JP2011194222A - Cuff pressure control device, and cuff pressure control method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent VAP (ventilator-associated pneumonia) caused by insufficient cuff pressure or the like of a cuff, and prevent VAP caused by wrinkles or the like formed in an outer circumferential surface of an unused cuff.SOLUTION: A control part 111 controls a cuff pressure adjustment part 120 to put cuff pressure of the cuff 10 within a prescribed range based on a detection result by a cuff pressure detection part 113, and informs abnormality when the cuff pressure has not reached in the prescribed range within prescribed time. Immediately after installation of the cuff, the control part 111 detects inner pressure of the cuff by the cuff pressure detection part 113, and when the detected inner pressure of the cuff is less than first pressure that is smaller than proper pressure, it controls the cuff pressure adjusting part 120 to set the maximum pressure of the inner pressure of the cuff at second pressure that is greatly larger than the proper pressure.

Description

  The present invention relates to a cuff pressure control device that controls an internal pressure of a cuff provided in an intubation tube connected to a ventilator.

  In the medical field related to ventilators, an intubation tube is inserted into the patient's trachea from the oral cavity or nasal cavity to secure the airway, and tracheal intubation is performed by feeding oxygen into the lungs through the intubation tube, and the skin and trachea of the throat are incised. A tracheotomy is known in which a cannula is inserted into a patient's trachea from the incised portion to secure an airway, and oxygen is sent to the lung through the cannula.

If there is a gap between the intubation tube or cannula and the inner wall of the trachea, secretions such as gastric juice and saliva may flow into the trachea. In order to prevent the inflow of such secretions, a cuff is attached to the outer wall of the intubation tube or cannula.
This cuff is also called a balloon cuff and is inflated by supplying gas 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.
In this way, the inflow of secretions into the trachea can be prevented by the cuff while securing the airway by the intubation tube or cannula (see, for example, paragraph [0002] of Patent Document 1).

It is known that the following problems occur when the internal pressure of the cuff (hereinafter referred to as “cuff pressure”) becomes a value outside a predetermined range.
For example, when the cuff pressure is greater than about 3.33 kPa (25 mmHg), which is the venous pressure of the tracheal mucosal tissue, the inflated cuff compresses the blood vessels of the tracheal mucosal tissue. When blood vessels are compressed, they become ischemic, and as a result, ulcers, necrosis, hemorrhage, granulation, and tracheal stenosis after tracheal extubation, tracheal softening, etc. may occur.
On the other hand, when the cuff pressure is less than about 2.67 kPa (20 mmHg), the expansion of the cuff becomes insufficient, and a gap is formed between the outer peripheral surface of the cuff and the inner wall of the trachea, and secretions such as saliva and gastric juice in the trachea. May flow in.
Therefore, conventionally, the management of the cuff pressure to maintain the cuff pressure within a predetermined range has been performed manually by a nurse or the like measuring the cuff pressure using a cuff pressure gauge every predetermined time and referring to the measurement result. This was done by adjusting the cuff pressure.

JP 2009-505715 A

By the way, in the medical field related to a ventilator, ventilator-associated pneumonia (VAP: Ventilator-associated pneumonia, hereinafter referred to as “VAP”) is known. VAP refers to pneumonia that develops after more than 48 hours have passed since a ventilator is attached for reasons other than respiratory infections. At present, it is said that VAP is a direct cause of death in about 30 to 40% of ventilator patients. Thus, VAP is a very serious problem and there is increasing interest in VAP prevention measures.
According to the knowledge of the present inventors, it has been found that VAP is caused by the cuff pressure. In other words, nurses and the like managed the cuff pressure as described above, but the present inventors, as a result, manually controlled the cuff pressure or the change over time of the cuff itself. It was found that there was a shortage and VAP was developed.
According to further consideration by the present inventors, the outer peripheral surface of the unused cuff is often wrinkled. For example, the cuff pressure is within the range of 20 to 25 mmHg after the cuff is attached to the patient's trachea. Even when pressed, wrinkles may remain on the outer peripheral surface of the cuff. Residual wrinkles may cause a gap between the outer peripheral surface of the cuff and the inner wall of the trachea, and secretions such as saliva and gastric juice may flow into the trachea. There is also a possibility that VAP is caused by such a cause.

In view of the circumstances as described above, an object of the present invention is to provide a cuff pressure control device and a cuff pressure control method capable of preventing VAP caused by insufficient cuff pressure or the like.
Another object of the present invention is to provide a cuff pressure control device and a cuff pressure control method capable of preventing VAP caused by wrinkles or the like formed on the outer peripheral surface of an unused cuff.

The considerations of the present inventors are as follows.
In order to maintain the cuff pressure at a predetermined value so far, nurses etc. measure the cuff pressure using a cuff pressure gauge during a tour every predetermined time, etc., and manually adjust the cuff pressure while referring to the measurement result. It was. However, with such manual cuff pressure adjustment, precise fine adjustment is difficult, and when the cuff pressure is accidentally reduced below a predetermined value during the operation of the cuff pressure gauge, etc. The secretions flowed into the tube, causing VAP.

  Furthermore, the cuff is gradually reduced in thickness and increased in volume by repeated expansion and contraction due to pressure reduction. As the cuff itself changes with time, the cuff pressure is lowered and the inflow of secretions into the trachea easily occurs, causing VAP. Further, due to the thinning of the cuff, a hole may be formed in the thinned portion or the cuff may burst. In such a case, the cuff pressure decreased rapidly and the inflow of secretions into the trachea was very likely to occur, causing VAP.

  In addition, since nurses etc. have adjusted the cuff pressure during patrols every predetermined time so far, once the cuff pressure is adjusted to a predetermined value during patrols, the cuff pressure is not adjusted for a while after that. . For this reason, when the cuff changes over time, even if the change over time is very small, the cuff pressure gradually decreases until the next cuff pressure adjustment, resulting in insufficient cuff pressure. And VAP develops. In addition, when the cuff changes with time and the volume of the cuff increases, it takes more time than usual to pressurize the cuff to a predetermined value. When manually adjusting the cuff pressure, it may be difficult for a nurse or the like to recognize such a change in pressurization time. For this reason, it is delayed to notice a minute change in the cuff pressure over time, resulting in the onset of VAP.

  The present inventors have found that there is a limit to manual management of the cuff pressure for the reasons described above, and as a result, the cuff pressure is insufficient due to the change over time of the cuff itself and the VAP is developed. It was.

  The present inventors have investigated these causes and, as a result, decided to adopt a cuff pressure control device having the following configuration as the cuff.

That is, the cuff pressure control device according to an aspect of the present invention includes a cuff pressure adjustment unit, a cuff pressure detection unit, and a control unit.
The cuff pressure adjusting unit pressurizes a cuff used for tracheal intubation.
The cuff pressure detection unit detects the internal pressure of the cuff.
The control unit controls the cuff pressure adjusting unit so that the internal pressure of the cuff falls within a predetermined range based on a detection result by the cuff pressure detection unit, and the internal pressure of the cuff is set to the predetermined value within a first time. When it is not within the range, an abnormality is notified.
Further, immediately after the cuff is mounted, the control unit detects an internal pressure of the cuff by the cuff pressure detection unit, and when the detected internal pressure of the cuff is equal to or lower than a first pressure smaller than the predetermined range, The cuff pressure adjusting unit is controlled so that the internal pressure of the cuff becomes a second pressure exceeding the predetermined range.

A cuff pressure control method according to an embodiment of the present invention is a cuff pressure control method for controlling an internal pressure of a cuff used for tracheal intubation.
Immediately after mounting the cuff, the internal pressure of the cuff is detected.
When the detected internal pressure of the cuff is equal to or lower than a first pressure smaller than a predetermined range, the cuff is pressurized so that the internal pressure of the cuff becomes a second pressure exceeding the predetermined range.
Thereafter, the internal pressure of the cuff is detected.
Based on the detection result, the cuff is pressurized so that the internal pressure of the cuff falls within a predetermined range.
When the internal pressure of the cuff does not fall within the predetermined range within the first time, an abnormality is notified.

