JP7029725B2 - measuring device - Google Patents

Description

The present invention relates exclusively to a device for measuring air pressure in the thoracic cavity.

Pneumothorax is a condition in which air flows into and accumulates in the thoracic cavity through holes in the side wall pleura that covers the inner surface of the chest wall and the visceral pleura that covers the lungs, causing the lungs to collapse (small atrophy). Depending on the cause of the hole, it is roughly divided into three types: spontaneous pneumothorax, traumatic pneumothorax, and iatrogenic pneumothorax. It develops when the formed alveoli rupture and inspiration leaks into the thoracic cavity (air leakage).

The thoracic cavity is the internal space of humans and animals surrounded by ribs, thoracic vertebrae, sternum, and diaphragm, and the pressure in the thoracic space is called intrathoracic pressure. According to the experience of the present inventors, the inside of the thoracic cavity is maintained at a negative pressure (-4 to -10 cmH ₂ O from the atmospheric pressure), whereby the lung is pulled in the dilation direction, and the elasticity (contracting force) of the lung itself. It is balanced with and keeps the expanded state. However, when pneumothorax occurs, the intracranial pressure changes in the direction of increasing and the negative pressure cannot be maintained, and as a result, the lungs cannot swell and atrophy.

In pneumothorax practice, chest tube drainage is often performed. Chest tube drainage is for draining body fluids (blood, pus, oozing / leaking fluid, etc.) and air accumulated in the thoracic cavity to the outside of the body. There is a water seal in the chest cavity drainage, and the air discharged from the patient's chest cavity becomes air bubbles and passes through this water seal to be discharged to the outside.

As a method for detecting pneumothorax, a method in which a medical worker visually observes air bubbles generated in a water seal of a chest tube due to the occurrence of air leak is generally performed, but it is only a qualitative method. .. To avoid the uncertainty of this visual observation, the pressure between the water seal chamber and the suction source or transmission suction pump is measured, and the generation of bubbles is detected based on the pressure fluctuation to detect the patient's air leak. -A device for diagnosing has been proposed (for example, Patent Document 1).

Japanese Unexamined Patent Publication No. 2014-136104

However, thoracic drainage is a treatment that requires hospitalization, and during the procedure, there is strong pain due to the drainage tube pressing the intercostal nerves, and body movement is restricted, which causes great pain for the patient. .. Chest tube drainage is less necessary when asava is stopped, but it is difficult to accurately determine if it is necessary before treatment.

In addition, chest X-rays and CT are currently objective evaluations that can be performed as a diagnosis of pneumothorax, but these are still images, and a dynamic finding as to whether or not air leakage is continuous can be obtained with only one image. It is not possible to infer air leaks by comparing images after a lapse of time. As a method of determining air leakage, it is possible to measure the intrathoracic pressure, but it is possible to make a visual judgment by observing the drain bag under chest tube drainage, but it is easy to make a visual judgment without performing chest drainage. The internal pressure cannot be measured.

The present invention has been made in consideration of the above-mentioned conventional problems and requests from medical practice, and can easily measure the air pressure in the thoracic cavity, and the air pressure in the thoracic cavity does not depend on the skill and experience of a doctor. It provides a measuring device that can easily grasp the state.

The present inventors have been diligently studying to solve the above-mentioned problems, and first, the intracranial pressure in the thoracic cavity is a negative pressure (for example, about -8 _cmH2O with respect to the atmospheric pressure in the measurement environment) in a physiological state. Measuring the air pressure in this range is a high-speed sampling (eg 10 msec) and highly accurate (eg 0.5% F.S.) gas pressure measuring device used in industrial and research applications. I thought it could be done by using it. If the intracranial pressure can be measured in real time, it is possible to immediately determine the presence or absence of asava, and it is possible to measure whether the intracranial pressure is physiologically normal, high, or low. I arrived.

Furthermore, the present inventors have proceeded with the study and also examined the provision of a gas pressure measuring device that can be used in the field of thoracic cavity medical care without depending on the proficiency level of the gas pressure measuring device.

