WO2003049655A2

WO2003049655A2 - Portable fluid dispenser

Info

Publication number: WO2003049655A2
Application number: PCT/GB2002/005633
Authority: WO
Inventors: Phil Yates; Daniel Mcwalter; Suzanne Brannan; Colin Dewar
Original assignee: Adnex Systems Ltd
Priority date: 2001-12-12
Filing date: 2002-12-12
Publication date: 2003-06-19
Also published as: AU2002350944A1; GB0129714D0; WO2003049655A3

Abstract

A dispenser for dispensing measured doses of fluids at predetermined time intervals. The dispenser comprising a casing (10) in which is located one or more sachets (16, 18). The, or each sachet (16, 18) having an outlet communicating with a flexible resilient deformable outlet tube (21). Means (14) are provided for pressurising the sachet or sachets (16, 18). Obturating means (24) are provided for selectively obturating the, or each, outlet tube (21). An actuation means (27, 28, 32, 33 34) is provided for actuating the obturating means (24) to move the obturating means (24) to and from a first position, where the obturating means obturates the outlet tube (21), to, and from, a second position where the obturating means (24) opens the outlet tubes (21). The operation of the actuation means is controlled by a control circuit (38) to dispense a predetermined quantity of fluid from the, or each sachet at set time intervals.

Description

PORTABLE FLUID DISPENSER

This invention relates to fluid dispensers and in particular to portable fluid dispensers. The invention has particular relevance to dispensers for delivering a predetermined dose of a fluid such as eye drops to a patient, or subcutaneous administration of medicine, but is not limited to such uses.

Currently patients that have undergone surgery on an eye, such as for example to remove a cataract, require the administration of medication in the form of eye drops over an extended period of time. There are a number of reasons why patients are not able to administer eye drops themselves. For example some patients may have hand deformity due to arthritis. The vast majority of eye drop medications are prescribed to elderly patients and therefore there is a significant proportion of patients who require assistance using their prescribed eye drops. There are a large number of post-operative cataract patients per year requiring District Nurse attendance to administer eye drops. This requires a medical professional or qualified nurse to visit the patient every three or four hours, or more frequently, to administer the eye drops. This is not only very time-consuming for a nurse who has to visit a number of similar patients a day, but it is also very costly.

There is therefore a need for a totally portable dispenser that could be worn by a person and which can reliably administer accurate doses of one or more medications to a patient in the form of eye drops at pre-set time intervals. Commercially available devices are usually based on using a conventional eye drop bottle that is held in a device that assists the patient to administer the drops from the bottle. These devices are simple but unreliable because they require the patient to remember to use the device at the required time interval and to make sure that the correct amount of drops is placed in the eye. Often these devices overcome problems associated with lack of dexterity of the patient, but still require the patient to tilt their head back to place the drops in the eye.

An object of the present invention is to provide a portable fluid dispenser that can deliver a predetermined dose of fluid at an outlet nozzle at pre-set time intervals.

According to the present invention as set out in the attached claims, there is provided a dose dispenser that is capable of delivering predetermined doses of a fluid at pre-set time intervals.

The present invention will now be described, by way of an example, with reference to the accompanying drawings, in which: -

Figure 1 is a schematic front view of a first dose dispenser constructed in accordance with the present invention;

Figure 2 is a cross sectional side view of the dose dispenser of Figure 1 ;

Figure 3 is a cross sectional end view of the dose dispenser of Figure 1 ; and Figures 4 and 5 are views of the cam system of a second dose dispenser constructed in accordance with the present invention.

