Abstract: A diaper change alert system, method, and computer-readable medium a diaper with wetness detection circuit installed inside a seat portion of the diaper, an ionic composition sensor installed inside the seat portion of the diaper, a humidity sensor installed inside the seat portion of the diaper, processing circuitry. The processing circuitry is configured to compute number of waste cycles per diaper change based on a signal received from the wetness detection circuit, compute a total time per diaper change based on a signal received from the wetness detection circuit, compute a rash threshold using rash information, receive sensor data, determine whether the rash threshold is reached, and transmit, via a network, a diaper change alert to an external device.

Abstract: A secondary line purging system (40) having a blower (22) for pressurizing a flow of gas and a first pressure sensor (28) for measuring a first pressure of the flow of gas at or near the blower. The system also includes a secondary line (36) communicating with the blower and a subject circuit (32). The system further includes a second pressure sensor (30) for measuring a second pressure of the flow of gas within the secondary line. A valve system (42) is operable in 1) a first mode of operation to isolate the blower from the secondary line and 2) a second mode of operation to permit communication between the blower to the secondary line to purge the secondary line of obstructions with the pressurized flow of gas. A controller (16) switches operation of the valve system between the first mode of operation and the second mode of operation, based on the first pressure and the second pressure.

Abstract: A system includes an apparatus and a controller, according to an embodiment. The apparatus is configured to maintain an airway of a subject open while the subject is sleeping by applying to the airway a pressure having a magnitude, and the controller is configured to cause the apparatus to change the magnitude of the pressure over a period that begins at a settable start time. For example, the system can be configured to treat a subject's sleep apnea with positive or negative pressure, and to function as an alarm clock by beginning to change the pressure magnitude at a settable start time, and to continue changing the pressure over a period with a settable duration (or settable stop time) to gently awaken the subject by the end of the period.

Abstract: A breathing apparatus (1) is disclosed that is adapted to determine a transpulmonary pressure in a patient (125) when connected to said breathing apparatus. A control unit (105) is operable to set a first mode of operation for ventilating said patient with a first Positive End Expiratory Pressure (PEEP) level; set a second mode of operation for ventilating said patient with a second PEEP level starting from said first PEEP level; and determine said transpulmonary pressure (Ptp) based on a change in end-expiratory lung volume (?EELV) and a difference between said first PEEP level and said second PEEP level (?PEEP). Furthermore, a method and computer program are disclosed.

Abstract: A breath pacing apparatus and a method for pacing a respiration of a person include a haptic output unit with a variable haptically perceivable feature. The haptic output unit is configured to change the haptically perceivable feature periodically according to a sequence of desired respiration cycles, where a characteristic of the change of the haptically perceivable feature is related to a length of the respiration cycles in the sequence of desired respiration cycles.

Abstract: A process for operating a respirator and/or an anesthesia device with measurement of a set percent Peak Expiratory Flow (% PEF) (15) or percent Peak Inspiratory Flow (% PIF) and regulation of the measured % PEF (15) or % PIF to the set % PEF (15) or % PIF. Furthermore, a suitable respirator and/or anesthesia device are provided.

Abstract: Apparatus and a method for the provision of topical negative pressure therapy to a wound site are described, the apparatus comprising: vacuum generating means for generating a negative pressure at said wound site said vacuum generating means being operably connected to a dressing at said wound site by aspiration conduit means; pressure sensing conduit means in fluid communication with said aspiration conduit means at a junction adjacent said dressing; first pressure sensing means between said junction and said vacuum generating means; second pressure sensing means operably associated with said pressure sensing conduit means; diagnostic means in communication with said first and second pressure sensing means; and control means in communication with said diagnostic means for controlling pressure in said aspiration and said pressure sensing conduit means.

Abstract: The present invention relates to a method for the ventilation of a living being (3), the respiration airflow (v) flowing into the living being (3) and out of the living being (3) being detected, it being ascertained from the detected respiration airflow (v) whether an inhalation phase or an exhalation phase is present, and the air pressure (p) in a respiratory organ of the living being (3) being regulated, characterized in that, upon recognition of an inhalation phase, the air pressure (p) in the respiratory organ is raised at the beginning of the inhalation phase and lowered again with progressing respiration cycle.

