Ventilator systems and methods

A ventilator system includes a ventilator and a host. The ventilator comprises a ventilation drive configured to drive ventilation gas from a gas source to a patient and a patient interface section configured to guide inspiratory gas along an inspiratory path from the ventilation drive to a patient connection, and guide expiratory gas along an expiratory path from the patient connection out of the ventilator. The patient interface section is configured to releasably connect to the ventilation drive. The ventilator is configured to removably connect to the host such that at least one of the inspiratory path and the expiratory path are diverted through the host when the ventilator is removably connected to the host.

BACKGROUND

The present disclosure is related to the field of patient ventilation, including mechanical ventilation, and more particularly to a portable ventilation drive and adaptable ventilation system to facilitate ventilation of a patient in multiple different settings where mechanical ventilation or other respiratory support is required.

Over the course of a medical treatment, a patient may require some form of respiratory support provided by a ventilator or may require multiple different types of respiratory support which is generally provided by different types of ventilation devices in different settings. Respiratory support may include assisted breathing, wherein the ventilator detects breath attempts and provides supplemental pressure and gas flow for the patient to complete and effective respiratory cycle. Other forms of respiratory support include mechanical ventilation, whereby the ventilator also initiates the respiratory phase of each respiratory cycle.

Different types of mechanical ventilators are available that each provide mechanical ventilation for a particular setting, such as an intensive care ventilator configured to provide mechanical ventilation support for an extended duration of time and an operating room ventilator configured to provide anesthetic gas to the patient and to provide respiratory support to the patient while they are under general anesthesia. During treatment, the patient receiving respiratory support may need to be transferred between ventilator systems. One example of this transfer may occur when a patient is switched between receiving respiratory support from an anesthesia ventilator used during surgery to an intensive care unit (ICU) ventilator to which the patient may be connected before and/or after the surgical procedure. This transfer necessarily requires disconnection of the patient from one ventilator before connection to another, leaving a period when the patient is disconnected from receiving respiratory support from either ventilator. This connection and disconnection of the patient also exposes the patient's airway to pathogens and can lead to acquisition of a nosocomial infection.

SUMMARY

In one embodiment, a portable ventilator includes a ventilation drive configured to drive ventilation gas from a gas source to a patient, wherein the portable ventilator is configured to removably connect to a host such that when the portable ventilator is connected to the host the ventilation drive drives ventilation gas from a host gas source to the patient and when the portable ventilator is not connected to the host the ventilation drive drives ventilation gas from a portable gas source to the patient.

One embodiment of a patient ventilation system includes a first host connected to a first host gas source, a portable ventilator configured to removably connect to the first host, and a portable gas source connected to the portable ventilator. The portable ventilator includes a ventilation drive configured to drive ventilation gas from the first host gas source to a patient when the portable ventilator is connected to the first host and to drive ventilation gas from the portable gas source to the patient when the portable ventilator is not connected to the first host.

In certain examples, the inspiratory gas from the portable gas source is at a first pressure and the inspiratory gas from the anesthesia gas source is at a second pressure, wherein the second pressure is greater than the first pressure. In certain embodiments, the portable ventilator may further comprise a portable gas source input valve configured to automatically open to allow the ventilation gas to flow from the portable gas source when the portable ventilator is not connected to the host gas source. For example, the portable gas source input valve may be configured to open when a delivery pressure of ventilation gas from the host gas source is lower than a delivery pressure of ventilation gas from the portable gas source.

In certain embodiments, the portable ventilator may include a ventilation drive section and a patient interface section. In certain examples, the ventilation drive section and a patient interface section may be configured to removably connect together and may be separable for cleaning and/or maintenance.

One embodiment of a method of ventilator operation includes operating a ventilation drive of a portable ventilator to drive ventilation gas from a portable gas source through a patent interface to a patient, wherein the ventilation gas from the portable gas source is at a first pressure. Upon connection of the portable ventilator to a host, the ventilation drive is operated to drive ventilation gas from a host gas source through the patent interface to the patient, wherein the ventilation gas from the host gas source is at a second pressure, wherein the second pressure is greater than the first pressure. In certain examples, the ventilation drive may automatically revert back to driving ventilation gas from the portable gas source through the patent interface to the patient upon the second pressure of the host gas source becoming less than the first pressure of the host gas source.

One embodiment of a ventilator includes a ventilation drive configured to drive ventilation gas from a gas source to a patient and a patient interface section configured to guide inspiratory gas from the ventilation drive to a patient connection, receive expiratory gas from the patient connection, and expel the expiratory gas out of the ventilator. The ventilation drive and patient interface section are configured to removably connect to at least one host comprising a ventilation path portion so as to divert the inspiratory gas through the ventilation path portion of the host when connected thereto.

In one embodiment, the host may be an anesthesia host comprising a circle breathing system and the ventilation drive is configured to removably connect to the anesthesia host and the circle breathing system. In certain examples, the ventilation drive may be configured to drive inspiratory gas from a host gas source, such as an anesthesia gas source, through the patient interface section to the patient when connected to the host, and to drive inspiratory gas from a portable gas source through the patent interface section to the patient when the ventilator is not connected to the host.

One embodiment of an anesthesia ventilator system includes a portable ventilator comprising a ventilation drive configured to drive inspiratory gas from a gas source to a patient and a patient interface section configured to guide inspiratory gas from the ventilation drive to a patient connection, receive expiratory gas from the patient connection, and expel the expiratory gas out of the portable ventilator. The anesthesia ventilator system further includes a circle breathing system, a scavenging system, and a host gas source. The portable ventilator is configured to removably connect to the circle breathing system, the scavenging system, and the host gas source, wherein the ventilation drive is configured to drive inspiratory gas from the host gas source to the patient through the patient interface section when connected, and to drive inspiratory gas from a portable gas source to the patient through the patent interface section when disconnected.

One embodiment of a method of ventilator operation includes operating a ventilation drive to drive inspiratory gas through a patent interface section to a patient. Upon connection of the ventilation drive and the patient interface section to an a host comprising a ventilation path portion, operating the ventilation drive to drive inspiratory gas from an anesthesia gas source through the ventilation path portion and the patent interface section to the patient.

In certain embodiments, upon connection of the ventilation drive and/or the patient interface section to the host, a host source connection valve is opened to facilitate flow of inspiratory gas from a host gas source to the ventilation drive and closing a portable gas source input valve to stop flow of inspiratory gas from the portable gas source to the ventilation drive. In further embodiments, upon connection of the ventilation drive and/or the patient interface section to the host, at least one inspiratory diverter valve in the patient interface section is opened, wherein the inspiratory diverter valve is configured to divert the inspiratory gas from the patient interface section through the circle breathing system.

In one embodiment, a ventilator system includes a ventilator and a host. The ventilator comprises a ventilation drive configured to drive ventilation gas from a gas source to a patient and a patient interface section configured to guide inspiratory gas along an inspiratory path from the ventilation drive to a patient connection, and guide expiratory gas along an expiratory path from the patient connection out of the ventilator. The patient interface section is configured to releasably connect to the ventilation drive. The ventilator is configured to removably connect to the host such that at least one of the inspiratory path and the expiratory path are diverted through the host when the ventilator is removably connected to the host. In certain embodiments, the expiratory path does not enter the ventilation drive such that the ventilation drive does not receive any patient expiratory gas and, in further embodiments, the patient interface section is separately removable from the ventilator system while the ventilation drive is connected to the host and is a cleanable and sterilizable unit.