[1] One aspect of the present invention that has solved the above problems is a device for measuring intrathoracic air pressure, which is characterized in that it emits at least one of a first signal and a second signal described below. It is a device.
(1) First signal: A signal emitted when the intrathoracic pressure with respect to atmospheric pressure is higher than the first predetermined negative pressure value, which is a negative value. (2) Second signal: The intrathoracic pressure with respect to atmospheric pressure is negative. Signal emitted when it is lower than the second predetermined negative pressure value which is the value of

In a normal gas pressure measuring device, the barometric pressure value is most commonly displayed by a digital display on the barometric pressure display window, and the user of the gas pressure measuring device grasps the intrathoracic pressure of the patient by visually observing the display. obtain. The doctor performs an operation to exhaust the gas in the thoracic cavity so that the air pressure in the thoracic cavity of the patient becomes a preferable value. However, there is room for improvement from the viewpoint of efficiency and safety if the exhaust treatment is performed in parallel while paying close attention to the gas pressure measuring device. In addition, it may be difficult for an inexperienced doctor to understand how to end the exhaust.

According to the measuring device according to the above item [1], the type of the first signal or the second signal (for example, sound or light) emitted from the measuring device even when the doctor is focusing on the exhaust treatment. It is possible to immediately grasp whether the intrathoracic pressure is higher or lower than the predetermined negative pressure value by switching between.

Other aspects of the present invention that have solved the above problems are, for example, those of the following items [2] to [7].
[2] The measuring device according to item [1], wherein the first predetermined negative pressure value and the second predetermined negative pressure value are in the range of -30 cmH ₂ O or more and -3 cmH ₂ O or less.
[3] The measuring device according to the item [1] or [2], wherein at least one of the first and second signals is sound.
[4] The measuring device according to any one of the items [1] to [3], wherein at least one of the first and second signals is light.
[5] The measuring device according to any one of Items [1] to [4], wherein the intrathoracic pressure with respect to the atmospheric pressure is measured by a differential pressure sensor, and the sampling interval of the differential pressure sensor is 30 msec or less.
[6] When the intrathoracic pressure with respect to the atmospheric pressure is a negative value but lower than the third predetermined negative pressure value (provided that the value is lower than the first predetermined negative pressure value and the second predetermined negative pressure value). 3. The measuring device according to any one of items [1] to [5] that emits a signal.
[7] Items [1] to [6] having a graph of the intrathoracic pressure with respect to the atmospheric pressure and a display unit in which a straight line representing the first predetermined negative pressure value or the second predetermined negative pressure value is displayed in an overlapping manner. ] The measuring device according to any one of the items.

The device for measuring the intrathoracic air pressure of the present invention is the presence / absence of a first signal or a second signal (for example, sound or light) emitted from the measuring device even when the doctor is focusing on the exhaust operation, and the first. By switching the characteristics of the signal and the second signal, it is possible to immediately grasp whether the intrathoracic air pressure is higher or lower than the first or second predetermined negative pressure value. Therefore, since the doctor can focus on the treatment itself, the treatment can be performed efficiently and safely. In addition, since the degree of skill required for the treatment is reduced, it is expected that the treatment will become more widespread.

The schematic perspective view of the measuring apparatus which concerns on embodiment of this invention. The system block diagram of the measuring apparatus which concerns on embodiment of this invention. The graph displayed on the display part of the measuring apparatus which concerns on embodiment of this invention.

Hereinafter, the present invention will be described in more detail based on the embodiments, but the present invention is not limited by the following embodiments as well as the present invention, and appropriate modifications are made to the extent that it can meet the purposes of the preceding and the following. Of course, it is also possible to carry out the above, and all of them are included in the technical scope of the present invention.

The measuring device according to the embodiment of the present invention is a measuring device for the intrathoracic air pressure, which is characterized in that it emits at least one of the following first signal and second signal.