Abstract: A bi-level pressure support system and method of treating disordered breathing that optimizes the pressure delivered to the patient during inspiration and expiration to treat the disordered breathing while minimizing the delivered pressure for patient comfort. The pressure generating system generates a flow of breathing gas at an inspiratory positive airway pressure (IPAP) during inspiration and at an expiratory positive airway pressure (EPAP) during expirations. A controller monitor at least one of the following conditions: (1) snoring, (2) apneas, (3) hypopneas, or (4) a big leak in the pressure support system and adjusts the IPAP and the EPAP based on the occurrence of any one of these conditions.

Abstract: An initial signature may be generated from an initial set of biometric data. A subsequent set of biometric data may be received along with diagnostic data, and a subsequent signature may be generated from the subsequent set of biometric data. The initial signature and the subsequent signature maybe compared to determine if there is an acceptable degree of matching between the signatures. If the signatures match, such as for example within a threshold percentage, the second set of biometric data is determined to be from the same a subject as the initial set of biometric data, and the diagnostic data is processed for that subject. If the signatures do not match, the initial and subsequent sets of biometric data are determined to be from different people and the diagnostic data is not processed.

Abstract: The invention relates to a device, with which one is to prevent a patient who breathes on Ms own and who desires a lower CO2-partial-pressure than is achieved by the set Ventilation from tiring. It comprises the following means for the regulation of a changing intensity of a mechanical Ventilation: • means for determining a target frequency RRsp, • means for determining a spontaneous frequency RRspont • means for comparing the spontaneous frequency RRspont with the target frequency RRsp. wherein adapting a Ventilation target value (% MinVol, V?gAsp) on account of the result of the comparison of the spontaneous frequency RRspont with the target frequency RRsp and • means for adapting the parameters determining the intensity of the Ventilation, on account of the Ventilation target value (% MinVol, V?gAsp). This so-called pump support System (PSS) is activated (PSS on) when the patient breathes in an adequately spontaneous manner (Criterion 1).

Abstract: Described are methods and devices for therapeutic or medical gas delivery that utilize at least one proportional control valve and at least one binary control valve. The proportional control valve may be in series with the binary control valve to provide a valve combination capable of pulsing therapeutic gas at different flow rates, depending on the setting of the proportional control valve. Alternatively, the proportional control valve and binary control valve may be in parallel flow paths.

Abstract: The present invention is related to a device and method for improvement of sleep testing and sleep therapy using acoustic data to examine various aspects of a subject's sleep quality. More particularly, the method and device of the present invention includes the use of an acoustic actuator and an acoustic sensor to acoustically monitor the state of a subject's airway during sleep in order to determine airway obstructions and their locations as they relate to, among other variables, a subject's sleep stage, body position and sleep quality.

Abstract: A controlling device (110) is configured for controlling a state of an alarm limit of an alarm device (108). The alarm device (108) is configured for generating an alarm signal in association with a monitored physiological parameter of a patient. The alarm limit triggers the generation of the alarm signal. In order to automatically control the state of the alarm limit, the controlling device (110) comprises a receiving unit (146) configured for receiving information indicating an administration of a treatment to the patient, a determining unit (148) configured for determining whether the treatment is administered to the patient based on the received information, and a controlling unit (150) configured for controlling the state of the alarm limit based on a result of the determination of the determining unit (148).

Abstract: A method and system for detecting an ineffective effort of a patient being mechanically ventilated by a ventilator comprises (i) monitoring a respiratory flow of air of the patient after said ventilator has cycled; (ii) creating a signal indicative of said flow; (iii) removing artifact from said signal; (iv) monitoring said signal for perturbations; and (v) determining that an ineffective effort has occurred when said perturbation is significant.

Abstract: Automatically adjusting the trigger sensitivity of a respiratory therapy system includes detecting errors that indicate the trigger sensitivity should be increased, as well as detecting errors that indicate the trigger sensitivity should be reduced. Error detection may be based on the determined muscle pressure of a subject during an inhalation, an attempted inhalation, and/or a suspected attempt of an inhalation.

Abstract: Methods and apparatus are disclosed for determining the occurrence of a closed or open apnea. Respiratory air flow from a patient is measured to give an air flow signal. The determination of an apnea is performed by applying an oscillatory pressure waveform of known frequency to a patient's airway, calculating a complex quantity representing a patient admittance (12) and comparing its value with ranges (14,16) indicative of open or closed apneas. The method distinguishes open from closed apneas even when the model used to calculate admittance is not based on details of the respiratory apparatus. In addition the patient admittance may be compared with admittance during normal breathing to avoid having to characterize the airway.