It is a schematic diagram which shows the mode of tracheal intubation, Comprising: A mode that the intubation tube was inserted in the trachea from the nasal cavity is shown. It is the schematic which shows the cuff pressure control apparatus which concerns on one Embodiment of this invention. It is a flowchart which shows a cuff pressure setting operation | movement and a cuff pressure maintenance operation | movement. It is a graph for demonstrating cuff pressure setting operation | movement (the 1). It is a graph for demonstrating cuff pressure setting operation | movement (the 2). It is a graph which shows roughly the relation between elapsed time and the number of times of air supply. It is a flowchart which shows the cuff pressure maintenance operation | movement at the time of a rest mode. It is a flowchart which shows the cuff pressure maintenance operation | movement at the time of normal mode. It is a flowchart which shows the cuff pressure maintenance operation | movement at the time of activity mode. It is a flowchart which shows a cuff abnormality detection operation | movement. 5 is a flowchart showing a cuff pressure setting operation and a cuff abnormality inspection operation. It is a schematic diagram which shows the state of tracheal intubation, Comprising: A state where the intubation tube was inserted in the trachea from the oral cavity is shown. It is a schematic diagram which shows the mode of a tracheotomy, Comprising: A cannula is shown in a trachea from the throat.

A cuff pressure control device according to an aspect of the present invention includes a cuff pressure adjustment unit, a cuff pressure detection unit, and a control unit.
The cuff pressure adjusting unit pressurizes a cuff used for tracheal intubation.
The cuff pressure detection unit detects the internal pressure of the cuff.
The control unit controls the cuff pressure adjusting unit so that the internal pressure of the cuff falls within a predetermined range based on a detection result by the cuff pressure detection unit, and the internal pressure of the cuff is set to the predetermined value within a first time. When it is not within the range, an abnormality is notified.
Further, immediately after the cuff is mounted, the control unit detects an internal pressure of the cuff by the cuff pressure detection unit, and when the detected internal pressure of the cuff is equal to or lower than a first pressure smaller than the predetermined range, The cuff pressure adjusting unit is controlled so that the internal pressure of the cuff becomes a second pressure exceeding the predetermined range.

As a result, the desired internal pressure of the cuff can be maintained in response to a change in the internal pressure of the cuff, and an abnormality can be notified when there is an abnormality in the adjustment of the internal pressure of the cuff.
Also, immediately after the cuff is attached, when the detected internal pressure of the cuff is equal to or lower than the first pressure smaller than the predetermined range, the cuff is still regarded as an unused cuff that has not been pressurized so far. In some cases, the internal pressure of the cuff is the second pressure exceeding the predetermined range, so that wrinkles and the like formed on the outer peripheral surface of the unused cuff are extended by this pressure, and VAP caused by the wrinkles can be prevented. . Since some gas remains in the cuff that has already been used and reused, the detected internal pressure of the cuff exceeds the first pressure. Since such a cuff is not pressurized to the second pressure, the influence of stress due to the pressure on the cuff can be further reduced.

  The control unit starts pressurization of the cuff by the cuff pressure adjusting unit by a predetermined operation immediately after mounting, and the cuff pressure detection unit detects the cuff pressure by the internal pressure detected by the cuff pressure detection unit after a predetermined time from the start. The volume of the cuff and the gas supply tube leading to the cuff may be estimated, and at least the first time may be set according to the estimated volume.

  Thereby, the cuff pressure can be adjusted according to the individual cuff and the gas supply tube communicating with the cuff.

You may further have a memory | storage part which memorize | stores the time-dependent change of the internal pressure of the said cuff detected by the said cuff pressure detection part.
The control unit may notify the abnormality when the change in the internal pressure of the cuff stored by the storage unit is abnormal.

  Accordingly, since the abnormality of the cuff change with time is notified, it is possible to prompt the user to replace the cuff that is changing with time in advance.

The storage unit may store a usage time of the cuff.
The control unit may estimate the replacement time of the cuff based on the use time of the cuff stored by the storage unit, and may notify the estimated replacement time.

  Accordingly, since the cuff replacement time is notified, it is possible to prompt the user to replace the cuff in advance over time.

  The controller estimates the volume of the cuff and the gas supply tube leading to the cuff based on the volume of gas necessary to change the internal pressure of the cuff by a certain amount. May be notified.

  Thereby, since the abnormality of the volume of the cuff of the cuff and the gas supply tube leading to the cuff is notified, it is possible to prompt the user to replace the cuff that is changing with time.

A cuff pressure control method according to an embodiment of the present invention is a cuff pressure control method for controlling an internal pressure of a cuff used for tracheal intubation.
Immediately after mounting the cuff, the internal pressure of the cuff is detected.
When the detected internal pressure of the cuff is equal to or lower than a first pressure smaller than a predetermined range, the cuff is pressurized so that the internal pressure of the cuff becomes a second pressure exceeding the predetermined range.
Thereafter, the internal pressure of the cuff is detected.
Based on the detection result, the cuff is pressurized so that the internal pressure of the cuff falls within a predetermined range.
When the internal pressure of the cuff does not fall within the predetermined range within the first time, an abnormality is notified.

As a result, the desired internal pressure of the cuff can be maintained in response to a change in the internal pressure of the cuff, and an abnormality can be notified when there is an abnormality in the adjustment of the internal pressure of the cuff.
Further, it is possible to prevent VAP caused by wrinkles or the like formed on the outer peripheral surface of the unused cuff.

Pressurization to the cuff may be started by a predetermined operation immediately after mounting.
The volume of the cuff and the gas supply tube communicating with the cuff may be estimated based on the internal pressure of the cuff detected by the cuff pressure detection unit after a certain time from the start.
At least the first time may be set according to the estimated volume.

  Thereby, the cuff pressure can be adjusted according to the individual cuff and the gas supply tube communicating with the cuff.

A change with time of the detected internal pressure of the cuff may be stored.
When there is an abnormality in the stored change in the internal pressure of the cuff, an abnormality may be notified.

  Accordingly, since the abnormality of the cuff change with time is notified, it is possible to prompt the user to replace the cuff that is changing with time in advance.

The usage time of the cuff may be stored.
The replacement time of the cuff may be estimated based on the stored use time of the cuff.
The estimated replacement time may be notified.

  Accordingly, since the cuff replacement time is notified, it is possible to prompt the user to replace the cuff in advance over time.

The volume of the cuff and the gas supply tube leading to the cuff may be estimated based on the volume of gas necessary to change the internal pressure of the cuff by a certain amount.
When there is an abnormality in the estimated volume change over time, the abnormality may be notified.

  Thereby, since the abnormality of the volume of the cuff of the cuff and the gas supply tube leading to the cuff is notified, it is possible to prompt the user to replace the cuff that is changing with time.

Embodiment of the present invention
Hereinafter, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a schematic view showing a state of tracheal intubation, and shows a state where an intubation tube is inserted into a trachea from a nasal cavity. FIG. 11 is a schematic diagram showing a state of tracheal intubation, and shows a state where the intubation tube is inserted into the trachea from the oral cavity. FIG. 12 is a schematic view showing a state of tracheostomy, and shows a state where a cannula is inserted into the trachea from the throat.
When the airway is secured by tracheal intubation or tracheostomy when using the ventilator, a gap is formed between the intubation tube 1 inserted from the nasal cavity 7 or the oral cavity 5 or the cannula 9 inserted from the throat 8 and the inner wall 6 of the trachea 2. If this occurs, secretions such as gastric juice and saliva from the esophagus 3 may flow into the trachea 2. In particular, in tracheal intubation, since the epiglottis 4 is opened, gastric fluid from the esophagus 3 tends to flow into the trachea 2. In order to prevent the inflow of such secretions, a cuff 10 is attached to a predetermined position on the outer periphery of the intubation tube 1 or the cannula 9. The cuff 10 is expanded by being pressurized from outside the body through the gas supply tube 125. 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. In this way, the inflow of secretions into the trachea 2 can be prevented by the cuff 10 while the airway is secured by the intubation tube 1 and the cannula 9.

[Configuration of cuff pressure control device]
FIG. 2 is a schematic diagram showing a cuff pressure control apparatus 100 according to an embodiment of the present invention.
The internal pressure of the cuff 10 (hereinafter referred to as “cuff pressure”) is controlled by the cuff pressure control device 100. The cuff pressure control device 100 includes a control system 110 and a cuff pressure adjustment unit 120.

  The control system 110 includes a control unit 111, a storage unit 112, a cuff pressure detection unit 113, an input operation unit 114, a display unit 115, a notification unit 116, and a time measurement unit 117.

  The control unit 111 controls each unit in the cuff pressure control device 100, and adds the cuff pressure adjustment unit 120 based on the detection result acquired from the cuff pressure detection unit 113, the time information acquired from the time measurement unit 117, and the like. The pressure pump 126 and the exhaust valve 122 are controlled.

  The time measuring unit 117 measures time. The control unit 111 refers to the time measurement unit 117 and acquires time information such as elapsed time.

