WO1996014892A2

WO1996014892A2 - Infusion apparatus

Info

Publication number: WO1996014892A2
Application number: PCT/GB1995/002657
Authority: WO
Inventors: Marc Peter Vollenweider
Original assignee: Arcomed Ag; Auty, Brian
Priority date: 1994-11-14
Filing date: 1995-11-13
Publication date: 1996-05-23
Also published as: AU3852195A; WO1996014892A3

Abstract

An infusion apparatus may be provided with a drop detector (20) which includes first and second arrays of devices (21, 22), each array including a signal transmitter (24, 26) and several signal sensors (23, 25). The drop detector (20) may be incorporated in a clip (1) which is adapted to be releasably attached to a drip chamber. The drop detector (20) may be magnetically mounted (5) to a part of the apparatus.

Description

INFUSION APP.ARATUS

The present invention relates to an infusion apparatus.

An infusion apparatus is used for enteral or parenteral infusion of liquids to patients. A reservoir of infusion liquid is provided which is pumped into a patient via an infusion set and then into a patient. The infusion set usually includes a drip chamber and a drop detector as well as other components such as tubing, and one or more clamps and connectors. The drop detector can be used to determine when the infusion reservoir is becoming empty so that it can be replaced with another infusion reservoir.

However, conventional drop detectors are not always effective in detecting drops falling into the drop chamber. Furthermore there are often difficulties in correctly positioning drop detectors and/or drip chambers.

According to a first aspect of the present invention there is provided an infusion apparatus comprising a drip chamber for receiving drops of infusion fluid from an infusion fluid reservoir and a clip adapted for removable attachment to said drip chamber; wherein the clip incorporates a drop detector for detecting said drops of infusion liquid and wherein the clip is oriented generally vertically when the apparatus is in use.

The clip can be in any appropriate form, although preferably it comprises two gripping members. These are desirably co-pivotally mounted. The clip may be provided with a spring or other resilient member which urges the gripping members together. It may be provided handles which extend from the gripping members. An operator can then press these handles together to open up the clip in order to receive a drip chamber. By releasing pressure on the handles the gripping members are caused to move together and thereby to grip the drip chamber. Such a clip can be particularly easy to use since it may generally be operated using a single hand. This contrasts with prior art clips which often require two hands in order to be operated properly.

The clip will usually have a center of gravity which is arranged to be below a level at which drops of infusion fluid are detected by the drop detector. This enables the clip to hang from the drip chamber in a desired, generally vertical orientation.

The clip may advantageously be provided with a mounting adapted to enable it to be mounted to another component (e.g. to a pump) via magnetic attraction. For precise fitting of the clip to the other component, mounting may be achieved by inserting an insertion member into a receiving member. Desirably when such insertion has occurred the insertion member is held in a fixed position relative to the receiving member (until it is desired to dismount the clip) . Thus rotation of the inserting member in the receiving member can be prevented.

The magnetic mounting can be provided simply to allow the clip to be conveniently stowed when it is not in use. However, in some embodiments it may be desired to use the clip to attach to the drip detector whilst the clip is mounted to another component via said magnetic mounting.

Although the magnetic mounting can be provided in combination with a clip as aforesaid, this is not essential since a magnetic mounting may be advantageously used whether or not such a clip is also used.

Thus, according to a second aspect of the present invention there is provided an infusion apparatus comprising a drip chamber and a drop detector for detecting a drop of infusion liquid passing from an infusion fluid reservoir to said drip chamber, wherein said drip detector is provided with a magnetic mounting.

The magnetic mounting is advantageous in that it assists in correctly mounting the drip detector. Thus it is particularly useful for mounting the clip under dark conditions or when the apparatus is being used by an inexperienced user.

Desirably the magnetic mounting comprises an inserting member which is adapted to removably insert into a receiving member so that, when so inserted, the drop detector can be held in a fixed position relative to a part of the apparatus to which the drop detector is magnetically mounted. This enables the clip to be fixedly mounted to another component (without rotation etc.) until it is desired to remove it.