Abstract: Disclosed are advances in the arts with novel methods and apparatus for detecting faulty connections in an electrical system. Exemplary preferred embodiments include basic, ASIC, AC, DC, and RF monitoring techniques and systems for monitoring signals at one or more device loads and analyzing the monitored signals for determining fault conditions at the device loads and/or at the main transmission lines. The invention preferably provides the capability to test and monitor electrical interconnections without fully activating the host system.

Abstract: The present technology relates to methods and apparatus to provide ventilation to patients. In particular, the present technology relates to changing ventilator parameters to match changing patient metabolic demand.

Abstract: In certain example embodiments, a system and/or method of guiding transitions between therapy modes in connection with the treatment and/or diagnosis of a patient for a respiratory disorder is/are provided. Respiratory disorder treatment according to a first therapy mode is provided. Input indicating a second therapy mode to be transitioned to following provision of the first therapy mode is received, with the second therapy mode being different from the first therapy mode. At least one default treatment parameter suitable for the second therapy mode is assigned or calculated. Each default treatment parameter of the second therapy mode is presented, with each default treatment parameter being adjustable by an operator during the presenting. Transitioning from the first therapy mode to the second therapy mode is performed by providing respiratory disorder treatment in accordance with the second therapy mode and each default treatment parameter and any adjustments made thereto prior to the transitioning.

Abstract: A substrate processing apparatus includes a substrate processing apparatus, including: a substrate processing chamber configured to accommodate a substrate and process the substrate; a piping coupled to the substrate processing chamber to allow a gas for processing the substrate to be introduced therethrough; and a simulation apparatus configured to simulate a path in which the gas for processing the substrate flows through the piping. The simulation apparatus includes: an information acquisition unit configured to acquire gas flow information defined by an operation mode in which the substrate is processed; a path determination unit configured to determine a gas path based on the gas flow information acquired by the information acquisition unit; and a simulation unit configured to simulate a flow of the gas by putting a color defined according to the type of gas on the gas path determined by the path determination unit.

Abstract: An ultrasound probe (3) of an ultrasound diagnostic apparatus (1) includes an acceleration sensor (5) provided for outputting acceleration information for use in obtaining an angle of the ultrasound probe at the time of diagnosing a subject. The acceleration information is converted into angle information of the ultrasound probe by an angle conversion section (11). The ultrasound diagnostic apparatus (1) includes a monitor (4) for displaying a diagnosing image of the subject obtained with the ultrasound probe (3), and a body mark (16) corresponding to the diagnostic mode selected at the time of diagnosing and a probe icon (15) placed at an angle corresponding to the angle information with respect to the body mark (16) are displayed on the monitor (4). This makes it possible to provide an ultrasound diagnostic apparatus which can display an angle of the ultrasound probe at the time of diagnosing the subject.

Abstract: A sensor for measuring a respiration is disclosed herein. The sensor includes at least one housing (7) having a first cavity (12) with a first port (11) allowing a respiration gas flow, and a second cavity (22) with a second port (21) also allowing a respiration gas flow. The sensor also includes at least one breathing detector (51) for acquiring a signal indicative of the respiration gas flowing through the first cavity and the second cavity. The at least one housing is equipped with at least one additional port (31) for removing the respiration gas flow coming from the first cavity and the second cavity, which additional port being separate from the first port and the second port.

Abstract: A monitoring device configured to monitor whether a look of a target person is in a proper state suitable for a working environment, and comprising: an image input unit configured to input an image of the target person; a detector configured to analyze the image input by the image input unit and detect a predetermined region of a human body of the target person; a state estimator configured to estimate a state of the predetermined region detected by the detector; a proper state acquisition unit configured to acquire proper state information on a proper state of the predetermined region according to the working environment; and a controller configured to determine whether a present state of the predetermined region of the target person is proper by comparing an estimation result of the state estimator to the proper state information, and perform control according to a determination result.