One embodiment of a ventilator includes a ventilation drive configured to drive ventilation gas from a gas source to a patient and a patient interface section configured to guide inspiratory gas along an inspiratory path from the ventilation drive to a patient connection, and guide expiratory gas along an expiratory path from the patient connection out of the ventilator. The patient interface section is configured to releasably connect to the ventilation drive. The ventilation drive is configured to removably connect to a host such that when the ventilation drive is connected to the host the ventilation drive is configured to drive inspiratory gas from a host gas source through the patient interface section to the patient, and when the ventilation drive is not connected to the host the ventilation drive is configured to drive inspiratory gas from a portable gas source through the patient interface section to the patient.

DETAILED DESCRIPTION

The inventors have identified that several challenges exist for providing continuous respiratory support to a patient, particularly when an intubated patient must be transferred between ventilators. One major issue is continuous maintenance of positive end expiratory pressure (PEEP), another is infection avoidance as described above. Further, the inventors have recognized that the best patient care can be provided when a consistent and continuous ventilation connection is maintained, including constant connection to the ventilator via the patient connection device(s) and utilizing consistent ventilation parameters with no break in continuity.

Maintenance of PEEP is an important aspect of continuous mechanical ventilation, especially when the patient is receiving lung volume recruitment therapy. Certain medical conditions, including but not limited to atelectasis, result in collapsed alveoli. Collapsed alveoli can create a significant loss of lung volume and impair the efficiency of gas exchange. Typically, the gas exchange removes carbon dioxide from the patient's blood while introducing oxygen to the patient's blood. Specialized forms of respiratory support known as recruitment procedures have been developed to progressively open or “recruit” collapsed alveoli. Recruitment procedures may use specialized medical gases such as helium in addition to other medical gases of oxygen, nitrogen and air or other additives such as surfactant to reduce airway resistance. Still, recruitment procedures typically involve a series of prescribed ventilation pressure, including, but not limited to inspiratory pressure and expiratory pressure. PEEP is a common component of a prescribed recruitment procedure. PEEP puts a positive pressure on the patient's airway at the end of an expiratory phase of a breathing cycle to “hold open” open alveoli which would normally collapse under ambient pressure. Thus, the PEEP therapy preserves recruited lung volume, maintaining the lung volume gains achieved through the recruitment procedure.

Recruitment procedures typically occur over a prescribed period of time which may be hours or days. The recruitment procedure must take place over a time period as patients in need of lung recruitment typically also have low lung compliance and the recruited volume is desired to be gained from opening of alveoli rather than lung distension. Therefore, the recruitment procedure slowly increases the pressure applied to the lung over time as more alveoli are recruited and lung volume is gained.

However, as noted above, typically when a patient is transferred between ventilators at some point in the transition the patient must be disconnected from one ventilator and reconnected to the other ventilator. Even if this transition period is a short period of time (e.g., within seconds) the loss of the PEEP maintained in the system can cause the recruited alveoli to collapse, giving up any physiological gains that have been made through the previous recruitment procedure and other respiratory support. A new recruitment procedure or procedures must be performed over the aforementioned hours or days in order to re-recruit the lost lung volume. Therefore, embodiments of the portable ventilator2disclosed herein preserves the numeric conditions of the patient such that recruited lung volume is maintained and constant ventilation is performed.

The inventors have recognized that it is beneficial to the patient to maintain full ventilation functionality at all times, including oxygen supply and continuous and consistent ventilation pressure and ventilation parameters. The inventors developed the disclosed solution based on the above described problems and challenges in the relevant art of patient ventilation. In the disclosed system and method, one ventilation drive and patient connection thereto is continuously maintained such that the patient is continuously ventilated and no disconnection of the patient is ever necessary. The portable ventilator2and ventilation system1described herein allows continuous use of the same ventilation drive4and patient interface section6, which connect and disconnect from various hosts.

The portable ventilator2also operates on its own to provide full ventilation support to the patient, including full mechanical ventilation, assisted ventilation support, peep, etc. The portable ventilator2can attach to any of the various portable ventilation gas sources, such as oxygen tanks or wall gas, and can travel with the patient, such as when being transported between the surgical ward and the ICU, etc. The portable ventilator2can also connect to a host providing a high pressure gas source, such as a large oxygen cylinder or wall gas, to provide extended duration ventilation. The portable ventilator2may be configured to automatically utilize a host gas source12when connected thereto when the host10, provided that the host gas source12is available and functioning. The portable ventilator2may be configured to automatically revert to independent function and/or maintenance of ventilation from a portable gas source8whenever the portable ventilator2is disconnected from a host and/or the host gas source12is unavailable (e.g. is empty or has malfunctioned).

The portable ventilator2connects to any one of a plurality of hosts, alternately one at a time, in order to provide additional ventilation functions for particular situations, such as extended ICU ventilation, specialized ventilation maneuvers or tests, or anesthesia-related ventilation during surgical or other procedure. Thus, the portable ventilator is configured to connect to a plurality of different host types with differing ventilation functionalities depending on the patient care needs. The portable ventilator may be correspondingly designed with the various host types to enable connection and disconnection of the portable ventilator from each of the various hosts, one at a time.

In the embodiment atFIG.1, the ventilation system1includes a portable ventilator2removably connectable to one or more hosts, alternately one at a time. A portable gas source8is connected to the portable ventilator2and a host gas source12is connected to the host10. The portable ventilator2is configured to deliver ventilation gas to the patient16from either one of at least one portable gas source8and a host gas source12. For example, the portable ventilator2may be configured to deliver ventilation gas from the host gas source12whenever the portable ventilator2is connected to the host10and to deliver ventilation gas from the portable gas source8to the patient16whenever the portable ventilator2is not connected to any host. In certain embodiments, the host gas source12may be regulated at a higher delivery pressure of ventilation gas compared to the portable gas source8and the portable ventilator2may be configured to drive ventilation gas to the patient from whichever gas source is available and has the highest delivery pressure.

The portable ventilator2may include a ventilation drive4and a patient interface section6. The ventilation drive4is configured to drive ventilation gas from a gas source, which may be a portable gas source8directly to the portable ventilator2or a host gas source12connected to a host10to which the portable ventilator2is connected. The ventilation drive4drives the ventilation gas through the patient interface section6to the patient16. The patient interface section6is configured to deliver inspiratory gas from the ventilation drive4to the patient16and to receive expiratory gas exhaled by the patient16. The patient interface section6is further configured to expel the expiratory gas out of the portable ventilator2, which may be expelled to atmosphere or, in some embodiments, delivered to a scavenging system or delivered to the host10for further processing and/or recirculation to the patient (e.g. scavenging and/or CO2scrubbing and recirculation to the patient). The patient interface section6includes an inspiratory path60providing ventilation gas to be inhaled by the patient (inspiratory gas) from the ventilation drive4to the patient16. The patient interface section6further includes and defines an expiratory path70that receives expiratory gases exhaled from the patient16and expels the exhalation gas out of the portable ventilator2.

