Abstract: The invention relates to estimation of a patient's propensity to suffer from symptomatic hypotension during extracorporeal blood treatment. An electromagnetic test signal, which is applied over a thoracic region of the patient via at least one transmitter electrode. A result signal produced in response to the test signal is received via at least one receiver electrode on the patient. A test parameter is derived based on the result signal. The test parameter expresses a fluid status of the thoracic region of the patient, and it is determined whether the test parameter fulfills an alarm criterion. If the test parameter fulfills an alarm criteria, an alarm signal is generated. This signal indicates that the patient is hypotension prone, and that appropriate measures should be taken.

Abstract: Ventilatory systems and methods are disclosed for detecting weaning readiness of a patient. In one aspect the method includes the steps of collecting patient data; analyzing the collected patient data to generate at least one patient parameter; comparing the at least one patient parameter to predetermined weaning readiness threshold criteria; and providing an advisory proposition to a clinician indicating a readiness of the patient to start a weaning trial if the at least one patient parameter meets the weaning readiness threshold criteria. The weaning trial may additionally or alternatively be automatically executed if the at least one patient parameter meets the weaning readiness threshold criteria.

Abstract: A system and method for monitoring respiration of a user, comprising: a respiration sensing module including a sensor configured to detect a set of respiration signals of the user based upon movement resulting from the user's respiration; a supplementary sensing module comprising an accelerometer and configured to detect a set of supplemental signals from the user; an electronics subsystem comprising a power module configured to power the system and a signal processing module configured to condition the set of respiration signals and the set of supplemental signals; a housing configured to facilitate coupling of the respiration sensing module and the supplementary sensing module to the user; and a data link coupled to the electronics subsystem through the housing and configured to transmit data generated from the set of respiration signals and the set of supplemental signals, thereby facilitating monitoring of the user's respiration.

Abstract: An EIT device with a plurality of electrodes, which can be arranged about the chest of a patient, with a control and analyzing unit for feeding electrode pairs of a set of electrodes to record a voltage or current signal as a measured signal with electrode pairs acting consecutively as the feeding electrode pair to provide a matrix of image elements. A time series of the impedance change from the sequence of reconstructed matrices over at least one breath is obtained and compared to a determined time series of the mean impedance change or a time series of a measured respiration volume, by calculating for each image element a scalar value as an indicator of a deviation. The control and analyzing unit assesses and marks the corresponding image element as being non-ventilated if the indicator of the deviation meets a preset threshold value criterion.

Abstract: An electric impedance tomography device with chest electrodes, a display and a control and analyzing unit to determine a time series of a global ventilation curve from the sequence of reconstructed matrices as a time series of the mean impedance change or of a measured respiration volume, to divide an inspiration or expiration phase into a number of steps of equal volume change, to determine the times corresponding to these steps, to determine the change in local impedance between these times for each image element, the ratio of this local change in impedance to the global equal volume change to form a local sequence of relative impedance changes of the image element as a function of the steps of equal volume change, to determine a scalar indicator characteristic as a function of the steps of equal volume change and to display each image element based on the respective scalar indicator.

Abstract: In a respiratory apparatus for treatment of sleep apnea and other disorders associated with an obstruction of a patient's airway and which uses an airflow signal, an obstruction index is generated which detects the flattening of the inspiratory portion of the airflow. The obstruction index is used to differentiate normal and obstructed breathing. The obstruction index is based upon different weighting factors applied to sections of the airflow signal thereby improving sensitivity to various types of respiration obstructions.

Abstract: The invention relates to a spirometer for measuring pulmonary respiration of a test subject, comprising a body and a sensor unit, wherein the sensor unit can be interchanged with further sensor units. In a corresponding method, such a spirometer is operated with a sensor unit and the sensor unit is subsequently interchangeably replaced by a further sensor unit.

Abstract: The invention provides a system for measuring respiratory rate (RR) from a patient. The system includes an impedance pneumography (IP) sensor, connected to at least two electrodes, and a processing system that receives and processes signals from the electrodes to measure an IP signal. A motion sensor (e.g. an accelerometer) measures at least one motion signal (e.g. an ACC waveform) describing movement of a portion of the patient's body to which it is attached. The processing system receives the IP and motion signals, and processes them to determine, respectfully, frequency-domain IP and motion spectra. Both spectra are then collectively processed to remove motion components from the IP spectrum and determine RR. For example, during the processing, an algorithm determines motion frequency components from the frequency-domain motion spectrum, and then using a digital filter removes these, or parameters calculated therefrom, from the IP spectrum.