Abstract: In a method for positioning linear array of electrodes (LAE) mounted on distal end section of elongated flexible member in patient's respiratory airways (PRA) at level of diaphragm, a length of the member pre-determined to position LEA at the level of the diaphragm is inserted through PRA. Signals representative of an electrical activity of the diaphragm (EAdi) are detected through LAE, presence/absence of ECG signal components is detected in EAdi signals, and position of LAE in PRA is detected in response to presence/absence of ECG signal components in EAdi signals. Lower esophageal sphincter activity may be detected in EAdi signals, and position of LAE in PRA determined in response to the detected lower esophageal sphincter. End-expiratory occlusion of PRA may be performed to verify that the electrical activity of the diaphragm coincides with a negative deflection of PRA pressure again in view of determining adequate positioning of LAE.

Abstract: An apparatus and method for resuscitating a patient suffering from cardiac arrest or another condition in which normal circulation has been interrupted. A ventilator is used for delivering a gas mixture to the patient. The ventilator is configured to adjust the partial pressure of CO2 to one or more partial pressures high enough to slow expiration of CO2 from the patient's lungs and thereby maintain a reduced pH in the patient's tissues for a period of time following return of spontaneous circulation.

Abstract: A respiratory assistance device is disclosed. There is a variable speed blower with an output, and a patient ventilation interface configured for fitment on a patient respiratory passageway. A gas passage conduit couples the output of the blower to the patient ventilation interface. A pilot line from the gas passage conduit is coupled to a piloted exhalation valve of the patient ventilation interface. A pressure sensor measures a mask pressure in the patient ventilation interface, and a blower speed sensor measures a speed of the blower. A pressure controller in communication with the pressure sensor and the blower speed sensor detects a patient inspiratory phase and a patient expiratory phase from at least one of the measured speed of the blower and a set speed of the blower. The pressure controller adjusts an operating speed of the blower and actuates the piloted exhalation valve based upon the measured mask pressure.

Abstract: To provide a breath pacing system and a corresponding method for pacing the respiratory activity of a subject that provide the possibility to adapt the output signal to the respiration characteristics of the subject automatically and effectively a breath pacing system (10) for pacing the respiratory activity of a subject and a respective method is proposed, comprising: an input unit (14) for generating or determining an input signal related to a respiration characteristic of a subject, a signal analyzing unit (16) provided to recognize a signal pattern within the input signal, and an output unit (12) for outputting output signals corresponding to a desired breathing sequence, wherein said output unit (12) is provided to be activated, upon a starting signal, to output a sequence of output signals comprising a signal pattern related to a previously recognized signal pattern.

Abstract: A ventilator including an inspiration flow control unit and an expiration flow control unit coupled to the inspiration flow control unit. The ventilator also includes a nasal intermittent mandatory ventilation (NIMV) control system coupled to the inspiration flow control unit and the expiration flow control unit. The NIMV control system is configured to automatically and simultaneously adjust an inspiration flow and an expiration flow. A pressure of the inspiration flow is increased from a baseline pressure to a control pressure. A pressure of the expiration flow is returned to the baseline pressure.

Abstract: A method for administering a gas containing oxygen to a patient. The method includes: measuring an oxygen-dependent physiological parameter in the patient; determining an optimal gas delivery parameter based on the oxygen-dependent physiological parameter; and administering the gas to the patient in accordance with the optimal gas delivery parameter. In some embodiment of the invention, the method also includes monitoring the oxygen-dependent physiological parameter.

Abstract: A respiratory flow limitation detection device, which can include an airway pressure treatment generator, determines a flow limitation measure (506) based one or more shape indices for detecting partial obstruction and a measure of a patient's ventilation or respiratory duty cycle. The shape indices may be based on function(s) that ascertain the likelihood of the presence of M-shaped breathing patterns and/or chair-shaped breathing patterns. The measure of ventilation may be based on analysis of current and prior tidal volumes to detect a less than normal patient ventilation. The duty cycle measure may be a ratio of current and prior measures of inspiratory time to respiratory cycle time to detect an increase in the patient's inspiratory cycle time relative to the respiratory cycle time. A pressure setting based on the flow limitation may then be used to adjust the treatment pressure to ameliorate the patient's detected flow limitation condition.

Abstract: A system and method for operating a ventilator to compensate for external gas flow reaching a patient from an external device, such as a nebulizer. A control unit of the ventilator monitors the gas flow rate from the ventilator and compares the gas flow rate from the ventilator to an expired gas flow rate from the patient. The difference between the inspired flow rate and the expired flow rate is due to the external device. The control unit modifies the operation of the ventilator to compensate for the external gas flow rate such that the flow of gas reaching the patient is maintained at a desired level.

