187 results about "Respiratory Airflow" patented technology

A method for controlling breathing gas flow of a ventilator for assisted or controlled ventilation of a patient as a function of a tracheobronchial airway pressure of the patient. A ventilator tube, such as a tracheal tube or tracheostomy tube, can be introduced into a trachea of the patient and subjected to the breathing gas, and has an inflatable cuff and at least one lumen that is continuous from a distal end of the tube to a proximal end of the tube. An apparatus detects an airway pressure, in which the tracheobronchial airway pressure is ascertained by continuous or intermittent detection and evaluation of an intra-cuff pressure prevailing in the cuff of the tube inserted into the trachea. The breathing gas flow of the ventilator is controlled as a function of the intra-cuff pressure detected.

CPAP treatment apparatus is disclosed having a controllable flow generator (34, 38, 40) operable to produce breathable gas at a treatment pressure elevated above atmosphere to a patient by a delivery tube (32) coupled to a mask (30) having connection with a patient's airway. A sensor (44, 50, 56, 58) generates a signal representative of patient respiratory flow, that is provided to a controller (54, 62, 64). The controller (54, 62, 64) is operable to determine the occurrence of an apnea from a reduction in respiratory airflow below a threshold, and if an apnea has occurred, to determine the duration of the apnea and to cause the flow generator (34, 38) to increase the treatment pressure. In one preferred form the increase in pressure is zero if the treatment pressure before the apnea exceeds a pressure threshold. Below the pressure threshold the increase in pressure is an increasing function of the duration of the apnea multiplied by the difference between the pressure threshold and the current treatment pressure.

A system is provided for delivering a flow of breathing gas to an airway of a patient. The system includes a pressurizing flow module that generates a pressurized flow of breathing gas and a patient circuit coupled to the pressurizing flow module configured to communicate the flow of breathing gas to an airway of a patient. The system includes a sensor for monitoring a characteristic of a breathing pattern of the patient a controller that communicates with the sensor configured to increase a fraction of inspired carbon dioxide if the characteristic exceeds an upper threshold value and to provide servo-ventilation if the characteristic is less than a lower threshold value. The upper threshold value and the lower threshold value are changed based on the monitored characteristic of the breathing pattern of the patient.

An improved ventilator which delivers ventilatory support that is synchronized with the phase of the patient's respiratory efforts and guarantees a targeted minimum ventilation. Improved synchronization is achieved through an instantaneous respiratory phase determination process based upon measured respiratory airflow as well as measured respiratory effort using an effort sensor accessory, preferably a suprasternal notch sensor. The ventilator processes a respiratory airflow signal, a respiratory effort signal and their respective rates of change to determine a phase using standard fuzzy logic methods. A calculated pressure amplitude is adjusted based upon the calculated phase and a smooth pressure waveform template to deliver synchronized ventilation.

An improved ventilator which delivers ventilatory support that is synchronized with the phase of the patients respiratory efforts and guarantees a targeted minimum ventilation. Improved synchronization is achieved through an instantaneous respiratory phase determination process based upon measured respiratory airflow as well as measured respiratory effort using an effort sensor accessory, preferably a suprasternal notch sensor. The ventilator processes a respiratory airflow signal, a respiratory effort signal and their respective rates of change to determine a phase using standard fuzzy logic methods. A calculated pressure amplitude is adjusted based upon the calculated phase and a smooth pressure waveform template to deliver synchronized ventilation.

Method and apparatus for the treatment of cardiac failure, Cheyne Stokes breathing or central sleep apnea are disclosed. A subject is provided with ventilatory support, for example positive pressure ventilatory support using a blower and mask. Respiratory airflow is determined. From the respiratory airflow are derived a measure of instantaneous ventilation (for example half the absolute value of the respiratory airflow) and a measure of longterm average ventilation (for example the instantaneous ventilation low pass filtered with a 100 second time constant). A target ventilation is taken as 95% of the longterm average ventilation. The instantaneous ventilation is fed as the input signal to a clipped integral controller, with the target ventilation as the reference signal. The output of the controller determines the degree of ventilatory support. Clipping is typically to between half and double the degree of support that would do all the respiratory work. A third measure of ventilation, for example instantaneous ventilation low pass filtered with a time constant of 5 seconds, is calculated. Ventilatory support is in phase with the subject's respiratory airflow to the fuzzy extent that this ventilation is above target, and at a preset rate conversely.