Referring also toFIGS.2A and5, the patient interface section6has an inspiratory connection port64that connects to an inspiratory portion of a patient connection14to deliver the inspiratory gas to the patient's lungs. An expiratory connection port74connects between an expiratory portion of the patient16and the patient interface section6to deliver expiratory gas exhaled by the patient to the expiratory path70. In embodiments, the patient connection14may include, for example, an endotracheal (ET) tube. In such embodiments, the patient connection is one that creates a pneumatic seal with the airway of the patient. Such a pneumatic seal enables the control and delivery of flows of medical gas and prescribed pressures into the respiratory system of the patient. In other embodiments, the patient connection14may include any patient end connector configured to deliver appropriate ventilation or respiratory support to a patient, such as a mask, nasal cannula, etc.

As will be described in further detail herein, various pressures within the patient's airway, including but not limited to inspiratory pressure and expiratory pressure, may be controlled during ventilation. A flow of medical gas and/or other ventilation gases is provided through the inspiratory path60to the patient16through the patient connection14in an inspiratory phase of a ventilation cycle and expired gases are directed from the patient16through the patient connection14through the expiratory path70in an expiratory phase of the ventilation cycle. The ventilation drive4may include a ventilation drive means, such as a blower56configured to drive inspiratory gas to the patient16. The blower56, or other drive means, may be controlled based on measured pressures and/or flow rates within the portable ventilator2.

In one embodiment, the patient interface section6is the only portion of the portable ventilator2that interfaces with the patient exhalation gas. Namely, in some embodiments the expiratory path70does not enter the ventilation drive4and thus contaminants from the expiratory path70do not enter or otherwise reach the drive4. However, in certain embodiments sensors, actuators, and/or other electronic devices that may sense or flow within the expiratory path may be located within the ventilation drive4section of the portable ventilator2. For instance, one or more pressure sensors57,58configured to sense pressure within the inspiratory path60or expiratory path70(referred to together as paths60and70) may be located in the ventilation drive4section. For instance, inspiratory pressure sensor57may be situated within the ventilation drive4and configured to sense a pressure within the expiratory path70in the patient interface section6, such as near the port64connecting to the patient connection14. Similarly, an expiratory pressure sensor58may be situated within the ventilation drive4and configured to sense a pressure within the expiratory path70, such as near port74.

One or more valve actuators that actuate valves in paths60and70may also be located in the drive portion. In certain embodiments, the patient interface section6may be removable from the drive section and may be a cleanable and sterilizable module since it interfaces with the patient exhalation gases. The ventilation drive4may be cleanable in that the housing and connection points or interfaces that connect with the patient interface section6are cleanable, and particularly that interface with the expiratory path70or otherwise can become contaminated by the exhalation gases. However, in certain embodiments the ventilation drive4is not sterilizable and/or autoclavable and thus does not include passageways that receive contaminated gas, such as exhalation gas from the patient.

Referring again toFIG.1andFIGS.2-4B(and also toFIGS.6and7), various hosts10,10a,10b,10cmay be incorporated within the ventilation system1. The portable ventilator2may be configured to connect with any various types of hosts10,10a,10b,10cproviding different functions including but not limited to high volume and high pressure gas sources to sustain long-term ICU ventilation, and anesthesia delivery in mechanical ventilation for maintaining a patient under general anesthesia. The portable ventilator2is configured to connect to each of such multiple types of hosts10,10a,10b,10cto act as the ventilation drive for that host device to deliver ventilation gas from the host gas source12to the patient16. The term “host10” is used herein to refer generically to a host, which may in various embodiments by any of the host-types described herein, including hosts10a,10b, and10c. In certain embodiments, the portable ventilator2is further configured to provide an inspiratory path that intersects with a ventilation path portion100of the host10. Alternatively or additionally, the portable ventilator2may provide and connect to the host10such that the expiratory gases from the patient are diverted to a ventilation path portion100of the host10. For example, in certain embodiments the host10may include a circle system for anesthesia delivery wherein the inspiratory pathways and expiratory pathways flow through the host10and connect to the pathways in the patient interface section6. In another example, the ventilation path portion100may only connect to the inspiratory pathway and may provide on/off valves, such as P01 valves as shown and described herein.

Each of the at least one host10includes a ventilator connection section50configured to removably receive the portable ventilator2and to connect the ventilation drive4and patient interface section6to the ventilation path portion100in the host10such that ventilation drive4receives the host gas and the patient interface section6interfaces as necessary with the ventilation path portion of the host. Pneumatic diagrams of a portable ventilator2and pneumatic connections to various host embodiments are shown inFIGS.5-8.

Additionally, the host may be configured to deliver power and/or communicate sensor and control information back and forth to and from the portable ventilator2. For example, the portable ventilator2may include a ventilatory controller20in communication with a user interface21on or associated with the portable ventilator2. For example, the user interface21may include devices through which a clinician can control ventilation parameters, such as pressure, breath rate, path flow rate, peak, and the like. Such input devices may include dials, buttons, or may be a touch screen configured to receive such input values from a clinician. The user interface21may also include a display configured to display ventilation information, including the various ventilation control settings, as well as patient information, such as certain patient monitoring information.

FIG.2Aillustrates an exemplary embodiment of a portable ventilator2disconnected from the host10. The portable ventilator2has a ventilator housing222encapsulating the portable ventilator2and providing various connections and interfaces. The ventilator housing222includes a user interface section21′ providing various user interface devices and systems through which the user can interact with elements of the portable ventilator2and see different patient parameters. The user interface21includes ventilator control inputs21a, including buttons, dials, knobs, and the like that enable manual control of the portable ventilator2functions by a clinician. The user interface21further includes a numerical display area21bproviding alphanumeric displays of values, such as ventilator control values and parameters. The numerical display area21bmay include, for example, numeric LED displays. Alternatively or additionally, the user interface21on the portable ventilator2may further include a ventilator display21cconfigured to display patient monitoring parameters for the patient16, as well as ventilation parameters and any other relevant control or function information for the portable ventilator2and/or a connected host10.

In certain embodiments, the ventilator controller20of the portable ventilator2may be configured to communicate with the host controller22of a host. The host10may further include a user interface23which may also be configured to allow a clinician to set ventilation parameters, which may include ventilation parameters that can be set at the ventilator user interface21, as well as additional parameters specific to the function of the host10. The host controller22may receive ventilator settings and other inputs from a clinician through the user interface23on the host10. In certain embodiments, the parameters set at either user interface21or23may be received at either ventilator controller20or host controller22when the portable ventilator2is connected to the host. In various embodiments, communication between the ventilator controller20and the host controller22may be by a physical communication connection, or may be via any wireless protocol, such as Bluetooth, Bluetooth Low Energy (ELE), ANT, nearfield communication (NFC), or any other wireless communication protocol.

The portable ventilator includes at least one battery43or other power storage device configured to store and provide power to the ventilator2. Thus, the ventilator2is portable and does not need to remain connected to an external power source. For example, the battery43may be rechargeable, such as when the ventilator2is connected to the host10. In certain embodiments, the battery may be removable and configured to be removed and recharged on a separate charging system. As shown inFIG.2A, the ventilator housing222of the ventilator2may be configured to facilitate easy removal and replacement of one or more batteries43.

In certain embodiments, the host10may receive power from and/or supply power to the ventilator2and/or may charge the battery43. In certain embodiments, the host may connect to a power source18, such as a power outlet on a wall. In such embodiments, the host10may include a power connector68configured to deliver power to the ventilator2when it is connected to the host10. In some embodiments, the host may further include a power controller, which may for example be integrated into the host controller22, situated to control power delivered to the power connector68. The power controller may distribute power throughout the host and to the portable ventilator2via power connector68.

