 1, wherein: An elastic band (6) is provided between the pull line (2) and the human body. The elastic band (6) is configured as an elastic and retractable elastic band. Both ends of the elastic band are fixed to both sides of the main unit (1). The pull line (2) and the elastic band (6) are configured as a double-layer wearable structure.

5. The method for measuring respiratory status in real time according to claim 1, characterized in that: An elastic belt (6) is provided between the pull line (2) and the human body, and the elastic belt (6) comprises an elastic belt segment 1 (62) and a fixed belt segment 2 (63). The elastic belt segment 1 (62) is configured as an elastic and retractable elastic belt, and the fixed belt segment 2 (63) is configured as an inelastic and non-retractable non-elastic belt. The other end of the pull line (2) is fixed to the fixed belt segment 2 (63).

6. A method for measuring respiratory status in real time according to claim 4 or 5, characterized in that: The elastic band (6) is provided with spaced-apart pull-wire limiting sleeves (61), and the pull wire (2) passes through the pull-wire limiting sleeves (61).

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