JP5110530B2 - Thoracic drainage unit, method of use thereof, and light transmission type flow measuring device for thorax drainage unit - Google Patents

Description

  The present invention relates to a thoracic drainage unit, a method for using the same, and a light transmission type flow rate measuring device for the thoracic drainage unit.

  Thoracic drainage unit is used for patients with pneumothorax where air leaks into the thoracic cavity, and collects body fluid (blood, pus, exudate / leakage fluid, etc.) and air accumulated in the thoracic cavity. It is a device for discharging outside the body. The chest drainage unit has a water seal, and air discharged from the patient's chest cavity becomes air bubbles and is discharged outside through the water seal.

  On the other hand, it is generally considered that there is a correlation between the amount of air leaking into the thoracic cavity and the size of the hole opened in the lung, the condition of the patient, and the like. Therefore, if the flow rate of air leaking into the thoracic cavity can be observed quantitatively, it becomes a clinically useful index.

  However, at present, doctors or nurses observe the flow rate of air leaking into the thoracic cavity qualitatively and subjectively by visually observing the passage of bubbles through the water seal. Moreover, the observation time is very short. In addition, it is hygienic to connect a microbial flow meter directly to the air flow path in the chest drainage unit.

  Therefore, it is necessary to develop a flow rate measuring device that does not directly touch the inside of the air flow path in the chest drainage unit. Onuki et al. Put a small amount of foaming agent harmless to the human body in the water seal part of the chest drainage unit, and tried to measure the flow rate quantitatively from the growth and movement of the foam. It has not been realized (see Non-Patent Document 1).

  The present inventors have focused on the difference in relative permittivity between water and air for the purpose of quantitative flow measurement without directly touching the inside of the air flow path in the chest drainage unit. Proposed a method for measuring the passage flow rate of bubbles by changing the electrostatic capacity of the part (see Non-Patent Document 2). In this method, a pair of electrode plates are attached so as to sandwich the water seal portion, an AC voltage is applied to the electrode plate on one side, and the voltage generated on the electrode plate on the opposite side is measured. The change in the capacitance of the water seal when passing through is determined.

Masanori Onuki, Takuko Matsumoto, Trial of quantitative analysis of lung air leakage using a Web camera, 18th ME Society Autumn Meeting, N1-0302, 2004 Kiyoshi Okawa, Jun Sugawara, 2007, Development of flow measurement device for medical drainage unit, Proceedings of 2007 Annual Conference of the Japan Society of Mechanical Engineers, vol. 5, p. 193-194

However, the technique proposed in Non-Patent Document 2 has a drawback that the flow rate measurement varies when the air flow rate is slightly increased.
Accordingly, the problem to be solved by the present invention is a chest drainage that can perform quantitative flow measurement hygienically and over a wider flow rate zone without directly touching the inside of the air flow path in the chest drainage unit. It is an object to provide a unit, a method of using the same, and a light transmission type flow rate measuring device for a chest drainage unit.

In order to solve the above problem, the first invention is:
A light-transmitting flow rate measuring device having a light-emitting element that irradiates light to the water-sealed part and a light-receiving element that receives light that is emitted from the light-emitting element and passes through the water-sealed part
The chest drainage unit is configured to obtain a flow rate of air passing through the water seal portion by measuring an amount of the light passing through the water seal portion using the light receiving element.

The second invention is
Using a thoracic drainage unit having a light-transmitting flow rate measuring device having a light emitting element that irradiates light to the water sealing part and a light receiving element that receives light that is emitted from the light emitting element and passes through the water sealing part,
A method of using a chest drainage unit in which a flow rate of air passing through the water seal portion is determined by measuring an amount of light transmitted through the water seal portion using the light receiving element.

  In the first and second aspects of the invention, the flow rate of air can be obtained by calculating the passage time of bubbles passing through the water seal from the amount of transmitted light measured using the light receiving element. Typically, the air flow rate is obtained by calculating the accumulated passage time of bubbles per predetermined time. The predetermined time is, for example, 1 minute, but is not limited to this, and may be another time. As the light emitting element, for example, one having an emission wavelength in the visible range is used, and specifically, for example, a blue light emitting element is used, but is not limited thereto. The light emitting element is typically a light emitting diode or a semiconductor laser. As the light receiving element, one having sufficient light receiving sensitivity with respect to the emission wavelength of the light emitting element to be used is used. The light receiving element is typically a photodiode. A light transmission type flow rate measuring device having a light emitting element for irradiating light to a water sealing part and a light receiving element for receiving light irradiated from the light emitting element and passing through the water sealing part is configured to be detachable from the chest drainage unit. Alternatively, it may be provided integrally with the chest drainage unit.