Preferably the drop detector has a centre of gravity which is below a level at which drops are detected (when the apparatus is in use) .

According to a third aspect of the present invention there is provided an infusion apparatus comprising a drip chamber for receiving fluid from a reservoir of infusion liquid and a drop detector, wherein the drop detector comprises a first array of devices and a second array of devices, said first array including a transmitter adapted to transmit a signal to a sensor in the second array and said second array including a transmitter adapted to transmit a signal to a sensor in the first array so that a drop of infusion liquid passing from the reservoir to the drip chamber can be detected by interrupting/altering at least one of said signals.

The arrangement of transmitters and detectors provided by the drop detector used in the first aspect of the present invention overcomes a major disadvantage of prior art detectors. Prior art detectors can fail to detect drops falling into a drip chamber which deviate slightly from an intended path. This often occurs where the drip chamber and/or drop detector is not precisely mounted in an intended position or where the apparatus is disturbed by an external influence e.g. by a vibration. Such failures to detect drops are especially likely where an infusion apparatus comprises a reservoir in the form of a flexible bag since the bag can flop to one side and thereby disturb the apparatus.

In contrast to the prior art, the present invention facilitates the detection of drops falling through a range of different paths relative to the drop detector since it is only necessary for one of the signals sent from a transmitter to a sensor to be interrupted/altered by the passage a falling drop for the drop to be detected. This aspect of the present invention also aids in the compact design of a drop detector since a high level of sensitivity can be achieved using transmitters and sensors which occupy a relatively small space.

Preferably each array of devices of the drop detector comprises a signal transmitter and a plurality of signal sensors. The signal transmitted may be an infra-red signal or any other suitable signal. The signal transmitter of each array is desirably mounted at one end of that array so as to be closer to the signal sensors of the other array than to the signal transmitter of that other array.

Each array may consist of a single signal transmitter and a plurality of signal sensors. These may be linearly arranged, although such an arrangement is not essential.

Preferably all of the sensors and transmitters of the arrays lie along a common plane.

An apparatus according to the present invention may include components in addition to those discussed in relation to the three aspects above.

A typical infusion apparatus may comprise a fluid reservoir (e.g. a bottle or a bag) , a drip chamber, means for inserting into the fluid reservoir to allow fluid to flow from the fluid reservoir to the drip chamber, infusion tubing, a pump, a drop detector and a connector for connecting an infusion tube with a cannula, catheter or needle (the connector may be a luer lock for example) . A plurality of components may be provided in a kit of parts, optionally including instructions for use.

A preferred apparatus of the present invention is an administration set. A typical administration set includes a drip chamber (normally provided with a spike or other means for inserting into a fluid reservoir) , a drop detector, a length of infusion tubing (usually including one or more clamps) and a connector for connecting to a cannula, catheter or needle. Although three different aspects of the present invention have been described above, a single apparatus may be provided having all of these aspects.

The present invention also includes within its scope a drop detector adapted for use according to any of the three aspects of the invention discussed above.

The present invention will now be described by way of example only, with reference to the accompanying drawings, wherein:

FIGURE 1 shows a side view of a drop detector which is in the form of a clip.

FIGURE 2 shows a rear view of the drop detector shown in Figure 1.

FIGURE 3 shows a partial front view of the drop detector shown in Figure 1.

FIGURE 4 shows a plan view of the drop detector shown in Figure 1.

FIGURE 5 shows a cross section through infra-red transmitters and sensors of the drop detector shown in Figure 1 when being used to detect a drop of infusion fluid.

FIGURE 6 is provided for reference purposes and shows an example of an administration set.

Referring now to Figure 1, there is shown a drop detector (1) , and which is provided with a magnetic mounting (5) . The center of gravity (2) of the drop detector is also shown as is a cord (3) which is connected to an electrical power supply (not shown) .

The rear of the drop detector (1) is shown in Figure 2, where an inserting member of generally oval cross-section

(6) is shown. This inserting member (6) fits into a correspondingly defined aperture (7) of a receiving member, which may be provided on another part of the infusion apparatus of the present invention, as shown in Figure 1. Thus movement (e.g. rotation) of the drop detector (1) relative to the receiving member is prevented when the drop detector (1) is held in a desired position. The drop detector (1) is in the form of a clip which is adapted to removably attach to a drip chamber (not shown) .

