WO2014192606A1

WO2014192606A1 - Cuff pressure control device

Info

Publication number: WO2014192606A1
Application number: PCT/JP2014/063413
Authority: WO
Inventors: 東山祐三
Original assignee: 株式会社村田製作所
Priority date: 2013-05-28
Filing date: 2014-05-21
Publication date: 2014-12-04
Also published as: JPWO2014192606A1; JP6037005B2

Abstract

The cuff pressure control device (100) is provided with a control unit (111), a cuff pressure-detecting unit (171), a suction pressure-detecting unit (173), a pump (110), a valve (120), a valve (130), a filter (176), and a tank (160). The valve (120) comprises: a first air hole (121) connected to the discharge hole (110B) of the pump (110); a second air hole (122) connected to the cuff (10) via an air supply tube (175); and a fifth air hole (125) that communicates with the outside of the valve housing (129). The valve (130) comprises: a third air hole (133) connected to the suction hole (110A) of the pump (110); a fourth air hole (134) connected to a suction tube (141), the tip (141A) of which faces the cuff (10), a suction tube (142), and a suction tube (143); and a sixth air hole (136) that communicates with the outside of the valve housing (139).

Description

Cuff pressure control device

The present invention relates to a cuff pressure control device for controlling the pressure in the cuff.

Conventionally, in a medical field related to a ventilator, an operator such as a doctor inserts an intubation or cannula into a trachea of a subject (mainly a human body) to secure an airway, and sends oxygen to the lungs through the intubation or cannula. Tracheal intubation is known.

When there is a gap between the intubation or the cannula and the inner wall of the trachea, secretions such as gastric juice and saliva flow into the trachea, and the subject is ventilator-associated pneumonia (VAP; VAP). May develop). In particular, in tracheal intubation, the epiglottis is opened, so that gastric fluid from the esophagus tends to flow into the trachea.

In order to prevent such inflow of secretions, a cuff is provided on the outer wall of the intubation or cannula.

This cuff expands when gas is supplied into the cuff. As the cuff expands, the outer peripheral surface of the cuff contacts the inner wall of the trachea and closes the trachea. Thus, conventionally, inflow of secretions into the trachea is prevented by the cuff while securing the airway by intubation or cannula.

It is known that the following problems occur when the internal pressure of this cuff (hereinafter referred to as “cuff pressure”) falls outside the proper range.

For example, when the cuff pressure exceeds an appropriate range, the expanded cuff presses the blood vessel of the mucosal tissue of the trachea. When a blood vessel is compressed, it becomes ischemic, and as a result, there is a risk of causing necrosis, bleeding, and the like.

On the other hand, when the cuff pressure is less than the proper range, the cuff does not expand sufficiently, creating a gap between the outer surface of the cuff and the inner wall of the trachea, and secretions such as saliva and gastric juice flow into the trachea. There are things to do.

Therefore, Patent Document 1 discloses a cuff pressure control device that controls the pressure in the cuff to be within a predetermined range.

FIG. 14 is a cross-sectional view showing a configuration of a cuff pressure control apparatus 900 according to Patent Document 1. The cuff pressure of the cuff 952 is controlled by the cuff pressure control device 900. The cuff pressure control device 900 includes an adapter 910, a pressurizing pump 917, a cuff internal pressure gauge 918, and a suction pump 927.

A breathing tube 941 and a cannula 951 are connected to the adapter 910. The respiratory tube 941 is connected to the artificial respirator 940. A cuff 952 is provided on the outer wall of the cannula 951.

The cuff 952 is connected to the pressurizing pump 917 through the pipe 953. The cuff 952 expands when gas is supplied by the pressurizing pump 917. As the cuff 952 expands, the outer peripheral surface of the cuff 952 comes into contact with the inner wall 6 of the trachea 2 and closes the trachea 2.

In the above configuration, the cuff pressure control device 900 controls the driving of the pressurizing pump 917 based on the cuff pressure detected by the cuff internal pressure gauge 918 so that the cuff pressure of the cuff 952 is within a predetermined range. With the cuff 952 inflated and the trachea 2 occluded, the artificial respirator 940 delivers oxygen to the lungs through the respiratory tube 941, the adapter 910, and the cannula 951.

Furthermore, the cuff pressure control device 900 controls the driving of the suction pump 927 in a state where the cuff 952 is expanded and the trachea 2 is closed. As a result, the suction pump 927 sucks secretions accumulated on the epiglottis 4 side of the cuff 952 in the trachea 2 through the tube 954.

JP 2002-219175 A

However, the cuff pressure control device 900 of Patent Document 1 needs to include both the pressurizing pump 917 and the suction pump 927 in order to supply gas to the cuff 952 and suck secretion.

Therefore, in Patent Document 1, the cuff pressure control device 900 is enlarged. Further, in the cuff pressure control device 900 of Patent Document 1, both the pressurization pump 917 and the suction pump 927 are prepared, or a manufacturing process for attaching both the pressurization pump 917 and the suction pump 927 to the apparatus main body is not set. In other words, it contributes to high manufacturing costs.

Therefore, an object of the present invention is to provide a cuff pressure control device that achieves downsizing of the device main body and reduction of manufacturing cost.

The cuff pressure control device of the present invention has the following configuration in order to solve the above-mentioned problems.

(1) a pump having a gas suction hole and the gas discharge hole;
A valve housing, a first vent hole connected to the discharge hole, a second vent hole connected to the cuff, a third vent hole connected to the suction hole, and a tip facing the cuff A fourth vent hole connected to the pipe, a fifth vent hole and a sixth vent hole communicating with the outside of the valve housing, and the first vent hole and the second vent hole or the fifth vent hole. A valve having a flow path connecting any one of the third vent hole and the fourth vent hole or the sixth vent hole, and a switching mechanism for switching the flow path;
The flow path is switched by the switching mechanism, the first vent hole and either the second vent hole or the fifth vent hole are connected, and the third vent hole, the fourth vent hole or the sixth vent hole is connected. A control unit that connects any of the pores.