The third invention is
A light transmission type flow measuring device for a chest drainage unit used by being attached to a chest drainage unit,
A light emitting element for irradiating light to the water seal part of the chest drainage unit;
A light receiving element that receives light emitted from the light emitting element and transmitted through the water seal,
The flow rate of the air passing through the water seal portion is obtained by measuring the amount of light transmitted through the water seal portion using the light receiving element.
In the third invention, what has been described in relation to the first and second inventions holds true.

  According to the present invention, since the flow rate of the air passing through the water seal portion is obtained by measuring the amount of light transmitted through the water seal portion, the air flow path in the chest cavity drainage unit is inside. It is hygienic without being touched directly, and quantitative flow measurement can be performed. Moreover, the air flow rate can be obtained over a wider flow rate zone. Furthermore, by configuring the light transmission type flow measurement device so that it can be attached to the outside of the chest drainage unit, the light transmission type flow measurement device can be attached without processing the chest drainage unit. Even if the flow rate measuring device becomes expensive to some extent, it is economical because the chest drainage unit can be disposable after removing the light transmission flow measuring device.

Hereinafter, a chest drainage unit according to an embodiment of the present invention will be described with reference to the drawings.
FIG. 1 shows the overall configuration of the chest drainage unit 10.
As shown in FIG. 1, the thoracic drainage unit 10 includes a drainage part 11, a water seal part 12, and a suction part (suction pressure control part) 13. A thoracic drain connection tube 14 is connected to the inlet of the drainage unit 11. A thoracic drain connection connector (not shown) is attached to the distal end of the thoracic drain connection tube 14. A chest drain (not shown) is connected to the chest drain connection connector, and the distal end of the chest drain is inserted into the chest cavity of a pneumothorax patient. The body fluid and air accumulated in the chest cavity of the patient enter the drainage part 11 through the chest cavity drain and the chest cavity drain connection tube 14.

  The drainage unit 11 is partitioned into three chambers, a first chamber 11a, a second chamber 11b, and a third chamber 11c, by partition walls 15a, 15b, 15c provided vertically upward from the bottom surface of the chest drainage unit 10. A gap is provided between the upper surface of the chest drainage unit 10 and the upper ends of the partition walls 15a, 15b, and 15c. The body fluid that has entered the drainage unit 11 is stored in the first chamber 11a, the second chamber 11b, and the third chamber 11c.

  A hanging partition wall 16 is provided vertically downward from the upper surface of the chest drainage unit 10 so as to face the partition wall 15c. The lower part of the hanging partition wall 16 is bent in parallel with the bottom surface of the chest drainage unit 10 and further bent vertically downward. A gap is provided between the bottom surface of the chest drainage unit 10 and the lower end of the hanging partition wall 16. A partition wall 17 is provided on the bottom surface of the chest drainage unit 10 so as to face the hanging partition wall 16. The partition wall 17 has a shape that extends vertically upward from the bottom surface of the chest cavity drainage unit 10, is bent in parallel to the bottom surface of the chest cavity drainage unit 10, and further extends vertically upward. A gap is provided between the upper surface of the chest drainage unit 10 and the upper end of the partition wall 17.

  The water seal portion 12 is made of sterilized distilled water injected to a height higher than the lower end of the hanging partition wall 16. As shown by the arrow in FIG. 1, the air that has entered the drainage unit 11 passes through the gap between the upper surface of the chest drainage unit 10 and the upper ends of the partition walls 15a, 15b, and 15c, and further, the partition wall 15c and the suspended partition wall 16 The inside of the small chamber 18 is lowered and enters the water seal portion 12. Thus, the air that has entered the water sealing portion 12 becomes air bubbles, passes through the water sealing portion 12, rises in the small chamber 20 between the hanging partition wall 16 and the partition wall 17, and is connected to the outlet of the suction unit 13. It is sucked and discharged from the device connection tube 21 to the outside by a suction device (not shown). In the suction part 13, a hanging partition wall 22 is provided vertically downward from the upper surface of the chest drainage unit 10 so as to face the partition wall 17. There is a gap between the hanging partition wall 22 and the side surface of the chest drainage unit 10. The lower end of the drooping partition wall 22 is located higher than the bottom surface of the chest cavity drainage unit 10. Sterilized distilled water 23 is injected into the suction part 13 to a height higher than the lower end of the hanging partition wall 22. The air taken from the outside through the gap between the drooping partition wall 22 and the side surface of the thoracic drainage unit 10 passes through the sterilized distilled water 23 of the suction unit 13 and enters the small chamber 24 between the partition wall 17 and the drooping partition wall 22. And is sucked and discharged from the suction device connection tube 21 to the outside. By doing so, the intrathoracic pressure of the patient can be maintained at a constant negative pressure.