Abstract: In at least one embodiment, a device for controlling and/or regulating a training and/or rehabilitation unit comprises a training and/or rehabilitation unit, a sensor unit having sensors for determining oxygen concentration and for determining carbon dioxide concentration, a control unit for the sensors, a microcontroller in the control unit for controlling the heating power of heating elements of the sensors, depending on breath flow volume, for maintaining constant sensor temperatures, and a resistance and/or braking arrangement of the training and/or rehabilitation unit that can be controlled and/or regulated based on a breathing gas composition determined by the sensor unit. The device can be used to increase endurance, preferably by way of altitude training.

Abstract: The disclosed embodiments relate to a system and method for assuring validity of monitoring parameters in combination with a therapeutic device. An exemplary embodiment of the present technique comprises perturbing a treatment administered to a patient, measuring at least one parameter of the patient reflecting the underlying physiological state and associated with the treatment, and comparing the perturbations of the treatment to measurements of the at least one parameter to determine if the perturbations to the treatment are reflected by the parameter.

Abstract: A system and method of calculating an accurate estimate of pulmonary mechanics of a patient, including but not limited to compliance, resistance, and plateau pressure without modification of ventilator flow pattern. The accurate estimation of pulmonary mechanics is derived from airway pressure and flow sensors attached to the patient using novel mathematical models. These estimated figures for pulmonary mechanics (respiratory system compliance and resistance) are important for monitoring patient treatment efficacy during mechanical ventilation and ensuring alveoli do not over distend to avoid baro- and/or volutrauma, especially in patients with restrictive lung diseases. The subject method of calculating these accurate estimated figures for pulmonary mechanics is based on linear or non-linear calculations using multiple parameters derived from the above-mentioned sensors.

Abstract: A method for use in an implantable medical device comprises the steps of monitoring respiration with an amplifier having a gain, generating a moving apneic threshold based on recent respiration cycles, accumulating differences between amplitudes of respiration cycles and the moving apnea detection threshold and comparing the accumulated differences against an apnea detection threshold to detect the onset of an episode of apnea. The method further comprises measuring respiration levels upon detecting the onset of apnea, confirming the episode of apnea based upon the respiration levels measured upon detecting the onset of apnea; and adjusting one of the gain of the amplifier and the apnea detection threshold so that the time from the detection of onset of apnea to the time of confirmation of the episode of apnea is within a predetermined time range following the detection of the onset of apnea.

Abstract: This disclosure describes systems and methods for monitoring and evaluating ventilatory parameters, analyzing those parameters and providing useful notifications and recommendations to clinicians. That is, modern ventilators monitor, evaluate, and graphically represent a myriad of ventilatory parameters. However, many clinicians may not easily identify or recognize data patterns and correlations indicative of certain patient conditions, changes in patient condition, and/or effectiveness of ventilatory treatment. Further, clinicians may not readily determine appropriate ventilatory adjustments that may address certain patient conditions and/or the effectiveness of ventilatory treatment. Specifically, clinicians may not readily detect or recognize the presence of Auto-PEEP during volume ventilation of a non-triggering patient.

Abstract: Respiratory diseases related to gastroesophageal reflux disease in a patient are diagnosed by detecting esophageal or pharyngeal impedance and pH in the patient, detecting oxygen saturation in the patient, and diagnosing the respiratory diseases from the esophageal or pharyngeal impedance, the pH, and the oxygen saturation.

Abstract: A system comprising implantable device, the implantable medical device including an intrinsic cardiac signal sensor, an impedance measurement circuit configured to apply a specified current to a transthoracic region of a subject and to sample a transthoracic voltage resulting from the specified current, and a processor coupled to the intrinsic cardiac signal sensor and the impedance measurement circuit. The processor is configured to initiate sampling of a transthoracic voltage signal in a specified time relation to a fiducial marker in a sensed intrinsic cardiac signal, wherein the sampling attenuates or removes variation with cardiac stroke volume from the transthoracic voltage signal, and determine lung respiration using the sampled transthoracic voltage signal.

