JP2008264181A - Sleep apnea syndrome treatment device - Google Patents

Abstract

[PROBLEMS] To maintain a therapeutic pressure of CPAP therapy at an optimal level at all times for a patient's airway resistance.
An application unit including a blower, a pipe, a tube, and a mask applies a therapeutic pressure to the upper respiratory tract of a sleeping patient. A measurement unit configured by a combination of the shutter 120, the shutter control unit 122, the pressure sensor 124, and the treatment pressure calculation unit 126 noninvasively measures the respiratory resistance during sleep of the patient. A control unit composed of a combination of the flow sensor 116 and the blower control unit 114 controls the applied treatment pressure according to the measured respiratory resistance during sleep.
[Selection] Figure 1

Description

  The present invention relates to a sleep apnea syndrome treatment apparatus.

  Sleep Apnea Syndrome (SAS) is roughly classified into central sleep apnea syndrome, obstructive sleep apnea syndrome, and mixed sleep apnea syndrome, depending on the cause of the occurrence. The central type is due to a brain disorder that gives a command of breathing, the obstructive type is due to stenosis of the upper airway, and the mixed type is a mixture of the central type and the obstructive type.

  An obstructive patient is often given continuous positive airway pressure (CPAP) therapy as a medical treatment. In this treatment method, a treatment device is used that applies a positive pressure (that is, a treatment pressure set to a value greater than zero) to the patient's upper airway to enlarge the narrowed portion of the upper airway (eg, Non-Patent Document 1). . Application of therapeutic pressure is achieved by sending air nasally through the dedicated mask to the patient's upper respiratory tract.

A conventional sleep apnea syndrome treatment apparatus that can be used for a treatment method called auto CPAP is, for example, that respiratory abnormalities (eg, apnea, hypopnea, flow limitation, snoring, etc.) occur during treatment at a certain treatment pressure. If detected, the treatment pressure can be increased, and if no respiratory anomaly is detected over a period of time during treatment at a certain treatment pressure, the treatment pressure can be reduced.
Department of Cardiology, Sapporo Welfare Hospital, “Sleep Apnea Syndrome”, Internet (http://www.gik.gr.jp/~skj/sas/sas.php3), September 15, 2005

  By the way, the optimal level of the treatment pressure is a level that cancels out the excessive airway resistance of the patient without excess or deficiency, but the treatment pressure varies because the airway resistance itself varies depending on the posture of the patient during sleep or the like. It is desirable to variably set following the airway resistance. However, in the conventional sleep apnea syndrome treatment apparatus, the treatment pressure is variably set according to the presence or absence of a change in breathing without following the changing airway resistance. Over and under levels can occur.

  This invention is made | formed in view of this point, and it aims at providing the sleep apnea syndrome treatment apparatus which can always maintain a therapeutic pressure at the optimal level with respect to a patient's airway resistance.

  The sleep apnea syndrome treatment apparatus of the present invention is applied with an application unit that applies therapeutic pressure to the upper respiratory tract of a sleeping patient, and a measurement unit that non-invasively measures the respiratory resistance of the patient during sleep. And a control unit that controls the treatment pressure according to the measured respiratory resistance during sleep.

  ADVANTAGE OF THE INVENTION According to this invention, a treatment pressure can always be maintained at the optimal level with respect to a patient's airway resistance.

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

  FIG. 1 is a diagram schematically showing a configuration of a CPAP device as a sleep apnea syndrome treatment device according to an embodiment of the present invention.

  In FIG. 1, the CPAP apparatus 100 is configured by connecting a main body 102 and a mask 104 by a tube 106. The main body 102 includes a connector 108, a pipe 110, a blower 112, a blower control unit 114, a flow sensor 116, a shutter 120, a shutter control unit 122, a pressure sensor 124, and a treatment pressure calculation unit 126.

  The blower 112 is composed of a fan that is rotatably supported and a drive unit thereof, and blows air by rotating the fan, thereby generating an airflow for applying therapeutic pressure to the upper airway of a patient with sleep apnea syndrome. Generate.

  The pipe 110 guides the airflow generated by the blower 112 to the connector 108 provided on the surface of the main body 102.

  One end of the tube 106 is connected to the connector 108 and communicates with the pipe 110 through the connector 108. The other end is provided with a mask 104 that can be worn on the patient's face. When the mask 104 is attached to the patient, the tube 106 communicates with the patient's nasal cavity. The tube 106 guides the airflow guided to the connector 108 by the pipe 110 to the patient's nasal cavity through the mask 104. The air (airflow) thus introduced into the body is supplied from the nasal cavity to the upper airway.

