Abstract: The systems and methods provide for novel a triggering mode that allows the patient to trigger or initiate the delivery of a breath during ventilation on a ventilator. Further, the systems and methods provide for triggering ventilation utilizing a statistical trigger mode. Additionally, the systems and methods provide for analyzing and/or displaying information related to a potential change in a triggering threshold for a currently utilized breath type.

Abstract: Methods and apparatus provide automated circuit disconnection monitoring such as for a respiratory apparatus or system. Disconnection of a patient circuit, including a patient interface and air delivery circuit, may be detected and a message or alarm activated. In some versions, detecting occurrences of circuit disconnection event(s), such as by a processor, may be based on an instantaneous disconnection parameter as a function of a disconnection setting. The disconnection setting may be determined based on patient circuit type. The instantaneous disconnection parameter may be determined from detected pressure and flow rate, and may be, for example, a conductance value or an impedance value. Disconnection events may be qualified by one or more detected respiratory indicators.

Abstract: A breathing air supply system (200) is configured to be carried by a person (300) and includes a breathing air supply device (130), a fastening device (1) for the breathing air supply device (130) and a vital parameter sensor (30.1). The vital parameter sensor (30.1) is mounted in or at a back section (22) belonging to a fastening section (20) of the fastening device (1). The vital parameter sensor (30.1) is configured to contactlessly measure a vital parameter of a user (300) of the breathing air supply system (200).

Abstract: Apparatus and methods are disclosed for controlling pressure delivery to a user such as a patient. A flow generator generates an outlet flow at an outlet port for delivery to a patient. At least one sensor measures properties of the flow of gas at the outlet port or being delivered to the patient. A controller is operatively connected to the flow generator and the at least one sensor, and is adapted to operate according to a pressure control mode in which the controller controls the flow generator to output a substantially steady pressure or a flow control mode in which the controller controls the flow generator to output a substantially steady flow. The controller operates in the flow control mode when a patient may be awake and in the pressure control mode when the patient may be asleep.

Abstract: A mask fitting level determination device includes a mask inner pressure detection unit inserted between a mask covering a mouth, nose and a face surface of a person to measure a pressure inside the mask. A circuit control unit derives information of a pressure value measured by the mask inner pressure detection unit and generates display information for the person wearing the mask. A determination display unit shows the person the display information generated by the circuit control unit. A battery unit supplies electricity to the circuit control unit and the determination display unit. A power supply switch starts and stops the supply of the electricity to the circuit control unit and the determination display unit. A start switch starts the mask inner pressure detection operation.

Abstract: An apparatus for treating a respiratory disorder in a patient includes a power supply, a first power supply circuit coupled to the power supply, a pressure generator to generate a flow of air, a transducer to generate a flow signal representing a property of the flow of air, and motor power supply circuitry. The motor power supply circuitry includes: a motor controller to control operation of a motor in the pressure generator based on the flow signal; one or more storage elements to store energy generated by motor deceleration; an energy dissipation circuit to dissipate a portion the energy generated by the deceleration of the motor; and an energy transfer circuit to couple the one or more storage elements to the first power supply circuit and transfer the energy generated by motor deceleration and/or the energy stored by the one or more storage elements to the first power supply circuit.

Abstract: Breathing assistance apparatus includes a gases supply unit adapted to, in use, deliver a stream of pressurised gases from an outlet. The gases supply unit is adapted to vary the pressure of the stream of pressurised gases. A supply path includes a flexible self-supporting gases transportation pathway having a first end connected to the outlet so that the gases transportation pathway receives the stream of gases and conveys the gases to a patient. A patient interface is connected to the second end of the gases transportation pathway receives a stream of gases. At least one sensor measures at least one information parameter of the supply path. A control system associated with the gases supply unit receives the information parameter. The control system contains reference data, and compares the received data to reference data, and determines a supply path based on the comparison.

Abstract: A respiratory information acquisition device used for a PSA type oxygen concentration device that switches and uses multiple adsorption cylinders includes a respiratory information acquisition means of measuring a first pressure of a periodic pressure fluctuation in an oxygen supply path when oxygen is supplied to a patient from the PSA type oxygen concentration device and a second pressure of a periodic pressure fluctuation in the oxygen supply path when oxygen is not supplied to the patient from the PSA type oxygen concentration device, a phase confirmation means of matching phases of the first pressure and the second pressure, and a subtraction processing means of calculating a difference between the first pressure and the second pressure in the condition where the phases are matched.