  The cuff pressure detection unit 113 is connected via a cuff pressure detection tube 118 that communicates with the gas supply tube 125. When the cuff pressure detection unit 113 acquires a cuff pressure detection command from the control unit 111, the cuff pressure detection unit 113 detects the cuff pressure of the cuff 10 and outputs the detected cuff pressure to the control unit 111.

  The storage unit 112 is a nonvolatile memory, and is set to, for example, a flash memory, an HDD (Hard Disk Drive), or other solid-state memory. The control unit 111 associates the information related to the cuff pressure acquired from the cuff pressure detection unit 113 with the time information acquired from the time measurement unit 117 and records the information in the storage unit 112 as a change with time of the cuff pressure. In the storage unit 112, information on a plurality of pressurization parameters corresponding to a product type such as the cuff 10, information on a plurality of operation modes, and the like are recorded.

  The input operation unit 114 has operation buttons, accepts an input operation from the user, and outputs it to the control unit 111.

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

  The notification unit 116 is, for example, a speaker, and outputs an alarm sound that notifies the user of an abnormality or the like of the cuff 10, for example, when a notification command is acquired from the control unit 111. The speaker as the notification unit 116 may be provided integrally with the cuff pressure control device 100, or may be provided as an external device, for example, at another place in the hospital. Alternatively, when the notification unit 116 acquires a notification command from the control unit 111, the notification unit 116 outputs it to a nurse call device or a PHS (Personal Handy-phone System) carried by a nurse or the like provided in another place in the hospital. May be an output interface. In the present embodiment, the notification unit 116 will be described below as a speaker that outputs an alarm sound.

  The cuff pressure adjusting unit 120 includes a pressurizing pump 126, a one-way valve 121, an exhaust valve 122, a safety valve 127, a flow rate adjusting valve 123, and a reservoir tank 124. The pressurizing pump 126, the one-way valve 121, the safety valve 127, the exhaust valve 122, the flow rate adjusting valve 123, and the reservoir tank 124 are connected in series in this order.

  The pressurizing pump 126 is an electric pump that is driven by the control unit 111 and pressurizes the cuff 10 via the gas supply tube 125. The pressure pump 126 is set with the magnitude and speed of pressurization to the cuff 10 under the control of the control unit 111.

  On the other hand, the valve 121 is connected to the downstream side of the pressurizing pump 126 and prevents the backflow of gas from the cuff 10 side to the pressurizing pump 126.

The safety valve 127 is a mechanical valve that uses a biasing force of a spring or the like, and is connected downstream of the one-way valve 121. When the internal pressure of the cuff 10 and the gas supply tube 125 exceeds a threshold value, the safety valve 127 is opened by pushing up a lid (not shown) by the biasing force of the spring and discharges the gas.
Here, the “threshold value” is a pressure at which wrinkles and the like formed on the outer peripheral surface of the unused cuff are stretched, and is preferably about 13.33 kPa (100 mmHg). When the unused cuff does not have a function of extending wrinkles or the like formed on the outer peripheral surface, the threshold is, for example, about an appropriate pressure (about 2.67 kPa (20 mmHg) to about 3.33 kPa (25 mmHg)). The value is about 1.33 kPa (10 mmHg) to about 2.00 kPa (15 mmHg). More specifically, the threshold value may be about 5.33 kPa (40 mmHg), for example.

The exhaust valve 122 is connected downstream of the safety valve 127. The exhaust valve 122 is controlled by the control unit 111 to be opened and closed. In the open state, the exhaust valve 122 releases the gas in the cuff 10 to the atmosphere via the gas supply tube 125 to decompress the cuff 10. In the closed state, the exhaust valve 122 stops the release of the cuff 10 to the atmosphere and stops the decompression of the cuff 10.
Note that a pressure reduction control valve (not shown) may be provided on the exhaust side of the exhaust valve 122. This pressure reduction control valve is, for example, a valve that controls the pressure not to be reduced to a pressure lower than about 2.67 kPa (20 mmHg), which is the lower limit of the appropriate pressure of the cuff. The pressure reducing control valve is preferably a mechanism that mechanically controls the pressure by an elastic force such as a spring. By providing such a pressure reducing control valve, for example, even when the cuff pressure adjusting unit does not function due to a malfunction of the control system, the internal pressure of the cuff can be maintained to the minimum so that the function of the cuff can be maintained. Become.

  The flow rate adjusting valve 123 is connected downstream of the exhaust valve 122 and adjusts the amount of gas flowing to the cuff 10 via the gas supply tube 125. The flow rate adjusting valve 123 may be configured to be operated by a user or may be configured to be controlled by the control unit 111.

  The reservoir tank 124 is connected downstream of the flow rate adjustment valve 123 and absorbs the cuff pressure fluctuation of the cuff 10.

[Operation of cuff pressure controller]
Next, the operation of the cuff pressure control device 100 configured as described above will be described. The operation will be described in the following order.
(1) Cuff pressure setting operation and cuff pressure maintenance operation (2) Cuff pressure maintenance operation in rest mode (3) Cuff pressure maintenance operation in normal mode (4) Cuff pressure maintenance operation in activity mode (5) Cuff abnormality Detection operation (6) Cuff pressure setting operation and cuff abnormality inspection operation

  The operations (1) to (5) mainly assume a case where the cuff pressure control device 100 is always connected to the cuff 10 attached to the patient's trachea. The operations (1) to (5) are useful when, for example, controlling the cuff pressure of the cuff 10 attached to a specific patient over a long period of time.

  On the other hand, the operation (6) mainly assumes a case where the user uses the cuff pressure control device 100 temporarily connected to the cuff 10 attached to the trachea of the patient. In the operation (6), for example, a user such as a nurse has one cuff pressure control device 100, and this one cuff pressure control device 100 is attached to a plurality of cuffs 10 attached to the trachea of a plurality of patients. This is useful when the cuff pressure of each cuff 10 is controlled by sequentially attaching.

[(1) Cuff pressure setting operation and cuff pressure maintaining operation]
FIG. 3 is a flowchart showing the cuff pressure setting operation and the cuff pressure maintaining operation.
This flowchart includes a cuff pressure setting operation (steps S101 to S114) and a cuff pressure maintaining operation (steps S115 to S125).

First, the cuff pressure setting operation (steps S101 to S114) will be described.
Prior to this cuff pressure setting operation, it is first determined whether the cuff 10 is an unused cuff or has been used (steps 100, 100a, 100b). The unused cuff contains almost no gas, whereas the cuff that has already been used still contains gas. In the present invention, paying attention to this point, this determination is performed by detecting the internal pressure of the cuff 10.
4A and 4B are graphs for explaining the cuff pressure setting operation.

First, the user attaches the cuff 10 to the patient's trachea. When the user wears the cuff 10, the user sets the cuff pressure using the input operation unit 114. The input operation unit 114 outputs the set value of the cuff pressure set by the user to the control unit.
Specifically, immediately after the cuff is attached, the control unit 111 detects the internal pressure of the cuff by the cuff pressure detection unit 113 (step 100), and the detected internal pressure of the cuff is an appropriate pressure (about 2.67 kPa (20 mmHg)). When the pressure is about 1.33 kPa (10 mmHg) or less, which is a first pressure smaller than about 3.33 kPa (25 mmHg)), it is determined that the surface of the cuff may be wrinkled. The maximum pressure of the cuff internal pressure is about 13.33 kPa (100 mmHg), which is a second pressure that greatly exceeds the appropriate pressure (about 2.67 kPa (20 mmHg) to about 3.33 kPa (25 mmHg)), that is, The cuff pressure adjusting unit 120 is set so that the maximum pressure is the initial pressurization value (step 100a). On the other hand, when the internal pressure of the cuff detected in step 100 exceeds the first pressure of about 1.33 kPa (10 mmHg), it is determined that the cuff that has already been used, that is, there is no possibility of wrinkling, for example, The cuff pressure adjusting unit 120 is set so that the maximum pressure of the cuff internal pressure is about 3.33 kPa (25 mmHg), which is the maximum value within the range of the appropriate pressure (step 100b).
The controller 111 rapidly pressurizes the cuff 10 by driving the pressurizing pump 126 based on the set cuff pressure (step S101). Moreover, the control part 111 acquires time information with reference to the time measurement part 117, and measures the elapsed time from the pressurization start based on the acquired time information. Here, FIG. 4A is a pressurization pattern when it is determined that the cuff has already been used in Step 100 and is set in Step 100b, and FIG. 4B is determined as an unused cuff in Step 100 and is set in Step 100a. This is a pressurizing pattern.