The ventilator controller20is configured to control various aspects of the portable ventilator2. In certain embodiments, when the portable ventilator2is connected to the host10, the host controller22may participate and/or take over control functions for the portable ventilator2, including to control aspects of the ventilation drive4and/or the patient interface section6. Referring toFIG.5, the ventilation controller20and/or the host controller22may control various aspects of the ventilation drive4, including pressure regulators, flow controller devices, valve actuators, and the blower module26. Further, one or more of the ventilation controller20and/or the host controller22may receive information from sensors within the drive4, such as O2sensors, pressure sensors, flow sensors, valve position sensors, etc. Additionally, the ventilation controller20and/or the host controller22may be configured to variously control the user interfaces21,23on the ventilator2and/or the host10.

FIGS.2A and2Bshow an embodiment of a portable ventilator2detached from a host10. The host includes a ventilator connection section50providing various ports and connectors, including the power connector68and pneumatic connection portions. Specifically, the ventilator connection section50includes a source connection port87configured to connect to ventilation gas port287on the ventilator2(seeFIG.2B). The host10includes a ventilation path portion100providing four ports201-204serving as inlets and/or outlets for inspiratory and/or expiratory gases to enter the ventilation path portion100of the host10.

In the depicted example, the ventilation path portion100is configured to interface with the inspiratory path and expiratory path of the patient interface section6. Further exemplary ventilation path portions, including inspiratory path portions113b,113cand expiratory path portions115cand are provided herein, including atFIGS.7and8. Connection ports101and102are configured to connect with inspiratory ports201and202, respectively, to connect an inspiratory path portion113b,113cin the host10to the inspiratory path60in the patient interface section6. Connection ports103and104on the host10connect to expiratory ports203and204on the ventilator to connect an expiratory path portion115cof the host10within the patient interface section6to an expiratory path within the ventilation path portion100of the host10.

Depending on the host type, various ventilator connection section50configurations may be provided, such as a ventilator connection section50only connecting one of the inspiratory or expiratory paths between the patient interface section6and the ventilation path portion100of the host10. In other embodiments, no inspiratory or expiratory path connections are made between the ventilator2and the host10, and thus the host10only provides a ventilation gas source connection between port87on the host and ventilation gas port287on the ventilator2.

In the depicted embodiment, the ventilator connection section50provides a horizontal surface on which the ventilator2sits. A bottom side222′ of the ventilator housing222contacts a topside48′ of a host housing48. In other embodiments, the ventilator connection section50may be oriented differently on the ventilator housing222and host housing48. For example, the ventilator connection section50may be a vertical surface configured to connect to a vertical surface on the ventilator housing222. In other embodiments, multiple connection sections and/or connection locations may be provided and the ventilator housing222and host housing48are correspondingly designed such that the multiple connections align when the ventilator2is connected to the host10. The various ports are provided on the ventilator housing222and host housing48and positioned such that the ports on the ventilator2connect with a corresponding port on the host10when the ventilator2is vertically lowered onto the ventilator connection section50.

The ventilator housing222includes a ventilation drive housing44and an interface housing46. The ventilation drive housing44has a connection side244providing the ventilation gas port287that connects to the source connection port87on the host10. The patient interface section6includes an interface housing having a connection end246providing ports201through204for inspiratory and expiratory path connections with the host10.

In certain embodiments, connections means may be provided on the ventilator housing222and on the host housing48to secure the ventilator2onto the host10. This may be important, particularly for portable hosts that may be moved, incur vibration and shock during transport, etc. In the embodiment atFIGS.2A and2B, each of the ventilator housing222and the host housing48have corresponding housing connectors that are configured to mate together to secure the ventilator2onto the host10.

As shown inFIG.2B, the ventilator housing222may have a first vent housing connector502and a second vent housing connector503. Each of the vent housing connectors502and503are configured and positioned to connect to corresponding host housing connectors512and513, respectively. Specifically, the first vent housing connector502connects to the first host housing connector512and the second vent housing connector503connects to the second host housing connector513. In various embodiments, the vent housing connectors502503and the host housing connectors512and513(referred to together as the “housing connectors”) may be any type of connectors or connection formation that releasably connects the ventilator housing222and host housing48. In certain examples, the housing connectors502,503,512,513may be, for example, latches, hooks, thumbscrews.

A release means is also provided in order to release the vent housing connectors502and503from the host housing connectors512,513. In the depicted example, one or more release levers501may be positioned on the ventilator housing222and/or the host housing48and operatively connected and configured to release the connections when operated by a user. Thus, removal of the ventilator2from the host10may include operating the release levers501, such as by turning or pulling up on the levers501. The release levers501have internal connections or linkages within the housing222to operate or move the vent housing connectors502and503into a disconnection position that disengages from the host housing connectors512and513. In other embodiments, other release mechanisms or means may be provided, such as buttons, screws, or the like. In still other embodiments, the housing connectors may be configured to provide a friction fit where no release mechanism is necessary and releasing the ventilator2from the host10is accomplished by pulling the ventilator housing222hard enough to overcome the friction force provided by the housing connectors502,503and512,513. In various embodiments, different numbers and/or locations of housing connectors may be provided. A person of ordinary skill in the art will understand in view of the present disclosure that the location and number of housing connectors502,503,512, and513are merely exemplary and other locations and numbers of connectors may be provided and such embodiments are within the scope of the present disclosure. In certain embodiments, a handle224may be connected to the housing222and configured to allow a clinician to easily lift and carry the ventilator2. This facilitates easy movement and transport of the ventilator2, as well as connection and disconnection from the hosts10.

The ventilator housing222may comprise of two sections, the ventilation drive housing44and the interface housing46. The ventilation drive housing44houses the ventilation drive4, including the blower module26and other elements such as those described below with respect toFIG.5. The interface housing46includes an inspiratory path60and an expiratory path70configured to guide the inspiratory and expiratory gas to and from the patient16. The interface housing46and the ventilation drive housing44are configured to releasably connect together such that the patient interface section6can be removed from the drive4. For example, the patient interface section6and interface housing46may be a cleanable, sterilizable, and/or autoclaveable portion. For example, the patient interface section may be comprised of polyphenylsulfone (PPSU) or other autoclaveable plastic material configured to withstand temperatures of 130 degrees C., or higher, for an extended period of time sufficient to provide sterilization. For example, the patient interface section6may an injection molded piece, such as a single continuous piece with smooth interior cavities to form the inspiratory path cavity and expiratory path cavity. In other embodiments, the patient interface section6may be formed of a machined metal, such as machined stainless steel. In still other embodiments, the patient interface section6may be a disposable unit that is intended for single-patient use. In such an embodiment, the patient interface section6may be comprised of a less expensive polymer material, for example, that does not need to be autoclaveable or otherwise sterilizable.

In certain embodiments, the ventilation drive housing44may include a drive housing connector505configured with and interface housing connector506on the interface housing46. The drive housing connector505and interface housing connector506are configured to releasably mate so as to releasably connect the interface housings46and ventilation drive housing44. The housing connectors505and506may be any of the above-listed connector types.

In certain embodiments, the expiratory path does not enter the ventilation drive housing44such that the ventilation drive4is not exposed in any significant way to any patient expiratory gas, other than perhaps at exterior connectors on the ventilation drive housing44. Thus, the ventilation drive4and interior of the ventilation drive housing44are not exposed to the contaminants in the expiratory gases and may be cleanable by, for example, wiping down the exterior of the ventilation drive housing44, particularly at the connection interface with the interface housing46.

