FR2624377A1 - Microdelivery instillator - Google Patents

Abstract

The invention relates to a portable and disposable instillator device intended to deliver, with a low and extended delivery rate, medicinal or other fluids or solutions. The device comprises a flat, deformable and inextensible reservoir bag 1, subjected 600 to an outside pressure which causes it to empty through a drainage channel 5, which reaches, via a capillary flow-rate limiter device 400, 401 or 402, an instillation device such as a catheter or instillation needle 44. A constant pressure is exerted on the reservoir bag placed in an inextensible chamber, by virtue of a release of gas resulting from an effervescent reaction.

Description

 The invention relates to an apparatus making it possible to deliver, from a previously constituted reserve, fluids containing or not substances in solution or in suspension with a low and fairly constant flow rate over several hours or consecutive days. The device is initially designed to deliver by instillation for medical or experimental purposes, natural or synthetic pharmacodynamic substances in living organisms, but can be used for any purpose other than the transport and instillation of pharmacodynamic substances, by not limited to supplying aqueous or non-aqueous solvents, and possibly solutes present in these solvents, compatible with the materials used for the construction of the device. The device is autonomous in the sense that it does not require a constant supply of energy. This autonomy and its small size allow it to be used notably but not exclusively as a portable permanent instillation system by patients receiving outpatient medical treatment. The relative simplicity of the device should make it inexpensive industrial manufacturing thus making it a disposable device. For an additional improvement not required the device can in some versions, receive a supplement to transform the constant flow in a flow with pre-programmed transient increases or decreases.

 The device is essentially characterized by a reservoir bag, the wall of which is made of a flexible material which is deformable but not extensible, capable of withstanding a relatively significant mechanical stress, impermeable to the fluid contained therein delimiting an interior corpartinent with variable volume. by deformation, which interior corpartinent is connected in a leaktight manner with the outside by a flexible or rigid non-crushable channel, carrying at its free outer end a connection nozzle with any pipe making it possible to conduct the contents of the tank bag to such or such desired destination, especially within a living organism. The deformation of the reservoir bag, and therefore its emptying, is obtained by inserting the bag into a pressing device developing a propellant pressure transmitted to the walls of the bag and therefore to the contents of the bag.

In this embodiment, the propellant pressure is supplied by raising the pressure of a fluid surrounding the reservoir bag, the
all enclosed in an inextensible enclosure through the wall of
which passes the evacuation channel of the contents of the reservoir bag. The pressure rise is rapid by effervescent release of a gas and in this case a flow limiter is necessary at the outlet of the bag
tank.

Figure 1 shows in profile an example of a tank bag 1 to
insert into a pressure system described in the text.

 FIG. 2 represents three embodiments (400, 401 and 402) of the flow-limiting device using a capillary duct, two of which (400 and 402) are shown in section and the third (401) in exploded view.

 Figure 3 shows in section a presser system (600) implementing an effervescent release in the rigid and sealed enclosure surrounding the reservoir bag.

 Continuously, the invention uses a reservoir bag made of flexible, deformable and non-extensible material, preferably transparent or translucent, impermeable to the fluid which it must contain, chemically inert and not releasing any substance capable of mixing with the contents of the bag or dissolve in it; its shape and dimensions are a function of the quantities of fluid to be stored as well as of the device providing the propellant pressure but the best results can be expected from a bag which can be drained completely without the formation of folds or noticeable surface reliefs.

According to a first embodiment, the reservoir bag 1 is made up according to FIG. 1 of two flat sides united on their periphery 2 by welding, gluing, molding or any other procedure ensuring the tightness of the compartment thus delimited, or by molding in a single piece of
the whole flat bag. An orifice 3 provides for the crossing of the wall of the bag by a flexible, non-squeezable tube 5 and the junction 4 between the tube 5 and the wall 1 of the bag is sealed, mechanically capable of withstanding the pressure to which the contents of the bag, and of a shape such that it can be used to position the bag in the pressing device described in the invention. The tube 5 has at its end outside the bag a nozzle 20 allowing its connection with any other
tube or channel. Inside the bag, the tube 5 and its end are arranged so as not to create by their presence an obstacle to the complete application one on the other of the sides of the bag, as well as to the
free distribution of the contents of the bag in it under the action of
propellant pressure to cause emptying of the bag.

For medical applications, the bag 1 and tube bundle
5 drain is built previously but in materials
bearing the constraints of sterilization necessary for this type
of applications.

The pressing device (600), Figure 3: this device may not include any metal part. It uses as a pressurizing agent a release of effervescent gas, coming from the mixture at the time of use.
of two components generally a solvent and an effervescent salt, to
inside an inextensible enclosure containing it neye the bag
tank. This device generally involves the use of a
flow limiter at the outlet of the tank bag.