Referring to Figure 1 there is shown a dose dispenser comprising an outer casing 10 made of a plastics material adapted to be worn on the head of a patient. The casing 10 is typically of about 40mm X 40mm and about 12 mm deep. The case 10 has a removable lid 12 on which is mounted a shallow "V" shaped leaf spring 14. The front part of the case 10 (best seen in Figure 3) is shaped to accommodate two thin walled flexible sachets 16, 18 (made of for example flexible PVC) within the cavity of the casing 10. Each sachet 16, 18 has a cylindrical outlet chamber 20 made of a flexible resilient deformable material with an internal diameter of 4 mm and a length of 16 mm. Half of the length of the outlet chamber 20 is accommodated within the respective sachet 16, 18. Within the outlet chamber 20 at the end adjacent the sachet 16, 18 is a semi-permeable membrane 22. The membrane 22 prevents contaminants passing into the respective sachet and thereby prevents contamination of the contents of the sachet, but allows the contents to pass through the membrane 22 into the outlet chamber 20. The outlet chamber 20 has a micro-tube outlet passage 21 of 1-mm internal diameter and of variable length to reach to the eye of the patient (in the drawings the whole length of the tubes 21 is not shown). The micro-tube is formed of a resilient deformable material. The leaf spring 14 exerts pressure on the sachets 16, 18 to assist in the expulsion of the contents of the sachets 16, 18 as will be explained later.

The membrane 22 also restricts the contents of the outlet chamber 20 from being squeezed back into the sachets 16, 18. Located at the lower region of the front part of the casing 10 are two obturating means 24, one. for each sachet 16, 18. Each obturating means is in the form of a lever 24 pivotally mounted at the lower part 10(a) of the casing by way of a horizontal pivot 26, and has a long arm 24(a) that, when the lid 12 is in place, rests against the wall of the outlet chamber 20 of a respective sachet, and a short arm 24(b) that in use obturates or closes the tube 21. Each lever 24 is held in a position where the short arm (24(b) of the lever squeezes the micro-tube 21 shut, and the short arm is urged towards the micro-tube by a compression spring 25 located between the lower end of the lever and the front part 10(a) of the casing.

A motor 27 is mounted on the front part of the casing at a position between the sachets 16, 18. The motor 27 has a drive shaft 28 that has a screw thread on which is screwed a captive nut 30. The nut 30 engages two discs 32, each of which has a cam 34 that faces towards, and engages with, the long arm 24(a) of one of the levers 24. Each disc 32 has a second cam 33 against which the nut 30 pushes to rotate each disc 32. The second cam 33 of one disc 32 is engaged by the top surface of the nut 30 when the nut 30 travels upwards and the second cam 33 of the other disc 32 is engaged by the lower surface of the nut 30 when the nut 30 travels downwards.

The motor 27 is driven by lithuim batteries 36 and the electrical power supplied by the batteries is controlled by a programmable electronic control circuit 38 that switches on the motor 27 at predetermined time intervals and runs the motor 27 in one direction for sufficient time to wind the nut 30 along the screw thread in one direction. This causes the nut 30 to rotate one of the discs 32 (for example the one shown on the right in Figure 1) and causes the cam 34 to push the long arm 24(a) of the right hand obturating member 24 towards the outer chamber 20. This causes the short arm 24(b) of the lever 24 to open one of the micro- tubes 21 for a period of time sufficient to dispense a predetermined dose of medication to one eye. At the same time the long arm 24(a) of the lever 24 engages the wall of the outlet chamber 20 to squeeze a predetermined volume of contents from the outlet chamber 20. The membrane 22 restricts the flow of the contents of the outlet chamber 20 back into the sachets 16, 18 so that a predetermined volume of the contents of the outlet chamber 20 are discharged through the open outlet tube 21 by squeezing the wall of the outlet chamber 20. The motor is then reversed to reposition the nut 30 at a central position along its path of travel to allow the right hand lever 24 to close off the respective micro-tube 21 and move the arm 24(a) to release the squeezing pressure exerted on the wall of the outlet chamber 20.

If the motor is operated to move the nut 30 upwards, the nut 30 engages the second cam 33 on the left hand disc 32 and rotates the disc 32 to cause the left short arm 24(b) of the hand lever 24 to open the respective micro-tube 21 and cause the long arm 24(a) of the lever to squeeze the wall of the outlet chamber 20 and thereby discharge a measured volume of the contents of outlet chamber 20 through the opened tube 21 as described above. Again, as described above, the nut 30 is returned to a central position along its length of travel to allow the arm 24(a) the left hand lever 24 to release pressure on the wall of the outlet chamber 20 and the short arm 24(b) to close off the left-hand micro-tube 21.