  When the control unit 111 determines that a certain time has elapsed from the start of pressurization based on the measured elapsed time, the control unit 111 outputs a cuff pressure detection command to the cuff pressure detection unit 113. When the cuff pressure detection unit 113 acquires a cuff pressure detection command from the control unit 111, the cuff pressure detection unit 113 detects the cuff pressure (step S <b> 102) and outputs the detected cuff pressure to the control unit 111. The “certain time” is a value less than a time and a ′ time (see FIGS. 4A and 4B).

  When the control unit 111 acquires the cuff pressure from the cuff pressure detection unit 113, the control unit 111 estimates the volume of the cuff 10 and the gas supply tube 125 communicating with the cuff 10 based on the acquired cuff pressure. The control unit 111 determines which of the products A to C is used according to the estimated volume. Based on the determination result, the control unit 111 selects a pressurization parameter suitable for the currently used product from the plurality of pressurization parameters stored in the storage unit 112, and sets the selected pressurization parameter. Here, “product” refers to, for example, the cuff 10 and the gas supply tube 125.

  For example, when the acquired cuff pressure is the pressure A, the control unit 111 determines that the product A is used, and selects the product A pressurization parameter A from the pressurization parameters stored in the storage unit 112. Select and set (step S103).

  Here, the “pressurization parameter” refers to the pressurization time (a time in FIG. 4A, a ′ time in FIG. 4B) and depressurization time (see FIG. 4), which are individually set according to the product type. 4A c time, c ′ time of FIG. 4B), cuff pressure, and the like parameters. The cuff 10, the gas supply tube 125, and the like have different shapes, lengths, volumes, and the like depending on products. Therefore, if the control part 111 sets the pressurization parameter A suitable for the cuff 10 of the product A, the gas supply tube 125, etc. by step S103, it will perform cuff pressure setting operation | movement based on this pressurization parameter A after that. Thereby, the cuff pressure can be adjusted in accordance with the individual cuff 10 and the gas supply tube 125. In this embodiment, three types of pressurization parameters A to C can be set. However, the present invention is not limited to this, and a plurality of parameters are set according to a plurality of products and stored in the storage unit 112 in advance. Can do.

  On the other hand, when the cuff pressure acquired from the cuff pressure detection unit 113 is the pressure B, the control unit 111 determines that the product B is used, and the product B is selected from the pressurization parameters stored in the storage unit 112. The pressurization parameter B is selected and set (step S104). Further, when the cuff pressure acquired from the cuff pressure detection unit 113 is the pressure C, the control unit 111 determines that the product C is used, and the product C is selected from the pressurization parameters stored in the storage unit 112. The pressurization parameter C is selected and set (step S105).

  Subsequently, the control unit 111 drives the pressure pump 126 to pressurize the cuff 10. The control unit 111 also outputs a cuff pressure detection command to the cuff pressure detection unit 113 every predetermined time. Upon obtaining a cuff pressure detection command from the control unit 111, the cuff pressure detection unit 113 detects the cuff pressure and outputs the detected cuff pressure to the control unit 111. The control unit 111 determines whether the cuff pressure acquired from the cuff pressure detection unit 113 has reached the maximum pressure.

  Here, the “maximum pressure” refers to the maximum pressure that does not affect the human body by temporary pressurization and is unlikely to cause thinning or deterioration of the cuff 10. The maximum pressure is, for example, in the range of about 4.00 kPa (30 mmHg) to about 5.33 kPa (40 mmHg).

  Based on the cuff pressure acquired from the cuff pressure detection unit 113 and the elapsed time from the start of pressurization measured based on the time information acquired from the time measurement unit 117, the control unit 111 before the cuff pressure reaches the maximum pressure. It is determined whether or not a time to a ′ time (see FIGS. 4A and 4B) have passed (step S106).

  Here, “a time” to “a ′ time” is, for example, the time that the normal cuff 10 is expected to take from the start of pressurization to the maximum pressure reaching, and depending on each pressurization parameter A to C. Different values may be set.

  When the control unit 111 determines that the time a to the time a ′ has elapsed before the cuff pressure reaches the maximum pressure, the control unit 111 outputs a notification command to the notification unit 116. When the notification unit 116 acquires the notification command from the control unit 111, the notification unit 116 outputs an alarm sound that notifies the user of an abnormality such as the cuff 10 (step S107).

  Here, the case where “a time to a ′ time has passed before the cuff pressure reaches the maximum pressure” is a case where the cuff pressure increases to some extent but the rate of increase is slower than usual. In such a case, the volume of the cuff 10 is increased due to a state in which the gas is likely to leak from the cuff 10 due to, for example, thinning and breakage of the cuff 10 or breakage of the gas supply tube 125, or sagging of the cuff 10. It is assumed that the cuff 10 is inflated by the state or the intubation tube 1 or the cannula 9 is damaged and contracted. In such a case, the secretion easily flows into the trachea and causes VAP. Therefore, by notifying the user of the abnormality using the notification unit 116, the user can take measures such as replacing the cuff 10, the gas supply tube 125, the intubation tube 1, the cannula 9, or the like. Note that the notification of the abnormality of the cuff 10 or the like to the user is not limited to that performed only by the notification unit 116, and may be performed together with the display by the display unit 115. The same applies to the notification described below.

  The control unit 111 continues to drive the pressurizing pump 126 to pressurize the cuff 10. If the controller 111 determines that the cuff pressure has reached the maximum pressure before the time a to the time a 'has elapsed (step S108), the controller 111 determines that pressurization has been completed and stops driving the pressurization pump 126. Then, after the drive of the pressurizing pump 126 is stopped, the system waits for time b to time b ′ (see FIGS. 4A and 4B) (step S109). Here, “b time” is, for example, about 0.5 to 30 seconds, and “b ′ time” is, for example, about 0.1 to 2 seconds, and varies depending on each pressurization parameter A to C. Is set.

  Subsequently, the control unit 111 opens the exhaust valve 122 to depressurize the cuff 10 at a low speed (step S110), and measures an elapsed time from the start of depressurization. The control unit 111 can adjust the pressure reduction speed of the cuff 10 by controlling the opening time, timing, or opening area of the exhaust valve 122.

  The reason why the pressure is reduced at such a low speed is that when the pressure of the cuff 10 is rapidly reduced, a gap is formed between the outer peripheral surface of the cuff 10 and the inner wall of the trachea, and the secretions stored in the upper part of the cuff extremely flow into the trachea. It is easy to cause VAP, and this is to prevent this. On the other hand, the reason why pressurization is performed at the maximum speed is to prevent the inflow of secretions into the trachea by quickly closing the trachea with a cuff pressure that does not affect the human body with temporary pressurization. This is to prevent VAP. Moreover, it is for absorbing the dispersion | variation in the time concerning the pressurization between products or between patients.

  Based on the cuff pressure acquired from the cuff pressure detection unit 113 and the elapsed time from the start of pressure reduction measured based on the time information acquired from the time measurement unit 117, the control unit 111 determines whether the cuff pressure has reached the appropriate pressure. It is determined whether c time to c ′ time (see FIGS. 4A and 4B) has elapsed (step S111). Here, the “appropriate pressure” is set to a different value depending on each pressurization parameter A to C in a range of about 2.67 kPa (20 mmHg) to about 3.33 kPa (25 mmHg).

  Further, the “c time” to “c ′ time” are times that the normal cuff 10 is supposed to take from the start of pressure reduction to reaching the appropriate pressure. The “c time” is, for example, about 10 to 30 seconds, and the “c ′ time” is, for example, about 2 to 22 seconds. Different values may be set depending on the pressurization parameters A to C.

  When the control unit 111 determines that the c time to the c ′ time have elapsed before the cuff pressure is reduced to an appropriate pressure, the control unit 111 outputs a notification command to the notification unit 116. When the notification unit 116 acquires a notification command from the control unit 111, the notification unit 116 outputs an alarm sound that notifies the user of an abnormality such as the cuff pressure adjustment unit 120 (step S112).

  Here, the case where “c time to c ′ time has elapsed before the cuff pressure is reduced to an appropriate pressure” is a case where the cuff pressure is reduced to some extent but the rate of decrease is slower than usual. Such a case is assumed to be a state where the cuff pressure adjusting unit 120 is out of order. Therefore, by notifying the user of the abnormality using the notification unit 116, the user moves the cuff 10 to a site where stenosis or the like does not occur in the trachea, or replaces the cuff pressure adjustment unit 120. can do. Depending on the posture of the patient, the trachea may be compressed and the diameter of the trachea may be reduced than usual. In such a case, an alarm sound may be output. Therefore, the user should keep the patient's posture in a normal posture before using the cuff pressure control device 100, or the patient's posture after the alarm sound is output. It is good to confirm.

