| Patent application number | Description | Published |
|---|
| 20090241951 | LEAK-COMPENSATED PRESSURE TRIGGERING IN MEDICAL VENTILATORS - This disclosure describes systems and methods for compensating for inelastic and elastic leaks in a ventilation system. The disclosure describes a model-based enhancement to conventional pressure triggering methodology that optimizes the timing and patient work of pressure triggering performance. The methods and systems described herein compensate for the additional effort a patient has to exert to generate the same amount of airway pressure drops compared to no leak condition. One method described includes calculating an elastic leakage and an inelastic leakage based on current measurements of pressure and flow in the ventilation system and then compensating a pressure threshold for the effects of the inelastic and elastic leaks in the system. | 10-01-2009 |
| 20090241955 | LEAK-COMPENSATED FLOW TRIGGERING AND CYCLING IN MEDICAL VENTILATORS - This disclosure describes systems and methods for compensating for inelastic and elastic leaks in a ventilation system. The disclosure describes a model-based enhancement to conventional flow triggering and cycling methodologies that improves the timing and patient work of flow-based triggering and cycling performance. The methods and systems described herein compensate for the leak condition and minimize additional effort a patient has to exert to generate the same patient synchrony and comfort level compared to no leak condition. One method described includes calculating an elastic leakage and an inelastic leakage based on current measurements of pressure and flow in the ventilation system and then estimating a leak-compensated lung flow using the inelastic and elastic leaks and pneumatic attributes of the patient-ventilator system. | 10-01-2009 |
| 20090241962 | VENTILATOR LEAK COMPENSATION - A ventilator including a pneumatic system for providing and receiving breathing gas, and a controller operatively coupled with the pneumatic system. The controller is operable to control circulation by the pneumatic system of breathing gas to and from a patient, and to adjust at least one of a volume and pressure of breathing gas delivered to the patient, such adjustment being based upon elastic properties of a component used to fluidly couple the pneumatic system to a patient. | 10-01-2009 |
| 20100071696 | MODEL-PREDICTIVE ONLINE IDENTIFICATION OF PATIENT RESPIRATORY EFFORT DYNAMICS IN MEDICAL VENTILATORS - Systems and methods for efficient computation of patient respiratory muscle effort are provided. According to one embodiment, patient-ventilator characteristics are received, estimated and/or measured representing values of parameters of interest associated with properties or attributes of a ventilated patient system. Online quantification of respiratory muscle effort of the patient is continuously performed by (i) establishing a respiratory predictive model of the ventilated patient system based on an equation of motion and functions that approximate clinically-observed, patient-generated muscle pressures, (ii) determining an instantaneous leak flow value for the ventilated patient system, and (iii) based on the patient-ventilator characteristics and the instantaneous leak flow value, solving the respiratory predictive model to extract an estimated physiologic respiratory muscle effort value. Then, based on the respiratory muscle effort value or other parameters derived therefrom, the ventilation system is configured and operated for monitoring or breath delivery purposes. | 03-25-2010 |
| 20100081119 | CONFIGURABLE RESPIRATORY MUSCLE PRESSURE GENERATOR - Systems and methods are provided for etiologic-based breath simulation and/or ventilator test platforms that provide operator-configurable breathing patterns, patient respiratory muscular effort waveform characteristics and patient parameter values. According to one embodiment, multiple respiratory muscle effort waveform specifications, each of which have associated therewith one or more waveform parameters, are provided for use by a breathing effort generator. The waveform specifications include (i) a specification based upon an empirical model that approximates clinically-observed, patient-generated muscle pressures, (ii) a specification based on configurable etiology-driven templates and/or (iii) a specification based on a configurable piecewise trajectory template. A waveform engine of the breathing effort generator is configured in accordance with a selected waveform specification and corresponding waveform parameter values. Finally, the desired breathing pattern is simulated by a lung simulation system based on one or more model parameter values and a respiratory muscle effort waveform generated by the waveform engine. | 04-01-2010 |
