161 results about "Breathing cycle" patented technology

A signal source coupled to one or more electrodes in the vicinity of the diaphragm for mapping therapeutic electrode sites. A stimulus signal from the signal source may be applied to the one or more electrodes to produce activation of the diaphragm. Activation of the diaphragm is sensed to provide information that may be correlated with the stimulus signal. The correlated information may be used to identify a therapeutic locus for a therapeutic electrode. An electrical stimulus comprising a series of pulses may be applied to the one or more electrodes to elicit a desired breathing response. The electrical stimulus may be applied between intrinsic breathing cycles, or between regulated breathing cycles. More than one electrode may be supported on a single substrate. The substrate may configured to be positioned on the diaphragm. A hierarchy of stimuli may be applied to a set of electrodes.

A device and method is provided for electrically stimulating the diaphragm to control breathing while inhibiting respiratory drive. A stimulation phase is identified. The stimulation phase is a period of time within the breathing cycle in which stimulation will inhibit respiratory drive. The respiratory drive inhibition may be used in a number of applications including but not limited to: improving or remodeling the heart in heart failure patients, treating apnea, chronic obstructive pulmonary disorder (COPD), and hypertension.

An improved method and apparatus for respiratory audio-visual biofeedback are disclosed. A guide patterned after a breathing cycle comfortable to the patient serves as a target. The target is displayed as a bar moving vertically upward during inhale and vertically downward during exhale, between fixed end ex-hale and end in-hale limits. The patient's current respiratory position is also displayed as a bar, oriented parallel to the target bar so that the difference between the current position and the target position is easy for the patient to see.

A medical ventilator system and method that triggers, cycles, or both based on patient effort, which is determined from cross-correlating patient flow and patient pressure. The medical ventilator is also controlled such that sensitivity to a patient initiated trigger increases as the expiratory phase of the breathing cycle progresses. The present invention also provides adaptive adjustment of cycling criteria to optimize the cycling operation.

Techniques are provided for detecting the circadian state of a patient using an implantable medical device based on selected blood carbon dioxide (CO₂) parameters. In one example, the implantable device tracks changes in end tidal CO₂ (etCO₂) levels and changes in maximum variations of pCO₂ levels per breathing cycle (Δ_cycleCO₂) over the course of the day and determines the circadian state based thereon. It has been found that average etCO₂ levels are generally highest and average Δ_cycleCO₂ levels are generally lowest while a patient is asleep and opposite while a patient is awake. Hence, by tracking changes in average etCO₂ and Δ_cycleCO₂ levels over the course of the day, circadian states can be detected. Minute ventilation and activity levels are used to assist in the determination of the circadian state. Additional techniques are directed to detecting the stage of sleep.

A method and system for ventilating a patient that compensates for leaks occurring within the patient breathing circuit while limiting the volume of breathing gas delivered to the patient. During the operation of a ventilator to supply breathing gases to a patient, the ventilator monitors for leak volumes occurring during the inspiratory phase and expiratory phase of the breathing cycle. Based upon the leak volumes sensed, the volume of breathing gas delivered by the ventilator is increased such that the tidal volume delivered to the patient is the desired tidal volume set by a clinician. The ventilator operates to generate a leak alarm when the leak volume exceeds an alarm threshold. If the leak alarm is generated, the tidal volume delivered to the patient is limited to the tidal volume being delivered prior to generation of the leak alarm. During compensation of the breathing gases delivered to the patient, the system and method determines whether the compensated tidal volume exceeds a maximum tidal volume threshold and limits the compensated tidal volume to the maximum tidal volume threshold.

The invention relates to a method and a device for detecting leaks in respiratory gas supply systems. Both the pressure and the volume flow of the respiratory gas are detected and the relevant values are supplied to an evaluation device. The evaluation device is used to calculate both the respiratory parameter resistance and compliance and the leak for at least two successive breathing cycles. At least one control parameter with different signal amplitudes is pre-determined for the successive breathing cycles. The leak resistance is determined from the resulting differential sequences of pressure and flow for the successive breathing cycles.

