Apparatus and method for providing high frequency variable pressure to a patient

#1. Field of the Invention

#The present invention pertains to an apparatus and method of providing high frequency variable pressures to an airway of a patient, and, in particular, to an apparatus and method of providing high frequency variable pressures in which a valve generates the pressure oscillations in the delivery of gas to or from the patient independent of patient effort.

#2. Description of the Related Art

#FIG. 1 is a side view, partially in section, of a high frequency pressure oscillation device according to the principles of the present invention;

#FIG. 2 is an exploded view illustrating the components of an exemplary embodiment of a sleeve valve used in the high frequency pressure oscillation device of FIG. 1;

#FIGS. 3A and 3B are side and sectional views, respectively, of the barrel portion of the sleeve valve of FIGS. 1 and 2, with the barrel being rotated 90° in FIG. 3B from the position shown in FIG. 3A;

#FIG. 1 schematically illustrates a first exemplary embodiment of a high frequency pressure oscillation device 30 according to the principles of the present invention, and FIGS. 2-7 illustrate various components of that device. As shown in FIG. 1, high frequency pressure oscillation device 30 preferably includes a housing 32 having a handle 34 so that the device can be readily gripped by the user in one hand. A patient circuit 36 in the form of a conduit is defined in housing 32 between a patient end 38 and a breathing gas source end 40. In the illustrated exemplary embodiment, a mouthpiece 42, which preferably includes a bacteria filter, is removeably provided at patient end 38 so that the patient can breathe into patient circuit 36. Patient circuit 36 provides a path, as generally indicated by arrows 44, for the flow of gas between the patient and the breathing gas source, which in the illustrated embodiment is the ambient atmosphere.

#A valve assembly 46 is provided in the patient circuit to control the flow of gas between the patient and the gas source. More specifically, valve assembly 46 preferably operates between two positions: (1) an open position in which path 44 between the source of breathing gas and the airway of a patient is substantially unobstructed, as shown in FIGS. 1, 5A and 5B, and (2) a closed position, in which path 44 between the source of breathing gas and the patient's airway is at least partially obstructed, thereby restricting the flow of gas in path 44. In the embodiment illustrated in FIGS. 1-6B, valve assembly 46 is a reciprocating sleeve valve, the details of which are provided below.

#As the patient breathes into patient circuit 36 via mouthpiece 42, valve assembly 46 is actuated by an actuating system, generally indicated at 48, causing the valve to repeatedly open and close, which, in turn, repeatedly blocks and unblocks path 44. As the patient breathing into patient circuit 36, this abrupt blockage of path 44 from the patient to the source of breathing gas produces pressure spikes in the patient's airway that are conducive to clearing secretions from the airway. Actuating system 48 moves valve assembly 46 between the open position and the closed position independent of the flow of gas through patient circuit 36. That is, the means by which patient circuit 36 is repeatedly blocked and unblocked is not dependent on the effort of the patient, as is the case with the above-described conventional flutter valve. As a result, the pressure spikes are created in the patient's airway even if the patient is breathing into the patient circuit at very low flow rates. In addition, because actuating system 48 is not dependent on patient effort to move the valve between the open position and the closed position, the operation of high frequency pressure oscillation device 30 is not position sensitive. Also, the frequency of oscillation for the valve can be controlled and is not dependent on the rate of flow of gas generated by the patient.