Apparatus for monitoring respiratory muscle activity

Claim 1

An apparatus for monitoring respiratory muscle activity comprising: a pressure sensor for detecting air pressure in an air passage connecting a lung ventilator and an airway system of a patient and generating a detection signal in response thereto; a flow rate sensor for detecting flow rate in said air passage and generating a detection signal in response thereto; arithmetic constant detecting means for detecting resistance Rrs and elastance Ers of a respiratory system of the patient including the airway and thorax beforehand by using the detection signal generated by said pressure sensor and the detection signal generated by said flow rate sensor while said lung ventilator is supplying air to the patient whose spontaneous breathing is temporarily stopped; developed pressure calculating means for calculating pressure Pmus developed by the respiratory muscles during lung ventilation from the following expression Pmus=-Paw+Rrs(dV/dt)+∫(dV/dt)dt where Paw is airway opening pressure detected by said pressure sensor and dV/dt is flow rate detected by said flow rate sensor; and output means for outputting the obtained Pmus together with the detection signal generated by said pressure sensor along a common time axis.

Claim 2

An apparatus for monitoring respiratory muscle activity comprising: a pressure sensor for detecting air pressure in an air passage connecting a lung ventilator and an airway system of a patient and generating a detection signal in response thereto; a flow rate sensor for detecting flow rate in said air passage and generating a detection signal in response thereto; arithmetic constant detecting means for detecting resistance Rrs and elastance Ers of a respiratory system of the patient including the airway and thorax beforehand by using the detection signal generated by said pressure sensor and the detection signal generated by said flow rate sensor while said lung ventilator is supplying air to the patient whose spontaneous breathing is temporarily stopped; developed pressure calculating means for calculating pressure Pmus developed by the respiratory muscles during lung ventilation from the following expression Pmus=-Paw+Rrs(dV/dt)+∫(dV/dt)dt where Paw is airway opening pressure detected by said pressure sensor and dV/dt is flow rate detected by said flow rate sensor; and output means for outputting the obtained Pmus together with the detection signal generated by said pressure sensor along a common time axis.

Claim 3

An apparatus for monitoring respiratory muscle activity comprising: a pressure sensor for detecting air pressure in an air passage connecting a lung ventilator and an airway system of a patient and generating a detection signal in response thereto; a flow rate sensor for detecting flow rate in said air passage and generating a detection signal in response thereto; arithmetic constant detecting means for detecting resistance Rrs and elastance Ers of a respiratory system of the patient including the airway and thorax beforehand by using the detection signal generated by said pressure sensor and the detection signal generated by said flow rate sensor while said lung ventilator is supplying air to the patient whose spontaneous breathing is temporarily stopped; developed pressure calculating means for calculating pressure Pmus developed by the respiratory muscles during lung ventilation from the following expression Pmus=-Paw+Rrs(dV/dt)+∫(dV/dt)dt where Paw is airway opening pressure detected by said pressure sensor and dV/dt is flow rate detected by said flow rate sensor; time difference calculating means for detecting a time point when the obtained Pmus starts to decrease as an inspiration initial point, detecting a time when the level of the detection signal generated by said pressure sensor starts to increase as a air-supplying initial point, and obtaining a time difference between said inspiration initial point and said air-supplying initial point; and output means for outputting data of said time difference.

Claim 4

An apparatus for monitoring respiratory muscle activity comprising: a pressure sensor for detecting air pressure in an air passage connecting a lung ventilator and an airway system of a patient and generating a detection signal in response thereto; a flow rate sensor for detecting flow rate in said air passage and generating a detection signal in response thereto; arithmetic constant detecting means for detecting resistance Rrs and elastance Ers of a respiratory system of the patient including the airway and thorax beforehand by using the detection signal generated by said pressure sensor and the detection signal generated by said flow rate sensor while said lung ventilator is supplying air to the patient whose spontaneous breathing is temporarily stopped; developed pressure calculating means for calculating pressure Pmus developed by the respiratory muscles during lung ventilation from the following expression Pmus=-Paw+Rrs(dV/dt)+∫(dV/dt)dt where Paw is airway opening pressure detected by said pressure sensor and dV/dt is flow rate detected by said flow rate sensor; time difference calculating means for detecting a time point when the obtained Pmus starts to decrease as an inspiration initial point, detecting a time when the level of the detection signal generated by said pressure sensor starts to increase as a air-supplying initial point, and obtaining a time difference between said inspiration initial point and said air-supplying initial point; and output means for outputting data of said time difference.

