138 results about "End-expiration" patented technology

Methods and devices are provided that are effective to remove an obstruction in a human airway and/or maintain an open airway. The methods and devices are particularly useful for patients suffering from snoring and/or OSA, and/or preventing upper airway obstructions in patients undergoing anesthesia. In one embodiment, the device includes a mouthpiece that is adapted to form a substantially sealed cavity within a human mouth, and a hollow elongate member having a first end that is coupled to the mouthpiece and that is in communication with the substantially sealed cavity, and a second end that is adapted to be coupled to a negative pressure generator. In use, a negative pressure generator can be attached to the hollow elongate member to create a negative pressure in a human mouth in response to an obstructed airway, thereby removing the obstruction. In particular, this device is effective to counteract the collapse of a patient's soft tissues of the upper airway to reopen the airway. The mouthpiece can also be used in combination with a nasal mask. In another embodiment, the oral appliance above also comprises a nasal mask, wherein the nasal mask provides a means of ventilation support, including but not limited to total mechanical ventilation, positive-end expiratory pressure, or continuous positive airway pressure. In use, such a device can provide complete patient ventilation and maintain an open upper airway.

A portable mechanical ventilator having a Roots blower is configured to provide a desired gas flow and pressure to a patient circuit. The mechanical ventilator includes a flow meter operative to measure gas flow produced by the Roots blower and an exhalation control module configured to operate an exhalation valve connected to the patient circuit. A bias valve connected between the Roots blower and the patient circuit is specifically configured to generate a bias pressure relative to the patient circuit pressure at the exhalation control module. The bias valve is further configured to attenuate pulsating gas flow produced by the Roots blower such that gas flowing to the mass flow meter exhibits a substantially constant pressure characteristic. The bias pressure facilitates closing of the exhalation valve at the start of inspiration, regulates positive end expiratory pressure during exhalation, and purges sense lines via a pressure transducer module.

A method of automatically controlling a respiration system for proportional assist ventilation with a control device and with a ventilator. An electrical signal is recorded by electromyography with electrodes on the chest in order to obtain a signal u_emg(t) representing the breathing activity. The respiratory muscle pressure p_mus(t) is determined by calculating it in the control unit from measured values for the airway pressure and the volume flow Flow(t) as well as the patient's lung mechanical parameters. The breathing activity signal u_emg(t) is transformed by means of a preset transformation rule into a pressure signal p_emg(u_emg)(t)) such that the mean deviation of the resulting transformed pressure signal p_emg(t) from the respiratory muscle pressure p_mus(t) is minimized. The respiratory effort pressure p_pat(t) is determined as a weighted mean according to p_pat(t)=a·p_mus(t)+(1−a)·p_emg(t), where a is a parameter selected under the boundary condition 0≦a≦1. The airway pressure p_aw(t) to be delivered is calculated as a function of preselected degrees of assist VA (Volume Assist) and FA (Flow Assist) by sliding adaptation as

wherein t_i is a current point in time and t_i−j, wherein j=1, . . . , n, are previous points in time of a periodical time-discrete sampling, and k_j and h_j, wherein j=1, . . . , n are parameters dependent on resistance (R), elastance (E), positive end-expiratory pressure (PEEP), intrinsic PEEP (iPEEP), Volume Assist (VA) and Flow Assist (FA) and the sampling time Δt, and the ventilator is set by the control unit so as to provide this airway pressure p_aw(t_i)

The present invention describes a method and apparatus for non-invasive prediction of the “intrinsic positive end-expiratory pressure” (PEEPi) which is secondary to a trapping of gas, over and above that which is normal in the lungs; the presence of PEEPi imposes an additional workload upon the spontaneously breathing patient. Several indicators or markers are presented to detect and quantify PEEP_i non-invasively The markers may include an expiratory air flow versus expiratory air volume trajectory, an expiratory carbon dioxide flow versus expiratory air volume trajectory, an expiratory carbon dioxide volume to expiratory air volume ratio, an expiratory air flow at onset of inhalation, a model of an expiratory waveform, a peak to mid-exhalation airflow ratio, duration of reduced exhaled airflow, and a Capnograph waveform shape.