(1st signal)
The first signal is a signal emitted when the intrathoracic pressure with respect to the atmospheric pressure is higher than the first predetermined negative pressure value, which is a negative value. In order to determine whether the intrathoracic pressure with respect to the atmospheric pressure is higher or lower than the first predetermined negative pressure value, the measuring device according to the embodiment of the present invention acquires the pressure difference between the intrathoracic pressure and the atmospheric pressure. If the differential pressure is negative, the intrathoracic pressure is lower than the atmospheric pressure (negative pressure state). This first signal will not be transmitted if the intrathoracic pressure with respect to atmospheric pressure falls below the first predetermined negative pressure value, but as long as the first signal is transmitted, the intrathoracic pressure with respect to atmospheric pressure is still higher than the normal value. Can be judged.

In the present invention, the "atmospheric pressure" is the atmospheric pressure around the measuring device and can be changed depending on the weather and the altitude of the place where the measuring device is used.

(2nd signal)
The second signal is a signal emitted when the intrathoracic pressure with respect to the atmospheric pressure (hereinafter, may be simply referred to as "intrathoracic pressure") is lower than the second predetermined negative pressure value which is a negative value. .. The second predetermined negative pressure value may be the same value as or different from the above-mentioned first predetermined negative pressure value. Since this second signal is transmitted when the intrathoracic pressure falls below the second predetermined negative pressure value, it can be determined that the intrathoracic pressure has entered the normal value when the transmission of the second signal starts.

(Signal change during treatment)
The intrathoracic pressure in a patient with pulmonary pneumothorax is high (in some cases, positive pressure higher than atmospheric pressure), which is higher than the first predetermined negative pressure value. Therefore, the measuring device emits the first signal at the time when the doctor starts the operation of exhausting the gas in the thoracic cavity. As the exhaust procedure progresses, the intrathoracic pressure decreases, and the first signal stops when the pressure falls below the first predetermined negative pressure value. Further, when the intrathoracic pressure becomes lower than the second predetermined negative pressure value, a second signal is emitted from the measuring device. By detecting this signal change, the doctor can refer to the normalization of the intrathoracic pressure and the timing of stopping the exhaust, and the exhaust operation can be performed efficiently and safely.

(1st predetermined negative pressure value, 2nd predetermined negative pressure value)
The first predetermined negative pressure value and the second predetermined negative pressure value are values that serve as thresholds for transmitting / stopping the first signal and the second signal, and are preset values before the use of the measuring device. The first predetermined negative pressure value and the second predetermined negative pressure value may be prepared in the measuring device as invariant values determined from a medical point of view, but the specifications are such that the values can be set according to the age and medical condition of the person to be measured. It is more preferable that the value is prepared in the measuring device as one or a plurality of recommended values determined from a medical point of view, and the specifications are such that the value can be changed each time the measurement is performed.

The first predetermined negative pressure value and the second predetermined negative pressure value are preferably in the range of -30 cmH ₂ O or more and -3 cmH ₂ O or less. This is because when the value is -30 cmH ₂ O or more, the lungs tend to contract, which makes exhaust easier for the patient, and when the value is -3 cmH ₂ O or less, the lungs tend to swell, which makes inspiration easier. The lower limit is more preferably -20 cmH ₂ O, still more preferably -15 cm H ₂ O. The upper limit is more preferably -4 cmH ₂ O, still more preferably -5 cmH ₂ O. In any case, the first predetermined negative pressure value and the second predetermined negative pressure value are the values of Mymus (negative pressure), which are events peculiar to pneumothorax, and the measuring device also has a configuration peculiar to pneumothorax.

Since the measuring device for the intrathoracic air pressure in the embodiment of the present invention emits at least one of the first signal and the second signal, for example, the second signal is not used and is used by transmitting the first signal. Can be done. For example, it can be determined whether or not the intrathoracic pressure is higher than the first predetermined negative pressure value depending on the presence or absence of the first signal. On the contrary, it can be used depending on whether or not the second signal is transmitted without using the first signal.

The first predetermined negative pressure value and the second predetermined negative pressure value may be the same value or different values.
(A) When the first predetermined negative pressure value and the second predetermined negative pressure value are the same value, the first signal is obtained when the intrathoracic pressure becomes smaller than the first predetermined negative pressure value due to the progress of the exhaust treatment. Is stopped and the second signal is transmitted at the same time.