Claim 5

An apparatus for monitoring respiratory muscle activity comprising: a pressure sensor for detecting air pressure in an air passage connecting a lung ventilator and an airway system of a patient and generating a detection signal in response thereto; a flow rate sensor for detecting flow rate in said air passage and generating a detection signal in response thereto; arithmetic constant detecting means for detecting resistance Rrs and elastance Ers of a respiratory system of the patient including the airway and thorax beforehand by using the detection signal generated by said pressure sensor and the detection signal generated by said flow rate sensor while said lung ventilator is supplying air to the patient whose spontaneous breathing is temporarily stopped; developed pressure calculating means for calculating pressure Pmus developed by the respiratory muscles during lung ventilation from the following expression Pmus=-Paw-Rrs(dV/dt)-∫(dV/dt)dt where Paw is airway opening pressure detected by said pressure sensor and dV/dt is flow rate detected by said flow rate sensor; pressure-time product calculating means for detecting a time point when the obtained Pmus starts to decrease as an inspiration initial point, detecting a time point when the obtained Pmus starts to increase as an inspiration terminal point, and calculating pressure-time product between said inspiration initial point and said inspiration terminal point from the following expression PTP=∫Pmus dt; and output means for outputting data of said pressure-time product.

Claim 6

An apparatus for monitoring respiratory muscle activity comprising: a pressure sensor for detecting air pressure in an air passage connecting a lung ventilator and an airway system of a patient and generating a detection signal in response thereto; a flow rate sensor for detecting flow rate in said air passage and generating a detection signal in response thereto; arithmetic constant detecting means for detecting resistance Rrs and elastance Ers of a respiratory system of the patient including the airway and thorax beforehand by using the detection signal generated by said pressure sensor and the detection signal generated by said flow rate sensor while said lung ventilator is supplying air to the patient whose spontaneous breathing is temporarily stopped; developed pressure calculating means for calculating pressure Pmus developed by the respiratory muscles during lung ventilation from the following expression Pmus=-Paw-Rrs(dV/dt)-∫(dV/dt)dt where Paw is airway opening pressure detected by said pressure sensor and dV/dt is flow rate detected by said flow rate sensor; pressure-time product calculating means for detecting a time point when the obtained Pmus starts to decrease as an inspiration initial point, detecting a time point when the obtained Pmus starts to increase as an inspiration terminal point, and calculating pressure-time product between said inspiration initial point and said inspiration terminal point from the following expression PTP=∫Pmus dt; and output means for outputting data of said pressure-time product.

Claim 7

An apparatus for monitoring respiratory muscle activity comprising: a pressure sensor for detecting air pressure in air passage connecting a lung ventilator and an airway system of a patient and generating a detection signal in response thereto; a flow rate sensor for detecting flow rate in said air passage and generating a detection signal in response thereto; arithmetic constant detecting means for detecting resistance Rrs and elastance Ers of a respiratory system of the patient including the airway and thorax beforehand by using the detection signal generated by said pressure sensor and the detection signal generated by said flow rate sensor while said lung ventilator is supplying air to the patient whose spontaneous breathing is temporarily stopped; developed pressure calculating means for calculating pressure Pmus developed by the respiratory muscles during lung ventilation from the following expression Pmus=-Paw+Rrs(dV/dt)+Ers∫(dV/dt)dt where Paw is airway opening pressure detected by said pressure sensor and dV/dt is flow rate detected by said flow rate sensor; and expiration initiation detecting means for detecting a time point when the obtained Pmus starts to increase as an expiration initial point and outputting a signal indicating initiation of expiration.

Claim 8

An apparatus for monitoring respiratory muscle activity comprising: a pressure sensor for detecting air pressure in air passage connecting a lung ventilator and an airway system of a patient and generating a detection signal in response thereto; a flow rate sensor for detecting flow rate in said air passage and generating a detection signal in response thereto; arithmetic constant detecting means for detecting resistance Rrs and elastance Ers of a respiratory system of the patient including the airway and thorax beforehand by using the detection signal generated by said pressure sensor and the detection signal generated by said flow rate sensor while said lung ventilator is supplying air to the patient whose spontaneous breathing is temporarily stopped; developed pressure calculating means for calculating pressure Pmus developed by the respiratory muscles during lung ventilation from the following expression Pmus=-Paw+Rrs(dV/dt)+Ers∫(dV/dt)dt where Paw is airway opening pressure detected by said pressure sensor and dV/dt is flow rate detected by said flow rate sensor; and expiration initiation detecting means for detecting a time point when the obtained Pmus starts to increase as an expiration initial point and outputting a signal indicating initiation of expiration.