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 and apparatus for determining the presence or absence of a pulmonary embolism (PE) in a patient. The breathing gas CO₂ partial pressure (PCO₂) during the expiration of breathing gases by the patient, the end tidal (EtCO₂), CO₂ partial pressure, and the CO₂ partial pressure (PaCO₂) of the blood are measured. The volume (V) of breathing gases expired during the expiration of breathing gases by the patient is also measured and a relationship between changes in breathing gas CO₂ partial pressure (PCO₂) and changes in breathing gas volume (V) in an alveolar expiration phase of patient expiration is determined. The difference between the blood CO₂ partial pressure (PaCO₂) and the end expiration CO₂ partial pressure is divided by the relationship between PCO₂ and V produce a quantity which is compared to a threshold value. If the quantity is below the threshold value, the absence of a pulmonary embolism is indicated.

A tracheal tube ventilation apparatus to more effectively remove expired gases. In one preferred embodiment, one or more leak holes are created in the side walls of an endotracheal tube so that expired gases can leak out of the endotracheal tube above the larynx, such as into the back of the mouth (i.e., oropharynx). Each leak hole might advantageously have a diameter between 0.5 and 4.0 mm. In another preferred embodiment, a tube is attached to a proportionately larger leak hole (e.g., up to 8.0 mm) so that the expired gases can be directed away from the leak hole to a specific location, such as directed out of the mouth. In the case of mechanically controlled ventilation, a positive end expiratory pressure can be applied to this tube to mechanically assist with the process of exhaling. In each of these embodiments, it is preferred, but not required, that the endotracheal tube be an ultra-thin walled, two stage tube so as to further assist in the reduction of resistance to the flow of oxygen/air.

A mask interface device is provided for a protective mask of the type having a mask filter and a mask expiratory port, the mask expiratory port having an expiratory port valve of the type that is normally closed and openable upon expiration, the mask filter having an inspiratory air inlet, the mask interface device comprising: a mask interface assembly mountable to the mask and having a mounting interface for mounting an air pressure generator in fluid communication with the inspiratory inlet of the mask filter; and an expiratory port interface assembly mountable to the mask expiratory port and comprising at least one opening for venting expired gas to atmosphere and a one-way valve that is positioned to control the flow of expired gas out through the at least one opening, and wherein the one-way valve is set to an opening pressure that provides positive end expiratory pressure or PEEP. Optionally, this opening pressure is between 2.5 and 20 cm H2O. Optionally, the mask interface device interface directly with the mask filter. In one embodiment of the invention, this interface does not require the filter to have a mating connection and is therefore is universal for a broad class of filters, for example cylindrical filters that project from the mask.

A respiratory valve apparatus with a housing having an inner chamber, an endotracheal tube connection port, a respirator connection port and a resuscitation bag connection port. A valve positioned within the inner chamber can switch the flow between a manual resuscitation bag port and a ventilator port enabling the patient to be treated without having to disconnect the respirator support system to thereby connect the resuscitation bag. This prevents the loss of positive end expiratory pressure (PEEP) in the lungs and guards against lung collapse and hemodynamic compromise. The valve includes preloaded seals that will create minimal dragging during valve actuation and work under both positive and negative pressure. The apparatus includes a tethered cover for closure of the resuscitation bag port for sealably covering the port when a bag is not attached or the ventilator connector during patient transport. A sealing arrangement within the resuscitator bag port insures that PEEP in maintained when the resuscitator bag adapter is inserted into the housing.

System and method of monitoring a patient including acquiring a respiration waveform and an arterial pressure waveform and determining a window on the respiration waveform that represents end expiration and approximates an apnea condition. The method can include calculating a systolic pressure variation value, a delta up value, and a delta down value based on a portion of the arterial pressure waveform corresponding to the window on the respiration waveform. In some embodiments, the respiration waveform can be acquired without manual interruption of mechanical ventilation and the values can be calculated substantially continuously.