  Therefore, the combination of the blower 112, the pipe 110, the tube 106, and the mask 104 constitutes an application unit that applies therapeutic pressure to the patient's upper airway. Further, the combination of the pipe 110 and the tube 106 constitutes an air passage that communicates with the patient's nasal cavity and guides the airflow generated by the blower 112 to the nasal cavity.

  The shutter 120 is a valve provided at an intermediate portion of the pipe 110. Although the shutter 120 is provided so as to be freely opened and closed, the cross section of the pipe cannot be completely closed, and is provided so that it can be closed only partially. When the cross section of the pipe 110 is partially closed, the shutter 120 restricts the flow path of the airflow formed by the pipe 110, thereby forming a resistance to the flow path. On the other hand, when the shutter 120 is open, the flow path is not restricted, so that no resistance to the flow path is formed.

  The shutter control unit 122 is mainly composed of a microcomputer, and controls the timing for opening and closing the shutter 120. The shutter control unit 122 generates an aperture control signal and controls the aperture of the flow path by controlling the opening / closing operation of the shutter 120 with this signal. The throttle control signal is also sent to the treatment pressure calculation unit 126. When the aperture control signal is at a low level, the shutter 120 is opened, that is, there is no aperture in the flow path, and no resistance is applied to the airflow. On the other hand, when the aperture control signal is at a high level, the shutter 120 is closed, the flow path is throttled, and resistance is applied to the airflow.

  Therefore, the combination of the shutter 120 and the shutter control unit 122 constitutes a load unit that loads resistance against the airflow.

  The pressure sensor 124 is provided in the pipe 110 on the downstream side of the shutter 120, detects the pressure of the airflow, and notifies the treatment pressure calculation unit 126 of the detected pressure value.

  The treatment pressure calculation unit 126 is mainly configured by a microcomputer and performs various calculation processes. First, the treatment pressure calculation unit 126 calculates the flow velocity of the airflow from the pressure value notified from the pressure sensor 124. Further, the treatment pressure calculation unit 126 measures the respiratory resistance by calculating the respiratory resistance of the patient based on the flow velocity calculated when the resistance is applied to the airflow and the magnitude of the applied resistance. .

  Therefore, the combination of the shutter 120, the shutter control unit 122, the pressure sensor 124, and the treatment pressure control unit 126 constitutes a measurement unit that non-invasively measures a patient's respiratory resistance. A CPAP device capable of non-invasive measurement of respiratory resistance is provided at a low cost by adopting a simple configuration in which a shutter 120 and a pressure sensor 124 are provided in the pipe 110 in the main body 102 and the respiratory resistance is calculated by computer computation. Can be manufactured. The details of the respiratory resistance measurement method will be described later.

  Furthermore, the treatment pressure calculation unit 126 calculates an optimum treatment pressure from the calculated respiratory resistance, and notifies the blower control unit 114 of the calculated treatment pressure value.

  The flow sensor 116 is provided in the pipe 110 on the upstream side of the shutter 120, detects the flow rate of the airflow generated by the blower 112, and feeds back the detected flow rate value to the blower control unit 114.

  The blower control unit 114 is mainly composed of a microcomputer. The blower control unit 114 sets the treatment pressure (positive pressure) to be applied to the patient's upper airway according to the treatment pressure value prescribed by the doctor or the treatment pressure value notified from the treatment pressure calculation unit 126. From the set treatment pressure, the intensity of air blown by the blower 112 is derived, and control is performed to cause the blower 112 to blow air at the derived intensity. This control is performed based on feedback from the flow sensor 116. In this way, the treatment pressure applied to the patient's upper airway is controlled.

  That is, the combination of the flow sensor 116 and the blower control unit 114 constitutes a control unit that controls the treatment pressure to be applied to the patient according to the measured respiratory resistance of the patient.

  Next, a method for measuring respiratory resistance will be described with reference to FIGS.

  FIG. 2 (a) shows the breathing pattern of the patient. Because patients suffer from sleep apnea syndrome, they may cause respiratory abnormalities such as apnea, hypopnea, flow limitation, and snoring during sleep. It is assumed that no respiration abnormality has occurred and the repetition of exhalation and inspiration in a substantially constant cycle continues. It is also assumed that this patient is sleeping with the CPAP device 100 attached for the treatment of sleep apnea syndrome.

  FIG. 2B shows an aperture control signal output from the shutter control unit 122 to the shutter 120. This signal restricts the flow path of the airflow supplied to the patient for a short period during inspiration. The magnitude of resistance Rk applied to the airflow by narrowing the flow path is a known value.

