Nasal continuous positive airway pressure device for lowering patient work-of-breathing

A nasal continuous positive airway pressure device for lowering patient work-of-breathing is described. The device may include an inspiratory tubing in fluid communication with at least two nasal prongs; expiratory tubing; and a generator body coupled there between. The generator body may include at least two jets configured for receiving gas from the inspiratory tubing; and a flow enhancer configured for directing received gas. The flow enhancer may include a gas manager configured for channeling received gas towards a jet impingement point via at least two jet paths; a fluidic flip trigger configured for triggering a fluidic flip of channeled gas back towards the expiratory tubing by directing a first portion of exhaled patient breath towards the jet impingement point along a first pathway; and an isolated pathway manager configured for directing a second portion of the exhaled patient breath along a second pathway towards the expiratory tubing.

FIELD OF THE INVENTION

The present technology relates generally to the respiratory field. More particularly, the present technology relates to a variable flow nasal continuous positive airway pressure device.

BACKGROUND

In general, continuous positive airway pressure (CPAP) is a method of respiratory ventilation used primarily to treat patients experiencing respiratory difficulties and/or insufficiencies. For example, CPAP is used for critically ill patients in a hospital with respiratory failure. In these patients, PAP ventilation can prevent the need for tracheal intubation, or allow earlier extubation. Sometimes patients with neuromuscular diseases use this variety of ventilation as well.

With infants, however, a less invasive patient interface device is desirable. In particular, one that interfaces directly or indirectly with the nasal airways via the patient's nares, such as a mask or nasal prongs, is generally used. Such systems are commonly referred to as nasal continuous positive airway pressure (nCPAP) systems.

The drawings referred to in this description should not be understood as being drawn to scale unless specifically noted.

DESCRIPTION OF EMBODIMENTS

The discussion will begin with an overview of the general use of nasal continuous positive airway pressure devices and the limitations associated therewith. The discussion will then focus on embodiments of the present technology that provide a nasal continuous positive airway pressure device for lowering patient work of breathing.

OVERVIEW

In general, nasal continuous positive airway pressure (nCPAP) devices assist infants with under-developed lungs by preventing lung collapse during exhalation and assisting in lung expansion during inhalation. One type of interface device that couples the generator body of a nCPAP with the infant are nasal prongs.

With ventilator-based CPAP devices, a relative constant and continuous flow of gas (e.g., air, O2, etc.) is delivered into the patient's airways. This airflow creates a pressure within a patient's lungs via a restriction placed on outflow from the patient. However, the patient is required to exhale against the incoming gas, which increases the patient's work of breathing (WOB).

Embodiments of the present technology provide a nasal continuous positive airway pressure (nCPAP) device for lowering a patient's WOB. Firstly, in one embodiment, the flow enhancer of the nCPAP device redirects a jet flow of gas that was originally directed towards a patient's nares to a jet impingement point. Channeling the dual jet flows into a common jet flow that is moving toward the patient's nares enables the patient to more easily inhale the oxygen, and thus decreases WOB.

Secondly, in one embodiment, the flow enhancer of the nCPAP device directs a first portion of the exhaled patient breath towards the channeled jet flow directed at the jet impingement point. Directing the exhaled breath to meet this channeled jet flow head on causes, through a “fluidic flip” effect, the channeled jet flow (airstream) directed towards the patient's nares to reverse direction. Thus, both the channeled jet flow now traveling in the reverse direction and the exhaled patient breath now flow to the expiratory tubing. Thus, by causing the jetstream directed towards the patient's nares to reverse direction during the patient's exhalation, the patient does not have to expend lung energy exhaling into an continuously incoming stream of air. Consequently, reversing the direction of the jetstream during the first part of the patient's exhalation lowers the patient's WOB.

Thirdly, in one embodiment, the flow enhancer of the nCPAP device directs a second portion of the exhaled patient breath along a pathway, separate and isolated from the pathway caused by the “fluidic flip” effect, towards the expiratory tubing. This second portion does not encounter resistance as it flows to the expiratory tubing. Consequently, since the patient does not have to breath the second portion of exhaled air into any incoming airstream, the resistance to exhaled patient breath is lowered, thus lowering the patient's WOB.

Therefore, embodiments of the present technology provide for a method of lowering the patient's WOB by increasing an airflow to the patient during patient inhalation as well as reducing resistances to the patient's exhalation.

The following discussion will begin with a description of the structure of the components of the present technology. This discussion will then be followed by a description of the components in operation.

Structure

FIG. 1is a perspective view of a nasal continuous positive airway pressure (nCPAP) device for lowering patient WOB, in accordance with embodiments of the present technology.FIG. 2is a perspective view of a flow enhancer of a generator body of a nCPAP device for lowering patient WOB, in accordance with one embodiment of the present technology.