The present invention discloses a mechanical PEEP (Positive End-Expiratory Pressure) valve, and mainly relates to a medical positive end-expiratory pressure device which is adjusted manually. The mechanical PEEP valve of the invention mainly comprises a valve body (1), a connecting component (4), a guiding component (7) and a spring (8), wherein the valve body (1) and the connecting component (4) are connected by screw. The spring (8) is sleeved on the guiding component (7) and is positioned between the connecting component (4) and the guiding component (7). The connecting component (4) is sleeved on the guiding component (7). The connecting component and the guiding component (7) are in clearance fit. The mechanical PEEP valve with the structure can use the spring (8) for realizing the adjustment to PEEP value. The adjusting range is between 0 and 20cmH2O thereby adapting the requirement of patients with different states. Furthermore the gravity force exerted on the diaphragm (9) satisfies the opening pressure requirement of EN740 when the spring pressure is zero.

The invention discloses a control method and control system for implementing double horizontal pressures in an air passage. The control method comprises the following steps of: enabling the air inlet end of the air passage to be in a cut-off state or conducting state; enabling the air outlet end of the air passage to be in a cut-off state or conducting state with the external atmosphere by means of an expiratory valve; communicating a control air channel at the control end of the expiratory valve with an air supply source, and keeping the control air channel in a throttling state or full-conducting state, wherein the low-level pressure of the air passage can be set by regulating the throttling quantity of the control air channel in the throttling state; and controlling the state of the air inlet end of the air passage and the state of the control air channel of the expiratory valve in accordance with breath settings and the detected pressure of the air passage. The invention also discloses an anaesthetic machine and breathing machine with the control system. By using the method and system, the invention can completely achieve the functions which can be realized by adopting a proportional valve, an electronic PEEP (Positive End Expiratory Pressure) valve and closed-loop control, and has the advantages of simple design and low cost.

The invention relates to an air channel system of a pilot type control belt intelligent PEEP (positive end expiratory pressure) breathing machine. The air channel system is communicated with a user through an external interface, a communication pipeline and a Peep value (PEEP) and comprises an oxygen communication pipeline, a reduced pressure pump (REG1), an oxygen flow regulation valve (NV1), an air communication pipeline, an air inlet single-way valve (DV1), an air flow regulating valve (NV2) and a Venturi device (WENTURI), wherein the reduced pressure pump (REG1) and the oxygen flow regulation valve (NV1) are arranged on the oxygen communication pipeline; the air inlet single-way valve (DV1) and the air flow regulating valve (NV2) are arranged on the air communication pipeline; the output end of the Venturi device (WENTURI) is communicated with the external interface through a main pipeline, the input end of the Venturi device (WENTURI) is communicated with the oxygen communication pipeline, the bypass of the Venturi device (WENTURI) is communicated with the air communication pipeline; Peep valve controls a branch air channel as well as a proportion solenoid valve (PSOL1) and a safety solenoid valve (SOV1) which are arranged on the branch air channel; and the outlet end of the proportion solenoid valve (PSOL1) is communicated with the pneumatic control end of the Peep valve, the inlet end of the safety solenoid valve (SOV1) is communicated with the oxygen communication pipeline, and the air discharge end of the safety solenoid valve (SOV1) is communicated with the Venturi device (WENTURI). The air channel system is high in work stability, long in working life, continuous and adjustable in PEEP, high in safety coefficient and low in air consumption.