In this configuration, the distal end of the tube is arranged, for example, in the vicinity of the cuff epiglottis side surface in the trachea.

In this configuration, when the first vent hole and the second vent hole are connected and the third vent hole and the sixth vent hole are connected, the gas flows as follows by the operation of the pump.

That is, the gas outside the valve housing flows into the valve from the sixth vent and flows out from the third vent. The gas flowing out from the third vent hole flows into the pump through the suction hole and is discharged from the discharge hole, flows into the valve from the first vent hole, flows out from the second vent hole, and is supplied to the cuff. The As a result, the cuff expands.

On the other hand, when the first vent hole and the fifth vent hole are connected and the third vent hole and the fourth vent hole are connected, the gas flows as follows by the operation of the pump.

That is, the gas flows into the valve from the tip of the tube through the fourth vent and flows out from the third vent. The gas flowing out from the third vent hole flows into the pump through the suction hole, is discharged from the discharge hole, flows into the valve from the first vent hole, and is discharged from the fifth vent hole to the outside of the valve housing. Is done. As a result, the secretions accumulated on the epiglottis side of the cuff in the trachea are sucked through the tube by the operation of the pump.

Therefore, according to the cuff pressure control device of this configuration, the gas can be supplied to the cuff and the secretions can be sucked with a single pump, so that the device body can be downsized and the manufacturing cost can be reduced. Can do.

(2) A cuff pressure detection unit for detecting the pressure in the cuff is provided,
When the cuff pressure detection unit detects that the pressure in the cuff is smaller than a lower limit of a predetermined range, the control unit connects the first ventilation hole and the second ventilation hole, and connects the third communication hole. When the cuff pressure detector detects that the pressure in the cuff is within the predetermined range by connecting the air hole and the sixth air hole, the first air hole and the fifth air hole It is preferable to connect the third vent hole and the fourth vent hole.

In this configuration, when the pressure in the cuff is smaller than the lower limit of the predetermined range, the first vent hole and the second vent hole are connected, and the third vent hole and the sixth vent hole are connected. Gas outside the body is supplied to the cuff by the operation of the pump.

When the pressure in the cuff reaches a predetermined range, the first vent hole and the fifth vent hole are connected, and the third vent hole and the fourth vent hole are connected. No back flow into the valve from the second vent. Therefore, the cuff pressure is maintained without depending on the operation of the pump. During this time, the pump aspirates secretions through the tube.

That is, in this configuration, when the pressure in the cuff is below the lower limit of the predetermined range, the pump supplies gas to the cuff, and when the pressure in the cuff falls within the predetermined range, the pump Suck through.

(3) It is preferable that the fifth vent hole and the sixth vent hole are configured by sharing a single fifth vent hole. In this configuration, since the vent hole communicating with the outside is shared, the valve can be downsized, and the cuff pressure control device can be further downsized.

(4) It is preferable that the switching mechanism opens and closes a valve by electromagnetic driving to switch the flow path.

In this configuration, the flow path can be switched with high reliability.

(5) The controller switches the flow path by the switching mechanism while the pump is on, and connects the first vent hole and the second vent hole for a time shorter than the pump on time. Is preferred.

In this configuration, the flow rate of the gas supplied to the cuff can be finely adjusted by switching the valve at high speed.

(6) It is preferable that the pump includes a piezoelectric element as an actuator, and a vibration plate having a main surface bonded to the piezoelectric element and bending and vibrating by expansion and contraction of the piezoelectric element.

In this configuration, the efficiency is increased by using a piezoelectric element as the actuator. Therefore, according to the cuff pressure control device having this configuration, power consumption can be reduced.

(7) a tank for storing the liquid sucked through the tube;
A filter that allows the gas to pass therethrough and prevents the liquid from passing therethrough,
It is preferable that the filter and the tank are detachably connected to the fourth vent hole.

In this configuration, the filter and the tank can be separated from the cuff pressure control device. In this case, since a worker such as a doctor can easily discard the filter and the tank contaminated with the secretion, the risk of the subject being infected with VAP can be reduced.

According to this invention, it is possible to reduce the size of the apparatus main body and reduce the manufacturing cost.

It is a schematic diagram which shows a mode that the intubation 1 was inserted in the trachea from the oral cavity. It is sectional drawing of the principal part of the intubation 1 shown in FIG. It is a block diagram which shows the structure of the principal part of the cuff pressure control apparatus 100 which concerns on 1st Embodiment of this invention. It is sectional drawing of the principal part of the valve | bulb 120 shown in FIG. It is sectional drawing of the principal part of the valve | bulb 130 shown in FIG. FIG. 4 is a cross-sectional view of a main part of the valve 120 when the pump 110 shown in FIG. 3 is operating. 6A is a view when the first vent hole 121 and the second vent hole 122 are connected, and FIG. 6B is a view when the first vent hole 121 and the fifth vent hole 125 are connected. It is sectional drawing of the principal part of the valve | bulb 130 when the pump 110 shown in FIG. 3 is operate | moving. 7A is a view when the third vent hole 133 and the sixth vent hole 136 are connected, and FIG. 7B is a view when the third vent hole 133 and the fourth vent hole 134 are connected. It is a block diagram which shows the structure of the principal part of the cuff pressure control apparatus 200 which concerns on 2nd Embodiment of this invention. It is sectional drawing of the principal part of the valve | bulb 220 shown in FIG. It is an external appearance perspective view of the piezoelectric pump 101 with which the cuff pressure control apparatus which concerns on 3rd Embodiment of this invention is equipped. It is a disassembled perspective view of the piezoelectric pump 101 shown in FIG. FIG. 11 is a sectional view taken along line SS of the piezoelectric pump 101 shown in FIG. 10. FIG. 11 is a cross-sectional view taken along line SS of the piezoelectric pump 101 when the piezoelectric pump 101 shown in FIG. FIG. 13A is a diagram when the volume of the pump chamber is increased, and FIG. 13B is a diagram when the volume of the pump chamber is decreased. It is a block diagram which shows the structure of the principal part of the cuff pressure control apparatus 900 concerning patent document 1. FIG.