The ventilator2is configured to connect to one or more gas sources, including one or more portable gas sources8. The ventilator2is portable, and thus may also be referred to herein as “portable ventilator”. In certain embodiments, the portable ventilator2may also be configured to connect directly to wall gas via one or more wall gas lines158, and/or other gas sources including gas cylinders. In one embodiment, the portable ventilator2may include multiple gas source connections29aand29b, as shown inFIG.2A, to connect to different gas source types. For example, the portable ventilator2may be configured to connect to an oxygen tank, as well as to wall gas, such as a low-pressure wall gas source. In the depicted example, wall gas line158connects to the source connection29ato provide a low-pressure gas source. For example, the wall gas line158may be connected to a pressure regulator providing low-pressure oxygen at a pressure of 100 kilopascals (kPa) or less, from a wall gas source. Such low-pressure oxygen arrangements are known in the art.

The ventilator2may also be configured to connect to a higher pressure gas source at connection29b. The portable gas source8may be, for example, an oxygen tank, such as having a pressure of 242-648 kPa (35-94 psig).FIG.3illustrates one such embodiment where a portable gas source8bis an oxygen tank connected to the portable ventilator2and transported therewith. This configuration demonstrates a portable ventilator2utilized on its own during patient transport, such as where the patient is being transported from the OR to the ICU or vice versa. The portable ventilator2can be utilized to ventilate the patient for an extended period of time provided that the batteries43or other power source are exchanged or wall power is utilized and the portable gas source8bis sufficiently changed or swapped. Thus, use of the portable ventilator2is not only confined to patient transport or short utilization periods because the ventilator2provides full ventilation functionality for normal continued ventilation support.

In the depicted example, the patient16is intubated and the patient connection14′ is an endotracheal tube. The endotracheal tube patient connection14′ is connected to the inspiratory connection port64and the expiratory connection port74on the ventilator2, and particularly on the interface housing46on the patient interface section6. Patient monitors420are also operatively connected to the patient16to provide patient monitoring data to the ventilator2. In the depicted example, an SpO2patient monitor420aand an ECG patient monitor420b, and respective sensors therefore, are each connected to respective patient monitoring ports42on the ventilator housing222. Thereby, patient physiological data is provided to the ventilator2, which may be used by the controller20for controlling ventilation to the patient as well as for general patient monitoring and alarming. Patient physiological information based on the monitoring data may be displayed on the user interface section21b, such as on the ventilator display21c.

In certain embodiments, the portable ventilator2may be configured to hook or connect to the side of the patient's bed460. For example, the ventilator housing222may comprise hooks226or other attachment means for attaching the portable ventilator2to a side rail462of the patient's bed460. A person of ordinary skill in the art will understand in view of the present disclosure that other mounting means and locations are within the scope of the present disclosure.

The portable ventilator2is configured to connect to multiple different hosts10, one at a time.FIGS.4A and4Bdepict the portable ventilator2ofFIGS.2and3connected to different hosts10.FIG.4Ashows the portable ventilator2connected to an ICU host10bproviding on/off valves, such as P01 valves described below with respect toFIG.7. The ICU host10bincludes a host gas source12b, such as an oxygen tank, which in some embodiments may be a larger oxygen tank then the portable gas source8b. In other embodiments, the ICU host10bmay be connected to a wall gas source to serve as the host gas source12b.

The patient16remains connected to the connection ports64and74when the ventilator2is connected to the host10b. No disconnection of the patient is required when transferring and the ventilator2is configured to seamlessly switch from providing inspiratory gas from the portable gas source8bto providing inspiratory gas to the patient from the host gas source12b. Likewise, the patient monitors420remain connected to the patient monitoring ports42and thus no change or interruption in patient monitoring is required for connection to the host10b.

In certain embodiments, the ICU host10bmay include a host display210b. In some embodiments, the host display210bmay be configured to repeat the information displayed on the ventilator display21c. In other embodiments, the host display210bmay display different or additional parameters or information. The host display210bmay serve as the user interface23for the host10b, such as to provide control parameters for controlling the ventilation path portion100and/or other functions of the ICU host10b.

FIG.4Bdepicts a ventilation system1configuration where the portable ventilator2is connected to an anesthesia host10c. Again, the patient16remains connected to and continually ventilated and monitored by the ventilator2, including continued connection to connection ports64, and74and to the patient monitoring ports42. The anesthesia host10cprovides a host gas source12c, which is typically wall gas but may include a cylinder or other gas container and may further include an anesthesia gas source12c′. The anesthesia host10cincludes a ventilation path portion100that comprises a circle breathing system105. As exemplified in the embodiment atFIG.8, the circle breathing system105includes a circle drive unit114, such as a plenum and is configured to connect to both the inspiratory and expiratory paths to provide anesthesia ventilation to the patient. Various circle system configurations are known to those with skill in the art and are within the scope of the present disclosure.

In certain embodiments, the circle breathing system105is housed in a circle section housing107which may be removable from the anesthesia host10c. For example, the circle section housing107may be releasably connected to a housing of the host gas delivery section95. In certain embodiments, the interface housing46and the circle section housing107releasably connect. As illustrated inFIG.4B, the circle section housing107is adjacent and aligned with the interface housing46. A vent housing connector on the interface housing46is configured to releasably connect to a host housing connector on the host, which in some embodiments may be preferably located on the circle section housing107. In the depicted example, ventilation housing connector503is configured to connect to the host housing connector513.

In certain embodiments, the interface housing46can be released and disconnected from the ventilation drive housing44at the same time that the circle section housing107is released and disconnected from the host10csuch that they are removed together as a connected unit. The two housings, including interface housing46and circle section housing107, may then be cleaned, disinfected, and sterilized, which may be completed on the connected unit or the interface housing46and the circle section housing107may be disconnected prior to cleaning and/or sterilization. For example, the interface housing46and the circle section housing107may be configured to fit together as a clam shell and, once removed from the ventilator2and the host10c, then released from one another for cleaning, disinfection, and sterilization. In certain embodiments, the circle section housing107may be an injection molded or machined piece, such as manufactured in the same way as the interface housing46, examples of which are described above.

In certain embodiments, one or more valves may be configured to control flow of ventilation gas within the portable ventilator2and/or to and from the host10. In the example atFIG.5, the portable ventilator2includes two sets of diverter valves61-62and71-72controlling the inspiratory and expiratory path connections such that they either remain within the portable ventilator only or are diverted to the inspiratory path portion, the expiratory path portion, or both of the host.FIG.5is a pneumatic diagram demonstrating an exemplary embodiment of a portable ventilator2including a ventilation drive4that connects to a host gas delivery section95so as to receive inspiratory gas from a host gas source12. The ventilator2includes a patient interface section6that connects to multiple different host types providing differing ventilation path portions100and specialized ventilation functionality.

The sets of diverter valves include a set of inspiratory diverter valves61and62configured to control the inspiratory path60, and a set of expiratory diverter valves71and72configured to control the expiratory path70. Each set of valves61and62,71and72, may be configured to open or close simultaneously and together. For instance, the inspiratory diverter valves61and62may be configured such that either both are open or both are closed. Similarly, expiratory diverter valves71and72may be jointly actuated and configured such that both are open and closed simultaneously.

