44 results about "Functional residual capacity" patented technology

A ventilator for ventilating a patient has means integrated therewith for carrying out a determination of the functional residual capacity of the patient using an inert gas wash in / wash out technique. To this end, the ventilator operates to alter the inert gas content of breathing gases provided to the patient. The amount of inert gas expired by the patient is obtained and used to determine functional residual capacity on a breath-by-breath basis. A graph of the functional residual capacities for a given number of breaths is produced. Thereafter, the inert gas levels in the breathing gases are returned to the original levels and further functional residual capacity determinations and a graph of same provided. The functional residual capacity information may also be provided in tabular form. A log of functional residual capacity determinations and ventilator settings or patient treatments affecting same may also be provided.

A method for determining functional residual capacity (FRC) of a patient while ventilating the patient. The system may include a medical ventilator which provides inhalation and exhalation from the patient, a sensor which measures a fraction one or more gas components of the inhalation and a fraction of the same gas components of the exhalation. A step change of oxygen fraction is provided to the inhalation of the patient. Subsequent to the step change, The fractions of the gas components are measured in the inhalation and in the exhalation. The functional residual capacity of the lungs of the patient is measured based on the fraction of the gas components in the inhalation and in the exhalation. The step change is provided manually by a technician, or automatically by programming a programmable device to provide the step change automatically to the patient by the medical ventilator. The step change is either an increase or a decrease in of the oxygen fraction.

Methods for noninvasively measuring, or estimating, functional residual capacity or effective lung volume include obtaining carbon dioxide and flow measurements at or near the mouth of a subject. Such measurements are obtained during baseline breathing and during and shortly after inducement of a change in the subject's effective ventilation. The obtained measurements are evaluated to determine the amount of time required for exhaled carbon dioxide levels to return to normal—effectively an evaluation of carbon dioxide “washout” from the subject's lungs. Conversely, carbon dioxide and flow measurements may be evaluated to determine the amount of time it takes carbon dioxide to “wash in,” or reach peak levels within, the lungs of the subject following the change in the subject's effective ventilation. Apparatus for effective such methods are also disclosed.

The present invention relates to a method and an apparatus for measuring Functional Residual Capacity (CO). Further, it relates to a method and an apparatus for measuring cardiac output (CO). The method comprises the steps of determining the amount of oxygen and carbon dioxide being inhaled and exhaled during at least two breathing cycles, identifying at least one difference between said breathing cycles, and estimating the FRC and / or CO based on the determined uptake of oxygen and excretion of carbon dioxide and said identified difference.

A device and method is provided for increasing the functional residual capacity of lungs of a subject by electrically stimulating tissue associated with the diaphragm or phrenic nerve of the subject.

A device and a process for determining the change in the functional residual capacity (FRC) in a simple manner. Based on a first respiration phase for mechanical respiration, a recruitment maneuver is performed for this during a second respiration phase, and respiration is switched back to mechanical respiration during a third respiration phase. Reference values Uref / 1, Uref / 3 are formed from the end-expiratory values of the impedance measured signals U during the first respiration phase and the third respiration phase, and the difference ΔU (ΔFRC) between the reference value Uref / 3 of the third respiration phase and the reference value Uref / 1 of the first respiration phase is an indicator of the change in the functional residual capacity of the lung of the test subject.

A patient ventilator for assisting a clinician in determining a suitable PEEP for the patient. The amount of the lung volume recruited / de-recruited at various levels of PEEP may be determined for use in selecting a desired PEEP. To this end, the functional residual capacity of the lungs is determined for a first PEEP level. The PEEP is then altered to a second level and a spirometry dynostatic curve of lung volume and pressure data is obtained. The lung volume on the dynostatic curve at a lung pressure corresponding to the first PEEP value is obtained. The difference between the functional residual capacity of the lungs at the first PEEP level and that determined from the dynostatic curve represents the lung volume recruited / de-recruited when changing between said first and second PEEPs.

The functional residual capacity (FRC) value of a subject's lungs determined for each breath is related a volume dilution factor kn and the final FRC value is determined at the point where the volume dilution factor kn reaches a predetermined volume dilution factor value. The determination of the final FRC value can be based on interpolation or extrapolation from a measured breath data series. The volume dilution factor may be normalized value. This is achieved by division of all volume dilution factors with the initially determined volume dilution factor. With normalization, the compartments in which gas concentration change is achieved slowly are referenced with the faster, more effective compartments, thus giving a ventilation profile of the lungs.

The functional residual capacity (FRC) value of a subject's lungs determined for each breath is related a volume dilution factor kn and the final FRC value is determined at the point where the volume dilution factor kn reaches a predetermined volume dilution factor value. The determination of the final FRC value can be based on interpolation or extrapolation from a measured breath data series. The volume dilution factor may be normalized value. This is achieved by division of all volume dilution factors with the initially determined volume dilution factor. With normalization, the compartments in which gas concentration change is achieved slowly are referenced with the faster, more effective compartments, thus giving a ventilation profile of the lungs.