Abstract: The present invention provides a method of measuring an acoustic impedance of a respiratory system. The method comprises selecting a frequency range for an acoustic wave, directing the acoustic wave into the respiratory system and receiving an acoustic wave from the respiratory system. The method also comprises determining the acoustic impedance for a plurality of volumes or volume ranges of the respiratory system. Each volume, or the volumes within each volume range, is larger than RV or FRC and smaller than TLC whereby the determined acoustic impedances are specific for respective volumes or volume ranges. Further, the method includes determining a volume, or volume range, dependency of the acoustic impedance of the respiratory system and characterizing the respiratory system by analyzing the dependency of the acoustic impedance on the volume or volume range.

Abstract: Methods and devices to determine rate of particle production and the size range for the particles produced for an individual are described herein. The device (10) contains a mouthpiece (12), a filter (14), a low resistance one-way valve (16), a particle counter (20) and a computer (30). Optionally, the device also contains a gas flow meter (22). The data obtained using the device can be used to determine if a formulation for reducing particle exhalation should be administered to an individual.

Abstract: Lung conditions are diagnosed and optionally treated using a functional assessment catheter or a functional lung assessment and treatment catheter. A flow restrictive component is initially placed in a bronchus or lung passageway upstream from a diseased lung region. The isolated lung region is then functionally assessed through the catheter, while the flow restrictive component remains in place. If the patient is a good candidate for treatment by occlusive or restrictive treatment techniques, the flow resistive component may be left in place. If the patient is not suitable for such treatment, the flow resistive component may be removed.

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

Abstract: An audio/video recording method and device for recording a main audio/video file and at least one index audio/video file corresponding to the main audio/video file. A section of the index audio/video files can be transformed into text data serving as a portion of file names of the main audio/video file. When a user collates or uses the main audio/video file, the index audio/video file is used to accelerate distinguishing what the main audio/video files are, thereby facilitating searching, classification and management of the main audio/video file effectively.

Abstract: Ribs are automatically ordered and paired. After ordering ribs on each side, magnetic and spring functions are used to solve for rib pairing. The magnetic function is used to constrain possible pairs across sides, and the spring function is used to maintain the order on each side while accounting for missing or fused ribs.

Abstract: A method for determining dynamically a respiratory feature in a spontaneously breathing patient receiving mechanical ventilatory assist comprises: modifying a level of mechanical ventilatory assist to the patient, measuring an airway pressure, detecting a change of gradient of the measured airway pressure and determining the respiratory feature based on the measured airway pressure upon detecting the change of gradient of the airway pressure. Furthermore, the method also comprises: measuring a respiratory neural drive of the patient and detecting a lowest level of the measured respiratory neural drive for determining the respiratory feature based on the detected lowest level of respiratory neural drive.

Abstract: Minimally invasive methods, systems and devices are provided for qualitatively and quantitatively assessing collateral ventilation in the lungs. In particular, collateral ventilation of a target compartment within a lung of a patient is assessed by advancement of a catheter through the tracheobronchial tree to a feeding bronchus of the target compartment. The feeding bronchus is occluded by the catheter and a variety of measurements are taken with the use of the catheter in a manner which is of low risk to the patient. Examples of such measurements include but are not limited to flow rate, volume and pressure. These measurements are used to determine the presence of collateral ventilation and to quantify such collateral ventilation.

Abstract: A method and system for monitoring respiratory function that includes an impedance sensor configured to sense a first thoracic impedance waveform for at least one breath of a patient, a memory configured to store a first threshold slope value, and a processor configured to determine an first breath slope value in response to the impedance waveform, compare the first breath slope value to a first threshold slope value, and determine an indication of respiratory function of the patient in response to the comparing.

Abstract: A system and method for monitoring respiratory function that includes an acoustic sensing device sensing an acoustic waveform ocurring during one of an inspiration phase associated with at least one breath of a patient and an expiration phase associated with at least one breath of a patient, and a processor configured to determine changes in high frequency acoustic amplitude associated with the sensed acoustic waveform and, in response to the determined changes in high frequency acoustic amplitude, determine an indication of respiratory function.

