Control circuitry including tunable capacitor

Abstract

This invention discloses a control circuit system including an adjustable capacitor. The control circuit system (11) includes an adjustable capacitor (C1) and a bias source (111), the bias source (111) being configured to apply a bias voltage (V2) to the adjustable capacitor (C1) to adjust the capacitance value of the adjustable capacitor (C1). Such a control circuit system can, for example, be part of a sealing device (1) for sealing a medical tube (2), the sealing device (1) including a receiver (100) for receiving the medical tube (2), the receiver (100) including electrode devices for inducing heating action on the tube (2).

Description

Technical Field

[0001] This invention relates to a control circuit system, a sealing device for sealing medical tubes, and a method for operating the sealing device to seal the medical tubes. Background Technology

[0002] The control circuitry system of the type described herein can, for example, be part of a sealing device that includes a receiver for receiving the medical tube, the receiver including electrode devices for inducing a welding action on the tube. The control circuitry system can, for example, be operatively connected to the electrode devices of the receiver, and includes an adjustable capacitor and a generator device for supplying current to the electrode devices.

[0003] Sealing devices can be used, for example, to securely seal tubing that can be used on or with medical fluid containers containing, for example, blood, plasma, platelets, blood components, or any other bodily fluid collection. With the aid of a sealing device, the tubing can be effectively sealed, thereby sealing the container to allow for transport and handling and to prevent contamination of the fluid contained within.

[0004] However, it should be noted that the control circuit system described herein can be applied to other devices that include capacitor arrangements, such as resonator circuits.

[0005] In sealing devices known from US 2011 / 0313370 A1, the tube is received in a receiver of a handheld tube sealer, and a safety shield is used with the tube sealer to protect against blood splatter from the user holding the tube sealer.

[0006] WO 2016 / 083459 A1 describes a plastic tube sealing device comprising a clamp having a pair of jaws movable relative to each other to insert and press a plastic tube, the jaws including high-frequency jaw electrodes, and a power supply circuit including a generator. The device also includes an impedance control circuit for maintaining a constant impedance of the power supply circuit during corresponding welding operations by correspondingly controlling a variable impedance resonant circuit. For this purpose, the generator includes a variable impedance resonant circuit having a capacitor unit and a coil unit. The inductance of the coil unit, the ohmic resistance of the resonant circuit, and / or the capacitance of the capacitor unit are variablely adjustable.

[0007] Typically, such as in the sealing device discussed herein, the medical tube is sealed by supplying an alternating (RF) current through an electrode device to locally heat the tube and thus seal it. In this paper, to supply current to the electrode device, a resonator circuit comprising a capacitor is used, which is adjustable so that the capacitance of the capacitor is matched to the inductance of the circuit.

[0008] Especially in control circuit systems where capacitor adjustment must be done manually by the user, the adjustment process can be cumbersome.

[0009] Furthermore, adjustments may be difficult to make during operation. This can be particularly problematic if the sealing device is used on different medical tubes, for example, with different geometries or made of different materials. The capacitance between the electrodes of the electrode device may vary depending on the tube, necessitating adjustment of the adjustable capacitor, which can be difficult to perform.

[0010] Furthermore, during operation, the distance between the electrodes of the receiver's electrode assembly may change because the tube shape changes during welding. This change in electrode distance can lead to variations in capacitance, which may further affect the operation of the sealing device. However, if the control circuitry electrically alters its matching conditions during operation, the effectiveness of the excitation at the electrode assembly may deteriorate, resulting in, for example, a longer sealing time. Summary of the Invention

[0011] The object of the present invention is to provide a control circuit system, a sealing device, and a method for operating the sealing device, which allows adjustment of an adjustable capacitor in a simple manner, preferably automatically during operation.

[0012] This objective is achieved by means of a sealing device according to a specific embodiment.

[0013] Therefore, the control circuit system includes a bias source configured to apply a bias voltage to the adjustable capacitor to adjust the capacitance value of the adjustable capacitor.

[0014] For example, in a sealing device, the control circuit system should be tuned by means of an adjustable capacitor so that current can be effectively supplied to the electrode device to induce localized heating and thus seal the tube. The capacitor's capacitance can be adjusted herein by applying a bias voltage, which is applied by a bias source. The capacitance of the adjustable capacitor can be changed by means of the bias voltage, wherein it can be assumed that the capacitance is at its maximum when a bias voltage of 0 or close to 0 is applied to the adjustable capacitor, and the capacitance can be decreased by increasing the bias voltage applied to the capacitor.