The controller 111 continues to open the exhaust valve 122 to decompress the cuff 10. If the controller 111 determines that the cuff pressure has reached the appropriate pressure before the time c to time c ′ has elapsed (step S113), the controller 111 determines that the pressure reduction has been completed and closes the exhaust valve 122. Moreover, the control part 111 records the flow volume at the time of pressurization, and the flow volume at the time of pressure reduction in the memory | storage part 112 as a basic flow volume of used product, for example (step S114).
In addition, since information (flow rate at the time of pressurization and flow rate at the time of depressurization) recorded in the storage unit 112 is different for each patient in this way, it is better to record this information in association with each patient together with the date and the like. preferable. In that case, for example, a barcode reader can be connected to the cuff pressure control device, and the patient information is read from the IC tag of the patient using the barcode reader, and the flow rate during pressurization, the flow rate during decompression, etc. Information may be recorded in the storage unit 112 in association with the patient information. Accordingly, it is possible to appropriately set a nursing treatment history such as a record in which the cuff pressure is appropriately set for the patient. When the patient has patient information on the IC card, an IC card reader or the like may be used.

  The cuff pressure is set to an appropriate pressure by the cuff pressure setting operation described above (steps S101 to S114). Subsequently, the control unit 111 proceeds to a cuff pressure maintaining operation (step S115 to step S125) for maintaining the set cuff pressure at an appropriate pressure.

  First, the control unit 111 outputs a cuff pressure detection command to the cuff pressure detection unit 113 every predetermined time based on the time information acquired from the time measurement unit 117. When the cuff pressure detection unit 113 acquires a cuff pressure detection command from the control unit 111, the cuff pressure detection unit 113 detects the cuff pressure and outputs the detected cuff pressure to the control unit 111. The control unit 111 records information on the cuff pressure acquired from the cuff pressure detection unit 113 every predetermined time as a log associated with the time information acquired from the time measurement unit 117 in the storage unit 112. Start (step S115). In the following description, a log including information related to the cuff pressure recorded in association with each other and time information may be described as “cuff pressure maintenance record”.

  Subsequently, the control unit 111 sets an operation mode of the cuff pressure control device 100 (step S116). The operation mode may be set in advance and stored in the storage unit 112, or may be set by the user using the input operation unit 114. Or when the information regarding a patient, etc. are recorded on the memory | storage part 112 previously, you may set by the control part 111 based on this information. Here, the “operation mode” refers to a setting in which the cuff pressure is increased or decreased at a high speed or a low speed according to the type of patient and the use state of the ventilator. In the present embodiment, four modes can be set: a rest mode, a normal mode, an activity mode, and a cuff abnormality detection mode.

  When determining that the rest mode is set, the control unit 111 performs a cuff pressure maintaining operation in the rest mode (step S117). When determining that the normal mode is set, the control unit 111 performs a cuff pressure maintaining operation in the normal mode (step S118). When determining that the activity mode is set, the control unit 111 performs a cuff pressure maintaining operation in the activity mode (step S119). When determining that the cuff abnormality detection mode is set, the control unit 111 performs a cuff abnormality detection operation (step S120). The detailed operation of the cuff pressure control device 100 when setting each mode will be described later.

  Subsequently, the control unit 111 acquires a cuff pressure maintenance record from the storage unit 112. The control unit 111 estimates the replacement time of the cuff 10 based on the acquired cuff pressure maintenance record (step S121). A different value is set for the replacement time of the cuff 10 depending on the products A to C. The replacement time of the cuff 10 is set based on, for example, the usage time of the cuff 10, the number of times the pressure pump 126 is driven (number of times of air supply), and the like.

  As an example, the control unit 111 determines the replacement time of the cuff 10 based on the usage time of the cuff 10. When the control unit 111 determines that the usage time of the cuff 10 has exceeded a predetermined time based on the cuff pressure maintenance record, the control unit 111 outputs a notification command to the notification unit 116. When the notification unit 116 acquires the notification command from the control unit 111, the notification unit 116 outputs an alarm sound that notifies the user that the predetermined time has passed (step S122).

  Thus, the reason for notifying the user of the replacement time despite the fact that no substantial abnormality has occurred in the cuff 10 is as follows. That is, the cuff 10 is gradually thinned and slackened and the volume is increased by repeatedly performing expansion by pressurization and contraction by the depressurization. As the cuff itself changes with time, the cuff pressure is lowered and the inflow of secretion into the trachea is likely to occur, causing VAP. According to the cuff pressure control apparatus 100 of the present embodiment, by notifying the user of the replacement time, it is possible to prompt the user to replace the cuff 10 that is changing over time. Thereby, since the user can replace the cuff 10 that is changing with time before being damaged, it is possible to effectively prevent the onset of VAP.

The control unit 111 may determine the replacement time of the cuff 10 based on the number of times the pressure pump 126 is driven (the number of times of air supply). Alternatively, the replacement time may be determined by taking into account not only the number of times of driving (the number of times of air supply) but also the number of exhaust times and the leak amount of the apparatus itself.
FIG. 5 is a graph schematically showing the relationship between the elapsed time and the number of times of air supply.
As shown in the figure, an upper limit value is set in advance for the number of times the number of times the pressure pump 126 is driven (the number of times of air supply). When the control unit 111 determines that the number of times of driving the pressurizing pump 126 (the number of air supply times) exceeds the upper limit value, the control unit 111 outputs a notification command to the notification unit 116 and causes the notification unit 116 to output an alarm sound.

  On the other hand, the control unit 111 acquires a cuff pressure maintenance record from the storage unit 112 when it is not determined in step S121 that the usage time of the cuff 10 exceeds the predetermined time. The control unit 111 determines whether or not the cuff 10 has changed with time based on the cuff pressure recorded in the acquired cuff pressure maintenance record (step S123).

  Specifically, when the control unit 111 determines that the increase or decrease in the cuff pressure recorded in the cuff pressure maintenance record is larger than normal, the control unit 111 determines that the change with time of the cuff 10 is abnormal, and the notification unit 116. A notification command is output. When the notification unit 116 acquires the notification command from the control unit 111, the notification unit 116 outputs an alarm sound that notifies the user of an abnormality in the cuff 10 with time (step S124).

  This step also notifies the user of an abnormality of the cuff 10 over time even though no substantial abnormality has occurred in the cuff 10, so that the user can replace the cuff 10 that is changing over time in advance. Can be urged. Thereby, since the user can replace the cuff 10 that is changing with time before being damaged, it is possible to effectively prevent the onset of VAP.

  On the other hand, when the control unit 111 does not determine abnormality of the cuff 10 with time, the control unit 111 generates display information regarding the time change of the cuff 10 based on the cuff pressure maintenance record, and displays a display command including the generated display information. To 115. When the display unit 115 acquires the display command from the control unit 111, the display unit 115 displays the change over time of the cuff 10 on the display screen based on the display information included in the display command. For example, the display unit 115 displays the change over time of the cuff 10 as a graph on the display screen (step S125). And the control part 111 repeats the process from step S116.

  Next, the operation (steps S117 to S120) of the cuff pressure control device 100 in each mode in the flow of the cuff pressure maintaining operation will be described. By making the cuff pressure control mode variable, it is possible to control the adjustment sensitivity of the cuff pressure in accordance with, for example, the condition of the patient.

[(2) Cuff pressure maintenance operation in rest mode]
First, the cuff pressure maintaining operation in the rest mode (step S117 in FIG. 3) will be described. Here, the “rest mode” refers to a mode in which the pressure pump 126 is driven at a low speed to adjust the pressure at a low speed when the patient is hardly moving on the bed. In addition, by operating the cuff pressure control device 100 in the quiet mode, it is possible to suppress the temporal change of the cuff 10 and the consumption of the cuff pressure adjusting unit 120 and the battery. The suppression of the change of the cuff 10 with time and the wear of the cuff pressure adjusting unit 120 are useful, for example, at home care when each component cannot be easily replaced. Suppression of battery consumption is useful, for example, when going out, during a power failure, or during a disaster.

FIG. 6 is a flowchart showing the cuff pressure maintaining operation in the rest mode.
The cuff pressure maintaining operation in the rest mode shown in this flowchart includes a pressure reducing operation when the cuff pressure is increased (steps S201 to S206) and a pressurizing operation when the cuff pressure is reduced (steps S207 to S212). It is.