Abstract: A system for automatically predicting acute airway events in patients, comprising: a device for measuring the respiratory impedance of a human subject during a plurality of respiratory cycles of said human subject; said respiratory impedance comprising a real part and an imaginary part; said device measuring said respiratory impedance two times per day to provide a plurality of measurements; means for calculating the relative variation of said plurality of measurements; means for evaluating the probability of respiratory pathology presence in the subject under examination when the value of the imaginary part of said impedance is greater than 35%; means for predicting a relapse in the patent under examination within an established future time window, once the presence of the pathology has been ascertained, if the variation coefficient of the real part of said impedance is greater than 0.4.

Abstract: A system for measuring the mechanical impedance of a patient's respiratory system during spontaneous respiratory activity, characterised by comprising a fan; a motor which operates said fan; said motor and said fan being positioned within a cavity; said cavity comprising an initial end and a final end, both providing access to the outside; said cavity presenting an impedance between said initial and said final end of less than 1 cm H2O/L/s; said fan withdrawing air from said final end and providing pressure variations of small amplitude and of frequency >2 Hz to said initial end; said initial end comprising air pressure and air flow measurement means and a connection directly connected to the airway opening.

Abstract: In a method for diagnosing functional lung illnesses, image exposures of the lungs are obtained at various phase points in time of the respiration of a subject, such as at maximum inhalation and maximum expiration, and the image exposures are segmented and at least two of the image exposures are compared on a segment-by-segment basis to identify a change in tissue density between the compared segments, as an indicator of lung functioning.

Abstract: An implantable medical device used for thoracic fluid monitoring by detection of changes in impedance in a patient. The device measures impedances of the patient in a supine position and in an upright position. The device determines impedance differences between the supine and upright positions which correspond to a diurnal delta value, which may in turn be employed as a diagnostic parameter.

Abstract: A system comprising implantable device, the implantable medical device including an intrinsic cardiac signal sensor, an impedance measurement circuit configured to apply a specified current to a transthoracic region of a subject and to sample a transthoracic voltage resulting from the specified current, and a processor coupled to the intrinsic cardiac signal sensor and the impedance measurement circuit. The processor is configured to initiate sampling of a transthoracic voltage signal in a specified time relation to a fiducial marker in a sensed intrinsic cardiac signal, wherein the sampling attenuates or removes variation with cardiac stroke volume from the transthoracic voltage signal, and determine lung respiration using the sampled transthoracic voltage signal.

Abstract: A method of estimating upper airway resistance or lung compliance of a patient is provided that includes inducing a central apnea in the patient, providing a known pressure stimulus comprising a flow of breathing gas having a known pressure level to the patient while the patient is experiencing the central apnea, determining a patient flow-related parameter, such as flow rate and/or flow volume, associated with the known pressure stimulus, and estimating the upper airway resistance or the lung compliance of the patient using the patient flow-related parameter using, for example and without limitation, an input-output system identification method.

Abstract: A system (2, 2?, 2?, 2??) for performing respiratory diagnostics is provided that includes a pressure generator (14) configured to generate a first pressurized flow of breathable gas having a first pressure level above atmospheric pressure (e.g., at levels typical of common CPAP devices) and a patient interface device (4, 4?, 4?, 4??) coupled to the pressure generator. The patient interface device includes a body (6) having one or more subject interface openings (8) and one or more valves (18, 22, 24) disposed in the body, at least one of the one or more valves being selectively configurable to cause a second pressurized flow of breathable gas to be delivered through the one or more subject interface openings at a selectable pressure level anywhere between the first pressure level and atmospheric pressure in response to the patient interface receiving the first pressurized flow of breathable gas and without receiving any other pressurized flows of breathable gas.

Abstract: A respiratory interface apparatus (6) is provided that includes a patient contacting portion (21) structured to engage a face of the patient, a common chamber (30) fluidly coupled to the patient contacting portion (21), a first control chamber (26), a first flow regulating mechanism (32) provided between the first control chamber (26) and the common chamber (30), a second control chamber (28), and a second flow regulating mechanism (34) provided between the second control chamber (28) and the common chamber (30).