Provided is a configuration capable of executing a detection test for a comfort level including the quality of sleep, which is measurable at home without requiring the measurement of brain waves or electrocardiogram. The respiratory waveform of a subject during sleep is continuously measured and recorded from the respiratory gas flow, etc., and is window-Fourier transformed at each measurement time to generate a frequency spectrum, and a bandwidth including a respiratory frequency is extracted. The index indicating the regularity of the respiratory period of the subject is also calculated at each time point during the sleep, and the time-dependency of this index during the sleep is represented as a graph. A medical device includes a sleep evaluation system equipped with a control means for performing control so that a sleep cycle repeated at a cycle of about 90 minutes is clearly observed if the comfort level including the quality of sleep of the subject is favorable.

The invention prevents dynamic airway compression during ventilatory support of a patient. The respiratory airflow is determined by measurement or calculation, and a measure of the degree of dynamic airway compression is derived from the determined airflow. This measure is servo-controlled to be zero by increasing expiratory pressure if the measure of the degree of dynamic airway compression is large or increasing, and by reducing expiratory pressure if the measure of the degree of dynamic airway compression is small or zero.

Method and apparatus for the treatment of cardiac failure, Cheyne Stokes breathing or central sleep apnea are disclosed. A subject is provided with ventilatory support, for example positive pressure ventilatory support using a blower and mask. Respiratory airflow is determined. From the respiratory airflow are derived a measure of instantaneous ventilation (for example half the absolute value of the respiratory airflow) and a measure of longterm average ventilation (for example the instantaneous ventilation low pass filtered with a 100 second time constant). A target ventilation is taken as 95% of the longterm average ventilation. The instantaneous ventilation is fed as the input signal to a clipped integral controller, with the target ventilation as the reference signal. The output of the controller determines the degree of ventilatory support. Clipping is typically to between half and double the degree of support that would do all the respirator work. A third measure of ventilation, for example instantaneous ventilation low pass filtered with a time constant of 5 seconds, is calculated. Ventilatory support is in phase with the subject's respiratory airflow to the fuzzy extent that this ventilation is above target, and at a preset rate conversely.

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 artefact from said signal; (iv) monitoring said signal for perturbations; and (v) determining that an ineffective effort has occurred when said perturbation is significant.

A cannula receive respiratory airflows and ambient airflows. Another receives respiratory airflows and interface airflows. And another receives i) respiratory airflows from a subject and ii) interface airflows from an area near the cannula. Corresponding respiratory monitoring methods also receive the same.

A method and apparatus for treating sleep disordered breathing. An arousal index is determined for use in an outer loop of a control algorithm, the arousal index being a measure of the frequency of sleep arousals. The respiratory airflow signal in an inner loop of the control algorithm is monitored to detect an airway obstruction. If the arousal index is high, then the sensitivity of obstruction detection and / or the aggressiveness of the treatment is increased, and if the arousal index is low, then the sensitivity of the obstruction detection and / or the aggressiveness of the treatment is decreased

A method and apparatus for providing ventilatory assistance to a spontaneously breathing patient An error signal (56) is computed that is the difference between a function of respiratory airflow (54) over a period of time and a target value (52). Using a servo loop, air is delivered to the patient at a pressure that is a function of the error signal, the phase of the current breathing cycle, and a loop gain that varies depending on the magnitude of the error signal. The loop gain increases with the magnitude of the error signal, and the gain is greater for error signals below a ventilation target than for error signals above the ventilation target value. The target value (52) is an alveolar ventilation that takes into account the patient's physiologic dead space.

The invention prevents dynamic airway compression during ventilatory support of a patient. The respiratory airflow is determined by measurement or calculation, and a measure of the degree of dynamic airway compression is derived from the determined airflow. This measure is servo-controlled to be zero by increasing expiratory pressure if the measure of the degree of dynamic airway compression is large or increasing, and by reducing expiratory pressure if the measure of the degree of dynamic airway compression is small or zero.

A method for the detection and treatment of disordered breathing during sleep employs an artificial neural network (ANN) in which data related to breathing gas flow are analyzed. A respiratory circuit is established by connecting the patient to a continuous positive airway pressure (CPAP) system with pressurized breathing gas supply, the gas flow in the circuit is periodically sampled, one or several cepstrum parameters distinctive of various breathing patterns are periodically calculated; the parameter values are periodically fed to an ANN trained to recognize breathing patterns characteristic of sleep disordered breathing and are analyzed in the network, the CPAP pressurized breathing gas supply is controlled in response to the ANN output. Also disclosed is a corresponding apparatus.