[0015] It has been discovered that the capacitance of a capacitor can be changed by applying a bias voltage, particularly a direct current (DC) bias voltage. This is also known as the so-called DC bias effect. Specifically, during the operation of a control circuit system, the capacitance of an adjustable capacitor can decrease when an alternating current is applied to it while a DC bias voltage is applied simultaneously, compared to the case where no DC bias voltage is applied. The decrease depends on the magnitude of the applied bias voltage.

[0016] In ordinary circuits, the DC bias effect may be undesirable because it may require the use of a larger capacitor to avoid or at least reduce the negative effects caused by the DC bias. However, in this case, the DC bias effect can be used to adjust the capacitance value of an adjustable capacitor, where this adjustment can be achieved by purely electrical means, without any mechanical parts and therefore without any mechanical adjustment of the capacitor element. Thus, the capacitance adjustment can be performed quickly and efficiently during operation, and the adjustment can be easily automated by providing a bias source to apply a bias voltage to the adjustable capacitor.

[0017] In one embodiment, the bias voltage is a DC voltage. The bias voltage is supplied by a bias source, which in one embodiment is operatively connected to an adjustable capacitor to apply a bias voltage across the capacitor. In particular, different potentials of the bias source can be connected to different terminals of the adjustable capacitor, such that a bias voltage is applied across the capacitor and acts as a DC bias covering an AC voltage, such as that caused by a generator.

[0018] In another embodiment, the bias voltage comprises a non-constant, real-time variable waveform and is therefore not a DC voltage. For example, the bias voltage may have the shape of a sawtooth waveform, a square wave, a pulse width modulation (PWM) waveform, an AC waveform, etc.

[0019] The bias source can be controllable to adjust the bias voltage. Specifically, the control circuitry can include a control device for controlling the bias source, such as a microcontroller, which controls the bias source so that an adjustable capacitor is tuned to a capacitance value suitable for matching the capacitors and inductors of the control circuitry, thereby efficiently supplying current to the electrode assembly to induce the welding action on the medical tube.

[0020] Control circuitry systems can generally be used in any device employing a capacitor arrangement that includes adjustable capacitors. In particular, control circuitry systems can be used in resonator circuits, such as those in radios, televisions, mobile phones, and satellites, where, for example, the resonant frequency is adjusted using adjustable capacitors.

[0021] In one embodiment, the control circuitry is part of a sealing device configured to seal a medical tube, the sealing device including a receiver for receiving the medical tube, the receiver including electrode devices for inducing a sealing action on the tube. The control circuitry of the type described above is operatively connected to the electrode devices of the receiver, and the control circuitry includes a generator device for supplying current to the electrode devices.

[0022] In one embodiment, the electrode device includes a pair of electrodes arranged to receive a medical tube between them. Current is fed to the medical tube via the pair of electrodes, causing the medical tube to be locally heated and thus performing a welding action on the tube. The electrodes of the electrode device may herein be mechanically biased toward each other, for example by mechanically biasing one or both electrodes against each other by one or more spring elements, such that the electrodes are held on the tube under an elastic preload and thus receive the tube in close contact between the electrodes.

[0023] The electrodes of an electrode assembly typically function as capacitors. In particular, by means of a control circuit system, alternating (AC) current can be supplied to the electrodes of the electrode assembly, which causes the welding action on the tube, thereby providing a seal for the tube.

[0024] In one embodiment, the control device, such as a microcontroller, is configured to automatically control the bias source based on the measured capacitance value of the electrode device. Specifically, during operation of the sealing device, the impedance of the control circuit system can be measured by applying an AC voltage signal to the control circuit system to excite it and measuring the resulting current, and vice versa. Such measurements can be performed automatically by the control device during operation of the sealing device, such that changes in the capacitance of the electrode device can be automatically compensated for during operation of the sealing device.

[0025] Because the control device, such as a microcontroller, can automatically perform measurements during the operation of the sealing device, and can be matched with the control circuit system by appropriately controlling the bias source to apply a bias voltage to the adjustable capacitor, operation becomes easy for the user, especially when the sealing device is used to seal different types of tubes without any changes or adjustments.