2A and 2B schematically show how the air that has entered the water sealing part 12 becomes bubbles and passes through the water sealing part 12. As shown in FIG. 2A, the liquid level of the water seal portion 12 in the small chamber 18 is pushed down by the pressure of the air supplied to the water seal portion 12, and most of the water seal portion 12 moves to the lower portion of the small chamber 20. Thereafter, as shown in FIG. 2B, bubbles 25 are generated in the water seal portion 12. The bubbles 25 disappear after passing through the water seal portion 12 and enter the small chamber 20 as air.
At least the water sealing part 12, generally the most part of the chest drainage unit 10 including the water sealing part 12 is made of a transparent material, typically transparent plastic, so that the inside can be observed from the outside. It has become.

As shown in FIG. 1, in this thoracic drainage unit 10, a light transmissive flow rate measuring device 26 for measuring the flow rate of air passing through the water seal portion 12 is attached to the water seal portion 12. The light transmission type flow rate measuring device 26 may be configured to be detachable from the thoracic drainage unit 10 or may be provided integrally with the thoracic drainage unit 10. FIG. 3 shows the configuration of the light transmission type flow rate measuring device 26. As shown in FIG. 3, the light transmission type flow rate measuring device 26 is a light collecting diode 27 disposed on the back surface 12 a side of the water seal portion 12, and a light collecting diode composed of a convex lens disposed on the front surface 12 b side of the water seal portion 12. It has a lens 28 and a reverse-biased photodiode 29. Then, the light 30 generated from the light emitting diode 27 is applied to the water seal 12, and the light 30 transmitted through the water seal 12 is condensed by the condenser lens 28 and then incident on the photodiode 29 for detection. It can be done. The drive circuit for the light emitting diode 27 includes a DC power supply 31 and a resistor 32. The photodiode 29 is grounded on the anode side, and a positive voltage _Vcc is applied to the cathode side via a resistor 33. A voltage generated between both terminals of the photodiode 29 by the incidence of the light 30 is amplified by an amplifier circuit. For example, a blue light emitting diode 27 is used as the light emitting diode 27, and a photodiode 29 having sufficient light receiving sensitivity with respect to the light emitting wavelength of the light emitting diode 27 is used. Specifically, for example, a GaN-based light emitting diode is used as the blue light emitting diode 27.

  In the light transmission type flow measuring device 26 configured as described above, the water seal portion 12 is irradiated with the light 30 generated from the light emitting diode 27 during the flow rate measurement. When the light 30 passes through the water seal portion 12 without hitting the bubble 25, the transmitted light has almost the same intensity as the light 30, and when this transmitted light is received by the photodiode 29, a photocurrent corresponding to the amount of light is generated. To do. On the other hand, as shown in FIG. 4, when the light 30 strikes the surface of the bubble 25, the light 30 is reflected on the surface, and as a result, the amount of transmitted light that passes through the water seal portion 12 decreases. From this, it can be said that when the light transmission amount from the water seal portion 12 is small, the bubbles 25 are passing through the water seal portion 12. At this time, the relationship between the light transmission amount and the passage time of the bubbles 25 is as shown in FIG. As shown in FIG. 5, when the tip of the bubble 25 reaches the path of the light 30, the amount of light transmission decreases rapidly, and when the center of the bubble 25 enters the path of the light 30, the amount of light transmission is minimized. When the rear end of the bubble 25 moves away from the path of the light 30, the light transmission amount rapidly increases, and the light transmission amount when the light 30 does not hit the bubble 25 is restored. The passage time of the bubbles 25 increases as the size of the bubbles 25 increases.

FIG. 6 shows the time change of the light transmission amount detected by the photodiode 29 when the bubbles 25 traverse the path of the light 30 one after another. _Let the passage time of each bubble 25 be t ₁ , t ₂ ,..., T _n . However, here, in calculating each passage time, a threshold value lower than the light transmission amount when the light 30 does not hit the bubble 25 is set, and the difference in time when the light transmission amount becomes equal to this threshold value is referred to as the passage time. To do. Now, a unit time, for example, the accumulated passage time of the bubbles 25 per minute is defined as T = t ₁ + t ₂ +... + T _n = Σt _k (k = 1 to n). The integrated passage time T has a correlation with the total volume of all the bubbles 25 that pass through the water seal portion 12 per unit time, in other words, the flow rate of air that passes through the water seal portion 12. Therefore, if this correlation is obtained in advance, the flow rate of the air passing through the water seal portion 12 can be obtained by obtaining the accumulated passage time T.

