ACTUATING DEVICE FOR ADMINISTERING A BOLUS

Abstract

A device for administering a bolus, includes an actuating element to actuate a closing mechanism which opens and closes a hose segment. The hose segment can be connected to a fluid source and to a patient. The device also includes a movable element, a blocking element which locks the movable element in an upper position and which can be released by the actuating element, an elastic element which pushes the actuating element and movable element apart, a first actuation blocking element which locks the actuating element in a lower position and can be released by the movable element, and a bolus reservoir for holding a bolus quantity of fluid. The volume of the bolus reservoir can be reduced by displacing the movable element. A second actuation blocking element locks the actuating element in the upper position can be released by the movable element.

Claims

1. An actuating device for administering a bolus, the actuating device comprising: an actuating element, which is displaceable from an upper position to a lower position in order to actuate a closing mechanism which opens a hose segment in the lower position of the actuating element and closes the hose segment in the upper position of the actuating element, wherein the hose segment can be connected to a fluid source via an inflow line and to a patient via an outflow line, a movable element, which is displaceable from an upper position to a lower position, independently of the actuating element, or is deformable, a blocking element which locks the movable element in the upper position and which can be released by the actuating element by displacement thereof in a direction of the lower position, an elastic element, which pushes the actuating element and the movable element apart, a first actuation blocking element, which locks the actuating element in the lower position thereof and can be released by the movable element in the lower position thereof, a bolus reservoir for holding a bolus quantity of a fluid, the bolus reservoir comprising a volume wherein the volume of the bolus reservoir can be reduced by displacement or deformation of the movable element in the direction of the lower position thereof, and a second actuation blocking element, which locks the actuating element in the upper position thereof and can be released by the movable element in the upper position thereof.

2. The actuating device according to claim 1, wherein the bolus reservoir is connected to the inflow line and the outflow line via a bolus line.

3. The actuating device according to claim 2, wherein the hose segment has a lower flow resistance than the bolus line.

4. The actuating device according to claim 1, wherein the closing mechanism has a clamping spring which clamps off the hose segment, the clamping spring exerting a spring force that counteracts a displacement of the actuating element in the direction of the lower position thereof.

5. The actuating device according to claim 4, wherein the clamping spring has a spring arm that clamps off the hose.

6. The actuating device according to claim 5, wherein the actuating element has an actuating fork that actuates the spring arm.

7. The actuating device according to claim 1, wherein the blocking element has a latch mechanism with a latching lug which is arranged on a spring clip and which holds the movable element.

8. The actuating device according to claim 7, wherein the movable element has a latching web that engages on the latching lug.

9. The actuating device according to claim 1, wherein the movable element and the actuating element each have an engagement surface, wherein the engagement surfaces can be placed against each other in order to transmit a force from the actuating element to the movable element.

10. The actuating device according to claim 1, wherein the elastic element displaces the movable element after release of the blocking element by the actuating element.

11. The actuating device according to claim 1, wherein the first actuation blocking element has a resilient latching pawl which exerts a spring force, the latching pawl being arranged on the actuating element and which engages on a fixed housing part.

12. The actuating device according to claim 11, wherein the movable element has a first engagement surface which actuates the latching pawl counter to the spring force of the latching pawl.

13. The actuating device according to claim 1, wherein the second actuation blocking element has a spring clip which exerts a spring force and which locks the actuating element with respect to a housing of the actuating device.

14. The actuating device according to claim 13, wherein the movable element has a second engagement surface which actuates the spring clip counter to the spring force of the spring clip.

15. The actuating device according to claim 1, wherein at least a part of the movable element is guided with a sliding movement in the bolus reservoir.

16. The actuating device according to claim 1, wherein the movable element is a piston or a balloon.

17. The actuating device according to claim 1, wherein the movable element is mounted in the bolus reservoir in such a way as to be displaceable or deformable counter to a force of an elastic element.