Abstract: A breath analyzer for detecting breathing events of a person ventilated with a respiratory gas, comprising an electronic computing and storage unit configured to receive a signal corresponding to a ventilation pressure and/or a respiratory flow and/or a tidal volume of the respiratory gas delivered to the person and, during a predetermined analysis duration, to detect a curve of the signal by a curve analyzer. A ventilator for ventilating a person with a respiratory gas, which ventilator comprises the breath analyzer and a method for detecting breathing events of a person ventilated with a respiratory gas is also described.

Abstract: Systems and methods of identifying medical disorders in one or more subjects are disclosed herein. In one embodiment, sound is transmitted toward a subject and at least a portion of the sound reflected by the subject and is acquired as echo data. The acquired echo data is used to generate a motion waveform having a plurality of peaks detected therein. At least a portion of the plurality of peaks may be indicative of movement of the subject. One or more medical disorders in the subject can be identified based on, for example, time durations and/or amplitude changes between peaks detected in the motion waveform.

Abstract: The present invention relates to an adaptive hyperbaric oxygen chamber designed to function as a medical apparatus in order to treat a subject suffering from any FDA approved medical condition. The hyperbaric oxygen chamber is designed and constructed in such a way that only one subject can be allowed to sit in an upright seated position, unless the pediatric seat is occupied by a pediatric patient and the adult is seated in the standard seat to accompany the pediatric patient. The upright patient seat when treating a pediatric patient is in the extended position while the occupant enters and exits the mono medical hyperbaric oxygen chamber and the seat is returned to the fixed position inside the hyperbaric oxygen chamber while the overhead door is closed, the seat being operated by an extension device. The hyperbaric oxygen chamber is made, using additive manufacturing technology.

Abstract: A method of monitoring a subject for the risk of Acute Mountain Sickness (AMS) includes obtaining real-time pulse arterial oxygen saturation (SpO2) measurements from the subject. The SpO2 measurements are transformed into a novel metric known as Accumulated Hypoxic Debt (AHD). The AHD metric is used as the independent variable in a longitudinal generalized linear mixed model to calculate the probability D that the subject is at risk of AMS. Based on the probability D, appropriate courses of action may be communicated to the subject via the output device of a wearable or portable monitor.

Abstract: A ventilation system including a ventilator having a cooling fan configured reduce an internal temperature of the ventilator. The ventilator also includes a controller configured to control operation of the ventilator. A detector is configured to generate a detection signal when the ventilator is connected to a cold passover humidification (CPH) device. In response to the detection signal, the ventilator reduces or eliminates operation of the cooling fan in comparison to a default mode of operation. A method of providing increasing a temperature of a flow of air to a CPH device is also included.

Abstract: A respirator system includes a respirator with an air filter, a flow generator with a sensorless DC motor, a mask, a processor, a sensor, an electric power source, and a wireless transceiver. The respirator filters air, increase the pressure of the air, delivers the air to the mask at a pressure above ambient, gathers data with the sensor about operation of the respirator, and transmits the data. An intermediate electronic device is separate and remote from the respirator, and is configured to receive the transmitted data process the data, and re-transmit the data. A computer receives the data, processes the data and generates at least one report regarding the respirator or a user of the respirator.

Abstract: A ventilator system for a patient includes: an intubation tube configured to flow oxygen-enriched humidified air (OHA) toward patient lungs and to evacuate exhaust air exhaled from the lungs, the intubation tube includes: a distal end, configured to be inserted into patient trachea, and a proximal end, configured to be connected to tubes for receiving the OHA and evacuating the exhaust air; a first microgravity sensor, coupled to the intubation tube at a first position, and configured to produce a first signal indicative of a first micro-acceleration of the intubation tube at the first position; a second microgravity sensor, coupled to the intubation tube at a second different position, and configured to produce a second signal indicative of a second micro-acceleration of the intubation tube at the second position; and a processor, configured to control the ventilation system to apply a ventilation scheme responsively to the first and second signals.

Abstract: This disclosure describes systems and methods for controlling pressure and/or flow during exhalation. The disclosure describes novel exhalation modes for ventilating a patient.