Abstract: A method and apparatus for inductively measuring the bio-impedance of a user's body without complex circuitry. An apparatus is described for inductively measuring the bio-impedance of a user's body, wherein the apparatus includes a number of first inductors being adapted to induce an alternating magnetic field in the user's body and the apparatus further includes a number of second inductors being adapted to measure a secondary magnetic field in the user's body, wherein each of the number of first inductors overlaps at least one of the number of second inductors to form a number of measuring areas.

Abstract: A system and method of calculating an accurate estimate of pulmonary mechanics of a patient, including but not limited to compliance, resistance, and plateau pressure without modification of ventilator flow pattern. The accurate estimation of pulmonary mechanics is derived from airway pressure and flow sensors attached to the patient using novel mathematical models. These estimated figures for pulmonary mechanics (respiratory system compliance and resistance) are important for monitoring patient treatment efficacy during mechanical ventilation and ensuring alveoli do not over distend to avoid baro- and/or volutrauma, especially in patients with restrictive lung diseases. The subject method of calculating these accurate estimated figures for pulmonary mechanics is based on linear or non-linear calculations using multiple parameters derived from the above-mentioned sensors.

Abstract: An apparatus for determining functional lung characteristics of a patient includes an electrical impedance tomography (EIT) imaging device adapted to record the impedance distribution within a plane of the thorax of the patient. The EIT imaging device includes a control and analysis unit for performing the impedance measurement and deriving the impedance distribution within the plane of the thorax.

Abstract: The acoustic impedance of the respiratory system can be inferred from oscillations that are generated in an airway of a subject. The impedance describes the frequency-dependent relation between the resulting oscillations in flow and pressure. When the impedance varies from inspiration to expiration, it has to be estimated with a high time resolution. A method is provided that reliably estimates the impedance in time intervals that are short enough for physiological purposes. A simple version of the uncertainty principle has been derived for discrete time and frequency. A discrete time-frequency transform has been developed that gives an optimal time-frequency resolution according to this principle. The transform is orthonormal, which permits an analysis of variance in the discrete time-frequency domain. The impedance follows from bivariate least-squares analysis in the time-frequency domain, under the assumption that noise is present in both flow and pressure.

Abstract: A combination toothbrush and peak flow meter system for increasing the compliance of peak flow measurements in children and adults with asthma. The combination toothbrush and peak flow meter system includes a peak flow meter and a toothbrush head connected to an end of the peak flow meter. The peak flow meter transmits the peak flow measurement data to the hospital computer to be evaluated by a physician.

Abstract: A cardiac rhythm management device for obtaining transthoracic impedance. The device comprises a sensor for obtaining a signal indicative of an action of a heart, an impedance measurement circuit adapted to measure transthoracic impedance and a processor for utilizing the signal indicative of the action of the heart to sample the transthoracic impedance at sampling intervals commenced by fiducial markers in the signal indicative of the action of the heart, where the sampling of the impedance signal removes the component of a stroke volume of the heart from the signal and thereby provides lung ventilation information.

Abstract: The lung compliance of a subject that is at least partially self-ventilating is determined. The quantification of lung compliance may be an estimation, a measurement, and/or an approximate measurement. The quantification of lung compliance may be enhanced over conventional techniques and/or systems for quantifying lung compliance of self-ventilating subjects in the lung compliance may be quantified relatively accurately without an effort belt or other external sensing device that directly measures diaphragmatic muscle pressure, and without requiring the subject to manually control diaphragmatic muscle pressure. Quantification of lung compliance may be a useful tool in evaluating the health of the subject, including detection of fluid retention associated with developing acute congestive heart failure.

Abstract: Methods and systems that incorporate automated or manual control of ventilation and kinetic rotation therapy are provided. In one exemplary embodiment, an artificial ventilator is used to artificially ventilate one of the patient's lungs, the status of the artificially ventilated lung is determined by measuring one or more ventilation status measures, and one or more of the ventilation status measures is used to provide feedback for controlling the positioning of the patient. In some exemplary embodiments, the feedback is used for automated control of the positioning of the patient, while in other exemplary embodiments, the feedback is used as guidance for manual control of the positioning of the patient.

