Clamping Device for Acting onto a Medical Tubing

Abstract

A clamping device for acting onto a medical tubing includes a clamp arrangeable on the medical tubing and displaceable between an open position in which the clamp unblocks the medical tubing and a close position in which the clamp closes the medical tubing. The clamping device further includes a drive system configured to act on the clamp for switching the clamp between the open position and the close position. The clamping device also includes a main control circuit and a secondary control circuit electronically independent from the main control circuit, and a relay switchable between a first position and a second position. In the first position, the relay electronically couples the drive system to the main control circuit while the drive system is electronically decoupled from the secondary control circuit. In the second position, the relay electronically couples the drive system to the secondary control circuit while the drive system is electronically decoupled from the main control circuit. The secondary control circuit causes the clamp to adopt the close position when the relay is in the second position.

Claims

1-11. (canceled)

12. A clamping device for acting onto a medical tubing, comprising: a clamp which is arrangeable on the medical tubing and which is displaceable between an open position in which the clamp unblocks the medical tubing and a close position in which the clamp closes the medical tubing, a drive system that is configured to act on the clamp for switching the clamp between the open position and the close position, a main control circuit and a secondary control circuit that is electronically independent from the main control circuit, and a relay that is switchable between a first position and a second position, wherein in the first position the relay electronically couples the drive system to the main control circuit while the drive system is electronically decoupled from the secondary control circuit, wherein in the second position the relay electronically couples the drive system to the secondary control circuit while the drive system is electronically decoupled from the main control circuit, and wherein the secondary control circuit causes the clamp to adopt the close position when the relay in the second position.

13. The clamping device according to claim 12, wherein the drive system is energized by an energy storage when the drive system acts on the clamp for switching the clamp between the open position and the close position and when the relay is in the second position and wherein the drive system is not energized by the energy storage when the relay is in the first position.

14. The clamping device according to claim 12, wherein the secondary control circuit comprises an energy storage which is configured to energize the drive system for switching the clamp between the open position and the close position when the relay is in the second position and electronically couples the drive system to the secondary control circuit.

15. The clamping device according to claim 14, wherein the energy storage of the secondary control circuit comprises at least one capacitor.

16. The clamping device according to claim 15, wherein the capacitor is a supercapacitor.

17. The clamping device according to claim 12, wherein the secondary control circuit is configured to switch the relay between the first position and the second position.

18. The clamping device according to claim 12, wherein the secondary control circuit is configured to receive and to process a signal representing a system error or power failure and wherein, in case the signal is received by the secondary control circuit, the secondary control circuit causes the relay to switch from the first position into the second position.

19. The clamping device according to claim 12, wherein the relay is not energized when the relay is in the first position.

20. The clamping device according to claim 12, wherein the relay is energized when the relay is in the first position.

21. The clamping device according to claim 12, wherein the relay is a photoMOS-relay.

22. The clamping device according to claim 12, wherein the secondary control circuit comprises: two MOSFETs that are electronically arranged between an input for a signal representing an error in the main control circuit and a power supply and the relay, and two capacitors connected in parallel that serve as energy storage for the drive system when the relay electronically connects the drive system to the secondary control circuit.

23. The clamping device of claim 12, wherein the secondary control circuit comprises: four MOSFETs that are electronically arranged between an input for a signal representing an error in the main control circuit and a power supply and the relay, and two capacitors connected in parallel that serve as energy storage for the drive system when the relay electronically connects the drive system to the secondary control circuit.

24. The clamping device of claim 12, wherein the secondary control circuit comprises: five MOSFETs that are electronically arranged between an input for a signal representing an error in the main control circuit and a power supply and the relay, and six capacitors provided in parallel that serve as energy storage for the drive system when the relay electronically connects the drive system to the secondary control circuit.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The idea underlying the invention shall subsequently be described in more detail with respect to the embodiments shown in the figures. Herein:

[0021] FIG. 1 shows an overview of the main components of a clamping device, namely a clamp, a main control circuit and a secondary control circuit;

[0022] FIG. 2 shows a circuit diagram of the clamping device with a secondary control circuit according to a first embodiment;

[0023] FIG. 3 shows a circuit diagram of the clamping device with a secondary control circuit according to a second embodiment; and

[0024] FIG. 4 shows a circuit diagram of the clamping device with a secondary control circuit according to a third embodiment.