18. The actuating device according to claim 1, wherein the actuating element can be actuated along a first actuation path and along a second actuation path that goes beyond the first actuation path, wherein the actuating element, when traveling along the first actuation path, permits a manual administration of a first bolus quantity, and it is only when traveling along the second actuation path that it triggers an automatic administration of a second bolus quantity.

19. The actuating device according to claim 1, wherein an inlet valve is provided in the inflow line and an outlet valve is provided in the outflow line, wherein the inlet valve and the outlet valve are connected to the actuating element in such a way that, in a non-actuated state of the actuating element, the inlet valve frees the inflow line and the outlet valve blocks the outflow line, and in an actuated state of the actuating element, the inlet valve blocks the inflow line and the outlet valve frees the outflow line.

20. The actuating device according to claim 1, wherein the inflow line is provided with a bolus flow throttle.

21. A patient-controlled analgesia device (PCA device) with a fluid delivery pump, a patient port, a main fluid path formed between the fluid delivery pump and the patient port, and a bolus fluid path which is arranged between the fluid delivery pump and the patient port and is parallel to the main fluid path, wherein an actuating device according to claim 1 is provided in the bolus fluid path.

22. The PCA device according to claim 21, wherein the main fluid path has a main flow throttle.

23. The PCA device according to claim 21, wherein the main fluid path and/or the bolus fluid path have/has a manually adjustable filling throttle.

Description

BRIEF DESCRIPTION OF THE DRAWING FIGURES

[0033] An illustrative embodiment is explained in more detail below with reference to the figures, in which:

[0034] FIG. 1 shows a perspective view,

[0035] FIG. 2 shows an exploded view,

[0036] FIG. 3 shows a cross section in a first actuation state,

[0037] FIG. 4 shows a further cross section in the first actuation state,

[0038] FIG. 5 shows a further cross section in the first actuation state,

[0039] FIG. 6 shows a cross section in a second actuation state,

[0040] FIG. 7 shows a further cross section in the second actuation state,

[0041] FIG. 8 shows a further cross section in the second actuation state,

[0042] FIG. 9 shows a further cross section in the second actuation state,

[0043] FIG. 10 shows a cross section in a third actuation state,

[0044] FIG. 11 shows a perspective view in the third actuation state,

[0045] FIG. 12 shows a perspective view in a fourth actuation state,

[0046] FIG. 13 shows a further perspective view in the fourth actuation state,

[0047] FIG. 14 shows a perspective view in a fifth actuation state,

[0048] FIG. 15 shows a further perspective view in the fifth actuation state, and

[0049] FIG. 16 shows a schematic representation of the PCA device.

DETAILED DESCRIPTION

[0050] The movable element 14 is a piston. The elastic element 16 is a piston spring. The actuating element 12 is an actuating button, wherein the two actuation blocking means 24, 28 are first and second button locks.

[0051] The actuating button 12 and the piston 14, which are pushed apart by a piston spring 16, can be seen in FIGS. 1 and 2. In the piston spring 16 is a helical spring which bears on the rear end of the piston 14 and surrounds a cylindrical inner neck 13 of the piston.

[0052] An actuating fork 32 protrudes forward in the distal direction from the actuating button 12. The actuating fork 32 is an integral part of the button 12. The actuating fork 32 is provided with a recess which engages with a spring arm 30 of the clamping spring 50.

[0053] The clamping spring 50 forms a closing mechanism for a segment of a hose 18 which can be connected to a fluid source via an inflow line 20 and to a patient via an outflow line 22.

[0054] A piston lock 15 holds the piston in the upper, proximal position according to FIG. 3 (first actuation state). The piston lock 15 is formed as a latch mechanism by a latching lug 52 on a spring clip 54. The spring clip 54 is a part rigidly connected to the housing 42 of the actuating device. The latching lug 52 engages with a latching web 56 which protrudes laterally from the piston, transversely with respect to the longitudinal axis of the latter.