[0026] In one embodiment, the adjustable capacitor is arranged in a circuit path that is electrically parallel to the electrode device. Therefore, the adjustable capacitor is placed in parallel with the electrode device.

[0027] Additionally, the control circuit system may include an inductor electrically connected to the adjustable capacitor, which may be arranged, for example, in series with the adjustable capacitor and the electrode arrangement in parallel.

[0028] In one embodiment, the generator is configured to supply or excite AC current to the electrode assembly to provide welding action on the tube received on the receiver. The generator may be, in particular, an RF generator for providing RF signals to a control circuit system, such that the RF signals are in the frequency range of 1 kHz to 100 kHz, for example at 10 kHz, but may also be significantly less than 1 kHz or significantly greater than 100 kHz.

[0029] In one embodiment, the system voltage generated by the generator can be AC ​​voltage, but it can also deviate from AC voltage, such that the RF current fed to the electrode device can be in AC form or can be different from AC form.

[0030] Sealing devices are particularly well-suited for welding medical tubing made of PVC. However, sealing devices can also be used on tubing made of other plastic materials to provide a welding action for such tubing.

[0031] On the other hand, a method for operating a sealing device to seal a medical tube includes: receiving the medical tube in a receiver, the receiver including an electrode device for inducing a welding action on the tube; supplying current to the electrode device using a control circuit system operatively connected to the electrode device of the receiver, the control circuit system including an adjustable capacitor and a generator device; and applying a bias voltage to the capacitor using a bias source of the control circuit system to adjust the capacitance value of the capacitor.

[0032] The advantages and advantageous implementation methods for sealing devices described above also apply to the method, and therefore reference should be made to the above in this regard. Attached Figure Description

[0033] The basic idea of ​​the invention will then be described in more detail with respect to the embodiments shown in the figures. In this document,

[0034] Figure 1 An example of a sealing device for receiving medical tubes is shown;

[0035] Figure 2 A schematic diagram of the receiver of the sealing device is shown;

[0036] Figure 3 A schematic diagram of the control circuit system of the sealing device is shown;

[0037] Figure 4 A graph showing the capacitance change as a function of the applied DC bias voltage is shown; and

[0038] Figure 5A schematic circuit diagram of a control circuit system is shown, which includes an adjustable capacitor and a bias source for applying a bias voltage to the adjustable capacitor to adjust the capacitance value of the adjustable capacitor. Detailed Implementation

[0039] Figure 1 An embodiment of a sealing device 1 is illustrated schematically. This sealing device 1 is used to seal medical tubing, such as PVC tubing, by welding. The sealing device 1 can be specifically used to seal tubing used with medical containers, such as containers containing blood, plasma, platelets, blood components, or other bodily fluid collections. By sealing the tubing, containers can be prepared for transport and handling, and contamination of the container's contents can be prevented.

[0040] like Figure 1 As shown, the sealing device 1 includes a housing 12 and a sealing element 10 disposed on the housing 12. The sealing element 10 forms a receiver 100 in which a tube can be received for sealing the tube by welding.

[0041] The sealing element 10 is operatively connected to a control circuit system 11, which can be implemented to supply alternating (RF) current to the sealing element 10 in order to provide a sealing action on the tube received in the receiver 100, as will be further described below.

[0042] A display 13 may be arranged on the housing 12, which enables, for example, the output of information about the sealing process or the input of control commands.

[0043] Now refer to Figure 2 In one embodiment, the receiver 100 includes an electrode assembly having, for example, a pair of electrodes 101, 102 arranged and configured to receive the tube 2 between them, such that when the tube 2 is placed in the receiver 100, the tube 2 is held tightly between the electrodes 101, 102. The electrodes 101, 102 may be elastically biased, for example using a mechanical spring element, such that the tube 2 is held between the electrodes 101, 102 under an elastic preload, thereby ensuring close contact between the electrodes 101, 102 and the tube 2 between them.

[0044] As from Figure 2 Furthermore, electrodes 101 and 102 are operatively connected to the control circuit system 11, such that a supply current can be fed to electrodes 101 and 102 to perform a welding operation on tube 2.