Claim 9

An apparatus for monitoring respiratory muscle activity comprising: a pressure sensor for detecting air pressure in air passage connecting a lung ventilator and an airway system of a patient and generating a detection signal in response thereto; a flow rate sensor for detecting flow rate in said air passage and generating a detection signal in response thereto; arithmetic constant detecting means for detecting resistance Rrs and elastance Ers of a respiratory system of the patient including the airway and thorax beforehand by using the detection signal generated by said pressure sensor and the detection signal generated by said flow rate sensor while said lung ventilator is supplying air to the patient whose spontaneous breathing is temporarily stopped; tidal volume detecting means for detecting a tidal volume by integrating said detection signal generated by said flow rate sensor; work calculating means for calculating work Wmus performed by the respiratory muscles over an inspiratory period from the following expression Wmus=-Paw(dV/dt)dt+Rrs∫(dV/dt).sup.2 dt+(1/2)Ers(VT).sup.2 where Paw is airway opening pressure detected by said pressure sensor, dV/dt is flow rate detected by said flow rate sensor, and VT is a tidal volume detected by said tidal volume detecting means; and output means for outputting the obtained work Wmus.

Claim 10

An apparatus for monitoring respiratory muscle activity comprising: a pressure sensor for detecting air pressure in air passage connecting a lung ventilator and an airway system of a patient and generating a detection signal in response thereto; a flow rate sensor for detecting flow rate in said air passage and generating a detection signal in response thereto; arithmetic constant detecting means for detecting resistance Rrs and elastance Ers of a respiratory system of the patient including the airway and thorax beforehand by using the detection signal generated by said pressure sensor and the detection signal generated by said flow rate sensor while said lung ventilator is supplying air to the patient whose spontaneous breathing is temporarily stopped; tidal volume detecting means for detecting a tidal volume by integrating said detection signal generated by said flow rate sensor; work calculating means for calculating work Wmus performed by the respiratory muscles over an inspiratory period from the following expression Wmus=-Paw(dV/dt)dt+Rrs∫(dV/dt).sup.2 dt+(1/2)Ers(VT).sup.2 where Paw is airway opening pressure detected by said pressure sensor, dV/dt is flow rate detected by said flow rate sensor, and VT is a tidal volume detected by said tidal volume detecting means; and output means for outputting the obtained work Wmus.

Claim 12

An apparatus for monitoring respiratory muscle activity comprising: a pressure sensor for detecting air pressure in an air passage connecting a lung ventilator and an airway system of a patient and generating a detection signal in response thereto; a flow rate sensor for detecting flow rate in said air passage and generating a detection signal in response thereto; arithmetic constant detecting means for detecting resistance Rrs and elastance Ers of a respiratory system of the patient including the airway and thorax beforehand by using the detection signal generated by said pressure sensor and the detection signal generated by said flow rate sensor while said lung ventilator is supplying air to the patient whose spontaneous breathing is temporarily stopped; developed pressure calculating means for calculating pressure Pmus developed by the respiratory muscles during lung ventilation from the following expression Pmus=-Paw+Rrs(dV/dt)+Ers∫(dV/dt)dt where Paw is airway opening pressure detected by said pressure sensor and dV/dt is flow rate detected by said flow rate sensor; and output means capable of selectively outputting the generated detection signals of said pressure sensor and flow rate sensor and data calculated by said calculating means.

Claim 13

An apparatus for monitoring respiratory muscle activity comprising: a pressure sensor for detecting air pressure in an air passage connecting a lung ventilator and an airway system of a patient and generating a detection signal in response thereto; a flow rate sensor for detecting flow rate in said air passage and generating a detection signal in response thereto; arithmetic constant detecting means for detecting resistance Rrs and elastance Ers of a respiratory system of the patient including the airway and thorax beforehand by using the detection signal generated by said pressure sensor and the detection signal generated by said flow rate sensor while said lung ventilator is supplying air to the patient whose spontaneous breathing is temporarily stopped; developed pressure calculating means for calculating pressure Pmus developed by the respiratory muscles during lung ventilation from the following expression Pmus=-Paw+Rrs(dV/dt)+Ers∫(dV/dt)dt where Paw is airway opening pressure detected by said pressure sensor and dV/dt is flow rate detected by said flow rate sensor; and output means capable of selectively outputting the generated detection signals of said pressure sensor and flow rate sensor and data calculated by said calculating means.