With reference now toFIGS. 1 and 2, in one embodiment, the nCPAP device100includes inspiratory tubing102in fluid communication with at least two nasal prongs104, expiratory tubing106, and a generator body108coupled with the inspiratory and expiratory tubing,102and106, respectively. In one embodiment, the inspiratory tubing102is coupled with a ventilator134. In another embodiment, the at least two nasal prongs104are positioned within nare of a patient. It should be appreciated that the term “inspiratory tubing” may refer to an “inspiratory limb”, as is also used herein.

The generator body108includes at least two jets110aand110band a flow enhancer112. In one embodiment, the at least two jets110aand110bare configured for receiving gas111from the inspiratory tubing102and directing, via a jet flow113, the gas111towards the at least two nasal prongs104. In one embodiment, the at least two jets110aand110bhave a jet diameter128greater than 0.034 in. In one embodiment, the jet diameter128is 0.044 in. It should be appreciated that the larger the jet diameter128, the slower the jet flow113. In one embodiment, the at least two jet paths118aand118bare situated angularly with respect to each other. In other words, the jet paths118aand118b, are not parallel with each other.

In another embodiment, the flow enhancer112is configured for redirecting the gas111of the jet flow113. In one embodiment, the flow enhancer112is spaced a distance apart from an interior surface132of the generator body108to accommodate the second pathway126. While it is shown inFIG. 1that the expiratory tubing106is on top of the generator body108, it should be appreciated that the expiratory tubing may be coupled with other areas of the generator body108. For example, the expiratory tubing106may be coupled with the generator body108next to the flow enhancer112. In this case, the exhaled patient's breath traveling along second pathway126, exits the expiratory tubing106while next to the flow enhancer112.

In one embodiment, the flow enhancer112circles around the interior surface132of the generator body108. In one embodiment, the length of the flow enhancer112as viewed formFIG. 1, may vary. In one embodiment, the thickness of the flow enhancer112may be any thickness that is compatible with the nCPAP device that functions to lower the patient's WOB.

In one embodiment, the flow enhancer112is positioned in parallel with a nare path of a patient. The nare path of the patient is also parallel with the nasal prongs104of the nCPAP device100since the nasal prongs104are inserted into the patient's nares for functioning.

Referring still toFIGS. 1 and 2, in one embodiment, the flow enhancer112includes at least one of the following: a gas manager114; a fluidic flip trigger120and an isolated pathway manager124. In one embodiment, the gas manager114is configured for channeling115the jet flow113towards a jet impingement point116via at least two jet paths118aand118b.

In one embodiment, the fluidic flip trigger120is configured for triggering a fluidic flip121of channeled gas back towards the expiratory tubing106. The fluidic flip121is triggered by directing123a first portion of the exhaled patient breath towards the jet impingement point116along a first pathway122.

In another embodiment, the isolated pathway manager124is configured for directing125a second portion of the exhaled patient breath along a second pathway126towards the expiratory tubing106, the second pathway126isolated from the first pathway122.

Thus, embodiments of the present technology provide for a nCPAP device for lowering a patient's WOB. This is accomplished by reducing resistances throughout the generator body108to patient's inhalation and exhalation.

Operation

FIG. 3is a flow diagram of a method300for delivering a nasal continuous positive airway pressure to a patient, according to one embodiment of the present technology. Referring toFIG. 3, at302, in one embodiment and as described herein, during one of a stagnant and inhalation phase, jet gas111is directed from at least two jets110aand110btowards a patient's nares along at least two jet paths118aand118bto meet at a jet impingement point116.

In one embodiment and as described herein, at304ofFIG. 3, a fluidic flip121of jet gas flow back towards an expiratory limb106is triggered by directing123a first portion of exhaled patient breath towards the jet impingement point116.

In one embodiment and as described herein, at306ofFIG. 3, a second portion of the exhaled patient breath is directed125through an isolated path towards the expiratory limb106. The foregoing method300lowers a patient's WOB by providing a jet gas entrainment toward the expiratory limb106for the first portion of the exhaled patient breath and an unobstructed flow path for the second portion of the exhaled patient breath.

All statements herein reciting principles, aspects, and embodiments of the invention as well as specific examples thereof, are intended to encompass both structural and functional equivalents thereof. Additionally, it is intended that such equivalents include both currently known equivalents and equivalents developed in the future, i.e., any elements developed that perform the same function, regardless of structure. The scope of the present invention, therefore, is not intended to be limited to the exemplary embodiments shown and described herein. Rather, the scope and spirit of present invention is embodied by the appended claims.