Abstract: Described are methods and systems for delivering a pharmaceutical gas to a patient. The methods and systems provide varying quantities of pharmaceutical gas delivered to the patient in two or more breaths based on the monitored respiratory rate or changes in the patient's respiratory rate.

Abstract: A breathing apparatus has an expiratory flow sensor unit, an expiratory pressure sensor unit, an expiratory pressure regulator, and an expiratory control unit operatively connected to the expiratory pressure sensor unit for a feedback control of an expiratory pressure during an expiratory phase of a breathing cycle. The expiratory control unit is adapted to provide a real time target pressure value during the expiratory phase to the expiratory pressure regulator for adjusting a desired positive end expiratory pressure (PEEP) level (PEEPset) based on an inspiratory tidal volume of an inspiratory phase of the same breathing cycle and a currently accumulated expiratory tidal volume measured by the expiratory flow sensor unit. In this manner advantageous regulation of PEEP with minimized work of breathing is obtained.

Abstract: The invention relates to a device (7) for collecting particles and microorganisms present in ambient air, the device comprising a cyclone enclosure (8) for centrifuging air, the enclosure being of conical or frustoconical shape, external air inlet means (16) for admitting air into the enclosure (8), and air outlet means connected by coupling means (19, 20, 21) to air inlet filter means (4) of an individual motorized respiratory protection appliance (A).

Abstract: Headgear for use with a respiratory mask is described. The headgear comprises a continuous and substantially curved elongate member extending in use below a user's nose and at least two headgear straps capable of attachment to the ends of the elongate member. A mask attachment on the elongate member is disposed to sit below or on one of said user's nose, mouth, upper lip and an inlet to the mask. The attachment is capable of receiving the mask.

Abstract: The present invention describes systems and methods to provide variable flow oxygen therapy. An exemplary embodiment of the present invention provides a method of oxygen therapy involving delivering oxygen-enriched gas to a patient during a first portion of a breathing cycle at a first flow rate. Furthermore, the method of oxygen therapy involves delivering oxygen-enriched gas to the patient during a second portion of the breathing cycle at a second flow rate, where the second flow rate is greater than zero and less than the first flow rate.

Abstract: A pressurized flow of breathable gas is delivered to the airway of a subject in accordance with a therapy regime. Responsive to the subject resuming respiration after a respiratory event, delivery of the pressurized flow of breathable gas is resumed at an inhalation in the therapy regime. As such, the therapy regime is effectively re-synchronized with the respiration of the subject subsequent to a respiratory event.

Abstract: Described is a system including an air pressure supply arrangement, a sensor and a titration device. The air pressure supply arrangement provides air pressure to a patient's airways. The sensor detects input data corresponding to a patient's breathing patterns of a plurality of breaths. The titration device receives and analyzes the input data to determine existence of breathing disorder and corresponding characteristics. The titration device generates output data for adjusting the air pressure supplied to the patient as a function of an index of abnormal respiratory events included in the input data.

Abstract: A method of controlling bolus delivery in a pulse flow oxygen concentration system for a patient includes providing a pulse flow oxygen concentration system that delivers concentrated oxygen gas to the patient in boluses having a pulse bolus duration, the pulse flow oxygen concentration system including an open control for controlling the pulse bolus duration of the boluses; determining one or more respiratory conditions of the patient; and adjusting the open control to adjust the pulse bolus duration of the boluses in accordance with the determined one or more respiratory conditions of the patient.

Abstract: A system for diagnosis and treatment of breathing disorders in a patient, comprises a flow generator supplying an air flow to an airway of a patient via a flow path, a venting arrangement moveable between (i) a closed position in which the flow path is substantially sealed between the flow generator and the patient's airway and (ii) an open position in which the flow path is open to an ambient atmosphere, a sensor detecting data corresponding to flow through the patient's airway, and a processing arrangement controlling operation of the venting arrangement and the flow generator, wherein, in a diagnostic mode, the processing arrangement maintains the venting arrangement in the open position and in a therapeutic mode, the processing arrangement maintains the venting arrangement in the closed position and controls the flow generator to supply to the patient's airway via the flow path a calculated therapeutic pressure.