Abstract: A method for providing one or more customized alarm setting recommendations for a patient includes the steps of: providing a patient monitor configured to monitor the patient, the patient monitor comprising a patient sensor and a processor configured to receive the sensor data from the patient sensor, receiving, by the patient monitor, information about a patient; analyzing, by the processor using an alarm setting recommendation classifier, the received information about the patient to generate one or more alarm setting recommendations customized to the patient; providing the one or more alarm setting recommendations to the user, and receiving input from the user accepting, rejecting, and/or modifying the alarm setting recommendations.

Abstract: Disclosed herein are methods, systems, and devices for controlling a gas mixture within a mechanical ventilator. According to one embodiment, a computer implemented method includes receiving first peripheral arterial oxygen saturation (SpO2) data from a pulse oximeter via a pulse oximeter interface, wherein the pulse oximeter is configured to monitor a patient receiving invasive ventilation; determining a first mode of operation for a ventilator mechanism, wherein the ventilator mechanism is configured to provide at least a portion of the invasive ventilation; determining first partial pressure of oxygen (PaO2) data stored in a first lookup table using the first SpO2 data, wherein the first lookup table is derived from a sigmoid shaped oxyhemoglobin dissociation curve; determining first fraction of inspired oxygen in air (FiO2) data for setting a mixture in a gas blender in the ventilator mechanism based on the first PaO2 data and a variable offset; and providing the FiO2 data to the ventilator mechanism.

Abstract: The present invention relates to a method and a respiration device having a respiration unit for generating an airflow for the respiration and having a monitoring unit. The monitoring unit is used to detect a respiration parameter and to classify events in the respiration on the basis of monitoring of the respiration parameter. In this case, the monitoring unit is configured to carry out an event analysis to recognize an occurrence, which is characteristic for Cheyne-Stokes respiration, of chronologically successive events and for this purpose to ascertain the period length thereof and to compare them to one another and to register the presence of Cheyne-Stokes respiration when the compared period lengths each deviate by less than 40% from one another.

Abstract: An apparatus for monitoring a sleep parameter of a user includes an adhesive pad configured to conform to a surface of the user and a flexible element coupled to the adhesive pad. The flexible element includes a conductive fabric, and exhibits a modified electrical property in response to an applied force. The apparatus also includes a power source electrically coupled to the flexible element, and an electrical circuit electrically coupled to the power source and the flexible conductive element. The electrical circuit is configured to detect, during use, a change in an electrical property of the flexible element.

Abstract: A rapidly deployable, pressure sealed, cough and sneeze aerosol, containment apparatus and a system to virtually eradicate the cold, the flu, and Covid-19. A face mask having a rigid first section configured to hold a filter and a pliable second section configured to fit on a person's face; a face mask seal formed on an edge of the pliable second section of the face mask; a curved surface on the face mask seal configured to fold inward to form a seal on the person's face when pressed on the person's face.

Abstract: Various methods and systems are provided for controlling a supply of medical gas to a gas delivery system, such as an anesthesia machine, via a medical gas delivery module. In one example, a method includes supplying a medical gas from a pipeline gas supply source to a gas delivery system via a first conduit, measuring a quality of the medical gas in the first conduit, comparing the measured quality to an allowable range, switching to an alternative gas supply source for supplying the medical gas to the gas delivery system and communicating a pipeline gas supply fault in response to the measured quality being outside of the allowable range, and continuing supplying the medical gas to the gas delivery system from the pipeline gas supply source in response to the measured quality being inside of the allowable range.

Abstract: Ventilator enables operator to enter into the microprocessor estimate of a patient's individual characteristic, such as weight, which the microprocessor uses to control delivered tidal volume and other parameters to match the patient. The operator can select one of several ventilator operational modes (intube, mask, CPR). Sensors input data to the microprocessor to maintain parameter optimizations and accuracy. Visual/audible alarms and tools activate when one or more parameters exceed or fail to exceed predetermined values for patient's weight. Manual over-ride is available. The ventilator has a quick start capability in which the operator turns on power, selects the automatic operating mode, enters patient's characteristic, selects control option starting automatic ventilation of proper volumes inhalation/exhalation periods, pressure, and oxy-air mixture.