The amount of fluid dispensed from each sachet 16, 18 can be controlled by controlling the length of travel of the nut 30 in the selected direction to control the opening and closing of the respective micro-tube 21 , and the amount of squeeze on the wall of the outlet chamber 20. Similarly the time interval for dispensing fluids can be set independently for each sachet 16, 18, by programming the control circuit 38 to drive the motor 27 in a selected direction at selected times for a selected time period. The motor 27 may be a DC powered motor or a stepping motor that is capable of being driven precisely in two directions.

Referring to Figures 4 to 5 there is shown a second embodiment of the present invention. This embodiment differs from that shown in Figures 1 to 3 in that the design of the cams 33 and 34 are slightly different. In other respects the dose dispenser 10 of Figures 1 and 4 are identical and similar parts are given the same reference number.

Referring in greater detail to Figures 4 and 5 the rotary discs 32 and cams 33 and 34 as shown in Figure 1 are dispensed with and replaced by two linear cams 34 that form part of a slidable carriage 39 that is mounted on the captive nut 30.

The levers 24 are modified slightly; they still have a long arm 24(a) and a short arm 24(b) and they are mounted on pivots in a similar way to those of Figure 1.

One of the cams 34 on the carriage 39 has an operating part 34(a) located at a region near the motor 27 whereas the operating part 34(a) of the other cam 34 is located at a region on the carriage 39 furthest from the motor 27. In this way when the motor 27 is driven to drive the carriage in a first direction the operating part 34(a) of one cam operates on the surface 40 of the long arm 24(a) of the lever to cause the long arm 24(a) of that lever to squeeze one of the outlet chambers 20 and at the same time move the short arm 24(b) to open one of the tubes 21. When the motor 27 drive is reversed the working part 34(a) of the other cam 34 acts on the surface 40 of other lever 24 and rotates it and thereby causes the long arm 24(a) to squeeze the second of the outlet chambers 20 whilst at the same time moving the short arm 24(b) to open the other tube 21.

The levers 24 are provided with a torsion spring 42 that biases the levers 24 towards the cam 34 and cause the levers 24 to close off the tubes 21.

The casing 10 is preferably mounted on a headband or strap (not shown) that is used to hold the dispenser in place on the head of a patient. The micro-tubes 21 could be made much shorter than described above and could be provided with detachable extension micro-tubes attached to the ends of the micro-tubes 21 to extend effectively the micro-tubes 21. In use the micro-tubes 21 are attached to the patient's face so that each tube 21 terminates adjacent to the tear duct of one eye.

In use, a sachet 16, or 18 containing the medication to be administered in the form of a liquid or gel is opened and placed into the casing with the open end of the sachet connected to a micro-tube 21 (the sachet may have the micro-tube 21 formed as an integral part of the sachet 16,18). The control circuit 38 is pre-programmable set to administer a predetermined dose at predetermined intervals to each micro-tube 21 and is pre-programmed using a portable programmer (not shown). The lid 12 is snapped into place on the front part of the casing 10 so that the leaf spring 14 squeezes the sachets 16, 18. The obturating levers 24 obturate each tube 21 so that the contents of each sachet 16, 18 is not expelled from the respective sachet. The sachets 16, 18 prime the outlet chambers 20 by forcing the contents of the sachets 16, 18 through the respective semi-permeable membranes 22 and fills the tubes 21 up to the region where the levers 24 squeeze them to close them off. The dispenser 10 is strapped to the head of a patient and the micro-tubes 21 are attached to the patient's face so that both micro-tubes 21 terminate adjacent the tear duct of one eye.