  When the flow path is throttled, the pressure of the airflow continuously detected by the pressure sensor 124 slightly decreases for that period. Along with this, the flow velocity of the airflow calculated by the treatment pressure calculation unit 126 based on the detected pressure is slightly decreased during that period. FIG.2 (c) is a waveform which shows the time-dependent change of the flow velocity measured in this way. The change in the flow velocity measured here represents the change in the respiratory flow rate of the patient.

FIG. 3 shows an enlarged waveform of the measured flow velocity. As described above, a slight period by the control signal throttle (that is, the period from time T ₁ to the shutter 120 is closed until the time T ₂ where the shutter 120 is opened) when only temporarily the passage is throttled, the flow rate that period Only slightly lower. The respiratory resistance Rrs is a value of the flow velocity V ₁ immediately before the flow velocity decreases at time T ₁ , the value of the flow velocity V ₂ immediately after the flow velocity increases at time T ₂ , and the value of the resistance magnitude Rk. It is calculated by substituting into equation (1).
Rrs = Rk × (V ₁ −ΔV) / ΔV (1)
Here, ΔV = V ₁ −V ₂ .

  This measurement method enables non-invasive measurement of a patient's respiratory resistance, so that the respiratory resistance can be measured at any frequency without waking up the patient during sleep.

  Next, the treatment pressure adjustment operation in the CPAP device 100 will be described. FIG. 4 is a flowchart for explaining an example of the treatment pressure adjustment operation.

  First, in step S1, the blower control unit 114 controls the blower 112 to start blowing air. At this time, the treatment pressure to be applied to the upper airway of the patient is set in advance in the blower control unit 114 to a predetermined value. The blower control unit 114 determines the blower intensity of the blower 112 based on the set value, and controls the blower 112 according to the determined blower intensity. In addition, the shutter 120 is in an open state, and the airflow generated by the blowing is supplied to the patient nasally from the mask 104 attached to the sleeping patient via the pipe 110 and the tube 106. This applies therapeutic pressure to the patient's upper respiratory tract.

  In step S2, it is determined whether or not an event such as a change in body position or abnormal breathing has occurred. This determination process can be realized by providing the CPAP device 100 with a detector capable of detecting these events, for example. If an event is detected, this is notified to the pressure sensor 124 and the shutter control unit 122, and the process proceeds to step S4. If no event is detected, the process proceeds to step S3, where it is determined whether or not the state without an event has continued for a certain period (for example, 10 minutes, 30 minutes, etc.). This determination processing can be realized by providing the CPAP device 100 with a timer capable of measuring time, for example. If the state without an event continues for a predetermined period or longer, the process proceeds to step S4. If the state without an event has not continued for a predetermined period or longer, the process returns to step S2.

  As described above, since an event such as a change in body position or respiratory abnormality is detected, it is possible to quickly grasp the possibility that the treatment pressure being set is not optimal or that the optimum treatment pressure has changed. . Moreover, when the event does not occur, the measurement of respiratory resistance and the resetting of the treatment pressure can be paused.

  The processes in steps S2 and S3 are arbitrary, and instead of performing these processes, the processes in steps S4 to S8 are executed periodically (for example, 10 minutes, 30 minutes, etc.) or at a preset time. You may do it.

  In step S4, the pressure sensor 124 starts monitoring pressure (continuation detection). The pressure detected during monitoring is notified to the treatment pressure calculator 126. Based on the notified pressure, the treatment pressure calculation unit 126 calculates the flow velocity (V) of the airflow that flows through the pipe 110 and the tube 106 and is supplied to the patient. The calculated flow velocity is held in the treatment pressure calculation unit 126. In this way, the flow velocity of the airflow is monitored.

  In step S5, during pressure monitoring, the shutter control unit 122 controls the shutter 120 to temporarily close the shutter 120, thereby applying a resistance (Rk) to the airflow flowing through the pipe 110. The Notification of the resistance load start timing (that is, the timing to close the shutter 120) and the resistance load end timing (that is, the timing to open the shutter 120) is performed by the output of the aperture control signal from the shutter control unit 122 to the treatment pressure calculation unit 126 Is called.

In step S6, the treatment pressure calculation unit 126 calculates the value of the flow rate at the start of the resistive load (ie, V ₁ in FIG. 3) and the flow rate at the end of the resistive load (ie, FIG. 3) from the monitored flow rate (V). V ₂ ) is identified, and the respiratory resistance (Rrs) of the patient during sleep is calculated using the above-described equation (1).