[0045] Now refer to Figure 3In one embodiment, the control circuit system 11 includes a generator device 110 in the form of an RF generator, which is connected to the electrode assembly of the receiver 100 via a resonator circuit formed by an inductor L1 and a capacitor C1. Electrodes 101 and 102 of the electrode assembly of the receiver 100 form a capacitor C2, which is arranged in parallel with the capacitor C1. The inductor L1 is arranged in series with the parallel connection of the capacitor C1 and the electrode assembly of the receiver 100.

[0046] In operation, an alternating (RF) current is excited by means of an RF generator 110, which is supplied to the electrode assembly of the receiver 100, thereby causing local heating and thus causing welding of the tubes received on the receiver 100.

[0047] In order to effectively supply alternating current to the tube received in receiver 100 to deliver welding energy to the tube, the capacitance of capacitor C1 should be matched with the inductance of inductor L1. For this purpose, capacitor C1 is adjustable in terms of its capacitance value, so that capacitor C1 can be tuned to provide effective (resonant) operation of control circuit system 11.

[0048] To provide a simple circuit system that can be operated automatically to adjust the capacitance value of capacitor C1, this paper proposes to adjust capacitor C1 by applying a (DC) bias voltage to capacitor C1 to adjust the capacitance based on the so-called DC bias effect that causes a change in capacitance.

[0049] Typically, if an alternating current (AC) signal is applied to a capacitor while a DC bias voltage is also applied, the capacitor's capacitance changes according to the value of the applied bias voltage. Specifically, as... Figure 4 As the example qualitatively illustrates, the capacitance may decrease as the bias voltage increases. Figure 4 The capacitance variation (dC / C, in percentage) on the vertical axis is shown for different applied bias voltages as noted on the horizontal axis.

[0050] As from Figure 4 As can be seen, in some examples, by applying a suitable bias voltage, the capacitance of the capacitor can be significantly reduced, for example, by more than 80%.

[0051] In this paper, this is used to adjust the capacitance of capacitor C1 by applying a bias voltage V2 using bias source 111, such as... Figure 5 One of the implementation methods is shown.

[0052] exist Figure 5In this embodiment, capacitor C1 is divided into two capacitors C11 and C12 arranged in series, wherein a bias voltage V2 is applied to the terminals of capacitor C12 by a bias source 111 to adjust the capacitance of capacitor C12. The bias source 111 is connected to capacitor C12 via resistor R1 in this document to apply a bias voltage V2 across capacitor C12.

[0053] During operation, the control circuit system 11 is activated by applying an alternating current (RF) voltage V1 via the generator device 110, so as to supply alternating current (RF) to the electrodes 101, 102 of the electrode device of the receiver 100. The generator device 110 and the bias source 111 are controlled herein by a control device 112 in the form of a microcontroller, which is specifically configured to tune the capacitance value of the capacitor C12 during operation of the sealing device 1.

[0054] For this purpose, the control device 112 can be configured to measure the resulting impedance of the control circuit system 11 during operation and adjust the capacitor C12 to control the bias voltage V2 so that the total capacitance is properly matched with the inductor L1.

[0055] Therefore, manual tuning of capacitors C1 and C12 is unnecessary. The adjustment of capacitors C1 and C12 can be automatic, and thus the adjustment of capacitors C1 and C12 can be automatically performed by a control device 112 in the form of a microcontroller during the operation of the sealing device 1.

[0056] In particular, such as Figure 2 As shown, if the electrodes 101 and 102 of the receiver 100 change their relative positions to each other during operation due to the welding action of the tube 2, the change in capacitance of the electrode assembly of the receiver 100 can be automatically compensated by adjusting the capacitance values ​​of capacitors C1 and C12.

[0057] Furthermore, the sealing device 1 can be used with different types of pipes, particularly pipes made of PVC material and pipes made of another material with different geometric dimensions, without requiring special measures to adjust the control circuit system 11 of the sealing device 1. Instead, during operation, the control circuit system 11 can be automatically adjusted by appropriately tuning the capacitor C1 in an automatic and controlled manner to provide a sealing action on the pipe received in the receiver 100.

[0058] The embodiments described herein should not be construed as limiting the invention. On the contrary, the invention can be implemented in entirely different ways.

[0059] The sealing device can be fixed, and the tube must be placed on the sealing element to perform the welding operation on the tube.