  The above calculation and processing can be performed by a calculation device (computer or the like) built in or connected to the light transmission type flow rate measuring device 26. If necessary, the result can be displayed on a display connected to the arithmetic device, and can be printed by a printer connected to the arithmetic device. These computing devices, displays, printers, and the like can be installed in a doctor's room or a nurse station, etc., away from the patient's room, if necessary.

  An experiment was conducted to evaluate the air flow rate measurement by the light transmission type flow rate measuring device 26. The result will be described. FIG. 7 shows the configuration of the system used in this experiment. As shown in FIG. 7, the inlet of the drainage part 11 of the chest cavity drainage unit 10 having the light transmission type flow measuring device 26 and the air compressor 34 are connected by a tube 35. A gas meter 36 and a regulator 37 are provided in the middle of the tube 35. Air is supplied into the tube 35 by the air compressor 34, and the flow rate is measured by the gas meter 36. The air flow rate is adjusted by the regulator 37. The analog electrical signal output from the light transmission type flow rate measuring device 26 is converted into a digital signal by the analog-digital converter 38. This digital signal is processed by the personal computer 39. The chest drainage unit 10 has a height of 320 mm and a width of 230 mm.

The flow rate (steady flow rate) of air (steady flow) supplied to the drainage part 11 of the chest drainage unit 10 is changed in the range of 0.00 L / min to 1.00 L / min, and the accumulated passage time T of the bubbles 25 is measured. The results are shown in FIG. FIG. 8 shows a straight line obtained by the method of least squares using the measured value of the accumulated passage time T. When the flow rate of air is F, this straight line is expressed by an approximate expression T = 36.5F. It can be seen that the measured value of the accumulated passage time T is well on this straight line. The residual at this time is R ² = 0.9917.

  In order to verify the validity of the above approximate expression, unsteady flow air is supplied to the drainage part 11 of the thoracic drainage unit 10 and the instantaneous flow rate (updated every second) measured by the gas meter 36 and light transmission. The time change of the instantaneous flow rate obtained using the above approximate equation was measured by the equation flow rate measuring device 26. The result is shown in FIG. From FIG. 9, the instantaneous flow rate obtained using the above approximate expression by the light transmission type flow rate measuring device 26 when the instantaneous flow rate is in the range of 0.00 L / min to 1.00 L / min is the instantaneous flow rate measured by the gas meter 36. It can be seen that it agrees well. From this, it can be seen that even if the air supplied to the drainage part 11 of the thoracic drainage unit 10 is an unsteady flow, the light transmission flow rate measuring device 26 can measure the flow rate with high accuracy.

  Next, an experimental result in which the chest drainage unit 10 is applied to an animal will be described. Sheep that simulated pneumothorax was used as the target animal. Specifically, the sheep was anesthetized, and a 30 mm square wound was made on the lung by performing an operation, resulting in a pneumothorax state. When the experiment was conducted, the sheep were awake from anesthesia and were breathing spontaneously. The tip of the chest drain was inserted into the sheep's chest cavity, and the other end of the chest drain was connected to a chest drain connection tube. The chest cavity drain connection tube is connected to the inlet of the drainage part 11 of the chest cavity drainage unit 10. Similarly to FIG. 7, the analog electrical signal output from the light transmission type flow rate measuring device 26 is converted into a digital signal by the analog-digital converter 38, and this digital signal is processed by the personal computer 39, and the air flow rate is adjusted. taking measurement. Thus, the flow rate of air was measured by the light transmission type flow rate measuring device 26 for about 20 hours from 14:40 on the first day of the experiment to 10:59 on the next day. The result is shown in FIG. The vertical axis in FIG. 10 is the estimated flow rate averaged for one minute. From FIG. 10, it is possible to observe a change in flow rate corresponding to a change in sheep behavior.

