Disposable infusion device filling apparatus and method

#Tight control over the delivery of insulin in both type I diabetes (usually juvenile onset) and type II diabetes (usually late adult onset), has been shown to improve the quality of life as well as the general health of these patients. Insulin delivery has been dominated by subcutaneous injections of both long acting insulin to cover the basal needs of the patient and by short acting insulin to compensate for meals and snacks. Recently, the development of electronic, external insulin infusion pumps has allowed the continuous infusion of fast acting insulin for the maintenance of the basal needs as well as the compensatory doses (boluses) for meals and snacks. These infusion systems have shown to improve control of blood glucose levels. However, they suffer the drawbacks of size, cost, and complexity. For example, these pumps are electronically controlled and must be programmed to supply the desired amounts of basal and bolus insulin. This prevents many patients from accepting this technology over the standard subcutaneous injections.

#Hence, there is a need in the art for a convenient form of insulin treatment which does not require significant programming or technical skills to implement to service both basal and bolus needs. Preferably, such a treatment would be carried out by an infusion device that is simple to use and mechanically driven negating the need for batteries and the like. It would also be preferable if the infusion device could be directly attached to the body and not require any electronics to program the delivery rates. The insulin is preferably delivered through a small, thin-walled tubing (cannula) through the skin into the subcutaneous tissue similar to technologies in the prior art.

#While the idea of such a simple insulin delivery device is compelling, many obstacles must be overcome before such a device may become a practical realty. One problem resides in insulin supply. Patients vary greatly on the amount of insulin such a device must carry to provide treatment over a fixed time period of, for example, three days. This is one environment where one size does not fit all. Another problem is with cannula deployment to support insulin delivery. Cannula deployment to support delivery of the insulin beneath the patient's skin must be made easy and convenient. This is not as easy as it seems because cannula deployment, as generally and currently performed in the art, requires insertion of a cannula carrying needle into the patient and then retraction of only the needle to leave the cannula in place beneath the patient's skin. As will be seen subsequently, the present invention addresses these and other issues toward providing a simple, practical, and reliable insulin delivery device.

#The features of the present invention which are believed to be novel are set forth with particularity in the appended claims. The invention, together with further features and advantages thereof, may best be understood by making reference to the following description taken in conjunction with the accompanying drawings, in the several figures of which like reference numerals identify identical elements, and wherein:

#FIG. 1 is a schematic representation of a reservoir within a disposable wearable diffusion device being filled with a liquid medicant according to an embodiment of the present invention;

#FIG. 2 is perspective view of an infusion device embodying the present invention;

#Referring now to FIG. 1, it is a schematic representation of an infusion system embodying the present invention. The system 100 generally includes a disposable wearable infusion device 110 and a filler 130. The filler 130 is seen in FIG. 1. filling a reservoir 112 within the diffusion device 110 with a measured quantity of a liquid medicant, such insulin, for example, according to an embodiment of the present invention.

#The device 110 includes a body or enclosure 120 that is adhered to the skin 140 of a patient and that encloses the reservoir 112. The device 130 further includes a cannula 124 deployed from the device 110 to beneath the skin 140 of a patient to deliver the liquid medicant. The reservoir 112 is coupled to the cannula 124 by a pump 114 and a one-way check valve 116. Actuation of the pump provides a fixed quantity of the medicant to the cannula.

#The filler 130 is adapted to receive a vial 132 of the liquid medicant 133. A first conduit 136 provides fluid communication from the vial 132, through a filling port septum 126, and into the reservoir 112. A second conduit 138 provides fluid communication from a pump 135 to the vial. The pump 135 is employed to pump air into the vial 132 to displace a known quantity of the liquid medicant 133 from the vial 132. The medicant is then delivered to the reservoir through the first conduit 136. As will be seen subsequently, and in accordance with one aspect of the present invention, as the vial 132 is received by the filler 130, the interior space 134 within the vial 132 is vented to atmospheric pressure and then sealed. This venting of the vial 132 assures that a known volume of air being pumped into the vial will displace a like volume of medicant for filling the reservoir.