Abstract: A respiratory therapy system for providing continuous positive air pressure (CPAP) to a patient may include a flow generator for generating a supply of breathable gas, a sensor to measure a physical quantity while the breathable gas is supplied, and a computing device. The computing device may be configured to: receive sensor data that is based on measured physical property of the supply of breathable gas; control the flow generator to adjust a property of the supply of breathable gas; display a question and a plurality of selectable responses; receive a first input selecting one of the selectable responses; and display a coaching response corresponding to the selected response.

Abstract: Systems and methods for operating a controlled device via an activation accessory that includes a vibration motor, a wearable module including a clench-detection sensor (e.g., a Hal effect sensor), and a communication element. The sensor is coupled to a controller, which has an output coupled to a control signal interface and another output coupled to the vibration motor. The controller is programmed to receive and evaluate input signals from the sensor to determine whether or not they represent a command for the controlled device by assessing the input signals for a signal pattern indicative of a plurality of volitional jaw clench actions of a wearer of the wearable module. If/when the processor determines that the input signals represent the command, then it decodes the command and transmits an associated control signal to the controlled device via the control signal interface as well as an activation signal to the vibration motor.

Abstract: A method of managing a medical suction device through a network may be embodied by the management server through the steps of: storing operation information of at least one medical suction device in a storage unit provided in the management server, generating an operation start determination reference value of the medical suction device based on the operation information, receiving information on conditions of a patient from a medical suction device installed at an outside, and determining whether to start an operation of the medical suction device that has transmitted the information on conditions of the patient based on the operation start determination reference value and the information on conditions of the patient.

Abstract: A method of manufacturing a patient interface for sealed delivery of a flow of air at a continuously positive pressure with respect to ambient air pressure to an entrance to the patient's airways includes collecting anthropometric data of a patient's face. Anticipated considerations are identified from the collected anthropometric data during use of the patient interface. The collected anthropometric data is processed to provide a transformed data set based on the anticipated considerations, the transformed data set corresponding to at least one customised patient interface component. At least one patient interface component is modeled based on the transformed data set.

Abstract: A respiratory therapy device, which may include a flow generator, is provided. The RPT device includes a touch screen display that displays user interface screens to a user and accepts input from users to control parameters and functionality of the RPT device (e.g., a flow generator).

Abstract: A method of characterizing a patient's disordered breathing during a sleeping period includes performing a first partial characterization of a time axis of an audio signal in order to learn the most prominent and highly relevant events. Only at a later stage, i.e., after sufficient observation of the highly relevant events, is a full segmentation of the entire time axis actually carried out. Linear prediction is used to create an excitation signal that is employed to provide better segmentation than would be possible using the original audio signal alone. Warped linear prediction or Laguerre linear prediction is employed to create an accurate spectral representation with flexibility in the details provided in different frequency ranges. A resonance probability function is generated to further characterize the signals in order to identify disordered breathing. An output includes a characterization in any of a variety of forms of identified disordered breathing.

Abstract: This disclosure describes systems and methods for providing novel adaptive base flow scheduling during ventilation of a patient to optimize the accuracy of estimated exhaled tidal volume. Further, this disclosure describes systems and methods for providing novel adaptive inspiratory trigger threshold scheduling during the novel adaptive base flow scheduling.

Abstract: A method controls a device for extracorporeal blood gas exchange. The device has a membrane as a gas-liquid barrier between a bloodstream and a gas stream. The membrane further makes possible a passing over of the carbon dioxide content from the bloodstream into the gas stream. The device has at least one actuator. A change in a value of an operating parameter of the actuator brings about a change in a value of the carbon dioxide content that passes over from the bloodstream into the gas stream. The method further includes providing breathing gas information that indicates a carbon dioxide concentration in breathing gas and providing a control signal, which indicates a request for setting a value of the operating parameter and changing of the value of the operating parameter as a function of the carbon dioxide concentration in the breathing gas.

Abstract: Systems and methods for novel ventilation that allows the patient to trigger or initiate the delivery of a breath are provided. Further, systems and methods for triggering ventilation based on signal distortion of a monitored patient parameter are provided.

Abstract: A method of controlling a medical device is disclosed for delivering respiratory therapy to a user to treat sleep-disordered breathing, for instance obstructive sleep apnea, Cheyne-Stokes respiration etc. by estimating the user's CO2 percentage or concentration from a dynamic lung model driven by an observed respiration signal. The estimated user's CO2 percentage or concentration can be used to predict breathing events, such as hypopnea and apnea. The predictive capacity can be used for adjusting the respiratory therapy as required or for applying a ramp cycle therapy, in an attempt to reduce the prevalence and adverse effects of the breathing events. In other examples a variable ventilation therapy is provided in which pressure is supplied between first and second pressures, with the pressure being increased over more than one breath, and then dropped relatively rapidly, for example during expiration of a single breath.