First, the pressure reducing operation (step S201 to step S206) when the cuff pressure is increased will be described.
From step S115, the control unit 111 records the change over time of the cuff pressure in the storage unit 112. At the same time, the control unit 111 determines whether or not the cuff pressure acquired from the cuff pressure detection unit 113 exceeds the set upper limit value (step S201).

  Here, the “set upper limit value” is, for example, about 3.33 kPa (25 mmHg). Further, exceeding the set upper limit value of the cuff pressure may occur when the diameter of the trachea is reduced due to a change in the posture of the patient (for example, body movement such as turning over), and as a result, the cuff pressure increases.

  When the control unit 111 determines that the cuff pressure does not exceed the set upper limit value continuously for a certain period of time, for example, about 5 seconds (NO in step S201), the pressurizing operation when the cuff pressure is reduced (steps S207 to S212). ) In this way, by determining whether it has not exceeded for a certain period of time, it is possible to prevent erroneous determination due to temporary excess due to body movement or the like.

  On the other hand, when determining that the cuff pressure has exceeded the set upper limit value (YES in step S201), the control unit 111 records information on the cuff pressure in the storage unit 112 as a change over time of the cuff pressure (step S202).

  Subsequently, the control unit 111 opens the exhaust valve 122, performs low-speed decompression processing on the cuff 10 (step S203), and measures the elapsed time from the start of decompression based on the time information acquired from the time measurement unit 117. . Note that the air supply amount during low-speed processing may be, for example, about one half of the air supply amount during normal processing in the normal mode.

  Based on the cuff pressure acquired from the cuff pressure detection unit 113 and the elapsed time from the start of pressure reduction measured based on the time information acquired from the time measurement unit 117, the control unit 111 before the cuff pressure reaches the set upper limit value. It is determined whether a predetermined time has passed (step S204).

  When the control unit 111 determines that a predetermined time has elapsed before the cuff pressure is reduced to the set upper limit value, the control unit 111 outputs a notification command to the notification unit 116. When the notification unit 116 obtains a notification command from the control unit 111, the notification unit 116 outputs an alarm sound that notifies the user of the abnormality (step S205).

  The controller 111 continues to open the exhaust valve 122 to reduce the cuff 10 until the cuff pressure reaches the set upper limit value. If the control unit 111 determines that the cuff pressure has reached the set upper limit value before the predetermined time has elapsed (step S206), the control unit 111 determines that the pressure reduction has been completed and closes the exhaust valve 122.

  The cuff pressure exceeding the set upper limit value is reduced to the set upper limit value by the pressure reducing operation (step S201 to step S206) when the cuff pressure is increased as described above. In this way, a desired cuff pressure can be maintained by quickly following when the diameter of the trachea is reduced due to a change in the posture of the patient (for example, body movement such as turning over) and the cuff pressure is increased. At the same time, if there is an abnormality, the user can be notified of the abnormality.

Subsequently, the control unit 111 proceeds to a pressurizing operation (step S207 to step S212) when the cuff pressure is reduced.
The control unit 111 continuously records the change over time of the cuff pressure in the storage unit 112. At the same time, the control unit 111 determines whether the cuff pressure acquired from the cuff pressure detection unit 113 is less than the set lower limit value (step S207).

  Here, the “setting lower limit value” is, for example, about 2.67 kPa (20 mmHg). Further, the cuff pressure less than the set lower limit value may be generated when the trachea diameter increases with a change in the posture of the patient (for example, body movement such as turning over), and as a result, the cuff pressure decreases.

  When the control unit 111 determines that the cuff pressure is not less than the set lower limit value (NO in step S207), the control unit 111 proceeds to the process of step S121.

  On the other hand, when determining that the cuff pressure is less than the set lower limit value (YES in step S207), the control unit 111 records information related to the cuff pressure in the storage unit 112 as a change over time of the cuff pressure (step S208).

  Subsequently, the control unit 111 drives the pressurization pump 126 at a low speed to perform a low-speed pressurization process on the cuff 10 (step S209), and from the start of pressurization based on the time information acquired from the time measurement unit 117. Measure elapsed time.

  Based on the cuff pressure acquired from the cuff pressure detection unit 113 and the elapsed time from the start of pressurization measured based on the time information acquired from the time measurement unit 117, the control unit 111 reaches the set lower limit value. It is determined whether a predetermined time has passed before (step S210).

  When the control unit 111 determines that a predetermined time has elapsed before the cuff pressure is increased to the set lower limit value, the control unit 111 outputs a notification command to the notification unit 116. When the notification unit 116 acquires a notification command from the control unit 111, the notification unit 116 outputs an alarm sound that notifies the user of the abnormality (step S211).

  The control unit 111 continues to drive the pressurizing pump 126 to pressurize the cuff 10 until the cuff pressure reaches the set lower limit value. If the control unit 111 determines that the cuff pressure has reached the set lower limit value before the predetermined time has elapsed (step S212), the control unit 111 determines that pressurization has been completed and stops driving the pressurization pump 126. And the control part 111 transfers to the process of step S121.

  By the pressurization operation (steps S207 to S212) when the cuff pressure is decreased as described above, the cuff pressure that has decreased below the set lower limit value is increased to the set lower limit value. In this way, a desired cuff pressure can be maintained by quickly following a case where the diameter of the trachea has increased due to a change in the posture of the patient (for example, body movement such as turning over) and the cuff pressure has decreased. At the same time, if there is an abnormality, the user can be notified of the abnormality.

[(3) Cuff pressure maintenance operation in normal mode]
Next, the cuff pressure maintaining operation in the normal mode (step S118 in FIG. 3) will be described. Here, the “normal mode” means, for example, that the pressure pump 126 is driven at a normal speed at a normal speed when the patient moves on the bed, or moves on a walking or wheelchair. This is the mode to adjust the pressure. In the following description, the same processes as those described above are denoted by the same reference numerals, and the description thereof is omitted or simplified.

FIG. 7 is a flowchart showing the cuff pressure maintaining operation in the normal mode.
The control unit 111 performs the processing from step S201 to step S202. In step S201 in the normal mode, it may be determined whether the cuff pressure has continuously exceeded the set upper limit for a certain period of time, for example, about 3 seconds.
Subsequently, the control unit 111 opens the exhaust valve 122, performs normal pressure reduction processing on the cuff 10 (step S303), and measures the elapsed time from the start of pressure reduction based on the time information acquired from the time measurement unit 117. .
Subsequently, the control unit 111 performs the processing from step S204 to step S208.

Subsequently, the control unit 111 drives the pressurization pump 126 at a normal speed to perform normal pressurization processing on the cuff 10 (step S309), and from the start of pressurization based on the time information acquired from the time measurement unit 117. Measure the elapsed time.
Subsequently, the control unit 111 performs the processes of steps S210 to S212.

[(4) Cuff pressure maintenance operation in active mode]
Next, the cuff pressure maintaining operation in the active mode (step S119 in FIG. 3) will be described. Here, the “activity mode” means, for example, that the pressure pump 126 is driven at a high speed during an activity such as when a patient performs respiratory rehabilitation or squeezing while wearing a ventilator, bathing or exercising. In this mode, the pressure is adjusted at high speed. During patient activity, the posture of the patient may change abruptly, and the diameter of the trachea and the like may change rapidly. Also, in respiratory rehabilitation and squeezing, the diameter of the trachea may change rapidly. With the rapid change of the diameter of the trachea, the cuff pressure may also change rapidly. By adjusting the cuff pressure at high speed during the activity of such a patient, it is possible to prevent inflow of secretions into the trachea and prevent VAP.

FIG. 8 is a flowchart showing the cuff pressure maintaining operation in the active mode.
The control unit 111 performs the processing from step S201 to step S202. In step S201 in the active mode, it may be determined whether the cuff pressure has continuously exceeded the set upper limit for a certain period of time, for example, about 1 second. In this way, erroneous determination can be prevented more reliably by setting a continuous excess time appropriately for each mode.
Subsequently, the control unit 111 opens the exhaust valve 122, performs high-speed decompression processing on the cuff 10 (step S403), and measures the elapsed time from the start of decompression based on the time information acquired from the time measurement unit 117. . The air supply amount at the time of high-speed processing may be, for example, about 2 to 3 times the air supply amount at the time of normal processing in the normal mode. Subsequently, the control unit 111 performs the processing from step S204 to step S208.

  Subsequently, the control unit 111 drives the pressurization pump 126 at a high speed, performs high-speed pressurization processing on the cuff 10 (step S409), and based on the time information acquired from the time measurement unit 117, starts from the start of pressurization. Measure elapsed time. Subsequently, the control unit 111 performs the processes of steps S210 to S212.