In certain embodiments, each of the diverter valves61,62,71,72may be two-position three-way valves, and may be normally closed-type valves configured to be close in an unactuated, unpowered resting state and to open when the portable ventilator connects to the host10. Thus, when the inspiratory diverter valves61,62are closed, the inspiratory pathway60is maintained within the portable ventilator2. Thus, the inspiratory path flows along path portion60abetween the valves61and62. When the inspiratory diverter valves61,62are open, the inspiratory pathway is diverted into the host10along path section60b(traveling back from the host up path portion60c). Similarly, when the expiratory diverter valves71,72are no actuated, and thus closed, the expiratory path70is maintained within the portable ventilator2flowing between valves along path portion70a. When expiratory diverter valves71,72are forced open on connection to certain types of hosts, the expiratory gas is diverted along path portion70binto the host10(and returns along path portion70c). The diverter valves61,62,71,72may be mechanically actuated valves, such as actuated by the mechanical force of connecting the portable ventilator2to the host10, or electrically actuated valves, such as solenoids that are electrically configured to actuate the valves when the portable ventilator2is connected to the host10.

The portable ventilator2may further include one or more host source connection valve28configured to control connection of a host gas source12to the ventilation drive4such that ventilation gas can be provided therefrom. The host source connection valve28may be, for example, a two-way two-position valve. It may be a normally closed-type valve, and may be a mechanically actuated or electromechanically actuated valve. When the host source connection valve28is in the default closed position, such as when the portable ventilator2is not connected to a host10, then no gas flow is provided from the host gas source12. Conversely, when the host source connection valve28is opened, such as electrically or mechanically actuated, then gas is permitted to flow from the host gas source12into the vent drive4. Likewise, if the host gas source12gets depleted or malfunctions then the portable gas source8bis automatically utilized. Thus, input gases may be driven by the ventilation drive4to the patient from either a portable gas source8connected directly to the ventilation drive4or the host gas source12connected through the host10to the ventilation drive4.

In the depicted embodiment, the portable ventilator2is configured to receive ventilation gas from either of two gas sources8, including low-pressure oxygen source8aand high-pressure portable gas source8b. For example, the low-pressure oxygen source8amay be a lo-pressure regulated wall gas source, such as configured to provide 15 lpm and a pressure of 100 kPa, or less. Alternatively, the low-pressure gas source may be a small O2cylinder. The high-pressure oxygen is a higher-pressure gas source than the low-pressure source, such as ranging between 242-648 kPa (35-94 psi). When a high-pressure portable gas source8b(such as an oxygen source) is connected, the portable gas source input valve34a, such as a check valve, receives a higher pressure on the downstream side and prevents flow from the low-pressure gas source8a. However, if no high-pressure portable gas source8bis connected or the higher-pressure source is depleted, then gas may be automatically provided by the low-pressure oxygen source8aand gas source input valve34aforced open.

If gas is provided from the high-pressure portable gas source8b, which is connected to the portable source connection29band provides gas to the input gas path30b, the input gas is filtered at filter32b. Input pressure is measured by pressure sensor33and the input gas passes through portable gas source input valve34band provided to the pressure regulator36. Pressure regulator36is configured to regulate the delivery pressure of ventilation gas from the portable gas source8b. For example, the pressure regulator36may be configured to provide a delivery pressure of ventilation gas from the portable gas source of 172 kPa (25 psi). The pressure regulated gas is then provided to the flow controller40, such as a flow control valve. Pressure sensor39is configured to measure the delivery pressure of gas to the flow controller. A test port with a plug and check valve may be provided along the input gas path30bcdelivering gas to the flow controller40.

In certain embodiments, the host gas is delivered at a higher pressure than the gas from the portable gas source and the ventilation drive4is configured to provide gas only from the highest-pressure source.FIG.5exemplifies such an embodiment, where gas source input valves34aand34bin the input gas paths30aand30bprovide gas from one of the gas sources, including the low-pressure oxygen source8aand portable gas source8b(referred to collectively as gas sources8aand8b), when the portable ventilator2is not connected to any host10. When the portable ventilator2is connected to a host10, and thus to a host gas source12, the gas source input valves34aand34bclose to prevent any backflow and otherwise shut off the lines connecting to the gas sources8aand8b. For example, the gas source input valves34aand34bmay each be a check valve. When the host gas source connection valve28is closed, and thus the portable ventilator2is disconnected from the host, the gas source input valve34aor34bseeing the highest pressure between the gas path30aand the gas path30bwill open. Thus, gas source is provided from just one of the gas sources8a,8b, or alternatively the host source12, which is the one gas source providing the highest pressure.

Flow sensor41senses the flow rate outputted by the flow controller40, such as a flow control valve or other device for controlling gas flow, along gas flow path45provided to the blower module26. The blower module26is controllable to provide cyclical inspiratory and expiratory pressure as required for the patient. The blower56is controlled, such as by ventilator controller20to provide inspiratory gas flow at an appropriate inspiratory gas flow rate and to significantly reduce the airflow during the expiratory portion of the patient's ventilation cycle. Similarly, the flow controller40is configured to control flow of the ventilation gas to provide the inspiratory flow and to significantly reduce or turn off the ventilation gas flow during the expiratory phase. The blower56may be configured to intake air from atmosphere through the air intake port9along input path30d. The atmospheric air is filtered by the inlet filter47. The blower56thus can circulate ventilation gas into the patient interface section6provided by either the low-pressure gas source8a, or low-pressure oxygen source, the high pressure oxygen source8band/or from atmosphere. Output flow from the blower is sensed by the flow sensor47, which senses the total output flow from all gas sources provided by the blower56. An O2sensor49may be configured to sense the oxygen present in the output flow, which is provided in the inspiratory path60′ to the patient interface section6.

A check valve54may be provided at the interface between the ventilation drive4and the patient interface section6. Check valve54prevents backflow of gases back into the drive4. Inspiratory gases are provided to the patient on inspiratory path60. As described above, depending on the position of the inspiratory diverter valves61and62, the inspiratory path may travel directly from the drive connection to the patient connection14, or it may be diverted into a gas path section in the host10.

For the exhalation gas cycle, expiratory gases travel from the patient, through the patient connection14to the expiratory connection port74and into the patient interface section6. The expiratory gases follow the expiratory path70through the patient interface section6, where the expiratory gases are expelled out of the portable ventilator2. If the expiratory diverter valves71and72are closed, then gas travels along path70abetween the diverter valves and continues along the expiratory path70within the patient interface section6. If the expiratory diverter valves are open, then the gas is diverted to the host10. This example utilizes normally closed-type valves, in other examples, normally open-type valves may be utilized and the configuration may be adjusted accordingly, as will be understood by a person of ordinary skill in the art in view of the present disclosure. When the expiratory diverter valves71and72are positioned to divert flow into the host10, the expiratory gas travels down the path portion70binto the host. Where the host provides a circle system, such as exemplified atFIG.8, the gas may be returned from the host to the patient interface section6at path70cto continue along expiratory path70. Expiratory gas flows through the exhalation valve76, which is actuated by actuator76a. During the exhalation portion of the ventilation cycle, the exhalation valve76is positioned to open the flow path to the expiratory port78. An exhalation flow sensor77may be positioned and configured to measure the flow rate of the exhalation gas exiting the expiratory port78. When the portable ventilator2is not connected to any host, the expiratory port78vents the exhalation gases to atmosphere. In certain embodiments, a filter, scrubber, sterilizer, scavenging system, or some other gas processing system may be positioned at the expiratory port78to filter or sterilize the exhalation gases. In certain embodiments, a valve, such as a check valve, may be positioned at the expiratory port78so as to only allow output flow and prevent any intake at the exhalation port.

