Classifications

• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61M—DEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY; DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY; DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR
  • A61M5/00—Devices for bringing media into the body in a subcutaneous, intra-vascular or intramuscular way; Accessories therefor, e.g. filling or cleaning devices, arm-rests
  • A61M5/14—Infusion devices, e.g. infusing by gravity; Blood infusion; Accessories therefor
  • A61M5/142—Pressure infusion, e.g. using pumps
  • A61M5/145—Pressure infusion, e.g. using pumps using pressurised reservoirs, e.g. pressurised by means of pistons
  • A61M5/148—Pressure infusion, e.g. using pumps using pressurised reservoirs, e.g. pressurised by means of pistons flexible, e.g. independent bags

Definitions

• the invention relates to a system for infusing a liquid into a blood path, in particular a human being, of the type comprising a container containing said liquid, which is connected by a hose to the person under infusion, and means intended imparting to the liquid to be introduced into the blood path a predetermined pressure greater than the pressure prevailing inside said path.
• the container is suspended at a predetermined height from a bracket mounted on a carriage which is movable on the ground, the person on an infusion being connected to the container by said flexible hose.
• the height of the container is generally chosen so that it is at a distance of 130 cm above the point where the infusion needle enters the bloodstream. It is the column of liquid corresponding to this height which creates the perfusion pressure.
• This known system has the major drawback of having a bulky structure which makes the movements of the person under perfusion inconvenient if not impossible in certain cases.
• the object of the present invention is to propose a system of the type described above which is easily transportable by the person on an infusion.
• the system according to the invention is characterized in that at least the side wall of the container is made of a flexible material and has an axially compressible configuration, the container is placed in a portable case by the person under infusion, by taking support at its end before leaving the liquid on a support wall of the housing and by its rear end closed on an axially movable surface in the housing, under the effect of a pusher device of said surface, in the direction of axial compression of the container, to drive the liquid from it.
• the pusher device comprises spring means in the prestressed initial state which is supported by one end at the bottom of the housing and by its other end on a piston mounted axially movable in the housing and the surface opposite to the bearing surface of the spring forms the aforementioned movable surface and in that the system comprises means for adjusting the flow rate of the liquid expelled from the container when the spring is released.
• the pusher device comprises a cartridge filled with a pressurized gas forming a source of gas spreading in the housing at a substantially constant pressure and acting on a piston mounted axially movable in the housing and whose surface opposite to that exposed to the gas constitutes the aforementioned mobile surface.
• FIG. 1 is a view in axial section of a first embodiment of a system according to the present invention:
• Figure 2 is a sectional view along line II-II of Figure 1;
• Figures 3 and 4 are views in axial section, with cutaway, of two variants of the embodiment according to Figure 1;
• Figure 5 is an axial sectional view of a second embodiment of the invention.
• the system forming a first embodiment of the invention and shown in Figure 1 comprises a housing 1 of generally cylindrical shape closed at one end by a front wall 2 pierced in its center with an orifice 3 and capable of being closed at its other end by a hollow cylindrical member 4 which has on its external cylindrical surface a thread allowing its screwing in the end of the housing provided for this purpose with an internal thread.
• a piston 5 is mounted axially mobile in the housing 1 and divides the internal space into two chambers of variable volume 6 and 7.
• the chamber 6 delimited between the front wall 2 and the piston 5 houses a container 8 of generally cylindrical shape axially compressible under the effect of the displacement of the piston 5.
• the cylindrical wall 9 of the container advantageously has an accordion configuration.
• the container contains the infusion liquid to be discharged from the container into the bloodstream of a recipient, via a flexible tube indicated at 10 which extends inside the container through a stopper. closure 11 of the container engaged in the orifice 3 of the wall 2.
• the chamber 7 which is delimited between the piston 5 and the closing member 4 houses a helical spring 13 which bears at one end on the bottom of the member hollow 4 and by its other end on the corresponding front surface of the piston 5.
• the spring 13 occupies its compressed position shown .
• the latter moves to its position shown in phantom, thereby deforming in the manner shown the cylindrical wall 9 in accordion of the container 5, which causes the liquid to flow back out of the container 8 into the pipe 10.
• such a device essentially comprises two parallel friction rods 15 and 16 which have a substantially rectangular cross section and are in mutual friction contact by one of their malls.
• the two rods are engaged in a groove 18 formed in the cylindrical peripheral surface of the housing 1.
• the groove 18 extends parallel to the axis of the housing.
• the strip 16 rests on the bottom of the groove 18 while being axially oriented in the latter. It is fixed to the cylindrical surface of the piston 5 by a fixing means 19 of any suitable nature.
• the rod 16 is thus axially movable in the groove 18 while being driven by the piston 5.
• the rod 17 is fixed on an element 21 for closing the groove 18.
• This element is pivotally mounted around an axis 22 parallel to the groove and is lockable in its covering position of the groove 18 by means of rapid fixing means 23 of any suitable nature.
• a layer 20 of an elastically compressible material has been interposed in the example shown between the friction element 17 and the closing element 21.
• the length of the movable friction rod 16 is slightly greater than the length of the stroke of the piston 5 so that it still remains in contact with the fixed friction rod 17 over a small part of its length as indicated in the Figure 1 in broken lines, when the piston 5 occupies its end position of the rebound stroke.
• the housing 1 is equipped with two devices 14 intended to keep the flow rate of the container 8 constant. These devices are located diametrically opposite so as to prevent the piston from jamming under the effect of the spring force 13.
