Surgery – Respiratory method or device – Means for mixing treating agent with respiratory gas
Reexamination Certificate
2001-05-23
2004-04-20
Maust, Timothy L. (Department: 3751)
Surgery
Respiratory method or device
Means for mixing treating agent with respiratory gas
C128S203210, C128S203230, C604S058000, C141S329000
Reexamination Certificate
active
06722363
ABSTRACT:
The invention relates to a device for emptying powder-containing cavities by suction in accordance with the generic concept of claim
1
or
53
.
In the prior published solutions of this type (US-PS 25 49 303), the cavity is provided in a solid lower part which has a pot-shaped recess over whose pot rim the covering foil is stretched. The suction tube is fitted at its leading end with an annular collar which can be pushed in lid fashion onto the outer surface wall. Provided in the upper part in a re-entrant manner with respect to said rim is a truncated cone whose leading, narrower truncated-cone end face pierces the covering foil when the suction tube is pressed down. A channel-shaped cross-section is left in the inner surface of the encircling wall of the annular collar for the entrance of air while the cavity is being emptied by suction. The solutions are inadequate structurally and operationally: the outer enclosure leaving only a small air entrance cross section makes it impossible always to achieve a uniform, in particular complete, emptying of the cavity. This also contributes to the fact that the leading, cross-sectionally smaller truncated-cone end face does not make possible a controlled opening separation of the covering foil so that cases occur in which portions of the covering foil which have awkwardly folded into position propel residues of the powder to be sucked out into a concealed position which is also favoured by the fact that such cover-foil portions are possibly sucked onto the truncated-cone outer surface. The fact that the suction tube is rotatable relative to the lower part and may even be rotated further after the covering foil has been pierced during the manipulation adversely affects the reproducibility of the suction emptying process. That makes use in the field of medications which have to be precisely dispensed impossible. In addition, the lower part, which forms the cup-shaped cavity, is conceived as a disposable part and is thrown away after the covering foil has been pierced, which is an appreciable cost-increasing factor, apart from the storing for the cases of a regular medicinal taking of the powder.
Another solution which avoids the last mentioned disadvantage is prior published by DE-OS 196 19 536. In the latter, a carrier is provided to which a standard blister pack can be fitted with a multiplicity of cavities which each contain the powder in the appropriate dosage. This has not only the advantage of reusability of the carrier as a result of filling with a new blister pack, but also the advantage that a plurality of cavities is always provided and, in the case of medicinal application, the patient also has a certain inspection ability in regard to the covering foil already pierced and to the cavities still unused. In this connection, the carrier has a cover plate which has individual holes which align with the cavities of the blister. The suction tube is first positioned in the latter and then brought right into the suction position by further insertion. In this arrangement, flanks are fitted to the suction tube which cut at the leading end and which ensure a specific separation of the respective covering foil of the cavity, which separation optimizes the emptying by suction. The necessary air entrance cross sections which permit the replacement flow of air into the cavities when the latter are emptied by suction are in this case designed as axial tubular channels of the suction tube whose leading mouth cross sections are exposed in the cavity after the covering foil has been pierced.
The respective solutions are disadvantageous in regard to the fact that the freely projecting blades are very susceptible to damage during the initial positioning of the suction tube in the hole of the carrier. In order to protect them against damage to any extent at all during the piercing of the covering foil, the suction tube has to be already longitudinally guided into the holes before the blade contacts the covering foil. That necessitates a relatively great axial length of said insertion holes of the carrier, which in turn has the disadvantage that the blister covering foil is situated quite far below the upper side of the carrier and it is consequently often possible to check only with difficulty whether a certain cavity has already been sucked empty or not. In the case of this prior published solution, if the insertion end of the suction tube is made non-circular, it is true that a rotation of the suction tube is prevented after mutual engagement of this non-circular region in the correspondingly non-circular hole of the carrier, and there will be damage, associated therewith, to the blade as a result of rotation of the latter in the cut covering foil; the solution in regard to the air entrance cross sections to form them as tubular channels of the suction tube, however, thereby, becomes even more complicated. As uniform as possible a suction of said air from all sides into the cavity, which actually does give as equal treatment as possible to all the regions of the cavity, is not achievable.
The object of the invention is to form a generic device in such a way that it can be produced more inexpensively and can be manipulated more reliably.
In the case of claim
1
, this object is achieved in that the suction tube is positioned in slots of the carrier separated from the entrance hole for the blades or, in the case of the solution of claim
53
, in that a sleeve positions itself at the rim of the hole of the carrier and then undertakes the guidance of the suction tube during the insertion movement, said separate positioning means being in both cases a protection of the cutting flanks against damage even when not in use, which cutting flanks can thereby be adapted in an optimum way to provide the advantage of cutting through the covering foil portion and of folding in the individual cut covering foil sectors.
As a result, there is actually also the advantage of a concentrated control of the device. The cover of the carrier, which cover is provided with holes and under which the blister is situated may be very thin; nevertheless, there is an adequate positioning of the suction tube, in good time before the blades pass into the hole. The blister covering foil can thereby be situated more visibly because of the shorter axial length of the holes, which facilitates reliable manipulation, in particular in the case of older people. In the version with the flat extensions which plunge into the slots, the suction tube is secured against rotation starting from the instant of the first insertion of the extensions; in the version with a sleeve, the same can be achieved by securing against rotation between suction tube and sleeve and by placing the sleeve on a non-circular hole rim. The cutting flanks situated in a protected, set-back manner can also be designed in relation to the hole of the carrier so that an optimum air entrance cross section to the cavity remains free because this cutting region of the suction tube has no longer anything to do with positioning and guiding it. That promotes not only the always uniform emptying of the cavity by the air flowing in freely from all sides, but also prevents residues of the powder accumulating in the suction tube after repeated use of the latter, as may occur, for example, in the air inlet channels of the prior published solution in accordance with OS 196 19 536. In regard to the longitudinal guidance or positioning of the suction tube, it proves advantageous that the suction tube can be guided in slots, situated on either side of the holes, of the carrier. A type of carriage-like displacement capability then exists.
If the piercing flanks are designed as flat, projecting extensions, they form an excellent protection for the cutting edge and any plunger blades. In addition, they ensure that large air entrance cross sections remain. Moreover, they open up progressive possibilities in regard to the releasable fitting of the suction tube to the carrier and its correct fitting for manipulation, even when not in use. Th
Astrazeneca AB
Fish & Richardson P.C.
Maust Timothy L.
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