  According to the cuff pressure maintaining operation of (2) to (4) described above, the cuff pressure control device 100 is always connected to the cuff 10 and the cuff pressure detection unit 113 detects the cuff pressure every predetermined time. For example, it is possible to quickly follow a change in the cuff pressure caused by a change in the diameter of the trachea accompanying a change in the posture of the patient (for example, body movement such as turning over), and the desired cuff pressure can be maintained. When there is an abnormality, the user can be notified of the abnormality. Thereby, suppression of the onset of VAP resulting from the lack of cuff pressure can be aimed at effectively.

[(5) Cuff abnormality detection operation]
Next, the cuff abnormality detection operation (step S120 in FIG. 3) will be described. Here, “cuff abnormality detection” is based on the cuff pressure maintenance record, and abnormalities in the ventilator, such as changes in the cuff 10 over time, exhaustion of the gas supply tube 125, the intubation tube 1, the cannula 9, or the cuff pressure adjustment unit 120, etc. And a mode for detecting abnormalities such as stenosis and deformation of a patient's trachea.
FIG. 9 is a flowchart showing the cuff abnormality detection operation.

  From step S115, the control unit 111 records the change over time of the cuff pressure in the storage unit 112 (step S501).

  Subsequently, when the cuff pressure acquired from the cuff pressure detection unit 113 is less than a predetermined value (for example, about 2.80 kPa (21 mmHg)), the control unit 111 drives the pressure pump 126 to pressurize the cuff 10. When the cuff pressure is larger than the predetermined value, the exhaust valve 122 is opened to depressurize the cuff 10.

  The control unit 111 determines whether the cuff pressure acquired from the cuff pressure detection unit 113 has reached the predetermined value. When determining that the cuff pressure has reached the predetermined value, the control unit 111 stops driving the pressurizing pump 126 or closes the exhaust valve 122 (step S502).

  Subsequently, the control unit 111 pressurizes the cuff 10 by driving the pressurizing pump 126. The control unit 111 determines whether or not the cuff pressure acquired from the cuff pressure detection unit 113 has reached a predetermined value (for example, about 3.20 kPa (24 mmHg)). When the control unit 111 determines that the cuff pressure has reached the predetermined value, based on the cuff pressure maintenance record in the storage unit 112, the control unit 111 changes from about 2.80 kPa (21 mmHg) to about 3.20 kPa (24 mmHg). The flow rate value of the gas supplied to the cuff 10 is measured, and this flow rate value is recorded in the storage unit 112 (step S503).

  Subsequently, the control unit 111 refers to the storage unit 112 and determines whether or not the current measurement is the first measurement by determining whether or not there is a flow value recorded in association with the information related to the “initial flow rate recording”. Is determined (step S504).

  If control unit 111 determines that there is no flow value recorded in association with information related to “initial flow rate recording”, control unit 111 determines that the current measurement is the first measurement (YES in step S504). Then, the control unit 111 additionally records information relating to “initial flow rate recording” in association with the flow rate value recorded in the storage unit 112 (step S505). And the control part 111 transfers to the process of step S121.

  On the other hand, when it is determined that there is a flow value recorded in association with information related to “initial flow rate recording”, the control unit 111 determines that the current measurement is not the first measurement (NO in step S504). Then, the control unit 111 obtains a difference between the measured flow rate value and the flow rate value recorded in association with the information on the “initial flow rate recording” in the storage unit 112 (step S506). When the control unit 111 determines that the obtained value is within the predetermined range, the control unit 111 estimates that the change over time in the volume of the cuff 10 and the gas supply tube 125 is within the allowable range, and proceeds to the process of step S121.

  On the other hand, when the control unit 111 determines that the obtained value is outside the predetermined range, the control unit 111 estimates that the change over time in the volume of the cuff 10 and the gas supply tube 125 is abnormal, and outputs a notification command to the notification unit 116. . When the notification unit 116 obtains a notification command from the control unit 111, the notification unit 116 outputs an alarm sound that notifies the user of an abnormality such as the cuff 10 (step S507).

  This notifies the user of an abnormal change in the volume of the cuff 10 and the gas supply tube 125 even though no substantial abnormality has occurred in the cuff 10, so that the cuff 10 that is changing with time is being notified to the user. Can be exchanged in advance. Thereby, since the user can replace the cuff 10 that is changing with time before being damaged, it is possible to effectively prevent the onset of VAP.

[(6) Cuff pressure setting operation and cuff abnormality inspection operation]
FIG. 10 is a flowchart showing the cuff pressure setting operation and the cuff abnormality inspection operation.
This flowchart includes a cuff pressure setting operation (steps S601 to S612) and a cuff abnormality inspection operation (steps S613 to S617).

  First, the cuff pressure setting operation (steps S601 to S612) will be described. This cuff pressure setting operation (steps S601 to S612) corresponds to steps S102 to S113 in the cuff pressure setting operation of (1), respectively.

  First, the user uses the input operation unit 114 to select which product A to C is used, and the input operation unit 114 outputs the product selection result received from the user to the control unit 111 ( Step S601). Based on the product selection result acquired from the input operation unit 114, the control unit 111 selects a pressurization parameter suitable for the currently used product from a plurality of pressurization parameters stored in the storage unit 112, and selects the selected addition parameter. Set the pressure parameter.

  When determining that the product selection result acquired from the input operation unit 114 is the product A, the control unit 111 selects and sets the product A pressurization parameter A from the pressurization parameters stored in the storage unit 112. (Step S602). On the other hand, when the control unit 111 determines that the product selection result acquired from the input operation unit 114 is the product B, the control unit 111 selects the pressurization parameter B for the product B from the pressurization parameters stored in the storage unit 112. Setting is performed (step S603). When the control unit 111 determines that the product selection result acquired from the input operation unit 114 is the product C, the control unit 111 selects the pressurization parameter C for the product C from the pressurization parameters stored in the storage unit 112. Setting is made (step S604).

  Subsequently, the control unit 111 rapidly pressurizes the cuff 10 by driving the pressurizing pump 126. The control unit 111 measures an elapsed time from the start of pressurization based on the time information acquired from the time measurement unit 117. Further, the control unit 111 outputs a cuff pressure detection command to the cuff pressure detection unit 113 every predetermined time. Upon obtaining a cuff pressure detection command from the control unit 111, the cuff pressure detection unit 113 detects the cuff pressure and outputs the detected cuff pressure to the control unit 111. The control unit 111 determines whether the cuff pressure acquired from the cuff pressure detection unit 113 has reached the maximum pressure.

  The control unit 111 reaches the maximum pressure based on the cuff pressure acquired from the cuff pressure detection unit 113 and the elapsed time from the start of pressurization measured based on the time information acquired from the time measurement unit 117. It is determined whether a predetermined time (for example, a time in FIG. 4) has passed before (step S605).

  When the control unit 111 determines that a predetermined time has elapsed before the cuff pressure reaches the maximum pressure, the control unit 111 outputs a notification command to the notification unit 116. When the notification unit 116 acquires a notification command from the control unit 111, the notification unit 116 outputs an alarm sound that notifies the user of an abnormality such as the cuff 10 (step S606).

  The control unit 111 continues to drive the pressurizing pump 126 to pressurize the cuff 10. If the controller 111 determines that the cuff pressure has reached the maximum pressure before the predetermined time has elapsed (step S607), the controller 111 determines that pressurization has been completed, stops the pressurization pump 126, and pressurizes the pressurization pump. Wait for about 30 seconds (corresponding to time b in FIG. 4) after stopping driving 126 (step S608).

  Subsequently, the control unit 111 opens the exhaust valve 122 to depressurize the cuff 10 at a low speed (step S609), and measures an elapsed time from the start of depressurization.

  Based on the cuff pressure acquired from the cuff pressure detection unit 113 and the elapsed time from the start of pressure reduction measured based on the time information acquired from the time measurement unit 117, the control unit 111 determines whether the cuff pressure has reached the appropriate pressure. It is determined whether a predetermined time (for example, time c in FIG. 4) has elapsed (step S610).

  When the control unit 111 determines that a predetermined time has elapsed before the cuff pressure is reduced to an appropriate pressure, the control unit 111 outputs a notification command to the notification unit 116. When the notification unit 116 acquires a notification command from the control unit 111, the notification unit 116 outputs an alarm sound that notifies the user of an abnormality of the cuff pressure adjustment unit 120 (step S611).

  The controller 111 continues to open the exhaust valve 122 to decompress the cuff 10. If the controller 111 determines that the cuff pressure has reached an appropriate pressure before the predetermined time has elapsed (step S612), the controller 111 determines that the pressure reduction has been completed and closes the exhaust valve 122.