• Figure 3 shows another embodiment of the device 14.
• the housing has an axial peripheral channel 25 through which the pipe 10 extends axially.
• the latter is made of an elastically deformable material such as a plastic material.
• the radially outer surface 26 of the channel 25 is inclined at a predetermined angle relative to the axis of the housing 1.
• the channel 25 communicates with the internal space of the housing 1 by an axial slot 27.
• This device comprises at least one roller 29, advantageously several, as in the example shown, which are freely rotatable around axes perpendicular to the longitudinal direction of the channel 25 in a support 30 which is integral with the periphery of the piston 5 and extends through the slot 27.
• these rollers 29 are located in such a way-inside the channel 25 that the pipe 10 is engaged between the cylindrical peripheral rolling surfaces of the rollers 29 and the inclined surface 26 of the groove 25.
• the pipe 10 In the starting position of the piston 5 , which is shown in Figure 3, the pipe 10 is highly elastically compressed, that is to say crushed and has a minimum flow section. It is easily understood that during the displacement of the piston 5 under the effect of the spring 13 in the direction of the front wall 2 of the housing 1, due to the inclination of the surface 26, the degree of crushing decreases and the cross section of flow increases.
• the flow rate of the liquid discharged from the container 8 through the pipe 10 can be kept constant.
• the device 28 could be in the form of a carriage provided with a number of rollers 29 juxtaposed over a length corresponding to the length of the friction rod 16 in the figure 1.
• the surface 26 of the groove 25 extends parallel to the axis of the housing over a length corresponding to the length of the fixed friction rod 17 of FIG. 1.
• the pipe 10 does not undergo a deformation of its cross section by the rollers 29 as a function of the displacement of the piston 5 only over a length which depends on way substantially linear displacement of the piston.
• FIG. 5 shows a second embodiment of the system according to the invention in which the pusher device of the piston 5 is essentially formed by a cartridge 30 filled for example with pressurized air.
• the cartridge 30 is capable of being secured to the removable closing member of the housing 1 produced in the form of a cap 31 which can be screwed onto the housing 1.
• the cartridge has at its end opposite the piston 5 an orifice shown diagrammatically at 32 through which the pressurized air can gradually escape.
• a pressure can be established in the space 33 between the cartridge and the piston 5 of a value suitable for pushing the piston 5 in the direction of the axial compression of the container 8.
• the housing 1 is provided with a device 34 for regulating the pressure.
• the device 34 whose dimensions are exaggerated for the sake of greater clarity of the representation comprises a chamber 35 which communicates with the space 33 through a channel 36 which passes through the wall of the housing 1 and is closable by a valve 37 pushed back into its closed position by a spring 38, the restoring force of which can be adjusted using an adjusting screw 39 in the external wall of the chamber 35.
• the pressure in the chamber 33 which causes the valve 37 to open can be adjusted. It is easy to understand that the device 34 makes it possible to maintain inside the chamber 33 a pressure whose upper limit is determined by the spring 38.
• a second device 40 for adjusting the lower pressure in the space 33 is provided on the front wall 2 of the housing.
• This device allows a variation in the cross-section of flow of the liquid from the flexible pipe 10. It could comprise an adjustment screw 41 or be of any other suitable and known material.
• the pressure thus kept constant will be chosen so as to obtain that the flow rate of liquid discharged from the container 8 through the pipe 10 has the desired value.
• the cartridge 30 forming the source of the pressurized air can be produced so as to be easily refillable by equipping it, for example, with a valve device known per se, such as for example used for inflatable tires.
• the container 8 can be produced in any other suitable known manner. It only matters that it is axially compressible.
• any other suitable pusher device can be used to print on the piston its compression stroke of the container. One could also consider removing the piston by giving the bottom of the container sufficient rigidity so that it can replace the piston.
• the device for maintaining constant the flow rate of the liquid discharged from the container 8 can also be produced in any other known known manner suitable for example for varying the hydraulic resistance of the pipe 10 as a function of the displacement of the piston 5 to thereby compensate for the variation in the force of the piston plunger.
• the two adjustment devices 34, 40 for pressure in space 33 could be replaced by a regulator of the known type which would equip the outlet orifice of the cartridge.
• the housing 1 will advantageously be made of a light material, for example by molding, to reduce its weight as much as possible. It could be provided with a strap to be easily portable for example at the waist by the person on an infusion. Thus it can move easily without being particularly hampered by the infusion system that it carries on it.
• the dimensions of the housing depend on the volume of the container and the pusher device. They will be relatively small. For example, the diameter of the case could be of the order of 5 to 10 cm while the length could have a value of the order of 15 to 20 cm. Furthermore, it is also possible to associate with the piston 5 a movable index element making it possible to view the position of the piston relative to the housing 1.

Landscapes

• Health & Medical Sciences (AREA)
• Vascular Medicine (AREA)
• Engineering & Computer Science (AREA)
• Anesthesiology (AREA)
• Biomedical Technology (AREA)
• Heart & Thoracic Surgery (AREA)
• Hematology (AREA)
• Life Sciences & Earth Sciences (AREA)
• Animal Behavior & Ethology (AREA)
• General Health & Medical Sciences (AREA)
• Public Health (AREA)
• Veterinary Medicine (AREA)
• Infusion, Injection, And Reservoir Apparatuses (AREA)

Applications Claiming Priority (2)

Publications (1)

Family

ID=9366370

Family Applications (1)

Country Status (3)

Families Citing this family (4)

Family Cites Families (8)

• 1988
  • 1988-05-17 FR FR8806595A patent/FR2631551A1/fr not_active Withdrawn
• 1989
  • 1989-05-17 EP EP19890906134 patent/EP0372049A1/de not_active Withdrawn
  • 1989-05-17 WO PCT/FR1989/000234 patent/WO1989011303A1/fr not_active Ceased

Non-Patent Citations (1)

Also Published As

Similar Documents

Legal Events