The present invention discloses a method for improving control and detection precision of tidal volume by introducing R value, comprising the steps of: a plateau pressure Pplate is used to calculate a system compliance C with C=ΔV/(Pplate−PEEP); V_T, the tidal volume obtained currently at patient terminal, is calculated with V_T=ΔV×(C−Ctube)/C, wherein ΔV is the variation of tidal volume, PEEP is the positive end expiratory pressure and Ctube is the compliance C of the line. Depending on the calculated V_T, the tidal volume which is actually obtained by the patients during this period, the processing unit calculates the tidal volume V_T′, which the airway is intended to reach during the next expiration period, by V_T′=V_T+ΔV_T×K wherein K is a scaling factor for control and adjustment, V_T is the tidal volume obtained by the patient during the current period, V_Tset is the presetted tidal volume, ΔV_T=V_Tset−V_T. And the processing unit accordingly controls the opening position of the inspiratory valve during the next inspiration period, so as to achieve the purpose of improving control and detection of precision tidal volume.

A method for measuring lung collapse and for providing information regarding recruitment and successfulness of actions taken to recruit the lung is provided. Alveolar- and proximal pressures are determined at different lung pressures or volumes. Patient airway resistance is calculated combining these measurements with flow measurement. Plotting the resistance against the lung pressure or volume gives a within-breath distribution of the resistance. Increase of this resistance at end-expiration volume or pressure indicates lung collapse.

An anesthesia delivery and ventilation system (ADVS) includes an expiratory section, a circulation flow system (CFS), an inspiratory section, a ventilation drive system (VDS), and an anesthesia delivery system (ADS). The expiratory section receives gases from a patient and the inspiratory section and fresh gases from a fresh gas supply system. An elastic mixing reservoir receives and mixes the gases circulated by the CFS with residual gases via a connector element. The inspiratory section connects to the expiratory section at one end and to a patient connector tube at the other end. The ADS infuses an anesthetic agent into the mixed gases in the inspiratory section. The VDS delivers the mixed gases with the anesthetic agent to the patient. The VDS and the CFS are controlled and operate independently of each other to provide positive end-expiratory pressure control and ventilation control to the patient without use of a proportional valve.

The invention discloses an exhalation valve of a breathing machine. The exhalation valve comprises a cavity body and a diaphragm arranged in the cavity body, wherein the surface at one side of the diaphragm encloses a pressure buffer cavity communicated with an air source with the cavity body, and the surface at the other side of the diaphragm encloses an exhaled air buffer cavity used for accommodating air exhaled by a patient with the cavity body. When the diaphragm is at a first position, the exhaled air buffer cavity is not communicated with the outside, and when the diaphragm is at a second position, the exhaled air buffer cavity is communicated with the outside. The exhalation valve also comprises an air supplement pipe used for supplementing air into the exhaled air buffer cavity, wherein one end of the air supplement pipe is communicated with the air source, while the other end is communicated with the exhaled air buffer cavity. The invention abandons a conventional method, and does not pay attention to the point on how to reduce exhaled air leakage, but looks for another way to adopt the air supplement method; and pressure lost by the leakage is supplemented, which thoroughly avoids the reduction of the pressure of the exhaled air, thus the purpose of maintaining the positive end expiratory pressure constant is truly achieved.

A breathing apparatus (1) is disclosed that is adapted to determine a transpulmonary pressure in a patient (125) when connected to said breathing apparatus. A control unit (105) is operable to set a first mode of operation for ventilating said patient with a first Positive End Expiratory Pressure (PEEP) level; set a second mode of operation for ventilating said patient with a second PEEP level starting from said first PEEP level; and determine said transpulmonary pressure (Ptp) based on a change in end-expiratory lung volume (ΔEELV) and a difference between said first PEEP level and said second PEEP level (ΔPEEP). Furthermore, a method and computer program are disclosed.

A pressurized flow of breathable gas is delivered to the airway of a subject in accordance with a therapy regimen. The therapy regimen may be designed to maintain oxygenation of the subject. The therapy regimen dictates levels of fraction of inspired oxygen and/or positive end expiratory pressure to maintain a therapeutically beneficial level of oxygenation in a feedback manner. Within the therapy regimen, changes made to fraction of inspired oxygen and/or positive end expiratory pressure automatically and dynamically are constrained by user configured constraints such as the maximum incremental change, amount of time between adjustments, or the maximum rate of change This may provide a level of customization of the automated control of the therapy regime for individual subjects.