Disclosed herein is a method and apparatus for monitoring, identifying and determining the breathing cycle of an individual from processed acoustic signal waveform data. The breathing sounds of an individual are recorded using a microphone and digitized such that the breathing sounds may be plotted. The data is segmented and transformed to form a plurality of segments representative of a frequency spectrum. The frequency spectrum data is transformed so as to produce magnitude bins and the sum of lower magnitude bins and the sum of higher magnitude bins are determined in a sampling of segments. A Bands Ratio is determined from the sum of lower magnitude bins and the sum of higher magnitude bins in the sampling of segments. A first bands ratio is then determined within a given segment and compared to the mean bands ratio. If the first bands ratio of the given segment is greater than the mean bands ratio by at least a predetermined multiplier, the given segment is labeled as inspiration. If the first bands ratio of the given segment is less than the mean bands ratio by at least a predetermined multiplier, the given segment is labeled as expiration.

A small oxygen enriching apparatus which can supply oxygen-enriched gas at high flow rate without imparting unnatural sensation to a user, as well as a controller and recording medium therefore. In step 100, a judgment is made as to whether a flow rate set by use of a flow-rate setting unit 47 is equal to or less than a continuous base flow rate (2 liters/min). When the set flow rate is a low flow rate of not greater than 2 liters/min, breath-synchronized operation is not performed (continuous supply is to be performed), and therefore, in step 110, oxygen-enriched gas is supplied continuously at the set flow rate. When the set flow rate is a high flow rate of greater than 2 liters/min, breath-synchronized operation is to be performed (supply during the inhalation period only of each breathing cycle), and therefore, in step 120, oxygen-enriched gas is continuously supplied at the continuous base flow rate. In step 140, in order to perform breath-synchronized operation, control for opening and closing an electromagnetic valve 45 is performed. That is, oxygen-enriched gas is supplied during the inhalation period only of each breathing cycle, and supply of oxygen-enriched gas is stopped during the exhalation period.

An apparatus and method for providing a nebula or aerosol to a patient. In one aspect, a nebulizer is pressure sensitive so that nebulization is coordinated with a breathing cycle of the patient. The nebulizer includes a movable gas diverter that diverts pressurized gas across a liquid outlet. The diverter is moved in response to the patient's breathing cycle. In one aspect, a biasing member moves the diverter. According to another aspect of the nebulizer, an annular liquid orifice disperses an aerosol in a radial direction in response to a pressurized gas flow from an orifice located concentrically thereto. Multiple liquid orifices may be provided. In a further aspect of the nebulizer, a reservoir includes an upper, wide portion and a lower narrow portion to apply relatively uniform pressure at a liquid orifice.

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. The control and analysis unit automatically performs steps including determining a global impedance change, defined as the impedance change with respect to an earlier measured reference impedance distribution integrated over the electrode plane, and recording the global impedance change curve as a function of time, performing breath detection in order to identify a breathing cycle, subdividing each breathing cycle to define a plurality of intratidal intervals, subdividing an EIT image from each interval into a plurality of regions of interest and calculating for each region of interest the ratio of the integrated impedance change within this region of interest to the global impedance change of this EIT image, for each intratidal interval presenting indications of the ratios determined for the regions of interest to provide an intratidal gas distribution representation for each interval.

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 specifies a method and system for leading a person suffering from “sympathetic predominance”, a specific symptom of which is “hypertension”, to breathe according to a certain pattern for the express purpose of positively altering the condition of sympathetic predominance (over activation), having the effect of bringing the autonomic nervous system into the state of balance, with consequent reductions in “tenseness”, blood pressure, muscular tightness, and emotional strain, as well as the alleviation of the myriad of subtle neuro-physiological consequences resulting from sympathetic predominance potentially including headaches, anxiety, sleep disorders, allergies, and other maladies that have yet to be attributed to this condition, thus leading to a general improvement in health, well being, and homeostasis. It accomplishes this by systematically reducing the breathing frequency with consequent increases in breathing depth, the ultimate goal being the realization and ongoing maintenance of 1 complete breathing cycle in 11.76 seconds or 5 complete breathing cycles in 58.8 seconds, the result being improved health, well being, and homeostasis.