(B) When the first predetermined negative pressure value is higher than the second predetermined negative pressure value, the first signal is stopped when the intrathoracic pressure becomes smaller than the first predetermined negative pressure value due to the progress of the exhaust treatment. There is no signal without the first signal and the second signal, and when the intrathoracic pressure becomes lower than the second predetermined negative pressure value, the second signal is transmitted.

(C) When the second predetermined negative pressure value is higher than the first predetermined negative pressure value, the first signal is transmitted as the exhaust treatment progresses, and the intrathoracic pressure becomes the second predetermined negative pressure. When it becomes lower than the value, the first signal and the second signal are superimposed and transmitted, and finally when the intrathoracic pressure becomes smaller than the first predetermined negative pressure value, the first signal is stopped and the second signal is stopped. It changes to the state where only the signal is transmitted.

In the case of the above (B), the doctor can grasp the "no signal state" as the first stage of the transition to the "second signal", and in the case of the above (C), the "superimposed state of the first signal and the second signal". Can be grasped as the first stage of the transition to the "second signal", so that the doctor can more appropriately predict the timing of stopping the exhaust. In these cases, the section in the first period of the transition between the first predetermined negative pressure value and the second predetermined negative pressure value is the section corresponding to yellow in terms of the traffic light, and the first predetermined negative pressure value and the second predetermined negative pressure value. The difference from the pressure value is preferably about 1 to 4 cmH ₂ O, more preferably about 1.5 to 3 cmH ₂ O.
In the case of the above (B), the fourth signal may be transmitted in the section (the section between the first predetermined negative pressure value and the second predetermined negative pressure value) in which the “no signal state” occurs. Like the first signal and the second signal, the fourth signal can be composed of sound or light.

(Configuration example of measuring device)
FIG. 1 is a schematic perspective view of a measuring device according to an embodiment of the present invention. As shown in FIG. 1, the measuring device 1 includes an intrathoracic pressure measuring port 3 connected to the indwelling needle portion 2 and an atmospheric pressure measuring port 4 open to the atmosphere. Further, the measuring device 1 includes a liquid crystal display unit 5 for displaying the differential pressure between the intrathoracic pressure and the atmospheric pressure, and a signal transmitting unit 6 for emitting at least one of the first signal and the second signal. There is. Although FIG. 1 shows an example in which one signal transmitting unit 6 is provided, the first signal transmitting unit 6a and the second signal transmitting unit 6b (FIG. 2) may be provided separately.

(Example of signal processing in a measuring device)
There are many specific means for exerting the above-mentioned functions in the measuring device of the present invention, and one example thereof will be described. FIG. 2 is a system block diagram of the measuring device 1 according to the embodiment of the present invention.

As shown in FIG. 2, the above-mentioned intrathoracic pressure measurement port 3 and the atmospheric pressure measurement port 4 open to the atmosphere are connected to the differential pressure sensor 7. In the differential pressure sensor 7, the gas introduced from the intrathoracic pressure measurement port 3 and the gas introduced from the atmospheric pressure measurement port 4 are separated by a diaphragm (diaphragm: not shown), and the amount of deflection of this diaphragm. The stress corresponding to the pressure is applied to the gauge resistance (piezo resistance: not shown), and the electric resistance of the piezo resistance changes according to the change in the load stress. A digital signal obtained by analog-digital conversion (AD conversion) of this rate of change is output from the differential pressure sensor 7. This data is supplied to the control unit (central processing unit: CPU) 8. Since the measuring device 1 according to the embodiment of the present invention adopts such a MEMS (MICRO ELECTRO MEMHANICAL SYSTEM) method, differential pressure sensing with a very short sampling interval is possible, so that the difference from the atmospheric pressure is possible. It is suitable as a device for measuring intrathoracic air pressure in real time, where pressure is important. The sampling interval of the differential pressure sensor 7 is preferably 30 msec or less, more preferably 25 msec or less, still more preferably 20 msec or less.