Abstract: The present disclosure describes a pressure support therapy device valve that enables a subject to safely supplement therapy pressure support with low flow oxygen while using a heated (or non-heated) tube. The valve conducts a pressurized flow of breathable gas and the low flow oxygen to the heated tube. The valve includes electrical components configured to pass power from the pressure support therapy device to the heated tube, and a plunger biased to close a flow path from the pressure support therapy device when a pressurized flow of breathable gas is not provided (or is below a predetermined pressure threshold). Closing the flow path stops oxygen gas from flowing back through the valve toward the pressurized gas source.

Abstract: A method of estimating a parameter indicative of respiratory flow of a patient being administered flow therapy, comprising: optionally administering a gas at a flow rate to the patient using a flow therapy apparatus with a patient interface, determining a terminal pressure in, at or proximate the outlet of the patient interface or in, at or proximate the nares of the patient, determining nasal RTF, determining a nasal flow parameter being or indicative of nasal flow based on the pressure and a nasal RTF, and optionally outputting the nasal flow parameter or parameter derived therefrom.

Abstract: Respiratory assistance device suitable for Auto CPAP respiratory therapy. The respiratory assistance device includes: a blower device including a blower configured to generate pressurized air; an operation device including an operation interface configured to control the blower; a wireless or wired communication arrangement configured to connect the blower device and the operation device; an attachment part configured to be attached to a head of a patient so as to supply the pressurized air to an airway of the patient; and an air tube through which the pressurized air is introduced into the attachment part from the blower device. The blower device is accommodated in a blower device casing, and the operation device is accommodated in an operation device casing separate from the blower device casing.

Abstract: Described herein are various embodiments of an oxygen concentrator system and method of delivering oxygen enriched gas to a user. In some embodiments, oxygen concentrator system includes one or more components that improve the efficiency of oxygen enriched gas delivery during operation of the oxygen concentrator system. In some embodiments, time measurements based on the penultimate breath taken by the user are used to alter the oxygen delivery parameters.

Abstract: The device of the invention is equipped with a pressure sensor and a control unit, and the control unit judges a point at which a pressure gradient calculated from a signal of the pressure sensor becomes larger in the absolute value than a pressure gradient threshold as an inspiration sensing point and starts respiratory gas supply. In addition, the device judges from a frequency of the inspiration sensing point during predetermined time whether a pressure gradient threshold used as a criterion for the inspiration sensing point corresponds to an activity state of the user, and when the pressure gradient threshold does not correspond to the activity state, switches the pressure gradient threshold to another threshold and thus fits the pressure gradient threshold to the activity state.

Abstract: Disclosed is an apparatus for treating a respiratory disorder in a patient. The apparatus comprises a pressure generator configured to deliver a flow of air at positive pressure to an airway of the patient through a patient interface, a sensor configured to generate a signal representative of respiratory flow rate of the patient, and a controller.

Abstract: A breathing device comprises a respiratory gas source for generating a gas pressure for a patient, delivered by a respiratory mask, a measuring unit for measuring a measurement quantity characteristic of inhalation or exhalation, and a control unit which determines the patient's tidal volume from the measurement quantity and compares this with a setpoint value of the tidal volume. The control unit regulates the respiratory gas source such that the generated gas pressure is made available until the setpoint value of the tidal volume is reached. In addition, further regulation of a parameter characteristic of the patient's breathing is carried out. The method for controlling a respiratory gas source with a control unit for a patient's breathing comprises regulation of the patient's tidal volume by providing and applying inspiratory pressure and simultaneous regulation of a further breathing parameter.

Abstract: Several methods of supporting respiratory function of a patient before, during and/or after a medical procedure are disclosed. In certain arrangements, supporting respiratory function while a patient is under general anaesthesia can include providing a high gas flow that is greater than 15 L/min while the patient is under general anaesthesia. In certain arrangements, a method of providing ventilation while a patient is under general anaesthesia involves providing only a gas flow delivered through a nasal interface that is greater than 15 L/min while the patient is under general anaesthesia.