<< First Embodiment of the Invention >>
Hereinafter, the cuff pressure control apparatus 100 according to the first embodiment of the present invention will be described.

FIG. 1 is a schematic view showing a state in which the intubation 1 is inserted into the trachea from the oral cavity. FIG. 2 is a cross-sectional view of the main part of the intubation 1 shown in FIG.

When the airway is secured by tracheal intubation when using the ventilator, if a gap is formed between the intubation 1 inserted from the oral cavity 5 of the subject and the inner wall 6 of the trachea 2, gastric fluid from the esophagus 3 in the trachea 2. And secretions such as saliva may flow into the subject, and the subject may develop ventilator-associated pneumonia (VAP). In particular, in tracheal intubation, the epiglottis 4 is opened, so that gastric fluid from the esophagus 3 easily flows into the trachea 2.

In order to prevent such inflow of secretions, a cuff 10 is provided at a predetermined position on the outer periphery of the intubation 1. The cuff 10 expands by being pressurized from outside the body via an air supply pipe 175 described later. As the cuff 10 expands, the outer peripheral surface of the cuff 10 contacts the inner wall 6 of the trachea 2 and closes the trachea 2.

Thus, the cuff pressure control device 100 can prevent the inflow of secretions into the trachea 2 by the cuff 10 while securing the airway by the intubation 1. In the present embodiment, the volume of the cuff 10 is 20 ml.

Further, in the state where the cuff 10 is expanded and the trachea 2 is blocked, the secretion H accumulates on the surface of the cuff 10 on the epiglottis 4 side in the trachea 2 as shown in FIG. If the secretion H accumulates excessively, the secretion H may flow into the back of the trachea 2 through a minute gap between the cuff 10 and the trachea 2. The minute gap is generated, for example, when the cuff 10 is displaced due to body movement.

Therefore, in a state where the cuff 10 is inflated and the trachea 2 is occluded, the secretion H accumulated on the epiglottis 4 side of the cuff 10 in the trachea 2 needs to be removed.

FIG. 3 is a block diagram showing a configuration of a main part of the cuff pressure control apparatus 100 according to the first embodiment of the present invention. The cuff pressure control device 100 is connected to the cuff 10 via an air supply pipe 175. The “cuff pressure” in the cuff 10 is controlled by the cuff pressure control device 100.

The cuff pressure control device 100 includes a control unit 111, a storage unit 112, a cuff pressure detection unit 171, a suction pressure detection unit 173, an input unit 114, a display unit 115, a sound generation unit 116, and a drive circuit 119. . The cuff pressure control apparatus 100 further includes a pump 110,

valves

120 and 130, a filter 176, a tank 160, and an exhaust valve 172.

The control unit 111 controls each unit in the cuff pressure control device 100. The control unit 111 includes a timer circuit (not shown) that measures time. The control unit 111 measures time and acquires time information such as elapsed time.

The control unit 111 controls the cuff pressure detection unit 171, the suction pressure detection unit 173, the drive circuit 119, and the exhaust valve 172 so that the cuff pressure is within a predetermined range based on the detection result of the cuff pressure detection unit 171 and the like. Control. In the present embodiment, the predetermined range is a range of 20 cmH ₂ O to 30 cmH ₂ O.

Further, the control unit 111 switches the flow paths of the

valves

120 and 130 based on the detection result of the cuff pressure detection unit 171 and the like.

The cuff pressure detection unit 171 is connected to the cuff 10 via a cuff pressure detection pipe 118 that communicates with the air supply pipe 175. The cuff pressure detector 171 detects the cuff pressure of the cuff 10. Then, the control unit 111 reads the cuff pressure from the cuff pressure detection unit 171.

The storage unit 112 is a non-volatile memory, and includes, for example, a flash memory and an HDD (HardDisk Drive). The storage unit 112 stores range information related to the predetermined range. In addition, the control unit 111 records information on the cuff pressure read from the cuff pressure detection unit 171 and the time information acquired by the timer circuit in the storage unit 112 as a change with time of the cuff pressure. The storage unit 112 also stores information on a plurality of pressurization parameters according to product types such as the cuff 10, information on a plurality of operation modes, and the like.

The input unit 114 has operation buttons and accepts an input operation from an operator such as a doctor. The input unit 114 outputs a signal corresponding to the accepted input operation to the control unit 111.

The display unit 115 is configured by a liquid crystal display, for example. When the display unit 115 receives the display command from the control unit 111, the display unit 115 displays, for example, information on the cuff pressure, time information, and the like on the screen based on the display information included in the display command.

The sounding unit 116 is, for example, a speaker. The sound generation unit 116 is driven by the control unit 111 and outputs an alarm sound that notifies an operator such as a doctor of an abnormality of the cuff 10, for example.

The drive circuit 119 drives the pump 110 at a drive frequency of 100 Hz or less.

The valve 120 is connected between the pump 110 and the cuff 10, as will be described in detail later.

The pump 110 is a diaphragm pump using a motor as an actuator. The pump 110 has an air suction hole 110A and an air discharge hole 110B. The pump 110 is operated by the drive circuit 119 and sucks air from the suction hole 110A and discharges it from the discharge hole 110B. In the pump 110, the magnitude and speed of pressurization to the cuff 10 are set under the control of the control unit 111.

The exhaust valve 172 is connected to the cuff 10. The exhaust valve 172 is controlled by the control unit 111 to be opened and closed. In the open state, the exhaust valve 172 opens the interior of the cuff 10 to the atmosphere via the air supply pipe 175 and exhausts the air in the cuff 10. In the closed state, the exhaust valve 172 stops the release of the air in the cuff 10 to the atmosphere and stops the exhaust of the cuff 10.