Described is system and method of monitoring respiratory airflow and oxygen concentration. The system may include a first sensor producing data corresponding to an airflow in a respiratory system of a body; a second sensor producing data corresponding to an oxygen concentration in the body; a generator supplying a pressurized airflow; an oxygen source supplying oxygen; a conduit through which the pressurized airflow and oxygen are delivered to the respiratory system; and a processing arrangement for processing the data from the first and second sensors and for controlling the generator and the oxygen source based on the processed data.

Methods and apparatus for determining leak and respiratory airflow are disclosed. A pressure sensor (34) and a differential pressure sensor (32) have connection with a pneumotach (24) to derive instantaneous mask pressure and airflow respectively. A microcontroller (38) estimates a non-linear conductance of any leak path occurring at a mask (12) as being the low pass filtered instantaneous airflow divided by the low pass filtered square root of the instantaneous pressure. The instantaneous leak flow is then the conductance multiplied by the square root of the instantaneous pressure, and the respiratory airflow is calculated as being the instantaneous airflow minus the instantaneous leak flow. The time constants for the low pass filtering performed by the microcontroller (38) can be dynamically adjusted dependent upon sudden changes in the instantaneous leak flow.

An improved ventilator which delivers ventilatory support that is synchronized with the phase of the patients respiratory efforts and guarantees a targeted minimum ventilation. Improved synchronization is achieved through an instantaneous respiratory phase determination process based upon measured respiratory airflow as well as measured respiratory effort using an effort sensor accessory, preferably a suprasternal notch sensor. The ventilator processes a respiratory airflow signal, a respiratory effort signal and their respective rates of change to determine a phase using standard fuzzy logic methods. A calculated pressure amplitude is adjusted based upon the calculated phase and a smooth pressure waveform template to deliver synchronized ventilation.

A system and method for delivering a flow of breathing gas to an airway of a patient. A characteristic that varies based on variations of the flow of the breathing gas is monitored and used to determine a Target Flow for the gas delivered to the patient. The Target Flow is set to a level sufficient to treat Cheyne-Stokes respiration or a sleep disordered breathing event. The Target Flow is altered if the patient experiences a sleep disordered breathing event. In a further embodiment, the system determines an apnea detection time (Tapnea) as Tinsp plus a constant, and delivers a machine triggered breath if an amount since the start of inspiration reaches Tapnea. Yet another embodiment monitors the characteristic during an inspiratory phase of a respiratory cycle, and controls the flow of gas during the inspiratory phase of the respiratory cycle based on a result of this comparison.

A patient interface system for delivering a flow of breathable gas to a patient includes a patient interface structure configured to sealingly engage the patient's nares; a pair of strips configured to be connected to opposite sides of the patient interface structure; and adhesive configured to secure the patient interface structure in sealing engagement with the patient's nares. The adhesive maybe provided on the strips, and the strips are configured to be adhered to sides of the patient's nose by the adhesive. Another patient interface system includes a first component including adhesive ona first side and hook or loop fastener material on a second side. The patient interface structure includes a second component including a corresponding loop or hook fastener material configured to engage the corresponding hook or loop fastener material of the first strip. A patient interface system for delivering a flow of breathable gas to a patient includes a patient interface structure including a pair of nasal prongs or pillows configured to sealingly engage the patient's nares; and at least one spring configured to bias the nasal prongs or pillows outwards into engagement with the naresof the patient.

Devices and systems provide methods of detecting a heart failure condition of a patient that may be based on one or more respiratory parameters of a patient. In an example embodiment, a monitoring device determines one or more heart failure condition indicators based on a measure of the patient respiratory airflow and / or a measure of treatment pressure. Respiratory parameters such as respiration rate, hypopneas, apneas, Cheyne-Stokes breathing patterns or apnea-hypopnea counts may be compared to thresholds that are selected to represent a change in the condition of a heart failure patient such as an onset of a decompensation event. Results of the comparisons may trigger a pressure treatment change and / or one or more warnings or messages to notify a patient or physician of a pending change to the patient's heart failure condition so that the patient may more immediately seek medical attention to treat the heart failure condition.