Safety valve66and respective valve control actuator66aalso assist in actuating and controlling the valve66state. Valve66may comprise a flexible membrane, the movement of which is controlled by the ventilation drive using the actuator66a. Safety valve66acts as a release valve if airway pressure becomes too high, thereby preventing overly high lung pressure of the patient. In various embodiments, safety valve66may be configured to vent gas to atmosphere or to vent to a scavenging system. In certain embodiments, the valve66may vent gas to atmosphere when not connected to any host and/or when not connected to a host providing a scavenging system.

FIGS.6-8depict various hosts and the connection between the host and the portable ventilator2.FIG.6depicts a host providing a host gas source12a, which may be a larger oxygen cylinder or other oxygen reserve, or may be wall gas. For example, the host source may be stored and provided at 242-648 kPa (35-94 psig). In this example, the host10aonly provides gas to the ventilation drive4and does not connect to the patient interface section6. For example, the host module10a, joined with the portable ventilator2, may provide a simple ICU ventilator, with the host module10aproviding a host gas source that is larger than the portable gas source8. The host gas source12aconnects to the host module10aat port79aand is filtered at filter82a. The ventilation gas from the host gas source12athen travels through check valve83aand is provided to the pressure regulator86a. Pressure sensor85ameasures the input pressure to the pressure regulator. The gas then flows along the host input path80ato the ventilation drive4.

The pressure regulator86acan be configured to provide a higher delivery pressure than the regulator36in the ventilation drive4. Thereby, when the portable ventilator2is connected to the host, ventilation gas from the higher-pressure host will be provided by the ventilation drive to the patient. For example, the host pressure regulator86amay be configured to provide 28 psi, which is greater than the exemplary 25 psi of the pressure regulator along the portable gas input path30b. The ventilator source connection valve88amay be configured to open when the portable ventilator2is connected to the host10a. For example, the ventilator source connection valve88amay be configured to interact and/or cooperate with the host source connection valve28such that both valves open, either via mechanical or electrical actuation, when the portable ventilator2is properly connected to the host10a.

FIG.7exemplifies another host type, which in the depicted example is an ICU host10ballowing additional functionality to turn on and off the inspiratory flow, thus enabling a maneuver to measure patient inspiratory drive. In this example, the host10bprovides a host gas source12bthat provides higher pressure gas as described above with respect to host10a. In the depicted exemplary embodiment, the port79b, filter82b, check valve83b, pressure sensor85b, pressure regulator86b, and ventilator source connection valve88ball operate similarly to the correlating features inFIG.6and thus provide ventilation gas from the host gas source12bto the ventilation drive along path80b. In addition, the host module10bincludes a ventilation path portion100connects downstream in the inspiratory path. In the depicted embodiment, the ventilation path portion100includes at least one on/off valve94configured to enable a “P01” maneuver to measure patient inspiratory drive such as to perform a negative inspiratory force measurement from the patient. The host10bconnects to the inspiratory path60at path sections60band60cvia connection ports101band102b.

In certain embodiments, connection port101bmay be configured to mechanically actuate the diverter valve61and connection port102bmay be configured to mechanically actuate the diverter valve62in the portable ventilator2. Referring also to the embodiment depicted atFIG.2A, each connection port101and102may include an actuator141and142on the host housing48that is configured to mechanically actuate the valve61and62, such as to move the valve flap161,162thereof (see alsoFIG.9C). In the example shown atFIG.2A, the actuators141and142are upward projections that are adjacent to or otherwise associated with each connection port101and102and are configured to extend into the ports201and202on the ventilator housing222so as to push open the valves61and62. Thereby, mechanical connection of the portable ventilator2to the host10bmechanically actuates opening of the valves61and62that permit inspiratory gas flow to the inspiratory path portion113bof host10b. In other embodiments, such actuation may be electrical and the valves61and62may be electromechanical valves.

A pressure regulator89is positioned on flow path90. For example, the pressure regulator may be configured to provide 350 mbar of pressure. The flow path90travels to an inspiratory on/off valve94, or a P.01 valve. When the inspiratory on/off valve94, or P.01 valve, is open, gas travels along path section60bof the patient interface section6through the on/off valve94to connector102band further to patient interface section6channel60c. The on/off valve94may be a pneumatically driven valve comprising a flexible membrane separating the inspiration gas path between connection ports101band102bfrom the pneumatic drive pressure channel113b. The valve closes the inspiration channel between connection ports101band102bwhen actuated. Actuation occurs by electrical activation of the solenoid valves91and92, which allows the regulator89outlet pressure to drive on the on/off valve94. When the pressure measurement at the on/off valve94is passed, the valves91and92are de-activated, which allows the pilot drive pressure from the valve94to be exhausted to atmosphere, allowing the on/off valve94to open the path between connection ports101band102b. This opening may occur due to the elasticity of the flexible membrane or with aid of a spring biasing the membrane to keep the inspiration gas path open.

FIG.8depicts another host type, which in this depicted example is an anesthesia host10c. The anesthesia host10cincludes a host gas delivery section95and a circle breathing system105. The gas host gas delivery section95connects to a host gas source12cthat provides higher pressure gas as described above with respect to host10a. The port79c, filter82c, check valve83c, pressure sensor85c, pressure regulator86c, and ventilator source connection valve all88cmay all operate similarly to the correlating features described above with respect toFIG.6, and thus provide ventilation gas from the anesthesia source12c′ to the ventilation drive along path80c. In addition, the anesthesia host10cconnects downstream in the inspiratory path60to provide a circle system for providing anesthetic agent and corresponding ventilation for supporting anesthesia delivery to the patient. In conjunction with the circle breathing system, the host gas delivery section95of the anesthesia host10cmay include additional elements to deliver gas to the bag108through the bag on/off valve96aand the bag switch96b. Thereby, the bag108can be utilized to drive gas to and from the patient interface section6, including through the circle breathing system105. Additionally, certain embodiments of the host gas delivery section95may include a test port on/off valve97aand a test port switch97bthat control gas flow to a test port110.

The circle breathing system105of the anesthesia host10cconnects to the inspiratory path at path sections60band60c. Inspiratory gas is received to the host from path section60bwhich is delivered to and circulated through the circle system. Anesthesia breathing gas is provided back to the patent interface section6through path section60cfor delivery to the patient. The anesthesia host10cincludes connection ports101cand102cthat facilitate connection of the inspiratory path sections60band60cto the inspiratory path portion113cof the host10c. The inspiratory path portion113cis the gas path between the connection ports101cand102c, which includes the circle drive unit114and the CO2absorber118.

In certain embodiments, the connection port101cand102cmay be configured to mechanically actuate the respective diverter valves61and62, as described above. In other embodiments, the diverter valves61and62may be electromechanical valves that are electrically actuated upon connection of the portable ventilator2to the anesthesia host10and once proper connection is verified. For example, such electrical actuation may be based on pressure and/or electrical connection sensing to verify that the pneumatic and electrical connections are proper.