When the cuff pressure exceeds a predetermined range, the control unit 111 opens the exhaust valve 172 to exhaust air from the cuff 10. Accordingly, the control unit 111 can adjust the cuff pressure within a predetermined range.

The tank 160 is connected to a suction pipe 141 having a tip 141A facing the cuff 10 and a suction pipe 142. For example, the distal end 141A of the suction tube 141 is disposed in the vicinity of the surface of the cuff 10 on the epiglottis 4 side in the trachea 2 (see FIGS. 1 and 2). The tank 160 stores the secretion H sucked through the suction pipe 141. The tank 160 is connected to the filter 176 via the suction pipe 142.

The filter 176 is connected to the fourth vent hole 134 of the valve 130 via the suction pipe 143. The filter 176 allows air to pass from the suction tube 142 to the suction tube 143, and prevents passage of liquid (such as secretion H) from the suction tube 142 to the suction tube 143.

The suction pressure detection unit 173 is connected to the filter 176 and the valve 130 via the suction pipe 143. The suction pressure detection unit 173 detects the pressure in the suction pipe 143 by the operation of the pump 110. If any of the

suction pipes

141, 142, 143 is disconnected or any of the

suction pipes

141, 142, 143 is clogged, this pressure becomes zero or a very high value.

Therefore, when the suction pressure detection unit 173 detects that the pressure has become 0 or has a significantly high value, the control unit 111 notifies the abnormality by the sound generation unit 116 or the display unit 115.

The valve 130 is connected between the pump 110 and the filter 176.

Here, the structure of the

valves

120 and 130 will be described in detail with reference to FIGS.

4 is a cross-sectional view of the main part of the valve 120 shown in FIG. 3, and FIG. 5 is a cross-sectional view of the main part of the valve 130 shown in FIG. 6A and 6B are cross-sectional views of the main part of the valve 120 when the pump 110 shown in FIG. 3 is operating. 6A is a diagram when the first vent hole 121 and the second vent hole 122 are connected, and FIG. 6B is a diagram when the first vent hole 121 and the fifth vent hole 125 are connected. is there. 7A and 7B are cross-sectional views of the main part of the valve 130 when the pump 110 shown in FIG. 3 is operating. 7A is a diagram when the third vent hole 133 and the sixth vent hole 136 are connected, and FIG. 7B is a diagram when the third vent hole 133 and the fourth vent hole 134 are connected. is there. Note that arrows in FIGS. 6A and 6B and FIGS. 7A and 7B indicate the flow of air.

The valve 120 has a valve housing 129 and a valve body 128 as shown in FIG.

The valve housing 129 includes a first ventilation hole 121 connected to the discharge hole 110B of the pump 110 via the relay pipe 178, and a second ventilation hole 122 connected to the cuff 10 via the air supply pipe 175. A fifth vent hole 125 communicating with the outside of the valve housing 129 is provided.

The valve body 128 has rectangular

parallelepiped end portions

128A and 128B and a rod-shaped central portion 128C connecting the

end portions

128A and 128B. The valve body 128 is slidably provided in the valve housing 129 in the direction of the arrow shown in FIG. And the valve body 128 comprises the flow path which connects the 1st ventilation hole 121 and either the 2nd ventilation hole 122 or the 5th ventilation hole 125 with the valve housing 129.

The control unit 111 slides the valve body 128 based on the detection result of the cuff pressure detection unit 171 and switches the flow path of the valve 120. The valve body 128 slides by being electromagnetically driven by a solenoid (not shown), closes either the second vent hole 122 or the fifth vent hole 125 and opens the other. Thereby, the control part 111 connects the 1st ventilation hole 121 and either the 2nd ventilation hole 122 or the 5th ventilation hole 125, as shown to FIG. 6 (A) (B). Therefore, the valve 120 can realize the switching of the flow path of the valve 120 with high reliability.

The structure of the valve 130 is the same as the structure of the valve 120 as shown in FIG. The valve 130 also has a valve housing 139 and a valve body 138.

The two

valves

120 and 130 constitute the “valve” of the present invention. Each of the

valve bodies

128 and 138 corresponds to the “switching mechanism” of the present invention.

The valve housing 139 is connected to the third vent hole 133 connected to the suction hole 110A of the pump 110 via the relay pipe 177 and the

suction pipes

141, 142, and 143 with the tip 141A facing the cuff 10. A fourth ventilation hole 134 and a sixth ventilation hole 136 communicating with the outside of the valve housing 139 are provided.

The valve body 138 has rectangular

parallelepiped end portions

138A and 138B, and a rod-shaped central portion 138C connecting the

end portions

138A and 138B. The valve body 138 is provided in the valve housing 139 so as to be slidable in the direction of the arrow shown in FIG. The valve body 138 configures a flow path connecting the third ventilation hole 133 and either the fourth ventilation hole 134 or the sixth ventilation hole 136 together with the valve housing 139.

The control unit 111 slides the valve body 138 based on the detection result of the cuff pressure detection unit 171 and switches the flow path of the valve 130. The valve body 138 slides by being electromagnetically driven by a solenoid (not shown), and closes either the fourth vent hole 134 or the sixth vent hole 136 and opens the other.

Thereby, as shown in FIGS. 7A and 7B, the control unit 111 connects the third ventilation hole 133 and either the fourth ventilation hole 134 or the sixth ventilation hole 136. Therefore, the valve 130 can realize the switching of the flow path with high reliability.

In the above configuration, after an operator such as a doctor inserts the intubation 1 from the oral cavity 5 of the subject, the cuff pressure control device 100 starts filling the cuff 10 with air. When the cuff 10 starts to be filled with air, that is, when the cuff pressure detection unit 171 detects that the cuff pressure of the cuff 10 is smaller than the lower limit of the predetermined range, the control unit 111 is connected to the first vent hole 121 and the first cuff 10. The second vent hole 122 is connected, and the third vent hole 133 and the sixth vent hole 136 are connected.