Abstract: A mechanical ventilator (10) is controlled by an electronic processor (14) to provide respiratory support to a patient (12) using a pressure controlled ventilation mode while being monitored by an airway pressure sensor (30) and an airway flow sensor (32). The electronic processor also controls the ventilator to perform a respiratory system measurement process (44) including: controlling the ventilator to provide a pressure controlled breath at a preset pressure (Ppreset) over an extended inspiratory breath interval that is extended by an extension time interval (TIE) beyond end of physiological inspiration; controlling an exhalation valve (40) at least during the extension time interval to maintain airway pressure at the preset pressure (Ppreset). Lung compliance or elastance is determined from airway pressure measurements and airway flow measurements acquired during the extended inspiratory breath interval.

Abstract: The disclosed device serves for artificial respiration and has a blower connected to a control. The blower is held by a supporting part, which assumes the task of decoupling and other functions. The blower and the supporting part are arranged in a blower box. Both the control and the blower box are arranged in a housing. The control is connected to at least one indicating device and also to at least one operating element.

Abstract: Various embodiments are described herein for devices, methods and systems for a breathing assistance device controller for controlling the operation of a breathing assistance device that provides breathing assistance to a user. The controller may include sensors for measuring airflow parameters of the airflow and generating measured signals; and a processor that is electronically coupled to the sensors to receive the measured signals and to generate a control signal based on the measured signals and at least one characteristic of the user's respiratory system to adjust the operation of the breathing assistance device during use.

Abstract: An apparatus for oxygenation and/or CO2 clearance of a patient. The apparatus comprising: a flow source or a connection for a flow source for providing a gas flow, a gas flow modulator, a controller to control the gas flow. The controller is operable to: receive input relating to heart activity and/or trachea gas flow of the patient, and control the gas flow modulator to provide a varying gas flow with at least two oscillating components. One oscillating component has a frequency based on the heart activity and/or trachea flow of the patient. One oscillating component has a frequency to: promote bulk gas flow movement, or promote mixing.

Abstract: The invention relates to a respiratory assistance apparatus for delivering a respiratory gas, such as air, to a patient during cardiopulmonary resuscitation (CPR), having a source (1) of respiratory gas, means (4) for measuring the CO2 content, and signal-processing and control means (5). The signal-processing and control means (5) are configured to process the CO2 content measurement signals corresponding to measurements performed by the CO2 content measurement means (4) during a given period of time (dt), and to calculate at least one mean CO2 content value (Vmean) from the maximum CO2 content values (Vmax) obtained over the time window (Ft), and to transmit said at least one mean CO2 content value (Vmean) to the graphical user interface (7) which displays it.

Abstract: A patient ventilator system includes a patient delivery circuit having an inspiratory section that delivers an inspiratory gas flow to a patient and an expiratory section that receives expiratory gas flow from the patient, wherein a bidirectional blower motor drives the inspiratory gas flow in the inspiratory section and controls the expiratory gas flow in the expiratory section. A flow sensor measures gas flow rate between the bidirectional blower motor and the patient delivery circuit. A four quadrant controller is configured to control speed and direction of the bi-directional blower motor based on the measured flow rate so as to effectuate ventilation for the patient.

Abstract: The present invention relates to an integrated sleep diagnosis and treatment device, and more particularly to an integrated apnea diagnosis and treatment device. The present invention additionally relates to method of sleep diagnosis and treatment.

Abstract: Embodiments of the present invention provide reliable, convenient, and cost-effective methods and apparatuses to determine the hemodynamic status of the patent. The methods and apparatuses provide for the noninvasive determine of hemodynamic status by using systematic perturbations of venous return or trend observation over time. Embodiments do not require invasive pressure monitoring or the use of ventilator but instead can be an entirely noninvasive system.

Abstract: A pressure support device for providing pressure support therapy to a patient includes an airflow generator structured to generate pressure to provide pressure compensation to the patient via a patient circuit, one or more sensors structured to gather data related to effectiveness of the pressure compensation, and a processing unit structured to analyze outputs of the sensors while pressure support therapy is provided to the patient to determine if the pressure compensation provided to the patient is improper and to initiate action to confirm whether components of the patient circuit have been changed in response to determining that the pressure compensation provided to the patient is improper.