DESCRIPTION

[0025] FIG. 1 shows components of a clamping device 1 without a housing. The clamping device 1 is shown in combination with a medical tubing 2. The clamping device 1 comprises a clamp 11 and an electromotor 12. In FIG. 1 the clamp 11 is arranged on the medical tubing 2. The clamp 11 is displaceable between an open position in which the clamp 11 unblocks the medical tubing 2 and a close position in which the clamp 11 closes the medical tubing 2. The electromotor 12 forms a drive system for acting on the clamp 11 in order to displace the clamp 11 between its open position and close position. The clamping device 1 is energized by a power supply 15, such as a battery.

[0026] The clamping device 1 comprises a main control circuit 13 which controls the main functions of the clamping device 1 during normal operation of the clamping device 1. The main functions of the clamping device 1 comprise opening the clamp, closing the clamp or bringing the clamp into any position by means of the main control circuit (with an encoder). The clamping device 1 further comprises a secondary control circuit 14. The secondary circuit 14 is adapted to receive a signal representing a system error (an error in the main control circuit) and a signal representing a failure of the power supply of the clamping device 1.

[0027] By means of a relay 16 the electromotor 12 can be electronically connected either to the main control circuit 13 or to the secondary control circuit 14.

[0028] In FIG. 2 a circuit diagram of the secondary control circuit 14 according to a first embodiment is shown. On the left of the circuit diagram are shown the power supply 15 of the clamping device 1 and an input 17 for the signal representing an error in the main control circuit 13. The signal is provided by a watchdog system monitoring the main control circuit 13. On the right of the circuit diagram are shown two contacts 131 of the main control circuit 13, two contacts 141 of the secondary control circuit 14 and the relay 16. The relay 16 is electronically connected to the electromotor 12. The relay 16 switches between a first position, in which the relay 16 is electronically connected to the two contacts 131 of the main control circuit 13 and the clamp 11 may be in the open position (not shown in FIG. 2), and a second position, in which the relay 16 is electronically connected to the two contacts 141 of the secondary control circuit 14 and the clamp 11 is in the close position (shown in FIG. 2). The position of the relay 16 depends on the signal provided by the watchdog and on the voltage level of the power supply 15. The secondary control circuit 14 comprises two MOSFETs M1, M2 that are electronically arranged between the input 17 for the signal representing an error in the main control circuit 13 and the power supply 15 on the one hand and the relay 16 on the other hand. Depending on said signal and the voltage level of the power supply 15 the MOSFETs M1, M2 are conductive or non-conductive.

[0029] The secondary control circuit 14 comprises two capacitors C connected in parallel that serve as energy storage for the electromotor 12 when the relay 16 electronically connects the electromotor 12 to the secondary control circuit 14. The energy storage C is charged by the power supply 15 only if the voltage level of the power supply 15 is normal and if no error in the main control circuit 13 occurs.

[0030] The relay 16 and the secondary control circuit 14 shown in FIG. 2 are designed such that the relay 16 is energized (by the power supply 15 via the secondary control circuit 14) when the relay 16 is in its first position, that is to say when the clamp 11 may be in its open position. This is the case if the voltage level of the power supply 15 is normal and if the input 17 receives no signal representing an error in the main control circuit 13.

[0031] In the following will be described different scenarios for illustrating the operation of the clamping device 1 comprising the secondary control circuit 14 shown in FIG. 2.

[0032] In a first scenario the voltage level of the power supply 15 is normal (above a predefined threshold) and the signal provided by the watchdog is high indicating that the main control circuit 13 operates properly. In this scenario MOSFET M1 which is an enhancement mode n-channel MOSFET is conductive and MOSFET M2 which is an enhancement mode p-channel MOSFET is conductive. As a consequence, the capacitors C are charged by the power supply 15, the relay 16 is energized by the power supply 15 and the relay 16 is in its first position in which the relay 16 electronically connects the electromotor 12 to the main control circuit 13 (not shown in FIG. 2). The clamp 11 may be in its open position. This scenario corresponds to a normal operation mode of the clamping device 1.

[0033] In a second scenario the voltage of the power supply 15 is low (below a predefined threshold) and the signal provided by the watchdog is high indicating that the main control circuit 13 operates properly. In this scenario MOSFET M1 is conductive and MOSFET M2 is non-conductive. As a consequence, the relay 16 is no longer energized by the power supply 15. Therefore, the relay 16 switches into its second position in which the relay 16 electronically connects the electromotor 12 to the secondary control circuit 14 (shown in FIG. 2). Also, the capacitors C are no longer charged by the power supply 15, but provide the stored electrical energy to the electromotor 12. The electromotor 12 acts on the clamp 11 and the clamp 11 switches into its close position.