The differential pressure data output from the differential pressure sensor 7 is sent to the liquid crystal display unit 5 according to the instruction of the control unit 8. The control unit 8 monitors whether the differential pressure data is larger or smaller than the first predetermined negative pressure value, and whether the differential pressure data is larger or smaller than the second predetermined negative pressure value, and the differential pressure data is the predetermined value described above. When the condition of is satisfied, a sound or light signal is transmitted from the first signal transmitting unit 6a and / or the second signal transmitting unit 6b. When outputting a sound signal, the first signal transmitting unit 6a and / or the second signal transmitting unit 6b is, for example, a speaker. Various variations of sound types can be applied, for example, changes in pitch of sound, changes in loudness, changes in time interval between sounds, and the like. When outputting an optical signal, the first signal transmitting unit 6a and / or the second signal transmitting unit 6b uses a light source element such as an LED, an incandescent lamp, or an organic EL. As variations of the type of light, various applications such as light intensity, light color, pulse light interval, and the like can be applied. In addition, as the information output from the first signal transmitting unit 6a and / or the second signal transmitting unit 6b, one is sound and the other is light, and one is sound or light and the other is no signal (first). There is also a method (setting only one of a predetermined negative pressure value and a second predetermined negative pressure value). From the viewpoint that the doctor concentrates on the exhaust treatment of the gas in the thoracic cavity without gazing at the measuring device 1, it is preferable that the first signal transmitting unit 6a and the second signal transmitting unit 6b emit a sound.

An input unit 9 and a memory 10 are connected to the control unit 8. The input unit 9 is composed of key buttons and performs basic settings and data input. The memory 10 stores information such as time-series differential pressure data and first and / or second predetermined negative pressure values. A predetermined negative pressure value setting unit 11 is further connected to the control unit 8 and is used when changing the predetermined negative pressure value. The predetermined negative pressure value setting unit 11 may be a dial type or may have a two-button configuration of "UP (up)" and "DOWN (down)". It is preferable that the input unit 9 can also change the predetermined negative pressure value by using a key button.

In the measuring device according to the embodiment of the present invention, the intrathoracic pressure with respect to the atmospheric pressure is a negative value, that is, a third predetermined negative pressure value (however, a value lower than the first predetermined negative pressure value and the second predetermined negative pressure value). It is preferable to emit the third signal when the pressure is lower than. It is normal for the intrathoracic pressure to be negative, but excessive negative pressure should be avoided. In normal treatment, setting at least one of the first predetermined negative pressure value and the second predetermined negative pressure value is sufficient, but if the third predetermined negative pressure value is set, the intrathoracic pressure is lowered excessively by any chance. Even if it does, the exhaust treatment can be stopped by detecting the third signal. Since the third signal is emitted for safety, it is louder than the first or second signal to attract human attention (sound is louder, and light is flashed). It is preferable to use a signal having a large amount of light, or a signal for simultaneous transmission of sound and light).

The control unit 8 may be further provided with a third signal transmission unit (for example, a sound generation unit 12) dedicated to the third signal, in addition to the first signal transmission unit 6a and / or the second signal transmission unit 6b. The sounding unit 12 can notify the abnormality of the air pressure in the thoracic cavity (when it becomes the third predetermined negative pressure value or less) by a synthetic sound or an announcement sound.

As the setting range of the third signal, the lower limit value is preferably -40 cmH ₂ O for safety, more preferably -30 cmH ₂ O, and further preferably -30 cmH ₂ O. The upper limit value is preferably -12 cmH ₂ O, more preferably -15 cmH ₂ O, and further preferably -18 cmH ₂ O so as not to overlap the range in which the first predetermined negative pressure value and the second predetermined negative pressure value are set. be.