| 20100147303 | DETERMINATION OF PATIENT CIRCUIT DISCONNECT IN LEAK-COMPENSATED VENTILATORY SUPPORT - This disclosure describes systems and methods for detecting disconnect conditions in a ventilator. The disclosure describes a model-based enhancement to conventional disconnect detection. The methods and systems described herein compensate for the additional leakage that occurs due to inelastic and elastic leaks in the ventilation system. One method described includes calculating the actual leakage from the ventilation system including leaks from elastic leakage and inelastic leakage based on measurements of pressure and flow in the ventilation system for a breath and then comparing this leakage to a calculated hypothetical maximum allowable leakage determined based on an operator-selected maximum allowable leakage and the measurements of pressure for the same breath. Disconnection is assumed if the actual leakage is greater than the maximum allowable leakage. | 06-17-2010 |
| 20100218765 | FLOW RATE COMPENSATION FOR TRANSIENT THERMAL RESPONSE OF HOT-WIRE ANEMOMETERS - Systems and methods are described for application of a transitory corrective modification to a hot-wire anemometer flow voltage and/or calculated flow rate to compensate for transient thermal response of the anemometer during a change in mixture of a mixed gas being measured. According to one embodiment a method of applying the transitory corrective modification is provided. An output signal of an exhalation flow sensor of a medical ventilator is received. The flow sensor includes a hot-wire anemometer. The output signal is indicative of a rate of flow of expired gas by a patient. Transient thermal response of the hot-wire anemometer is compensated for by applying a corrective modification to the output signal or a value based thereon. The corrective modification is based at least in part on a fraction of inspired oxygen (FiO2) being supplied by the medical ventilator to the patient. | 09-02-2010 |
| 20100218767 | LEAK-COMPENSATED RESPIRATORY MECHANICS ESTIMATION IN MEDICAL VENTILATORS - This disclosure describes systems and methods for compensating for leakage when determining the respiratory mechanics of a patient during delivery of gas from a medical ventilator to a patient. The systems and methods include monitoring an instantaneous flow in the ventilation system based on one or more measurements of pressure and flow in ventilation system. The leakage is modeled using a predetermined leakage model. A leak-compensated instantaneous lung flow of gas inhaled or exhaled by the patient is estimated. Using the leak-compensated lung flow and a predetermined respiratory mechanics model, the respiratory mechanics of a patient may be estimated including at least one of a leak-compensated lung compliance and a leak-compensated lung resistance. The method may include using a dynamic respiratory mechanics model or a static respiratory mechanics model that requires use of a pause maneuver to collect the necessary data. | 09-02-2010 |
| 20100236553 | LEAK-COMPENSATED PROPORTIONAL ASSIST VENTILATION - This disclosure describes systems and methods for compensating for leakage when during delivery of gas from a medical ventilator in a proportional assist mode to a patient. The technology described herein includes systems and methods to compensate the delivery of PA ventilation for leakage in the patient circuit by using leak-compensated lung flows as well as leak-compensated respiratory mechanics parameters (lung compliance and lung resistance) estimated in a manner that compensates for elastic and inelastic leaks from the ventilation system. | 09-23-2010 |
| 20100236555 | LEAK-COMPENSATED PRESSURE REGULATED VOLUME CONTROL VENTILATION - This disclosure describes systems and methods for compensating for leakage when during delivery of gas to a patient from a medical ventilator in a pressure regulated volume control (PRVC) ventilation mode. The technology described herein includes systems and methods that compensate the delivery of PRVC ventilation for leakage in the patient circuit by using leak-compensated lung flows as well as respiratory mechanics (lung compliance and lung resistance) estimated in a manner that compensates for elastic and inelastic leaks from the ventilation system. | 09-23-2010 |
| 20110146681 | Adaptive Flow Sensor Model - The disclosure describes a novel approach of estimating patient sensor data for sensors in sensor tubing or sensor lines during purging or autozeroing or any other situations under which no measurement is provided by the sensor. | 06-23-2011 |
| 20110146683 | Sensor Model - The disclosure describes a novel approach of utilizing a model-based approach for estimating a parameter at the wye without utilizing a sensor at the wye in the circuit proximal to the patient. | 06-23-2011 |