At a predetermined time, the control circuit 38 operates the motor 27 to drive the nut 30 in the appropriate direction for a predetermined distance so that the cam 34 on the appropriate disc 32 (or carriage 39) pushes the long arm of the selected lever 24 and thereby open the selected micro tube 21 and simultaneously squeeze the contents of outlet chamber 20 out of a tube 21 to dispense a measured dose of medication into one eye. Rotation of the motor 27 is then reversed to return the nut 30 (or carriage 39) to a parked central position to close off the selected micro-tube 21. The procedure is repeated to dispense the medication from the other sachet to the other eye by driving the motor 21 in the opposite direction to open the other micro-tube 21 that terminates adjacent the tear duct of the eye and squeeze the wall of the other outlet chamber 20.

The semi-permeable membrane 22 resists rapid flow out of the tubes 21 due to the pressure created by the spring 19 this ensures that the chambers 20 are replenished slowly and also ensures that the dose is expelled down the micro-tube 21 in a controlled manner and prevents the medication being squeezed back into the sachet 16 or 18 when the levers 24 squeeze the wall of the outlet chambers 20.

In those cases where it is only desired to administer drops to one eye, only one sachet needs to be loaded into the casing. Similarly, if it is necessary to administer more than one medication to an eye then the two sachets 16, 18 would be used with different medications in each, and both of the micro-tubes 21 would terminate adjacent the tear duct of one eye. It may be possible to make the casing 10 large enough to accommodate two sets of sachets 16, or 18, with different medications in each sachet of each set and to connect each sachet of each set to a common manifold (not shown) connected to common outlet tube 21. In this case, a mixture of different medications could be administered at the same time to each eye.

Although the present invention has been described with reference to the administration of eye drops, the dispenser can be used for other applications where it is necessary to dispense a measured quantity of a fluid at pre-set time intervals. The invention may be useful, for example in the veterinary field.

The invention could be used for the subcutaneous administration of medications, painkillers, analgesics or other pharmaceuticals to a patient or animal at pre-set time intervals. The invention could be used for dispensing measured quantities of fluids in the food processing or chemical industries.

Claims

1. A dispenser for dispensing measured doses of fluids at predetermined time intervals, having a casing (10) in which is located one or more sachets (16,18), characterised in that the, or each, sachet (16, 18) has an outlet communicating with a flexible resilient deformable outlet chamber (20) connected to a flexible resilient deformable outlet tube (21), means (14) for pressurising the sachet or sachets (16,18), obturating means (24) for selectively obturating the, or each, outlet tube (21) and operable to squeeze the outlet chamber (20), an actuation means (27, 32, 34, 39) for actuating the obturating means (24) to move the obturating means (24) , to and from, a first position where the obturating means obturates the, or each outlet tube (21), to and from, a second position where the obturating means (24) squeezes the outlet chamber (20) and simultaneously opens the or each outlet tube (21) and thereby dispenses a predetermined quantity of fluid from the outlet chamber (20).

2. A dispenser according to claim 1 wherein the or each obturating means (24) comprises a pivoted lever (24) having a first arm (24(a)) that, in the first position, squeezes the outlet tube (21) thereby to close off the outlet tube (21), and in a second position allows the outlet tube (21) to open, and a second arm (24(b)) that is engaged by the actuation means (32, 34, 39) and operates to squeeze the outlet chamber (20) when the lever

(24) is in the second position.

3. A dispenser according to claim 1 or Claim 2 wherein a semi-permaeble membrane (22) is provided between the outlet chamber (20) and the sachet (16,17).

A dispenser according to claim 2 or claim 3 wherein the actuation means (32, 34) comprises a rotatable disc (32) on which is provided a first cam (34) that engages the second arm (24(a)) of a lever (24) of the obturating means (24), said first cam (34) being shaped, positioned and arranged relative to the lever (24) such that it moves the lever (24) from the first position to the second position, when the disc (32) is rotated in a first direction.

5. A dispenser according to any one of the preceding Claims wherein there are two sachets (16,18) each having an outlet chamber (20) and an outlet tube (21).