Then, the control unit 111 instructs the drive circuit 119 to drive the pump 110 while being repeatedly turned on and off at a predetermined cycle (for example, 0.5 seconds). At this time, the control unit 111 switches the flow path of the valve 120 at a cycle shorter than the predetermined cycle, and connects the first vent hole 121 and either the second vent hole 122 or the fifth vent hole 125. In the cuff pressure control apparatus 100, the control unit 111 can finely adjust the flow rate of the air supplied to the cuff 10 by switching the flow path of the valve 120 at high speed.

When the first vent hole 121 and the second vent hole 122 are connected and the third vent hole 133 and the sixth vent hole 136 are connected, air flows as follows according to the operation of the pump 110.

First, air outside the valve housing 139 flows into the valve 130 from the sixth vent hole 136 and flows out from the third vent hole 133. The air that has flowed out of the third vent hole 133 flows into the pump 110 through the suction hole 110A, is discharged from the discharge hole 110B, flows into the valve 120 from the first vent hole 121, and is discharged from the second vent hole 122. It flows out and is supplied to the cuff 10. As a result, the cuff 10 is inflated, and the trachea 2 is closed by the cuff 10.

When the cuff pressure detection unit 171 detects that the cuff pressure of the cuff 10 is within the predetermined range, the control unit 111 temporarily stops the driving of the pump 110, and the first ventilation hole 121 and the fifth ventilation hole 125. And connect.

Here, since the first vent hole 121 and the fifth vent hole 125 are connected, the air in the cuff 10 does not flow backward from the second vent hole 122 of the valve 120 to the pump 110 side. Therefore, the cuff pressure of the cuff 10 is maintained without depending on the operation of the pump 110. During this time, the control unit 111 connects the third vent hole 133 and the fourth vent hole 134 to resume the driving of the pump 110 and sucks the secretion H through the suction pipe 141.

When the first vent hole 121 and the fifth vent hole 125 are connected and the third vent hole 133 and the fourth vent hole 134 are connected, air flows as follows according to the operation of the pump 110.

First, air flows from the tip 141A of the suction pipe 141 into the valve 130 via the fourth vent hole 134 and flows out from the third vent hole 133. The air that has flowed out of the third vent hole 133 flows into the pump 110 through the suction hole 110A, is discharged from the discharge hole 110B, flows into the valve 120 through the first vent hole 121, and is discharged from the fifth vent hole 125. It is discharged to the outside of the valve housing 129.

Thereby, the secretion H collected on the epiglottis 4 side of the cuff 10 in the trachea 2 is sucked together with air from the tip 141A of the suction tube 141 by the operation of the pump 110 and is collected in the tank 160.

That is, in the cuff pressure control device 100, when the cuff pressure of the cuff 10 is smaller than the lower limit of the predetermined range, the pump 110 supplies air to the cuff 10, and when the cuff pressure of the cuff 10 falls within the predetermined range, The pump 110 continues to suck the secretion H through the suction pipe 141. Alternatively, when the cuff pressure of the cuff 10 falls within a predetermined range, the pump 110 repeatedly turns on and off at regular time intervals, and continues to suck the secretion H through the suction pipe 141.

Therefore, according to the cuff pressure control device 100, the air can be supplied to the cuff 10 and the secretion H can be sucked by one pump 110. Therefore, according to the cuff pressure control apparatus 100, it is possible to reduce the size of the apparatus main body and reduce the manufacturing cost.

<< Second Embodiment of the Invention >>
Hereinafter, the cuff pressure control apparatus 200 according to the second embodiment of the present invention will be described.

FIG. 8 is a block diagram showing a configuration of a main part of the cuff pressure control apparatus 200 according to the second embodiment of the present invention. FIG. 9 is a cross-sectional view of the main part of the valve 220 shown in FIG. The cuff pressure control device 200 according to the second embodiment is different from the cuff pressure control device 100 according to the first embodiment in that a single valve 220 is provided instead of the two

valves

120 and 130. Since other configurations are the same, description thereof is omitted.

More specifically, the valve 220 includes a valve housing 229 and a valve body 228.

The valve housing 229 includes a first ventilation hole 221 connected to the discharge hole 110B of the pump 110, a second ventilation hole 222 connected to the cuff 10 via the air supply pipe 175, and a suction hole of the pump 110. A third vent hole 223 connected to 110A, a fourth vent hole 224 to which the

suction pipes

141, 142, 143 with the tip 141A facing the cuff 10 are connected, and a first vent communicating to the outside of the valve housing 229. 5 vent holes 225 are provided.

The valve body 228 is provided in the valve housing 229 so as to be slidable in the direction of the arrow shown in FIG. The valve body 228 connects the first ventilation hole 221 and either the second ventilation hole 222 or the fifth ventilation hole 225, and the third ventilation hole 223, the fourth ventilation hole 224, or the fifth ventilation hole 225. Are formed together with the valve housing 229.

The control unit 111 slides the valve body 228 based on the detection result of the cuff pressure detection unit 171 and switches the flow path of the valve 220. The valve body 228 slides by being electromagnetically driven by a solenoid (not shown), and closes either the second vent hole 222 or the fourth vent hole 224 and opens the other. The valve body 228 always opens the fifth ventilation hole 225.

As a result, the control unit 111 connects the first ventilation hole 221 and either the second ventilation hole 222 or the fifth ventilation hole 225, and the third ventilation hole 223, the fourth ventilation hole 224, or the fifth ventilation hole 225 is connected. Connect one of them. Therefore, the valve 220 can realize the switching of the flow path with high reliability.

In the above configuration, after an operator such as a doctor inserts the intubation 1 from the oral cavity 5 of the subject, the cuff pressure control device 200 starts filling the cuff 10 with air. When the cuff 10 starts to be filled with air, that is, when the cuff pressure detection unit 171 detects that the cuff pressure of the cuff 10 is smaller than the lower limit of the predetermined range, the control unit 111 controls the first vent 221 and the first cuff 10. The second vent hole 222 is connected, and the third vent hole 223 and the fifth vent hole 225 are connected.