The invention discloses a sleep apnea syndrome detecting system. The sleep apnea syndrome detecting system is composed of a sleep respiration detecting device, a processing and diagnosing device, a thermistor sensor, positive electrodes and negative electrodes, wherein the sleep respiration detecting device is composed of a protecting circuit, a resistance type respiration detecting module, an electrocardio signal detecting module, an acceleration detecting module, a oral-nasal respiration detecting module, a processor module and a wireless communication module; the thermistor sensor is used for detecting oral-nasal respiratory airflow; the positive electrodes and the negative electrodes are used for detecting body chest breathing and electrocardio signals. Through the sleep apnea syndrome detecting system, a patient does not need to be hospitalized; the sleep apnea syndrome detecting system is simple and avoids physiological and psychological burdens. The sleep apnea syndrome detecting system can comprehensively detect the respiratory status of different parts of a human body to achieve the aim of sleep apnea syndrome classification and diagnosis, and meanwhile is simple in operation and can be used at home.

A cannula receives respiratory airflows and ambient airflows and a differential pressure transducer determine pressures differentials between the respiratory airflows and the ambient airflows. Another receives respiratory airflows and interface airflows and a differential pressure transducer determine pressures differentials between the respiratory airflows and the interface airflows. And another receives i) respiratory airflows from a subject and ii) interface airflows from an area near the cannula; and a differential pressure transducer determines pressure differentials between the respiratory airflows and the interface airflows. Corresponding respiratory monitoring methods also receive and determine the same.

A method for delivering a medicament to a mechanically ventilated patient receiving a flow of breathing gas comprises delivering a respiratory maneuver to such a patient, monitoring the physiological effects of the respiratory maneuver on such patient, automatically establishing an optimized respiratory maneuver in response to the monitored physiological effects, and delivering the optimized respiratory maneuver to such a patient. A system for delivering an aerosolized medicament to a ventilated patient is also provided.

A system for controlling and regulating breathing gas supplied to a patient that includes a pressure generator system that provides breathing gas to a patient and a patent circuit that delivers the breathing gas to the patient. The system includes an interface device coupled to the patient circuit to communicate the flow of gas to the patient' airway. A sensor detects a parameter indicative of a flow of breathing gas delivered to the patient. A controller coupled to the sensor and the pressure generator system measures at least one characteristic of respiratory airflow of a patient and calculates a target breath-amplitude -based parameter and a time -based parameter of at least a portion of the patient's respiratory cycle to be delivered to the patient based on the at least one characteristic of respiratory airflow.

This invention relates to medical treatment and monitoring of a living body, and more particularly to a multipurpose apparatus and method for measuring a living body's respiratory airflow, analyzing the composition of a gas exhaled by a living body and / or insufflating a treating gas into the living body.

A nasal airway for insertion in the nose for the delivery of volatile compositions into air entering the nose or, in a second embodiment, for the detection of targeted airborne pathogenic organisms present in the respirated airstream. The volatile compositions include aromatherapeutic compositions and scents.

A cannula receives respiratory airflows and ambient airflows; a differential pressure transducer determine pressure differentials between the respiratory airflows and the ambient airflows; and a ventilator responds to the pressure differentials. Another receives respiratory airflows and interface airflows; a differential pressure transducer determine pressure differentials between the respiratory airflows and the interface airflows; and a ventilator responds to the pressure differentials. And another receives respiratory airflows from a subject and interface airflows from an area near a cannula; a differential pressure transducer determine pressure differentials between the respiratory airflows and the interface airflows; and a ventilator responds to the pressure differentials. Corresponding respiratory monitoring methods receive, determine, and control the same.

A single sensor capable of detecting both airflow in spirometry and the full range of sound frequencies needed to track clinically relevant breath sounds is provided. The airflow sensor includes a movable flap with one or more integrated strain gauges for measuring displacement and vibration. The airflow sensor is inherently bidirectional. The sensor is an elastic flap airflow sensor that is capable of detecting data needed for both spirometry and auscultation measurements. The sensor is sterilizable and designed for the measurement of human respiratory airflow. The sterilizable sensor is also suitable for non-medical fluid flow metering applications. Additional devices such as sensors for the ambient level of various chemicals, sensors for temperature, sensors for humidity and microphones, may be affixed to the flap. When the strain gauge is placed in a conventional Wheatstone bridge configuration, the sensor can provide the airflow measurements needed for medical spirometry.