A simulated lung for use in real time simulated medical procedures comprising a positive pressure source of a gas, a vacuum pressure source, a fixed interior volume vessel having an inlet, an outlet, and a breath passage port, the inlet in communication with the positive pressure source, and the outlet in communication with the vacuum pressure source, a first flow valve intermediate the positive pressure source and the inlet, a second flow valve intermediate the vacuum pressure source and the outlet, a pressure sensor in communication with the interior volume of the vessel, and means for continuously evaluating a pressure signal generated by the pressure sensor to a desired pressure level within the vessel during the breathing cycle such that a flow of gas entering and exiting the breath passage port of the vessel is synchronized with a predetermined desired flow rate of breathing during the breathing cycle. The desired pressure level depends upon any one of i) a time and event based script, ii) a computer model, iii) or a combination of a time and event based script and a computer model based on a physiological state of a simulated patient.

A ventilation apparatus for treating sleep apnea is provided. A ventilator controlled by a control system may deliver ventilation gas through a ventilation gas delivery circuit to a ventilation catheter and a distal tip on the ventilation catheter. One or more sensors may detect a breathing cycle and the control system may operate the ventilator in synchrony with the breathing cycle. The distal tip may deliver the ventilation gas superiorly from the transtracheal ventilation catheter towards an upper airway, inferiorly from the transtracheal ventilation catheter towards a lung, or a combination of both. The ventilation catheter may be a transtracheal catheter, a trans-oral catheter or a trans-nasal catheter.

A pneumatic sealing system for a gas mask, which seals the mask to the face of the user by using a pump that employs air from inside the gas mask to variably inflate a mask seal during the breathing cycle. A double diaphragm pump, which has a driving diaphragm and a driven diaphragm, is connected to the inflatable mask seal via a hose duct. The double diaphragm pump is driven by the pressure difference inside the gas mask. During inhalation, the driving diaphragm fills with ambient air and the driven diaphragm fills with filtered air. During exhalation, the driving diaphragm and the driven diaphragm compress, releasing and trapping air in the mask seal.

In accordance with one aspect of the present invention for controlled delivery of medicament to the respiratory system of a patient, a measured quantity of a medicament, i.e., a bolus 32 is introduced into the inspiratory flow stream of a patient, via a breathing tube 18, and inhaled by the action of the patient's breathing cycle of the course of a breathing cycle of the patient, numerous properties or characteristics of the medicament, i.e., the bolus, the inspiratory flow, like properties or characteristics of the expiratory flow, and/or other useful information are derived. The derived information is employed to control subsequent delivery of boli to the patient, including the delivery of each bolus as a function of the commencement or progression of the breathing cycle, as input for calculations or determinations which are useful in analyzing the effectiveness of delivery of the medicament to the patient, patient compliance, direction of flow through the breathing tube, and other uses.

Motion artifacts and patient dose during 4D CT imaging are reduced by adaptive control of data acquisition. The respiration signal (310) and CT data acquisition (340) are linked, such that ‘bad’ data from erratic breathing cycles that cause artifacts is not acquired by pausing CT data acquisition (360) when erratic breathing is detected, and not resuming CT data acquisition until steady-state respiration is resumed. Training data is used to develop a tolerance envelope for a respiratory signal such that for erratic breathing cycles the respiratory signal is not within the tolerance envelope (330).

A respiratory volume/flow monitoring system, including a pneumotach that measures micromovements of a membrane in a MRI environment, gates (triggers) a MRI machine to start image acquisition at specific lung volumes or airflow rates during the breathing cycle or other breathing maneuvers of a patient. The system provides breathing motion artifact suppression for any imaging test susceptible to breathing motion artifact, allows respiratory monitoring of the subject during an MRI procedure, and provides the capability to perform spirometric testing while the subject is in the MRI environment. Embodiments of the invention are also applicable for patients undergoing CT imaging or any other imaging modality that allows external triggering.

Medical devices and methods for providing breathing therapy (e.g., for treating heart failure, hypertension, etc.) may determine at least the inspiration phase of one or more breathing cycles based on the monitored physiological parameters and control delivery of a plurality of breathing therapy sessions (e.g., each of the breathing therapy sessions may be provided during a defined time period). Further, each of the plurality of breathing therapy sessions may include delivering stimulation after the start of the inspiration phase of each of a plurality of breathing cycles to prolong diaphragm contraction during the breathing cycle.