In an inspiratory cycle, gas flows from the ventilation drive4to connection port101cto the flow selector valve112and into the circle drive unit114. The circle drive unit114may be, for example, a plenum as illustrated in the embodiment. In another example, the circle drive unit may involve a bellows configured to drive gas through the circle breathing system105. Gas is driven by the circle drive unit114through the set of valves116, which divert the gas through the CO2absorber118along the path to the inspiratory valve120. In the depicted example, the inspiratory valve120is a check valve. Gas that passes through the inspiratory valve120combines with gas from anesthetic gas source12c′, which includes fresh gas and anesthetic agent, such as vaporized anesthetic drugs and other anesthetic gases. The anesthetic gas and fresh gas mixture are conveyed along the gas flow path122, combine with the inspiratory gas conveyed through inspiratory valve120, and then exit the circle breathing system105of the host10cat connection port102c, where it is delivered to the inspiratory path section60cand eventually to the patient.

On the expiratory cycle, gas is delivered from expiratory flow path portion70bthrough the connection port103cand into the circle breathing system. Similar to connection ports101cand102c, connections ports103cand104cconnect to the gas flow paths of the portable ventilator2and may facilitate electrical and/or mechanical valve actuation in order to facilitate gas flow between the flow path within the patient interface section6and the circle breathing system105. The connection port103cconnects to the expiratory path portion70bfollowing diverter valve71and is configured to facilitate input of the expiratory gases from the patient interface section6into circle breathing system in the host10c. The connection port104cconnects to the expiratory flow path portion70cwhich delivers gas to diverter valve72and through the exhalation path70. Expiratory flow that enters through connection port103travels through the expiratory valve126, which may be a check valve, to the drive unit114and flow selector valve112to port104cthat connects to expiratory path portion70cin the patient interface section6. Connection port106may be configured to connect to the expiratory port78of the portable ventilator2to provide the expiratory gases to a scavenging system128. The circle breathing system105may also include a bag108and corresponding valve109to allow gas to be drive though the circle breathing system via a manually compressible bag, as is well known in the art. A bag flow sensor111may be provided along the flow path driven by the bag108in order to sense the driven gas flow through the bag valve109.

Diverter valves71and72may be mechanically or electrically actuated when the ventilator2is connected to certain hosts, such as anesthesia host10c, that interface with the expiratory path. In certain embodiments, connection ports103and104may have associated actuators143and144configured to mechanically actuate, or open, the valves71and72. As described above with respect to the inspiratory diverter valves71and72, in one example the actuators143, and144may be projections configured to push open the valve flaps171,172when the ventilator is seated onto the host10c.

FIGS.9A and9Bdepict an exemplary diverter valve arrangement exemplifying one embodiment of a potential diverter valve set61and62or71and72, which in the depicted example is an electromechanical arrangement. For example, each diverter valve61,62,71,72may be a two-position three-way valve.FIG.9Adepicts the valve set in a closed position where gas flow is maintained within the portable ventilator2.FIG.9Bdepicts the valve set in an open position where gas flow is diverted to the host10, be it an anesthesia host10ccomprising a circle system, an ICU host10bcomprising additional ventilation control element, or any other type of host where gas flow is exchanged from the portable ventilator2into a ventilation path portion100of the host10.

InFIG.9A, the gas flow path (be it the inspiratory gas flow in the inspiratory path60or the expiratory gas flow in the expiratory path70) passes through the inlet130which is open due to the diverter valve61,71being in the closed position. The gas flowing through the inlet130travels through the passage way60a,70ato the outlet132, which is open because the diverter valve62,72is in the closed position, closing off the passage way to any connected host. In certain embodiments, the valves61,71and62,72are normally-closed-type valves which remain closed when not powered or otherwise actuated.FIGS.9A and9Bshow electromechanical valves that are electrically actuated, where each valve is associated with an actuator134that when electrically powered actuates, and thus opens, the normally-closed valve. In other embodiments, each set of valves61and62,71and72may have an associated actuator that simultaneously actuates both valves in the set.

In electrically actuated embodiments, each valve61,62,71,72may be a normally-closed solenoid valve that opens when power is applied to the valve.FIG.9Ashows the actuators134not energized, and thus the valve flaps161,171,162,172are in a first position, the closed position which maintains the flow path within the ventilator2through path portion60a,60ain the patient interface section6. When the actuators134are energized, as illustrated inFIG.9B, the valve flaps161,171,162,172are then moved to a second position, the open position that permits the ventilation gas to flow to a host10.FIG.9Bdepicts the electromechanical valves61,71and62,72in an open, or actuated, position where the gas flow flows through inlet131into the flow path portions60b,70bthat lead to the host10. In the open position, as it is referred to herein, the bypass path60a,70a, between the valves61,71and61,72is closed off such that ventilation gases do not flow between the valves61,71and61,72without entering the host10. The gas flows through the pneumatic portion of the host and back up to the ventilator2through the outlet133to continue along the inspiratory path60or the expiratory path70, whatever the case may be.

As described above, the valves61,62,71,72may be mechanically actuated valves where the valves61,71and62,72are mechanically moved into an open position when the ventilator2gets connected to the host10.FIG.9Cillustrates one embodiment where valve flaps161,171,162,172are mechanically moved upward, such as by the above-described actuator projections141-144on the host housing48. The actuator projections141-144are inserted into the ports201-204in the ventilator housing222when the ventilator2is placed on the host10, thus forcing the valves open and permitting gas to flow into the ventilation path portion100of the host.

FIG.10depicts one embodiment of a method600of ventilator operation where a portable ventilator is first operated on its own to deliver ventilation gas from a portable gas source and then, upon connection to a host, to deliver ventilation from a host gas source. A ventilator2is operated to drive gas from a portable gas source (e.g.,8b) to a patient at step602. Pressure of ventilation gas from the portable gas source is monitored at step604, such as measured by pressure sensor33within the vent drive4. Upon connection of the ventilator2, various valves open and close and step606in order to facilitate pneumatic connection to the host gas source12and/or connection to the inspiratory and expiratory pathways in the host10, as appropriate depending on the host type. For example, connection to the host is facilitated by opening the connection valves28and88band automatically closing the gas source input valves34aand/or34b, as appropriate. As described above, in one embodiment the input valves34aand/or34bare each a check valve. For embodiments where the host includes a ventilation path portion100, connections of the inspiratory and/or expiratory pathways to the host may also be facilitated by opening the inspiratory diverter valves (e.g.61and62) and opening the expiratory diverter valves (e.g.71and72).

A pressure from the host gas source is then monitored at step608, such as measured at pressure sensor85in the host gas delivery section95. Upon this connection of a ventilator from the host and/or upon the pressure of the host gas source12becoming less than that of the portable gas source8, the ventilator2switches back to the portable gas source8to provide inspiratory gas to be delivered to the patient. As described above, in certain embodiments the ventilator2may be configured to provide inspiratory gas from the connected gas source having the greatest delivery pressure of ventilation gas and the switching occurs automatically by the check valve34bopening and check valve83bclosing. Thus, if the host gas source becomes depleted or the ventilator2is disconnected from the host10, then the pressure of the host gas source drops below that of the portable gas source causing the ventilator2to flip back to the portable gas source8for ventilating the patient. When that occurs, the host gas source connection valve28the ventilator2may remain open to support the on/off valve94or fresh gas02supply while one or more of the gas source input valves34aor34bopens. Additionally, if the ventilator2is disconnected from the host10and the host provides a ventilation path portion100that connects to the inspiratory or expiratory paths, and the respective diverter valves61,62,71,72will close.