The clip (1) comprises two gripping members (10) and (11), as shown in Figures 2 and 4. These members are joined to one another by a resilient member, such as a spring (not shown) and are co-pivotally mounted. When the clip is in use these members are preferably generally vertically oriented.

Figure 4 shows the clip when in a closed position, the two gripping members (10 and 11) facing one another so as to hold a generally cylidrical drip chamber (not shown) in a vertical position.

The clip (1) can be opened to release it from the drip chamber by forcing the two gripping members (10, 11) apart in the directions indicated by arrows A and B. For this purpose handles (42 and 43) are provided. These can be pressed together between the thumb and a forefinger of a user so as to move the gripping members (10,11) apart. When pressure is released the resilient member causes the clip (1) to close by bringing the gripping members (10,11) together.

The clip (1) incorporates a drop detector which is provided with infra-red sensors and receivers (not shown) . These may be integral or may be removably mounted. They enable drops falling past the horizontal plane (4) indicated in Figure 3 to be detected. This plane (4) is above the center of gravity (2) of the clip (see Figure 1) .

Turning now to Figure 5, a drop detector (20) comprising an arrangement of infra-red transmitters and sensors is shown. There is shown a first array of devices (21) and a second array of devices (22) . The first array (21) comprises a plurality of infra-red sensors (23) and an infra-red transmitter (24) . The second array (22) is arranged opposite to the first array (21) and also comprises a plurality of infra-red sensors (25) and an infra-red transmitter (26) . Both the first and second arrays (21,22) lie in the same horizontal plane. The transmitter (26) of the second array (22) is arranged to transmit signals to the sensors (23) of the first array (21) and the transmitter (24) of the first array (21) is arranged to transmit signals to the sensors (25) of the second array (22) .

Figure 5 shows a drop of fluid (27) interrupting signals transmitted by both the first and second transmitters (24,26) to their respective sensors (23,25). It will however be appreciated that the drop can still be detected even if it only interrupts a signal transmitted from one of the transmitters (24,26) to one of its sensors (23,25) . Thus the drop detector (20) can detect drops even if they deviate slightly from an intended path. This can occur where an infusion apparatus is disturbed (e.g. by external vibrations) or where the drop chamber is not precisely mounted in a desired position. Thus the present invention provides increased safety in detecting drops which may not be detected by prior art devices. The arrangement (20) of sensors and transmitters also facilitates the compact design of a drop detector.

Turning now to Figure 6, there is shown an administration set (30) which can be used with the present invention.

The administration set (30) includes a spike (31) for puncturing a reservoir of infusion fluid (not shown) . The spike is part of a drip chamber (32) .

The drip chamber (32) is provided with a sealable air inlet (33) and a filter (34) . Unlike conventional drip chambers the drip chamber (32) shown here is elongate along an axis which (when it is in use) coincides with a vertical axis through which fluid flows into the drip chamber (32) . (Thus, the drip chamber (32) is adapted to be held in a vertically oriented position by a clip as described previously herein.) The drip chamber (32) is generally cylindrical.

The drip chamber (32) is connected to a length of flexible tubing (35) , which is typically formed of PVC and may have a length of around 40 cm. A roller clamp (36) is shown attached to the tubing (37) so that flow of infusion fluid can be stopped when desired.

The tubing has a section (37) including a silicone pumping insert. This section of tubing is provided with connectors (38,39) at either end.

There is then provided a further section of tubing (40) and a luer lock fitting with a male taper (41) for connecting to a cannular, a catheter or a needle (not shown) .

Claims

1. Infusion apparatus comprising a drip chamber for receiving drops of infusion fluid from an infusion fluid reservoir and a clip adapted for removable attachment to said drip chamber; wherein the clip incorporates a drop detector for detecting said drops of infusion liquid and wherein the clip is generally vertically oriented when the apparatus is in use.