Furthermore, the control unit 111 instructs the drive circuit 119 to turn on and off the pump 110. At this time, the control unit 111 switches the flow path of the valve 220 in a time shorter than the ON time of the pump 110.

When the cuff pressure detection unit 171 detects that the cuff pressure of the cuff 10 is within the predetermined range, the control unit 111 temporarily stops driving the pump 110 and connects the first vent hole 221 and the fifth communication port. The air holes 225 are connected, and the third air holes 223 and the fourth air holes 224 are connected. Thereafter, the control unit 111 resumes driving of the pump 110.

That is, also in the cuff pressure control device 200, when the cuff pressure of the cuff 10 is smaller than the lower limit of the predetermined range, the pump 110 supplies air to the cuff 10 and when the cuff pressure of the cuff 10 falls within the predetermined range. The pump 110 continues to suck the secretion H through the suction pipe 141. Alternatively, when the cuff pressure of the cuff 10 falls within a predetermined range, the pump 110 continues to suck the secretion H through the suction pipe 141.

Therefore, the cuff pressure control device 200 according to the second embodiment has the same effect as the cuff pressure control device 100 according to the first embodiment. Furthermore, since the valve is integrated and the vent hole communicating with the outside is shared as compared with the first embodiment, the valve can be downsized, and the cuff pressure control device can be further downsized.

<< Third Embodiment of the Invention >>
Hereinafter, a cuff pressure control device according to a third embodiment of the present invention will be described.

The difference between the cuff pressure control device of the third embodiment and the cuff pressure control device 100 of the first embodiment is that a piezoelectric pump 101 is provided instead of the pump 110. Since other configurations are the same, description thereof is omitted.

The structure of the piezoelectric pump 101 will be described in detail with reference to FIGS.

FIG. 10 is an external perspective view of the piezoelectric pump 101 provided in the cuff pressure control device of the third embodiment. FIG. 11 is an exploded perspective view of the piezoelectric pump 101 shown in FIG. 12 is a cross-sectional view taken along line SS of the piezoelectric pump 101 shown in FIG.

The piezoelectric pump 101 includes an outer casing 17, a top plate 37, a side plate 38, a vibration plate 39, a piezoelectric element 40, and a cap 42 in order from the top, and has a structure in which these are stacked in order. The top plate 37, the side plate 38, and the diaphragm 39 constitute a pump chamber 36. The piezoelectric pump 101 has a size of width 20 mm × length 20 mm × height of the region other than the nozzle 18 1.85 mm.

The top plate 37, the side plate 38, the vibration plate 39, and the piezoelectric element 40 constitute a pump body.

The outer casing 17 has a nozzle 18 provided with a discharge hole 24 through which air is discharged, for example. The nozzle 18 has a size of an outer diameter of 2.0 mm × an inner shape (that is, a discharge hole 24) of a diameter of 0.8 mm × a height of 1.6 mm. Screw holes 56A to 56D are provided in the square of the outer casing 17.

The outer casing 17 has a concave opening at the bottom and has a U-shaped cross section. The outer housing 17 houses the top plate 37, the side plate 38, the vibration plate 39 and the piezoelectric element 40 of the pump chamber 36. The outer casing 17 is made of, for example, resin.

The top plate 37 of the pump chamber 36 has a disk shape and is made of metal, for example. The top plate 37 is provided with a central portion 61, a key-shaped protruding portion 62 that protrudes horizontally from the central portion 61 and contacts the inner wall of the outer casing 17, and an external terminal 63 for connecting to an external circuit. It has been.

In addition, the central portion 61 of the top plate 37 is provided with a vent hole 45 that allows the inside and outside of the pump chamber 36 to communicate with each other. The vent hole 45 is provided at a position facing the discharge hole 24 of the outer casing 17. The top plate 37 is provided on the upper surface of the side plate 38.

The side plate 38 of the pump chamber 36 has an annular shape, and is made of metal, for example. The side plate 38 is provided on the upper surface 39 </ b> A of the diaphragm 39. Therefore, the thickness of the side plate 38 is the height of the pump chamber 36.

The diaphragm 39 has a disk shape and is made of metal, for example. The diaphragm 39 constitutes a pump chamber 36 together with the side plate 38 and the top plate 37.

The piezoelectric element 40 has a disk shape and is made of, for example, a lead zirconate titanate ceramic. The piezoelectric element 40 expands and contracts according to the applied AC drive voltage. The piezoelectric element 40 is provided on the lower surface 39 </ b> B of the diaphragm 39 on the side opposite to the pump chamber 36.

The joined body of the top plate 37, the side plate 38, the vibration plate 39, and the piezoelectric element 40 has a central portion of the joined body with respect to the outer housing 17 by the four protrusions 62 provided on the top plate 37. It is supported so that it can be displaced.

The electrode conduction plate 70 includes an internal terminal 73 connected to the piezoelectric element 40 and an external terminal 72 connected to an external circuit. The tip of the internal terminal 73 is joined to the flat plate surface of the piezoelectric element 40 with solder. By setting the position to be joined by solder to a position corresponding to the bending vibration node of the piezoelectric element 40, the internal terminal 73 can be joined to the piezoelectric element 40 without inhibiting the bending vibration of the piezoelectric element 40. Thereby, the vibration of the internal terminal 73 can be suppressed.

The cap 42 is provided with a disk-shaped suction hole 53. The diameter of the suction hole 53 is larger than the diameter of the piezoelectric element 40. The cap 42 is provided with notches 55A to 55D at positions corresponding to the screw holes 56A to 56D of the outer casing 17.