[0034] In a third scenario the voltage of the power supply 15 is normal (above a predefined threshold) and the signal provided by the watchdog is low indicating an error in the main control circuit 13. In this scenario MOSFET M1 is non-conductive and MOSFET M2 is conductive. As a consequence, the secondary control circuit 14 is interrupted so that the relay 16 is no longer energized by the power supply 15. Therefore, the relay 16 switches into its second position in which the relay 16 electronically connects the electromotor 12 to the secondary control circuit 14 (shown in FIG. 2). Also, the capacitors C provide the stored electrical energy to the electromotor 12. The electromotor 12 acts on the clamp 11 and the clamp 11 switches into its close position.

[0035] In FIG. 3 a circuit diagram of the secondary control circuit 14 according to a second embodiment is shown. This circuit diagram differs from that shown in FIG. 2 in particular in that, instead of two, four MOSFETs M3, M4, M5 and M6 are electronically arranged between the input 17 for the signal representing an error in the main control circuit 13 and the power supply 15 on the one hand and the relay 16 on the other hand. The relay 16 and the secondary control circuit 14 shown in FIG. 3 are designed such that the relay 16 is not energized (via the secondary control circuit 14) when the relay 16 is in its first position, that is to say when the clamp 11 may be in its open position. Instead the relay 16 is energized (by the power supply 15 or by the energy storage C via the secondary control circuit 14) when the relay 16 is in its second position with the clamp 11 being in its close position. This is the case if the voltage level of the power supply 15 is low and/or if the input 17 receives a signal representing an error in the main control circuit 13.

[0036] In the following will be described different scenarios for illustrating the operation of the clamping device 1 comprising the secondary control circuit 14 shown in FIG. 3.

[0037] In a first scenario the voltage of the power supply 15 is normal (above a predefined threshold) and the signal provided by the watchdog is high indicating that the main control circuit 13 operates properly. In this scenario MOSFET M3 which is an enhancement mode n-channel MOSFET is conductive. MOSFET M4 which is an enhancement mode n-channel MOSFET is non-conductive. MOSFET M5 which is an enhancement mode p-channel MOSFET is non-conductive. MOSFET M6 which is an enhancement mode n-channel MOSFET is conductive. As a consequence, the capacitors C are charged by the power supply 15, the relay 16 is not energized by the power supply 15 and the relay 16 is in its first position in which the relay 16 electronically connects the electromotor 12 to the main control circuit 13 (shown in FIG. 3). The clamp 11 may be in its open position. This scenario corresponds to a normal operation mode of the clamping device 1.

[0038] In a second scenario the voltage of the power supply 15 is low (below a predefined threshold) and the signal provided by the watchdog is high indicating that the main control circuit 13 operates properly. In this scenario MOSFETs M3 and M5 are conductive and MOSFETs M4 and M6 are non-conductive. As a consequence, the relay 16 is energized by the capacitors C, because current can flow through the body diode of MOSFET M6 (in reverse mode). Therefore, the relay 16 switches into its second position in which the relay 16 electronically connects the electromotor 12 to the secondary control circuit 14 (not shown in FIG. 3). Also, the capacitors C are no longer charged by the power supply 15, but provide the stored electrical energy to the electromotor 12. (MOSFET M6 limits the energy provided to the electromotor 12 to only the energy available from the energy storage C.) The electromotor 12 acts on the clamp 11 and the clamp 11 switches into its close position.

[0039] In a third scenario the voltage of the power supply 15 is normal (above a predefined threshold) and the signal provided by the watchdog is low indicating an error in the main control circuit 13. In this scenario MOSFETs M3 and M6 are non-conductive and MOSFETs M4 and M5 are conductive. As a consequence, the relay 16 is energized by the power supply 15. Therefore, the relay 16 switches into its second position in which the relay 16 electronically connects the electromotor 12 to the secondary control circuit 14 (not shown in FIG. 3). Also, the capacitors C energize the electromotor 12 (the power supply 15 does not energize the electromotor 12 as MOSFET M6 is non-conductive). The electromotor 12 acts on the clamp 11 and the clamp 11 switches into its close position.