An apparatus for calculating a residual capacity of a secondary battery is provided. The apparatus calculates the residual capacity of energy in the secondary battery which is charged / discharged. The apparatus includes an arithmetic unit which estimates and calculates a first residual capacity based on a charge / discharge voltage corresponding to a residual capacity of the secondary battery, calculates a second residual capacity based on an integrated value of a charge / discharge current of the secondary battery, weights the charge / discharge voltage of the secondary battery with the first residual capacity or the second residual capacity according to the voltage changing rate, and combines the results of the weighting to obtain the residual capacity of the secondary battery.

The present disclosure relates to methods and systems for estimating an efficiency of lungs of a patient receiving respiratory care. A blender has a primary input port for receiving a first gas to bedelivered to the patient and one or more secondary input ports for receiving a second gas to be delivered to the patient from one or more gas sources. A patient-side port of the blender delivers the first and second gases to the patient. A gas composition sensor measures a fraction of the first gas and a gas flow sensor measures a flow of the first gas. A controller causes a sequential delivery ofthe first and second gases to the patient and estimates a functional residual capacity of the patient based on measurements from the gas composition sensor and from the gas flow sensor. The controller may also estimate a cardiac output of the patient.

A Comprehensive Integrated Testing Protocol (CITP) incorporates precise measurements of the dynamic and the static lung volumes and capacities at V30 for routine infant lung function testing. The static functional residual capacity (sFRC) in infants is measured after a short hyperventilation induces a post-hyperventilation apnea (PHA) that abolishes the infant's breathing strategies and creates a reliable volume landmark. A measurement of the sFRC is then obtained by inert gas washout; e.g., by measuring the volume of nitrogen expired after end-passive expiratory switching of the inspired gas from room air to 100% oxygen during the PHA. A true measurement of the total lung capacity (TLC) is obtained from the sum of (1) the passively exhaled gas volume from a Pao plateau of 30 cm H2O through a pneumotachometer (PNT) by integrating the flow signal to produce volume, which is the inspiratory capacity (IC), and (2) the sFRC. From intrasubject TLC and residual volume (RV), the difference is a reliable estimate of the slow vital capacity (SVC). Similar measurements may be obtained with a fastened squeeze jacket for comparison. Actual airway opening pressure (aPao) is measured during a 0.20 s airway occlusion after halting the inflating airflow and prior to activating the jacket inflation. An open mouth is maintained during forced expiration in order to generate an oronasal instead of a forced expiration.

A pulmonary expansion therapy (PXT) device may be a handheld device that covers specific lung fields and may generate negative pressure fields locally. The device also may provide vibratory / percussion therapy for airway clearance. The PXT may generate a localized negative pressure field non-invasively to the exterior of the chest wall, thereby increasing the functional residual capacity in underlying lung fields. As a result, increased ventilation and perfusion to the targeted internal lung field may be achieved by creating a decrease in the external barometric pressure relative to the more positive intrinsic airway pressures. The PXT device also may improve lung compliance by enabling a medical professional to grab and elevate the chest wall to compensate for the dysfunction of the respiratory musculature responsible for lifting the chest wall. In some embodiments, once a targeted functional residual capacity (FRC) has been established, vibration or percussion may be applied.

Described is a system for detecting a wearable device worn by a monitored individual, notifying a system of the detecting of the wearable device worn by the monitored individual, receiving provisioning information from the system, and provisioning the wearable device according to the provisioning information. The provisioning information can configure the wearable device to provide information associated with the monitored individual to a monitoring device to enable the monitoring device to provide healthcare services to the monitored individual.

Provided are a system and a method that determine the functional residual capacity of a subject in an automated manner. The determination of the functional residual capacity of the subject is made by analyzing the washout and / or wash-in of one or more molecular species present in gas breathed by the subject. The determination of the functional residual capacity can be made without a determination of oxygen consumption.

A Comprehensive Integrated Testing Protocol (CITP) incorporates precise measurements of the dynamic and the static lung volumes and capacities at V30 for routine infant lung function testing. The static functional residual capacity (sFRC) in infants is measured after a short hyperventilation induces a post-hyperventilation apnea (PHA) that abolishes the infant's breathing strategies and creates a reliable volume landmark. A measurement of the sFRC is then obtained by inert gas washout; e.g., by measuring the volume of nitrogen expired after end-passive expiratory switching of the inspired gas from room air to 100% oxygen during the PHA. A true measurement of the total lung capacity (TLC) is obtained from the sum of (1) the passively exhaled gas volume from a Pao plateau of 30 cm H2O through a pneumotachometer (PNT) by integrating the flow signal to produce volume, which is the inspiratory capacity (IC), and (2) the sFRC. From intrasubject TLC and residual volume (RV), the difference is a reliable estimate of the slow vital capacity (SVC). Similar measurements may be obtained with a fastened squeeze jacket for comparison. Actual airway opening pressure (aPao) is measured during a 0.20 s airway occlusion after halting the inflating airflow and prior to activating the jacket inflation. An open mouth is maintained during forced expiration in order to generate an oronasal instead of a forced expiration.

1,1,1,2-Tetrafluoroethane (norflurane) is used as a tracer / trace gas for measuring the lung function because of its simple detectability, physiological harmlessness, environmental friendliness and ready availability. Especially advantageous is the possibility of the optical concentration measurement of 1,1,1,2-tetrafluoroethane for the measurement of the lung function and especially for the determination of the FRC during respiration during anesthesia, without cross sensitivity occurring during the measurement with respect to anesthetics.