Patent Grant
8813746
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.
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.
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.
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.
With reference now to
The generator body 108 includes at least two jets 110a and 110b and a flow enhancer 112. In one embodiment, the at least two jets 110a and 110b are configured for receiving gas 111 from the inspiratory tubing 102 and directing, via a jet flow 113, the gas 111 towards the at least two nasal prongs 104. In one embodiment, the at least two jets 110a and 110b have a jet diameter 128 greater than 0.034 in. In one embodiment, the jet diameter 128 is 0.044 in. It should be appreciated that the larger the jet diameter 128, the slower the jet flow 113. In one embodiment, the at least two jet paths 118a and 118b are situated angularly with respect to each other. In other words, the jet paths 118a and 118b, are not parallel with each other.
In another embodiment, the flow enhancer 112 is configured for redirecting the gas 111 of the jet flow 113. In one embodiment, the flow enhancer 112 is spaced a distance apart from an interior surface 132 of the generator body 108 to accommodate the second pathway 126. While it is shown in
In one embodiment, the flow enhancer 112 circles around the interior surface 132 of the generator body 108. In one embodiment, the length of the flow enhancer 112 as viewed form
In one embodiment, the flow enhancer 112 is positioned in parallel with a nare path of a patient. The nare path of the patient is also parallel with the nasal prongs 104 of the nCPAP device 100 since the nasal prongs 104 are inserted into the patient's nares for functioning.
Referring still to
In one embodiment, the fluidic flip trigger 120 is configured for triggering a fluidic flip 121 of channeled gas back towards the expiratory tubing 106. The fluidic flip 121 is triggered by directing 123 a first portion of the exhaled patient breath towards the jet impingement point 116 along a first pathway 122.
In another embodiment, the isolated pathway manager 124 is configured for directing 125 a second portion of the exhaled patient breath along a second pathway 126 towards the expiratory tubing 106, the second pathway 126 isolated from the first pathway 122.
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 body 108 to patient's inhalation and exhalation.
Operation
In one embodiment and as described herein, at 304 of
In one embodiment and as described herein, at 306 of
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.
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| Entry |
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| Number | Date | Country | |
|---|---|---|---|
| 20120060844 A1 | Mar 2012 | US |