[0055] When the actuating button 12 is actuated by pressing the button 12 inward in the proximal direction (arrow direction in FIG. 3), the actuating fork 3 actuates the clamping spring 50 counter to the spring force of the latter. The spring arm 30 is thereby displaced, and the hose segment 18 is freed for fluid to flow through. FIGS. 4 and 5 show the actuated clamping spring 50 and the opened hose segment 18. Fluid from a fluid source connected to the inflow line 20 can flow through the hose segment 18 and the outflow line 22 in the direction of the patient.

[0056] At the same time, the two engagement surfaces 34 of the actuating button 12 and of the piston 14 are pressed against each other, such that the pushing force of the button 12 is transmitted to the piston 14, and the piston 14 is thrust forward in the distal direction. The latching web 56 is advanced over the latching lug 52 of the spring clip 54 as is shown in FIGS. 8 and 9. As soon as the latching web 5 has overcome the latching lug 52 in the distal direction, the force of the piston spring, 16 exerts its effect on the piston 14 and pushes the latter forward in the distal direction. The button 12 is held in the pressed-in state by the first button lock 24.

[0057] The first button lock 24 is formed by a latching pawl 36 on the button, which latching pawl 36 engages on a fixed part 38 of the housing 42. The housing part 38 is a projection. FIG. 3 shows how, when the button 12 is pressed in, and shortly before it reaches its lower position, the resilient latching pawl 36 of the button 12 is pushed over the housing part 38 (projection). When the lower position of the button 12 is reached, the latching pawl 36 is latched on the housing part 38, as can be seen in FIG. 6 (second actuation state). The first button lock 24 forms the abutment for the deployment of the three of the piston spring 16 onto the piston 14.

[0058] The piston 14 is thereby pressed into the bolus reservoir 26. As the piston 14 is pushed forward into the bolus reservoir 26, the liquid contained in the bolus reservoir is forced out.

[0059] FIG. 7 shows that, as the liquid is being forced out from the bolus reservoir 26, the clamping spring 50 is also further actuated and the hose segment 18 is freed. The fluid forced out from the bolus reservoir 26 is delivered to the outflow line 22 via a bolus line 48 and to a patient connected to the outflow line 22.

[0060] When the lower position of the piston 14 is reached, a first engagement surface 40 on a proximal collar of the piston 14 actuates the locking pawl 36 radially outwardly, as is shown in FIG. 10 (third actuation state). The latching pawl 36 is thus released from the fixed housing part 38. The first button lock 24 is therefore released automatically by the fact that the piston 14 reaches the lower position. The fluid is then forced completely out of the bolus reservoir 26. FIG. 11 shows that the latching web 56 has then reached its lowest position. The latching web 56 can thus serve as a level indicator. Based on the relative position of the level indicator 56, it is possible to deduce the level of the bolus reservoir 26. The button 12 is pushed back to its upper (proximal) position by the piston spring 16 in the proximal direction of the arrow in FIG. 10.

[0061] The button 12 is latched in its upper (proximal) position according to FIG. 12 by a second button lock 28 (fourth actuation state). The second button lock 28 is formed by a spring clip 44 which locks with respect to the housing 42 as is shown in FIG. 12. The spring clip 44 prevents the button 12 from being able to be pressed inward in the distal direction. An actuation of the actuating button 12 is thereby prevented.

[0062] While an actuation of the actuating button 12 is prevented by the second button lock 28, fluid flows from the fluid source (not shown in the figures) via the inflow line 20 and the bolus line 48 into the bolus reservoir 26. The fluid flowing into the bolus reservoir 26 presses the piston 14 upward in the proximal direction of the arrow in FIG. 12. The hose segment 18 is meanwhile closed by the clamping spring 50, since the button 12 is locked in the upper position by the second button lock 28. This is illustrated in FIG. 13. Therefore, no fluid can flow through the hose segment 18. The fluid pressure in the bolus reservoir 26 is therefore sufficiently increased in order to press the piston 14 upward and to fill the bolus reservoir 26.