  In step S7, the treatment pressure calculation unit 126 obtains an optimal treatment pressure from the calculated respiratory resistance. The determined treatment pressure is notified from the treatment pressure calculation unit 126 to the blower control unit 114.

  In step S8, the blower control unit 114 resets the treatment pressure by changing the set value of the treatment pressure from a preset value to a value notified from the treatment pressure calculation unit 126.

  In step S9, the blower control unit 114 determines the blowing intensity of the blower 112 based on the new set value, and adjusts the blowing intensity by controlling the blower 112 according to the decided blowing intensity. In this manner, the treatment pressure applied to the upper airway of the sleeping patient can be adjusted while maintaining the resting state of the sleeping patient.

  In resetting the treatment pressure, the value of the respiratory resistance during the awakening (when awakening) of the patient is held in advance, and this can be used for resetting the treatment pressure. For example, when the calculated respiratory resistance during sleep is higher than the respiratory resistance during awakening, control can be performed such that the adjusted treatment pressure becomes the respiratory resistance during awakening.

  As described above, according to the present embodiment, the respiratory resistance during sleep of a patient is measured non-invasively, and the treatment pressure to be applied to the patient's upper airway is controlled according to the measurement result. Respiratory resistance includes thoracic resistance and pulmonary resistance, and pulmonary resistance includes airway resistance and pulmonary tissue resistance. Therefore, airway resistance closely related to upper airway stenosis or obstruction is respiratory resistance. By roughly measuring, it is possible to grasp roughly. Therefore, since the applied treatment pressure is controlled according to the result of the non-invasive measurement of respiratory resistance, it is possible to always maintain the optimal treatment pressure following the change in the airway resistance of the sleeping patient.

  Although the CPAP device 100 of the present embodiment is mainly intended for use by patients with sleep apnea syndrome, it can also be used by patients with upper airway resistance syndrome.

  The embodiment of the present invention has been described above. The above description is an illustration of a preferred embodiment of the present invention, and the scope of the present invention is not limited to this, and the above embodiment can be implemented with various modifications.

The figure which shows the structure of the CPAP apparatus which concerns on one embodiment of this invention The figure for demonstrating the respiratory pattern at the time of the respiratory resistance measurement which concerns on one embodiment of this invention, a throttle control signal, and a measurement flow velocity The figure for demonstrating the measured value used for the respiratory resistance measurement which concerns on one embodiment of this invention The flowchart for demonstrating an example of the treatment pressure adjustment operation | movement of the CPAP apparatus which concerns on one embodiment of this invention

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 CPAP apparatus 104 Mask 106 Tube 110 Pipe 112 Blower 114 Blower control part 116 Flow rate sensor 120 Shutter 122 Shutter control part 124 Pressure sensor 126 Treatment pressure calculating part

Claims (7)

An application unit for applying therapeutic pressure to the upper respiratory tract of a sleeping patient;
A measurement unit for non-invasively measuring respiratory resistance during sleep of the patient;
A controller for controlling the applied treatment pressure according to the measured respiratory resistance during sleep;
A device for treating sleep apnea syndrome, comprising: The application unit includes:
A blower that generates airflow;
An air passage that communicates with the nasal cavity of the patient and guides the generated airflow to the nasal cavity,
The measuring unit is
A load portion that is provided in the air passage and loads resistance against the guided airflow;
A calculation unit for calculating respiratory resistance during sleep based on the resistance applied;
The sleep apnea syndrome treatment apparatus according to claim 1, wherein: The calculation unit calculates the respiratory resistance during sleep based on the magnitude of the resistance to be loaded and the flow velocity of the airflow guided at the timing when the resistance is loaded.
The sleep apnea syndrome treatment apparatus according to claim 2. The load section includes a shutter that forms a resistance against an air flow by narrowing the air path.
The sleep apnea syndrome treatment apparatus according to claim 2. The blower generates an air flow having a predetermined flow rate;
The control unit resets the flow rate of the generated airflow according to the calculated respiratory resistance during sleep,
The sleep apnea syndrome treatment apparatus according to claim 2. The control unit controls the applied treatment pressure according to a respiratory resistance during sleep measured when a change in the position of the patient during sleep occurs.
The sleep apnea syndrome treatment apparatus according to claim 1. The control unit controls the applied treatment pressure according to a respiratory resistance during sleep measured when a respiratory abnormality occurs in the patient during sleep.
The sleep apnea syndrome treatment apparatus according to claim 1.

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