The cap 42 has a protruding portion 52 that protrudes toward the top plate 37 on the outer peripheral edge. The cap 42 sandwiches the outer casing 17 with the protruding portion 52, and houses the top plate 37, the side plate 38, the vibration plate 39 and the piezoelectric element 40 of the pump chamber 36 in the outer casing 17. The cap 42 is made of resin, for example.

As shown in FIG. 12, a ventilation path 31 is provided between the joined body of the top plate 37, the side plate 38, the diaphragm 39 and the piezoelectric element 40 and the outer casing 17 and the cap 42.

In the cuff pressure control device of the third embodiment, the suction hole 53 of the piezoelectric pump 101 is connected to the third vent hole 133 of the valve 130, and the discharge hole 24 of the piezoelectric pump 101 is the first vent hole of the valve 120. 121 (see FIG. 3).

Hereinafter, the flow of air during the operation of the piezoelectric pump 101 will be described.

13A and 13B show the SS line of the piezoelectric pump 101 when the piezoelectric pump 101 shown in FIG. 10 is resonantly driven at the frequency (fundamental wave) of the primary vibration mode of the pump body. It is sectional drawing. Here, the arrows in the figure indicate the flow of air.

In the state shown in FIG. 12, when an AC drive voltage corresponding to the frequency (fundamental wave) of the primary vibration mode of the pump body is applied from the drive circuit 119 to the piezoelectric element 40 via the

external terminals

63 and 72, the diaphragm 39 is bent and vibrated concentrically. At the same time, the top plate 37 bends concentrically with the bending vibration of the vibration plate 39 (in this embodiment, the vibration phase is delayed by 180 °) due to the pressure fluctuation of the pump chamber 36 accompanying the bending vibration of the vibration plate 39. To do. Thereby, as shown in FIGS. 13A and 13B, the diaphragm 39 and the top plate 37 are bent and deformed, and the volume of the pump chamber 36 is periodically changed.

As shown in FIG. 13A, when an AC drive voltage is applied to the piezoelectric element 40 and the diaphragm 39 bends toward the piezoelectric element 40, the volume of the pump chamber 36 increases. Accordingly, air outside the piezoelectric pump 101 is sucked into the pump chamber 36 through the suction hole 53, the air passage 31, and the air hole 45. Although there is no outflow of air from the pump chamber 36, the inertial force of the air flow from the discharge hole 24 to the outside of the piezoelectric pump 101 works.

As shown in FIG. 13B, when an AC drive voltage is applied to the piezoelectric element 40 and the diaphragm 39 is bent toward the pump chamber 36, the volume of the pump chamber 36 decreases. Accordingly, the air in the pump chamber 36 is discharged from the discharge hole 24 through the vent hole 45 and the vent path 31.

At this time, by the air discharged from the pump chamber 36, the air outside the piezoelectric pump 101 is drawn through the suction hole 53 and the air passage 31 and discharged from the discharge hole 24. Therefore, the flow rate of air discharged from the discharge holes 24 is increased by the flow rate of air drawn from the outside.

As described above, according to the piezoelectric pump 101 of this embodiment, the discharge flow rate per power consumption is significantly increased. Therefore, the piezoelectric pump 101 can obtain a large discharge flow rate with low power consumption.

The operation of the cuff pressure control device of the third embodiment other than the piezoelectric pump 101 is the same as the operation of the cuff pressure control device 100 of the first embodiment.

Therefore, the cuff pressure control device of the third embodiment has the same effect as the cuff pressure control device 100 of the first embodiment.

Here, the flow rate of air discharged by one cycle of pumping of the piezoelectric pump 101 is smaller than the flow rate of air discharged by one cycle of pumping of the motor type pump 110, for example, 1/200 or less. The flow rate of air discharged by one cycle of pumping of the piezoelectric pump 101 is, for example, 1 nL (nanoliter) or more and 10 μL (microliter) or less. When the cuff pressure is within a predetermined range, the flow rate of the air discharged by one cycle of pumping of the piezoelectric pump 101 is, for example, about 0.2 μL. Further, the piezoelectric pump 101 is driven at a driving frequency of, for example, an audible range (20 Hz to 20,000 Hz) or more. On the other hand, as described above, the pump 110 is driven at a driving frequency of 100 Hz or less.

Therefore, when the control unit 111 controls the drive circuit 119 on the millisecond (ms) order, the control unit 111 can finely adjust the flow rate of the air supplied to the cuff 10 by the piezoelectric pump 101. That is, the cuff pressure control device according to the third embodiment does not need to switch the flow path of the valve 120 at a cycle shorter than the above-described predetermined cycle.

Therefore, the cuff pressure control device of the third embodiment can reduce power consumption compared to the cuff pressure control device 100 of the first embodiment.

<< Other Embodiments >>
In the embodiment, air is used as the gas, but the present invention is not limited to this. The gas can be applied even if it is a gas other than air.

In the above embodiment, the

valves

120 and 130 having the structure shown in FIG. 4 and the valve 220 having the structure shown in FIG. 9 are used. However, the present invention is not limited to this. Even a valve having a structure other than these structures can be applied.

In the above embodiment, the cuff pressure control device includes the exhaust valve 172, but the present invention is not limited to this. For example, in the cuff pressure control device 100, when the cuff pressure exceeds a predetermined range, the control unit 111 connects the first ventilation hole 121 and the second ventilation hole 122, and the third ventilation hole 133 and the sixth ventilation hole 136. Connect. Thereby, the cuff pressure control apparatus 100 exhausts the gas in the cuff 10 from the sixth vent hole 136 of the valve 130 via the valve 120 and the pump 110. Thereby, the cuff pressure control apparatus 100 can adjust the cuff pressure within a predetermined range.

In the above embodiment, the piezoelectric element is composed of lead zirconate titanate ceramics, but is not limited thereto. For example, it may be made of a non-lead piezoelectric ceramic material such as potassium sodium niobate and alkali niobate ceramics.

In the above embodiment, a unimorph type piezoelectric vibrator is used, but the present invention is not limited to this. A bimorph type piezoelectric vibrator in which the piezoelectric elements 40 are provided on both surfaces of the vibration plate 39 may be used.