  The cuff pressure is set to an appropriate pressure by the cuff pressure setting operation (steps S601 to S612) described above. Subsequently, the control unit 111 proceeds to the cuff abnormality inspection operation (steps S613 to S617). During this cuff abnormality inspection operation, steps S614 to S617 respectively correspond to steps S502, S503, S506, and S507 in the cuff abnormality detection operation of (5).

  First, the user selects the presence / absence of a cuff abnormality test using the input operation unit 114 (step S613), and the input operation unit 114 outputs the cuff abnormality test selection result received from the user to the control unit 111. When the control unit 111 determines that the cuff abnormality inspection selection result acquired from the input operation unit 114 is absent, the control unit 111 ends the flow.

  On the other hand, when the control unit 111 determines that the cuff abnormality inspection selection result acquired from the input operation unit 114 is present, the control unit 111 cuffs the cuff pressure detection unit 113 every predetermined time based on the time information acquired from the time measurement unit 117. Outputs pressure detection command. When the cuff pressure detection unit 113 acquires a cuff pressure detection command from the control unit 111, the cuff pressure detection unit 113 detects the cuff pressure and outputs the detected cuff pressure to the control unit 111.

  Subsequently, when the cuff pressure acquired from the cuff pressure detection unit 113 is less than a predetermined value (for example, about 2.80 kPa (21 mmHg)), the control unit 111 drives the pressure pump 126 to pressurize the cuff 10. When the cuff pressure is larger than the predetermined value, the exhaust valve 122 is opened to depressurize the cuff 10.

  The control unit 111 determines whether the cuff pressure acquired from the cuff pressure detection unit 113 has reached the predetermined value. When determining that the cuff pressure has reached the predetermined value, the control unit 111 stops driving the pressurizing pump 126 or closes the exhaust valve 122 (step S614).

  Subsequently, the control unit 111 pressurizes the cuff 10 by driving the pressurizing pump 126. The control unit 111 determines that the cuff pressure acquired from the cuff pressure detection unit 113 has reached a predetermined value (for example, about 3.20 kPa (24 mmHg)). When the control unit 111 determines that the cuff pressure has reached the predetermined value, the control unit 111 determines the flow rate value of the gas supplied to the cuff 10 until the cuff pressure is about 2.80 kPa (21 mmHg) to about 3.20 kPa (24 mmHg). Measurement is performed (step S615).

  Subsequently, the control unit 111 obtains a difference between the measured flow rate and the volume of the cuff 10 in the product A, B, or C currently in use (step S616). When the control unit 111 determines that the obtained value is within the predetermined range, the control unit 111 estimates that the temporal change in the volume of the cuff 10 and the gas supply tube 125 is within the allowable range, and ends the flow. The volume of the cuff 10 for each product A to C may be recorded in the storage unit 112 in advance.

  On the other hand, when the control unit 111 determines that the obtained value is outside the predetermined range, the control unit 111 estimates that the change over time in the volume of the cuff 10 and the gas supply tube 125 is abnormal, and outputs a notification command to the notification unit 116. . When the notification unit 116 acquires a notification command from the control unit 111, the notification unit 116 outputs an alarm sound that notifies the user of an abnormality such as the cuff 10 (step S617).

  This notifies the user of an abnormal change in the volume of the cuff 10 and the gas supply tube 125 even though no substantial abnormality has occurred in the cuff 10, so that the cuff 10 that is changing with time is being notified to the user. Can be exchanged in advance. Thereby, since the user can replace the cuff 10 that is changing with time before being damaged, it is possible to effectively prevent the onset of VAP.

  The embodiment according to the present invention is not limited to the above-described embodiment, and various other embodiments are conceivable.

  For example, the cuff pressure control device 100 may be provided with functions such as a low pressure alarm function for detecting leaks due to cuff leakage, a battery remaining amount alarm function capable of displaying a battery replacement time, and the like. Thereby, it is possible to notify the user of an insufficient cuff pressure or the like at an early stage, and it is possible to prevent the onset of VAP due to the insufficient cuff pressure or the like.

  In the present embodiment, the operation mode may be set in advance and stored in the storage unit 112, or may be set by the user using the input operation unit 114, and information on the patient or the like is stored in advance in the storage unit 112. However, the present invention is not limited to this, although it may be set by the control unit 111 based on this information. The controller 111 may change the mode based on the cuff pressure detected by the cuff pressure detector 113 every predetermined time. For example, the control unit 111 may switch the setting to the active mode when a sudden cuff pressure change continues for a certain period when the rest mode or the normal mode is set. Alternatively, the control unit 111 may switch the setting to the normal mode when there is no change in the cuff pressure for a certain period when the activity mode is set, and further switch the setting to the rest mode if the state without the cuff pressure change continues.

DESCRIPTION OF SYMBOLS 10 ... Cuff 100 ... Cuff pressure control apparatus 110 ... Control system 111 ... Control part 113 ... Cuff pressure detection part 120 ... Cuff pressure adjustment part

Claims (10)

A cuff pressure adjusting unit that pressurizes the cuff;
A cuff pressure detector for detecting the internal pressure of the cuff;
Based on the detection result by the cuff pressure detecting unit, the cuff pressure adjusting unit is controlled so that the internal pressure of the cuff falls within a predetermined range, and when the internal pressure of the cuff does not fall within the predetermined range within a first time. A controller for notifying abnormality,
Immediately after mounting the cuff, the control unit detects an internal pressure of the cuff by the cuff pressure detection unit, and when the detected internal pressure of the cuff is equal to or lower than a first pressure smaller than the predetermined range, A cuff pressure control device for controlling the cuff pressure adjusting unit so that an internal pressure becomes a second pressure exceeding the predetermined range. The cuff pressure control device according to claim 1,
The control unit starts pressurization to the cuff by the cuff pressure adjusting unit by a predetermined operation immediately after mounting, and the cuff pressure detecting unit detects the cuff pressure by the cuff pressure detecting unit by a predetermined time after the start. A cuff pressure control device that estimates a cuff and a volume of a gas supply tube that communicates with the cuff, and sets at least the first time according to the estimated volume. The cuff pressure control device according to claim 1,
A storage unit for storing a change over time of the internal pressure of the cuff detected by the cuff pressure detection unit;
The control unit is a cuff pressure control device that notifies an abnormality when there is an abnormality in a temporal change in the internal pressure of the cuff stored by the storage unit. The cuff pressure control device according to claim 3,
The storage unit stores the usage time of the cuff,
The said control part is a cuff pressure control apparatus which estimates the replacement time of the said cuff based on the usage time of the said cuff memorize | stored by the said memory | storage part, and alert | reports the estimated replacement time. The cuff pressure control device according to claim 2,
The control unit estimates the volume of the cuff and the gas supply tube connected to the cuff based on the volume of gas required to change the internal pressure of the cuff by a certain amount, and abnormal when the estimated change over time is abnormal. A cuff pressure control device. A cuff pressure control method for controlling the internal pressure of a cuff,
Immediately after wearing the cuff, the internal pressure of the cuff is detected,
When the detected internal pressure of the cuff is equal to or lower than a first pressure smaller than a predetermined range, the cuff is pressurized so that the internal pressure of the cuff becomes a second pressure exceeding the predetermined range,
After that, the internal pressure of the cuff is detected,
Based on the detection result, pressurize the cuff so that the internal pressure of the cuff is in the predetermined range,
A cuff pressure control method for notifying an abnormality when the internal pressure of the cuff does not fall within the predetermined range within a first time. The cuff pressure control method according to claim 6,
Start pressurizing the cuff by a predetermined operation immediately after mounting,
Estimating the volume of the cuff and the gas supply tube leading to the cuff by the internal pressure of the cuff detected by the cuff pressure detector after a certain time from the start,
A cuff pressure control method that sets at least the first time according to an estimated volume. The cuff pressure control method according to claim 6,
Storing the change over time of the detected internal pressure of the cuff;
A cuff pressure control method for notifying an abnormality when the stored internal pressure of the cuff is abnormal. The cuff pressure control method according to claim 8,
Memorize the usage time of the cuff,
Estimating the replacement time of the cuff based on the stored use time of the cuff;
A cuff pressure control method that notifies the estimated replacement time. The cuff pressure control method according to claim 7,
Estimating the volume of the cuff and the gas supply tube leading to the cuff by the volume of gas necessary to change the internal pressure of the cuff by a certain amount;
A cuff pressure control method that reports an abnormality when there is an abnormality in the estimated volume change over time.

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