  As described above, according to the chest drainage unit 10 according to this embodiment, the flow rate of air passing through the water seal portion 12 by the light transmission type flow rate measuring device 26 provided in the water seal portion 12, in other words, this chest drainage. The flow rate of air discharged from the chest cavity of the pneumothorax patient to which the unit 10 is connected and supplied to the drainage unit 11 of the chest drainage unit 10 can be quantitatively measured to a flow rate of at least 1.00 L / min. . This light transmission type flow rate measuring device 26 is hygienic because it can measure the air flow rate without directly touching the inside of the air flow path in the chest drainage unit 10. Moreover, since objective measurement can be performed without relying on the visual observation of a doctor or nurse, it is simple and has high measurement accuracy. Furthermore, since the air flow rate can be continuously measured over a long period of time, changes in the patient after the operation can be accurately grasped, and prompt measures can be taken as necessary. Furthermore, by configuring the light transmission type flow rate measuring device 26 so as to be attached to the outside of the chest cavity drainage unit 10, the light transmission type flow rate measuring device 26 can be attached without processing the chest cavity drainage unit 10. Therefore, even if the light transmission type flow rate measuring device 26 becomes somewhat expensive, it is economical because the chest cavity drainage unit 10 can be disposed after the light transmission type flow rate measuring device 26 is removed.

Although one embodiment of the present invention has been specifically described above, the present invention is not limited to the above-described embodiment, and various modifications based on the technical idea of the present invention are possible.
For example, the numerical values, configurations, arrangements, and the like given in the above-described embodiments are merely examples, and different numerical values, configurations, arrangements, and the like may be used as necessary.
For example, the configuration of the thoracic drainage unit 10 is only an example, and the thoracic drainage unit 10 having another configuration may be used.

It is sectional drawing which shows the whole structure of the chest cavity drainage unit by one Embodiment of this invention. It is sectional drawing which shows the structure of the vicinity of the water seal part of the chest cavity drainage unit by one Embodiment of this invention. It is a basic diagram which shows the structure of the light transmission type flow measuring device of the chest cavity drainage unit by one Embodiment of this invention. It is a basic diagram for demonstrating the measurement principle of the light transmission type flow measuring device of the chest cavity drainage unit by one Embodiment of this invention. It is a basic diagram for demonstrating the measurement principle of the light transmission type flow measuring device of the chest cavity drainage unit by one Embodiment of this invention. It is a basic diagram for demonstrating the measurement principle of the light transmission type flow measuring device of the chest cavity drainage unit by one Embodiment of this invention. It is a basic diagram which shows the structure of the optical transmission type flow measurement system used for evaluation of the chest cavity drainage unit by one Embodiment of this invention. It is a basic diagram which shows the correlation with the flow volume of the air of the steady flow measured using the light transmissive flow measurement system shown in FIG. 7, and the bubble integral passage time. It is a basic diagram which compares and shows the measurement result by the gas meter measured using the light transmission type flow measuring system shown in FIG. 7, and the measurement result measured using the light transmission type flow measuring device. It is a basic diagram which shows the result of the experiment which applied the thoracic drainage unit by one Embodiment of this invention to the animal.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Thoracic drainage unit, 11 ... Drainage part, 12 ... Water seal part, 13 ... Suction part, 14 ... Thoracic drain connection tube, 25 ... Air bubble, 26 ... Light transmission type flow measuring device, 27 ... Light emitting diode, 28 ... Condenser lens, 29 ... photodiode, 30 ... light

Claims (7)

A light-transmitting flow rate measuring device having a light-emitting element that irradiates light to the water-sealed part and a light-receiving element that receives light that is emitted from the light-emitting element and passes through the water-sealed part
A chest drainage unit that determines the flow rate of air that passes through the water seal by measuring the amount of light transmitted through the water seal using the light receiving element.   The thoracic drainage unit according to claim 1, wherein the flow rate of the air is determined by calculating a passage time of the bubbles passing through the water seal from the light transmission amount.   The thoracic drainage unit according to claim 1 or 2, wherein the flow rate of the air is obtained by calculating an accumulated passage time of the bubbles per predetermined time.   The thoracic drainage unit according to claim 3, wherein the predetermined time is 1 minute.   The thoracic drainage unit according to any one of claims 1 to 4, wherein the light emitting element is a blue light emitting element. Using a thoracic drainage unit having a light-transmitting flow rate measuring device having a light emitting element that irradiates light to the water sealing part and a light receiving element that receives light that is emitted from the light emitting element and passes through the water sealing part,
A method of using a thoracic drainage unit in which a flow rate of air passing through the water seal portion is determined by measuring an amount of light transmitted through the water seal portion using the light receiving element. A light transmission type flow measuring device for a chest drainage unit used by being attached to a chest drainage unit,
A light emitting element for irradiating light to the water seal part of the chest drainage unit;
A light receiving element that receives light emitted from the light emitting element and transmitted through the water seal,
A light transmission type flow rate measuring device for a chest cavity drainage unit, wherein a flow rate of air passing through the water seal portion is determined by measuring an amount of light transmitted through the water seal portion using the light receiving element.

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