The flow limiting device, Figure 2: it consists of a capillary channel whose section must be sufficient not to create a filter effect with respect to particles in solution or in suspension in the fluid contained in the reservoir bag. This channel obeys
the law of Poiseuilles ie
flow rate = P 1-2. (3.14. R4 / 8. H.

where P 1-2 is the pressure difference at the ends of the channel, R4 is the radius of the pipe raised to the power 4, h is the viscosity of the circulating fluid and I the length of the channel. This device possibly having to be portable, sterilizable and disposable, it is important that its cost price be as low as possible. According to one embodiment (400) Figure 2, it consists of a tube 12 of metal or other material such as catheter, of constant section, and whose length can vary from a few tens of centimeters to several meters depending on the radius selected for its section (a few fractions of a millimeter). In this case, the capillary wound on the luisreme is inserted into a suitable support device which can be but not exclusively consist of material molded around the capillary. According to another embodiment (402) Figure 2, the channel is formed by the confrontation of a threaded rod 13 of threadable material, moldable or other, inserted in a rigid and smooth cylindrical tube or cavity 14 so that the crest 15 of the thread pitch faced in a sealed manner against the smooth wall of the tube 14 separates each turn of the turn from the next turn, thus forcing the circulating fluid entered under pressure at one end of the device to go through all the turns of the turn before reaching at the other end: the capillary channel then has for section 16, that of the thread section and for length i, the total length of the screw thread sculpted in the threaded rod. According to a third embodiment (401) FIG. 2 , the capillary channel is formed by the sealed confrontation of a part having a smooth and flat face 17 against another part 18 also planar but whose surface is depressed by a spiral groove 19, or rectilinear folded in labyrinth or any other geo suitable metrics, and can be obtained by engraving, rolling, stamping or any process which facilitates manufacturing and which makes it possible to moderate the industrial cost: the capillary channel then has the length of that of the groove 19 and for section that of the delimited space between the bottom and the sides of the furrow 19 engraved in 18 on the one hand, the smooth face of the opposite piece 17 on the other hand. In the last two embodiments described above, the seal between crests of the furrows and tubular or flat face is ensured by forcing, gluing, poly or other welding or any other suitable process.

In all of these embodiments, furthermore, nozzles 20 make it possible to connect the flow limiter to the outlet nozzle of the reservoir bag.

 According to one embodiment of the presser in FIG. 3, the reservoir bag 1 is placed in a non-deformable and inextensible enclosure 39 so that the channel 5 for emptying the bag 1 passes tightly through the wall of the enclosure 39. The latter is provided with a filling orifice 40 with a sealed closure 41 through which the liquid element 43 necessary for the evolution of gas is poured. The reservoir bag 1 being filled and its channel 5 closed by a clamp or any suitable device, the flow limiter (400, 401 or 402) being put in place, a dose of reagent 42 determined according to the pressure to be obtained is then placed in the enclosure and it quickly blocked by 41.

 The easiest effervescent reactions 42/43 are the mixture of acidulated water - effervescent bicarbonate, or mmc water fragment of effervescent aspirin tablet.

Claims (5)

 1. Micro-flow instillator characterized in that it consists of a deformable and inextensible reservoir bag containing the fluid or the solution to be instilled, delivering its content to the outside of the bag by means of a channel connected to a limiter flow characterized in that it consists of a non-filtering capillary channel and at the outlet of which is connected the catheter channel, or the needle, for instillation, and of a pressure device characterized in that it consists a rigid container containing the said reservoir bag, the wall of which sealingly passes the passage of the discharge channel 5 and inside which an effervescent reaction raises the pressure by gassing.  2. Micro-flow instillator according to claim 1, characterized in that it peddles a reservoir bag consisting of 2 flat sides united by their edges in a leaktight manner, deformable, non-extensible, impregnable, the said bag 1 being provided with a channel filling and emptying 5 not obstructing the total application of the 2 sides against each other and having at its outer end a flow limiter (400, 401 or 402)  3. Micro-flow instillator according to claim 1, characterized in that it includes a flow-limiting device consisting (400), of a capillary tube of diameter such that it does not exert a filtration action on the fluids or solutions circulating therein, sterilizable or not depending on the purpose pursued, the length of which can reach several tens of centimeters depending on the desired final flow rate, wound on luismene, inserted in a support 'rolled or not, provided at its ends with suitable nozzles 20 to insert said flow limiter between the reservoir bag channel and the catheter, or the needle, to instillation.  4. Micro-flow instillator according to claim 1, characterized in that it peddles a flow-limiting device constituted (401 or 402), of a capillary channel resulting from the tight confrontation of a piece with smooth face against another part whose smooth face is engraved with a continuous groove terminated at its two ends by devices for connection to any channel conducting the fluid whose flow is to be limited.  5. Micro-flow instillator according to claim 1, characterized in that the pressure system (600) implements a gaseous release resulting from an effervescent reaction between a solvent 43 contained in an inextensible impermeable compartment 39 through the wall of which passes from tightly 38 the drain channel 5 of the reservoir bag 1 neutralizes it included in the aforesaid compartment 39, and an effervescent substance 42 such as the acid / bicarbonate mixture optionally in the form of effervescent aspirin and in the presence of water.