2. Apparatus according to claim 1 wherein the clip comprises two gripping members which are generally vertically oriented when the apparatus is in use and which are preferably co-pivotally mounted.

3. Apparatus according to claim 1 or claim 2 wherein the clip has a center of gravity which is located below a level at which drops are detected when the apparatus is in use.

4. Apparatus according to any of claims 1 to 3 wherein the clip is removably attached to a part of the apparatus via a magnetic mounting.

5. Apparatus according to claim 4 wherein the magnetic mounting comprises an inserting member which is removably insertable into a receiving member so that the clip can be held in a fixed position relative to said part of the apparatus when the apparatus is in use.

6. Infusion apparatus comprising a drip chamber and a drop detector for detecting a drop of infusion liquid passing from an infusion fluid reservoir to said drip chamber, wherein said drip detector is provided with a magnetic mounting.

7. Apparatus according to claim 6 wherein the magnetic mounting comprises an inserting member which is adapted to removably insert into a receiving member so that, when so inserted, the drop detector can be held in a fixed position relative to a part of the apparatus to which the drop detector is magnetically mounted.

8. Apparatus according to claim 6 or claim 7 wherein the clip has a centre of gravity which is below a level at which drops are detected when the apparatus is in use.

9. An apparatus according to any of claims 6 to 8 which is also an apparatus according to any of claims 1 to 5.

10. Infusion apparatus comprising a drip chamber for receiving fluid from a reservoir of infusion liquid and a drop detector, wherein the drop detector comprises a first array of devices and a second array of devices, said first array including a transmitter adapted to transmit a signal to a sensor in the second array and said second array including a transmitter adapted to transmit a signal to a sensor in the first array so that a drop of infusion liquid passing from the reservoir to the drip chamber can be detected by interrupting/altering at least one of said signals.

11. Infusion apparatus according to claim 10 wherein each array comprises a signal transmitter and a plurality of signal sensors.

12. Apparatus according to claim 11 wherein each array has a signal transmitter at one end of the array.

13. Apparatus according to any preceding claim wherein each array consists of a single signal transmitter and a plurality of signal receivers.

14. Apparatus according to any preceding claim including a reservoir of infusion liquid.

15. An apparatus substantially as hereinbefore described with reference to the accompanying drawings.

16. A clip suitable for use in an apparatus according to any of claims 1 to 4.

17. A drop detector suitable for use in an apparatus as described in any of claims 1 to 15.

18. A drop detector, characterised in that the drop detector is in the form of a vertical clip for fixing to a drip chamber.

19. A drop detector according to claim 18, characterised in that because of the vertical geometry both the centre of gravity of the drop detector and the pull point of a connecting cable are disposed far below the detection plane.

20. A drop detector according to claim 18 or 19, characterised in that the drop detector is retained on an infusion appliance by magnetic force.

21. A drop detector according to any of claims 18 to 20, characterised in that a non-rotationally symmetrical gate and a corresponding adapter on the main appliance locate the drop detector automatically and greatly facilitate removal of the drop detector in rotation.

22. A drop detector according to any of claims 18 to 21, characterised in that the detection area is greatly widened by a two-sided optical detection and is also reduced in its extent so that the casing shape near the detection plane can be greatly reduced.

23. A drop detector for detecting falling drops, characterised in that the drop detector is retained on an infusion appliance by a magnetic force.

24. A drop detector according to claim 23, characterised in that a non-rotationally symmetrical gate and a corresponding adapter locate the drop detector automatically and removal by rotation of the drop detector is greatly facilitated.

25. A drop detector according to claim 23 or 24, characterised in that the drop detector is in the form of a vertical clip for fixing to a drip chamber.

26. A drop detector according to any of claims 23 to 25, characterised in that because of the vertical geometry both the centre of gravity of the drop detector and the pull point of the connecting cable are disposed far below a detection plane.

27. A drop detector according to any of claims 23 to 26, characterised in that the detection range is greatly widened by a two-sided optical detector and is also reduced in its extent so that the casing shape can be greatly reduced in the region of the detection plane.