Abstract: A method of operating a ventilator or pressure support system that automatically determines a timed back up rate for the patient based on the patient's spontaneous breathing patterns. The aggressiveness of the determined rate increases as the patient takes less spontaneous breaths. Also, a method wherein one or more mechanisms are used to determine whether a machine breath should be issued. Each mechanism consists of a basic timing element coupled with one or more logical permits. Both the timing element and each of the one or more logical permits must be satisfied to allow the timing mechanism to trigger a machine breath.

Abstract: An apparatus for improving patient comfort during CPAP therapy includes a venting arrangement arranged to reduce expiratory pressure. A mask system for providing CPAP therapy to a patient includes a mask; a flow generator to provide a flow of pressurized breathable gas; a tube to connect the mask to the flow generator; and a venting arrangement arranged to reduce expiratory pressure.

Abstract: A process for automatic control of a respirator changes between two phases of respiration by checking a detected respiratory breathing activity signal for a threshold criterion. If the threshold criterion is met, a changeover is made.

Abstract: A system for controlling the delivery of medical gases includes a digital signal processor that receives at least one ventilation parameter value change, calculates a fresh oxygen flow rate, total fresh gas flow rate into the breathing circuit, and a reference oxygen flow rate representative of a predetermined oxygen concentration delivered to a patient. A graphical display presents the calculated fresh oxygen flow rate, total fresh gas flow rate, and reference oxygen flow rate. A method of controlling the delivery of medical gases to a patient includes calculating a total fresh gas flow rate into the breathing circuit, calculating a fresh oxygen flow rate into the breathing circuit, calculating a reference oxygen flow rate representative of a predetermined oxygen concentration delivered to the patient and presenting the total fresh gas flow rate, the fresh oxygen flow rate, and reference oxygen flow rate on a graphical display.

Abstract: A combination spirometer and PEP breathing exercise device is described. The device includes a spirometer with a volumetric air chamber having an atmospheric opening, an exhaust port, and an indicator of inhalation rate or volume; a breathing tube having a proximal end in communication with the exhaust port, a distal end with a mouthpiece, and a conduit between the proximal and distal ends; a one-way check valve adjacent the exhaust port allowing air to flow from the spirometer through the breathing tube to the mouthpiece, but preventing air from being exhausted through the spirometer; and a PEP valve in communication with the breathing conduit, whereby expiration of air from the mouthpiece into the breathing tube above a preset pressure causes the valve to oscillate.

Abstract: A ventilator intended to be connected to a patient for breathing therapy has a control unit having an input for receiving EMG signals from an EMG detector and an output for an EMG based control signal and a pneumatic unit for generating breathing gas flows dependent on the EMG based control signal is described. The ventilator has a detector for determining a parameter related to breathing dynamics for the patient, this detector being connected to the control unit and control unit controlling the pneumatic unit dependent on the parameter related to breathing dynamics in the case of loss of EMG signals at the input.

Abstract: The invention relates to a device for implementing a system for detecting the observance by a patient of an oxygen-therapy treatment involving an oxygen supply, and for recording the data of said treatment and transmitting said data. The invention also relates to the use of said device, and to a method for tracking the observance of an oxygen-therapy treatment.

Abstract: A ventilating system for providing inspiratory air to and receiving expiratory air from a patient in a respiratory cycle. A ventilator has an inspiratory outlet for providing inspiratory air and an expiratory inlet for receiving expiratory air. A patient circuit in fluid communication with the lungs of the patient conveys inspiratory air during the inspiratory phase and expiratory air during the expiratory phase. A flow transducer in fluid communication with the patient circuit detects a minimum volume of expiratory air in the patient circuit during the expiratory phase. An elastic reservoir in fluid communication with the patient circuit and the flow transducer expands to a first volume during the inspiratory contracts to a second volume during the expiratory phase. The volume difference between the first volume and the second volume is at least equal to the minimum volume threshold.

Abstract: A pressure support system includes a pressure generator, a pressure sensor, a flow sensor, and a controller cooperating with the pressure sensor and the flow sensor to control operation of the pressure generator. The controller is structured to automatically identify a patient interface device in use with the pressure support system by detecting a change of exhaust flow of up to a predetermined amount across a predetermined pressure gradient of a pressure range of the pressure support system.