6. A dispenser according to claim 4 wherein two actuation means (32, 34) are provided and each actuation means (32, 34) comprises a rotatable disc (32) on which is provided a first cam (34) that engages the second arm (24(a)) of a lever (24) of the obturating means (24), said first cam (34) of each disc (32) being shaped, positioned and arranged relative to the lever (24) such that it moves the lever (24) from the first position to the second position when the disc (32) is rotated in a first direction.

7. A dispenser according to claim 5 wherein actuation means (32, 34) comprises two rotatable discs (32) on each of which is provided a first cam (34), the first cam (34) of a first of the discs (32) being shaped, positioned and arranged relative to a first of the levers (24) such that that engages the second arm (24(a)) of the first lever (24) and moves the first lever (24) from the first position to the second position when the first disc (32) is rotated in a first direction thereby to squeeze a first of the outlet chambers (20) and open a first of the tubes (21), and the first cam (34) of a second of the discs (32) being shaped positioned and arranged relative to a second of the levers (24) such that it engages the second arm (24(a)) of the second lever (24) and moves the second lever (24) from the first position to the second position when the second disc (32) is rotated in a first direction thereby to squeeze a second of the outlet chambers (20) and open a second of the tubes (21).

8. A dispenser according to any one of Claims 1 to 5 wherein the actuation means (27,

34, 39) comprises a cam (34) provided on a slidable carriage (39), said cam (34) being positioned to engage the second arm (24(a)) of a lever (24) and being operable to move the lever to and from the first and second positions when the carriage (39) is moved respectively in a first or a second direction.

9. A dispenser according to Claim 8 wherein the carriage (39) is provided with two cams (34), one of which engages the second arm 24(a)) of a first of the levers (24) and the other of which engages the second arm (24(a)) of the other of the levers (24), so that movement of the carriage (39) in a first direction causes a first of the cams (34) to operate on a first of the levers (24) and movement of the carriage (39) in a second direction causes a second of the cams (34) to operate on a second of the levers (24).

10. A dispenser according to any one of Claims 1 to 9 wherein the actuation means includes a motor (27) that drives a screw-threaded shaft (26) on which is screwed a nut (30), said nut (30) co-operating with an actuation means (32, 34, 39) whereby rotation of the shaft (26) in a first direction moves the nut (30) axially along the shaft (26) in a first direction causing the actuation means (32, 34, 39) to operate on the obturating means (24) thereby to squeeze an outlet chamber (20) and simultaneously open an outlet tube (21), and movement of the nut (30) axially along the shaft (26) in a second direction causes the actuation means (32, 34, 39) to operate on the obturating means (24) thereby to close the outlet tube (21) and release the squeeze on the outlet chamber (20).

11. A dispenser according to any one of Claims 1 to 10 wherein the actuation means includes a motor (27) that drives a screw-threaded shaft (26) on which is screwed a nut (30), said nut (30) co-operating with an actuation means (32, 34, 39) whereby rotation of the shaft (26) in a first direction moves the nut (30) axially along the shaft (26) in a first direction causing the actuation means (32, 34, 39) to operate on a first obturating means (24) thereby to squeeze a first outlet chamber (20) and simultaneously open a first outlet tube (21), and movement of the nut (30) axially along the shaft (26) in a second direction causes the actuation means (32, 34, 39) to operate on the first obturating means (24) thereby to close the outlet tube (21) and release the squeeze on the first outlet chamber (20) and causes the actuation means (32, 43, 39) to operate on a second obturating means (24) thereby to squeeze a second outlet chamber (20) and simultaneously open a second outlet tube (21).

12. A dispenser according to any one of claims 2 to 11 wherein the second arm (24(a)) of lever or levers (24) is biased towards an associated first cam (34) by means of a spring.

13. A dispenser according to any one of the preceding claims wherein a control means (38) is provided which is operable to operate the actuation means (27, 32, 34, 39) at predetermined intervals and thereby control the amount of fluid dispensed from one or more of the outlet chambers (20).

14. A dispenser according to any one of the preceding claims wherein the pressurising means (14) for pressurising the sachets comprises a leaf spring (14) that squeezes the sachets (16, 18).