Abstract: Methods and systems for targeting, accessing and diagnosing diseased lung compartments are disclosed. The method comprises introducing a diagnostic catheter with an occluding member at its distal end into a lung segment via an assisted ventilation device; inflating the occluding member to isolate the lung segment; and performing a diagnostic procedure with the catheter while the patient is ventilated. The proximal end of the diagnostic catheter is configured to be attached to a console. The method may also comprise introducing the diagnostic catheter into the lung segment; inflating the occluding member to isolate the lung segment; and monitoring blood oxygen saturation. The method may further comprise introducing the diagnostic catheter into the lung segment; determining tidal flow volume in the lung segment; determining total lung capacity of the patient; and determining a flow rank value based on the tidal flow volume of the lung segment and the total lung capacity.

Abstract: A method of detecting malacia in airways includes providing a plurality of 3-dimensional (3D) digital lung images acquired over an inhalation/exhalation cycle from a same subject, each said image comprising a set of intensities on a 3-dimensional grid of points, registering a successive pair of images, wherein a registration mapping of the point grid of one image is calculated, locating airways in each of said pair of images, and collecting those points between the airways in each of said pair of images, wherein a volume of said collected points is a measure of an extent of malacia in said airways.

Abstract: Continuous measurement of breathing impedance with extremely high precision is enabled by executing noise elimination. A loudspeaker 21 applies an air vibration pressure by an oscillation wave to an oral cavity, the oscillation wave being obtained by frequency-culling so executed that the oscillation wave has only the frequency component that is left after the culling is executed from a plurality of different frequencies and being generated by a pulse signal for pulse drive with pulses made positive and negative separately in correspondence to the time of exhalation and the time of inhalation. A pressure inside the oral cavity is detected and a breathing flow is detected, and a signal obtained by the detection is Fourier-transformed by a Fourier transforming means 32 to obtain a spectrum. A breathing high frequency component that contributes as a noise is obtained by an extracting means 33, using a spectrum that corresponds to a frequency component culled from the result of the Fourier transformation.

Abstract: Determining the nasal resistance. At least some of the illustrative embodiments are methods including: forcing airflow into a first nare of a patient; measuring at least one property of the airflow during the forcing; and determining an indicia of nasal resistance of the patient, the determining based on the at least one property.

Abstract: The device relates to methods and devices for the treatment of obstructive sleep apnea syndrome.

Abstract: A method for determining lung function in a patient is disclosed, in which a multi-lumen catheter with an expandable occluding element at its end is used to isolate a targeted lung compartment, and respiratory characteristics at the targeted lung compartment are measured over multiple respiratory cycles. The relation between various characteristics of the respiratory cycle is used to determine compliance of lung tissue within the targeted lung compartment.

Abstract: Breathing effort of a patient, as determined (for example) from a photoplethysmograph (“PPG”) signal from the patient, can be calibrated in relation to air pressure in the patient's respiratory system. This calibration can be done by subjecting the patient to varying amounts of breathing resistance; and for each such amount, concurrently measuring (1) air pressure in the respiratory system (e.g., in the oral/nasal cavity) and (2) breathing effort (from the PPG signal). Use can be made of this calibration, e.g., during a sleep study of the patient. During such a study, breathing effort, again determined from the PPG signal and occurring, for example, during an apneic event of the patient, can be used to infer air pressure in the respiratory system by using the above calibration.

Abstract: The elastance and a resistance of a subject being ventilated are determined. The determination of elastance and resistance of the breathing of the subject is made without adjusting the ventilation of the subject to facilitate the determination. That is, the determination of elastance and resistance of the subject is made without manipulating one or more parameters of the ventilation in a manner not dictated by a treatment algorithm that is designed to ventilate the subject effectively and/or comfortably.

Abstract: Inhalation measurement systems and methods enable, during inhalant exposure, substantially real-time respiratory measurements of a test subject using techniques that obtain measurements of respiration directly from that test subject, instead of from inhalation chamber parameter measurements. Direct test subject respiratory measurements may be, by way of example only, impedance measurements. These respiratory measurements taken directly from the test subject may be transmitted, wirelessly for example, for processing during the course of the test to a processing system to determine a cumulative volume of inhalant inspired by the test subject. From that, a cumulative amount of inhalant (or dose) inspired by the test subject may be determined during the course of the inhalation compound test.