In the above embodiment, a disk-shaped piezoelectric element, a disk-shaped diaphragm, and a disk-shaped top plate are used, but the present invention is not limited to this. For example, these shapes may be a rectangular plate shape, a polygonal plate shape, or an elliptical plate shape.

In the above embodiment, the piezoelectric pump is driven to resonate at the frequency (fundamental wave) of the primary vibration mode of the pump body, but the present invention is not limited to this. At the time of implementation, resonance driving may be performed at a frequency of an odd-order vibration mode having a plurality of vibration antinodes and higher than the third-order vibration mode.

Moreover, in the said embodiment, the filter 176 and the tank 160 are connected to the 4th ventilation hole 134 of the valve | bulb 130, and are integrated with other components (valve 130 grade | etc.) As a cuff pressure control apparatus, However, it is not restricted to this It is not a thing. In implementation, the filter 176 and the tank 160 may be detachably connected to the fourth vent hole 134 of the valve 130 and separable from the cuff pressure control device.

For example, the suction pipe 141, the tank 160, the suction pipe 142, and the filter 176 are detachably connected to the suction pipe 143 connected to the fourth vent hole 134 of the valve 130, and can be separated from the cuff pressure control device. Good. In this case, since a worker such as a doctor can easily discard the portion contaminated with the secretion, the risk of the subject being infected with VAP can be reduced.

Finally, the description of the embodiment should be considered as illustrative in all points and not restrictive. The scope of the present invention is shown not by the above embodiments but by the claims. Furthermore, the scope of the present invention is intended to include all modifications within the meaning and scope equivalent to the scope of the claims.

H ... secretion 1 ... intubation 2 ... trachea 3 ... esophagus 4 ... epiglottis 5 ... oral cavity 6 ... inner wall 10 ... cuff 17 ... outer casing 18 ... nozzle 24 ... discharge hole 31 ... vent passage 36 ... pump chamber 37 ... top plate 38 ... side plate 39 ... diaphragm 40 ... piezoelectric element 42 ... cap 45 ... vent hole 52 ... protrusion 53 ... suction hole 61 ... central part 62 ... protrusion 63 ... external terminal 70 ... electrode conduction plate 72 ... external terminal 73 ... internal Terminal 100 ... Cuff pressure control device 101 ... Piezoelectric pump 110 ... Pump 110A ... Suction hole 110B ... Discharge hole 111 ... Control unit 112 ... Storage unit 114 ... Input unit 115 ... Display unit 116 ... Sound generation unit 118 ... Cuff pressure detection tube 119 ... Drive circuit 120 ... Valve 121 ... First vent 122 ... Second vent 125 ... Fifth vent 128 ... Valve body 129 ... Valve housing 130 ... Valve 133 ... Third vent 134 ... Fourth vent 136 ... Fourth 6 Hole 138 ... Valve body 139 ...

Valve housing

141, 142, 143 ... Suction pipe 160 ... Tank 171 ... Cuff pressure detection part 172 ... Exhaust valve 173 ... Suction pressure detection part 175 ... Air supply pipe 176 ...

Filter

177, 178 ... Relay Pipe 200 ... Cuff pressure control device 220 ... Valve 221 ... First vent 222 ... Second vent 223 ... Third vent 224 ... Fourth vent 225 ... Fifth vent 228 ... Valve body 229 ... Valve housing 900 ... Cuff pressure control device 910 ... Adapter 917 ... Pressure pump 918 ... Cuff internal pressure gauge 927 ... Suction pump 940 ... Respirator 941 ... Respiratory tube 951 ... Cannula 952 ...

Cuff

953, 954 ... Tube

Claims

A pump having a gas suction hole and the gas discharge hole;
A valve housing, a first vent hole connected to the discharge hole, a second vent hole connected to the cuff, a third vent hole connected to the suction hole, and a tip facing the cuff A fourth vent hole connected to the pipe, a fifth vent hole and a sixth vent hole communicating with the outside of the valve housing, and the first vent hole and the second vent hole or the fifth vent hole. A valve having a flow path connecting any one of the third vent hole and the fourth vent hole or the sixth vent hole, and a switching mechanism for switching the flow path;
The flow path is switched by the switching mechanism, the first vent hole and either the second vent hole or the fifth vent hole are connected, and the third vent hole, the fourth vent hole or the sixth vent hole is connected. A cuff pressure control device comprising: a control unit that connects any of the pores.
A cuff pressure detector for detecting the pressure in the cuff;
When the cuff pressure detection unit detects that the pressure in the cuff is smaller than a lower limit of a predetermined range, the control unit connects the first ventilation hole and the second ventilation hole, and connects the third communication hole. When the cuff pressure detector detects that the pressure in the cuff is within the predetermined range by connecting the air hole and the sixth air hole, the first air hole and the fifth air hole The cuff pressure control device according to claim 1, wherein the third vent hole and the fourth vent hole are connected.
The cuff pressure control device according to claim 1 or 2, wherein the fifth vent hole and the sixth vent hole are configured by sharing a single vent hole.
The cuff pressure control device according to any one of claims 1 to 3, wherein the switching mechanism switches a flow path by opening and closing a valve by electromagnetic drive.
The control unit switches the flow path by the switching mechanism while the pump is on, and connects the first vent hole and the second vent hole for a time shorter than an on time of the pump. 5. The cuff pressure control device according to any one of items 1 to 4.
The said pump has a piezoelectric element as an actuator, and a diaphragm which has a main surface joined to the said piezoelectric element, and bends and vibrates by expansion / contraction of the said piezoelectric element. Cuff pressure control device.
A tank for storing the liquid sucked through the tube;
A filter that allows the gas to pass therethrough and prevents the liquid from passing therethrough,
The cuff pressure control device according to any one of claims 1 to 6, wherein the filter and the tank are detachably connected to the fourth vent hole.