[0040] In FIG. 4 a circuit diagram of the secondary control circuit 14 according to a third embodiment is shown. This circuit diagram differs from that shown in FIG. 3 in particular in that instead of four, five MOSFETs M7, M8, M9, M10 and M11 are electronically arranged between the input 17 for the signal representing an error in the main control circuit 13 and the power supply 15 on the one hand and the relay 16 on the other hand. Furthermore, instead of two capacitors C, six capacitors C are provided in parallel that serve as energy storage for the electromotor 12 when the relay 16 electronically connects the electromotor 12 to the secondary control circuit 14. The secondary control circuit 14 comprises several resistances, wherein resistance R1 is provided to limit the loading current of the capacitors C and wherein resistance R9 is provided to limit the unload current of the capacitors C towards the electromotor 12. A diode D1 is provided to separate the power supply 15 from the secondary control circuit 14 in case of the second and third scenario described further below.

[0041] The relay 16 and the secondary control circuit 14 shown in FIG. 4 are designed such that the relay 16 is not energized (via the secondary control circuit 14) when the relay 16 is in its first position, that is to say when the clamp 11 may be in its open position. Instead the relay 16 is energized (by the power supply 15 or by the energy storage C via the secondary control circuit 14) when the relay 16 is in its second position with the clamp 11 being in its close position. This is the case if the voltage level of the power supply 15 is low and/or if the input 17 receives a signal representing an error in the main control circuit 13.

[0042] In the following will be described different scenarios for illustrating the operation of the clamping device 1 comprising the secondary control circuit 14 shown in FIG. 4.

[0043] In a first scenario the voltage of the power supply 15 is normal (above a predefined threshold) and the signal provided by the watchdog is high indicating that the main control circuit 13 operates properly. In this scenario MOSFETs M7 and M8 which are both enhancement mode n-channel MOSFETs and which are connected such as to form a logic AND connection are conductive. As a consequence, MOSFET M9 which is an enhancement mode n-channel MOSFET is non-conductive. This in turn leads to MOSFET M10 which is an enhancement mode p-channel MOSFET being non-conductive. MOSFET M11 which is an enhancement mode n-channel MOSFET is conductive. Due to conductive MOSFET M11 the capacitors C are charged by the power supply 15. Due to non-conductive MOSFET M10 the relay 16 is not energized by the power supply 15 and the relay 16 is in its first position in which the relay 16 electronically connects the electromotor 12 to the main control circuit 13 (shown in FIG. 4). The clamp 11 may be in its open position. This scenario corresponds to a normal operation mode of the clamping device 1.

[0044] In a second scenario the voltage of the power supply 15 is low (below a predefined threshold) and the signal provided by the watchdog is high indicating that the main control circuit 13 operates properly. In this scenario MOSFETs M7, M9 and M10 are conductive and MOSFETs M8 and M11 are non-conductive. As a consequence, the relay 16 is energized by the capacitors C, because current can flow through the body diode of MOSFET M11 (in reverse mode) and MOSFET M10 is conductive. Therefore, the relay 16 switches into its second position in which the relay 16 electronically connects the electromotor 12 to the secondary control circuit 14 (not shown in FIG. 4). Also, the capacitors C are no longer charged by the power supply 15, but provide the stored electrical energy to the electromotor 12. MOSFET M11 limits the energy provided to the electromotor 12 to only the energy available from the energy storage C. The electromotor 12 acts on the clamp 11 and the clamp 11 switches into its close position.

[0045] In a third scenario the voltage of the power supply 15 is normal (above a predefined threshold) and the signal provided by the watchdog is low indicating an error in the main control circuit 13. In this scenario MOSFETs M7 and M11 are non-conductive and MOSFETs M9 (M8) and M10 are conductive. As MOSFET M10 is conductive, the relay 16 is energized by the power supply 15. Therefore, the relay 16 switches into its second position in which the relay 16 electronically connects the electromotor 12 to the secondary control circuit 14 (not shown in FIG. 4). Also, the capacitors C are no longer charged by the power supply 15, but energize the electromotor 12. (MOSFET M11 limits the energy provided to the electromotor 12 to only the energy available from the energy storage C. For power supply 15, there is no conductive circuit) The electromotor 12 acts on the clamp 11 and the clamp 11 switches into its close position.

List of Reference Numerals

[0046] 1 Clamping device [0047] 11 clamp [0048] 12 Electromotor [0049] 13 Main control circuit [0050] 131 Contact of main control circuit [0051] 14 Secondary control circuit [0052] 141 Contact of secondary control circuit [0053] 15 Power supply [0054] 16 relay [0055] 17 input [0056] 2 Medical tubing [0057] C Capacitor [0058] D1 diode [0059] M1-M11 MOSFET [0060] R1, R9 resistance