[0063] As soon as the piston 14 reaches, the upper position as shown in FIG. 14, a second engagement surface 46 at the proximal collar of the piston 14 presses against the spring clip 44 and presses the latter radially inward, as a result of which the engagement between the spring clip 44 and the actuating button 12 is released (fifth actuation state). As soon as the bolus reservoir 26 is completely filled again with a bolus quantity of the fluid, the piston 14, in its upper position, frees the second button lock 28 via the second engagement surface 46. Thus, the button 12 is freed for a renewed actuation in order to trigger a further bolus. By contrast, actuation of the button 12 is prevented when the bolus reservoir 26 is not yet completely filled again.

[0064] FIG. 15 shows that in the completely filled state of the bolus reservoir 26, after the upper position of the piston 14 is reached, the hose segment 18 is still closed. It is only after a renewed actuation of the button 12 that the hose segment 18 is freed so that fluid can flow from the fluid source in the direction of the patient.

[0065] FIG. 16 shows the PCA device, which has a fluid delivery pump 112 and a patient port 114. A catheter inserted into a patient can be attached at the patient port 114. The fluid pump 112 delivers a painkiller through the fluid paths 116, 122 to the port 114. In this case, two fluid paths 116, 122 are provided between the pump 112 and the patient port 114. A first fluid path 116 forms a main fluid path, through which the fluid is delivered continuously from the pump 112 to the patient port 114. The flow cross section through the main fluid path 116 is defined by the main fluid throttle 118. A filter 120 is arranged between the main fluid throttle 118 and the fluid delivery pump 112.

[0066] Between the filter 120 and the patient port 114, a bolus fluid line 122 is connected in parallel to the main fluid line 116. The bolus fluid path 122 has an inflow line 20, connected to the filter 120 and to the pump 112, and an outflow line 22 connected to the patient port 114. Between the inflow line 20 and the outflow line 22, a fluid reservoir 26 is formed which is connected to the latter. The inflow line 20 and the outflow line 22 each open into the fluid reservoir 26.

[0067] A piston 14, movable counter to the force of a spring 16, is provided in the fluid reservoir 26. The fluid reservoir 26 is in this case formed as a cylinder in which the piston 14 is sealingly guided. Fluid flowing through the inflow line 20 into the fluid reservoir 26 displaces the piston 14 counter to the force of the spring 16 when the pressure applied by the fluid delivery pump 112 is sufficient to overcome the spring force.

[0068] Between the fluid reservoir 26 and the pump 112, the inflow line 20 has an inlet valve 134. Between the fluid reservoir 26 and the patient port 114, the outflow line 22 has an outlet valve 136. The inlet valve 134 and the outlet valve 136 each have a blocking position in which the respective fluid path 20, 22 is blocked, and a passage position in which the respective fluid path 20, 22 is freed. The inlet valve 134, the fluid reservoir 26 and the outlet valve 136 are connected to an actuating element 12, which at the same time actuates the inlet valve 134, the piston 14 and the outlet valve 136. The outlet valve 136 can be the closing mechanism for the hose segment 18.

[0069] The inlet valve 134 and the outlet valve 136 are displaced by the actuating element 12 transversely with respect to the direction of flow of the fluid. In the non-actuated state of the actuating element 12 as shown in FIG. 16, the inlet valve 134 frees the inflow line 20 and the outlet valve 136 blocks the outflow line 22. In this way, fluid delivered by the fluid delivery pump 112 can flow through the inlet valve 134 and through the inflow line 20 into the fluid reservoir 26, where it displaces the piston 14. By contrast, the fluid cannot flow from the fluid reservoir 26 to the patient port 114, since the outflow line 22 is blocked by the outlet valve 136.