FIG. 3 shows a graph which is an example of the display contents displayed on the liquid crystal display unit 5 of the measuring device according to the embodiment of the present invention. In the measuring device according to the embodiment of the present invention, the intrathoracic pressure with respect to the atmospheric pressure may be represented by a numerical value on the liquid crystal display unit 5, but as shown in FIG. 3, the horizontal axis is time (for example, seconds) and the vertical axis is vertical. It is also preferable and feasible to display by a graph in which is the intrathoracic pressure with respect to the atmospheric pressure. At this time, if a straight line representing the first predetermined negative pressure value or the second predetermined negative pressure value is superimposed and displayed on the graph as shown in FIG. 3, it is easy to grasp the current state of the intrathoracic pressure, and the doctor can easily grasp the current state of the intrathoracic pressure. The treatment can be performed with predictability. It should be noted that one mountain indicated by the curve of the graph corresponds to one breath of the patient.

The device for discharging the gas in the thoracic cavity is not particularly limited, and various devices can be used. For example, as shown in FIG. 1 shown above, the gas can be exhausted using the syringe 13. A first three-way stopcock 14 and a second three-way stopcock 15 are connected between the syringe 13 and the indwelling needle portion 2, and the measuring device 1 according to the embodiment of the present invention is connected to the first three-way stopcock 14. A syringe 13 is connected to the second three-way stopcock 15. By the action of the first three-way stopcock 14 and the second three-way stopcock 15, the measuring device 1 may be cut off when the gas in the thoracic cavity is discharged by the syringe 13, but the intrathoracic pressure is measured every moment. Therefore, it is preferable to open all three sides of the indwelling needle portion 2, the measuring device 1, and the second three-way stopcock 15.

As shown in FIG. 1, it is preferable to provide a hydrophobic sterility filter 16 between the measuring device 1 and the first three-way stopcock 14. This is to prevent the gas accumulated in the patient's thoracic cavity from flowing directly to the measuring device 1 in an unsterilized state, or to block the patient's body fluid.

1 Measuring device 2 Indwelling needle 3 Intrathoracic pressure measurement port 4 Atmospheric pressure measurement port 5 Liquid crystal display 6 Signal transmitter 6a 1st signal transmitter 6b 2nd signal transmitter 7 Differential pressure sensor 8 Control 9 Input 10 Memory 11 Predetermined negative pressure value setting part 12 Sounding part 13 Syringe 14 First three-way activation plug 15 Second three-way activation plug 16 Hydrophobic sterilization filter

Claims (7)

It is a measuring device for intrathoracic pressure , and a three-way activation plug having a first connection port, a second connection port, and a side tube port is connected to the measuring device, and an indwelling needle is connected to the first connection port. The second connection port is connected to an exhaust device for discharging gas in the thoracic cavity, and the side tube port is connected to the measuring device . A measuring device characterized by emitting at least one of a signal and a second signal.
(1) First signal: A signal emitted when the intrathoracic pressure with respect to atmospheric pressure is higher than the first predetermined negative pressure value, which is a negative value. (2) Second signal: The intrathoracic pressure with respect to atmospheric pressure is negative. Signal emitted when it is lower than the second predetermined negative pressure value which is the value of The measuring device according to claim 1, wherein the first predetermined negative pressure value and the second predetermined negative pressure value are in the range of -30 cmH ₂ O or more and -3 cmH ₂ O or less. The measuring device according to claim 1 or 2, wherein at least one of the first and second signals is sound. The measuring device according to any one of claims 1 to 3, wherein at least one of the first and second signals is light. The measuring device according to any one of claims 1 to 4, wherein the intrathoracic pressure with respect to the atmospheric pressure is measured by a differential pressure sensor, and the sampling interval of the differential pressure sensor is 30 msec or less. The third signal is emitted when the intrathoracic pressure with respect to the atmospheric pressure is lower than the negative third predetermined negative pressure value (provided that the value is lower than the first predetermined negative pressure value and the second predetermined negative pressure value). The measuring device according to any one of claims 1 to 5. Any one of claims 1 to 6 having a graph of the intrathoracic pressure with respect to the atmospheric pressure and a display unit in which a straight line representing the first predetermined negative pressure value or the second predetermined negative pressure value is displayed in an overlapping manner. The measuring device described in.

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