[0060] In another embodiment, the sealing device may be a handheld device, allowing the user to place the sealing device on the pipe in order to perform welding on the pipe.

[0061] Although embodiments of the sealing device have been described above, it should be noted that the control circuitry system described herein can generally be part of any device employing a capacitor arrangement including an adjustable capacitor, such as a device including a resonator circuit. For example, the control circuitry system described herein can generally be used in electronic devices such as radios, televisions, mobile phones, or satellites, or in other devices including resonator circuits.

[0062] List of reference numerals

[0063] 1. Sealing device

[0064] 10 Sealing elements

[0065] 100 receivers

[0066] Electrode elements 101 and 102

[0067] 11 Control Circuit System

[0068] 110 RF generator unit

[0069] 111 Bias Source

[0070] 112 Control device (microcontroller)

[0071] 12. Shell

[0072] 13 Monitors

[0073] 2 Medical Management

[0074] C1 and C2 capacitors

[0075] C11 and C12 capacitors

[0076] L1 inductor

[0077] R1 resistor

[0078] V1 voltage

[0079] V2 bias voltage

Claims

1. A sealing device (1) for sealing a medical tube (2), the sealing device (1) comprising a receiver (100) for receiving the medical tube (2), the receiver (100) comprising an electrode device for inducing a welding action on the medical tube (2), characterized in that Control circuit system (11). The control circuit system (11) includes an adjustable capacitor (C1) and a bias source (111) configured to apply a bias voltage (V2) to the adjustable capacitor (C1) to adjust the capacitance value of the adjustable capacitor (C1). The control circuit system (11) is operatively connected to the electrode assembly of the receiver (100). The control circuit system (11) includes a generator assembly (110) for supplying current to the electrode assembly.

2. The sealing device (1) according to claim 1, characterized in that, The bias voltage is a DC voltage or has the shape of a sawtooth waveform, square wave, pulse width modulation (PWM) waveform, or AC waveform.

3. The sealing device (1) according to claim 1 or 2, characterized in that, The bias source (111) is operatively connected to the adjustable capacitor (C1) to apply the bias voltage (V2) across the adjustable capacitor (C1).

4. The sealing device (1) according to claim 1 or 2, characterized in that, The bias source (111) can be controlled to adjust the bias voltage (V2).

5. The sealing device (1) according to claim 3, characterized in that, The bias source (111) can be controlled to adjust the bias voltage (V2).

6. The sealing device (1) according to claim 1 or 2, characterized in that, The electrode device includes a pair of electrodes (101, 102) arranged to receive the medical tube (2) between them.

7. The sealing device (1) according to claim 3, characterized in that, The electrode device includes a pair of electrodes (101, 102) arranged to receive the medical tube (2) between them.

8. The sealing device (1) according to claim 4, characterized in that, The electrode device includes a pair of electrodes (101, 102) arranged to receive the medical tube (2) between them.

9. The sealing device (1) according to claim 1 or 2, characterized in that, The control circuit system (11) includes a control device (112) for controlling the bias source (111).

10. The sealing device (1) according to claim 3, characterized in that, The control circuit system (11) includes a control device (112) for controlling the bias source (111).

11. The sealing device (1) according to claim 4, characterized in that, The control circuit system (11) includes a control device (112) for controlling the bias source (111).

12. The sealing device (1) according to claim 5, characterized in that, The control circuit system (11) includes a control device (112) for controlling the bias source (111).

13. The sealing device (1) according to claim 9, characterized in that, The control device (112) is configured to automatically control the bias source (111) based on the measured capacitance value of the electrode device.

14. The sealing device (1) according to claim 1 or 2, characterized in that, The adjustable capacitor (C1) is arranged in a circuit path that is electrically parallel to the electrode device.

15. The sealing device (1) according to claim 3, characterized in that, The adjustable capacitor (C1) is arranged in a circuit path that is electrically parallel to the electrode device.

16. The sealing device (1) according to claim 4, characterized in that, The adjustable capacitor (C1) is arranged in a circuit path that is electrically parallel to the electrode device.

17. The sealing device (1) according to claim 5, characterized in that, The adjustable capacitor (C1) is arranged in a circuit path that is electrically parallel to the electrode device.

18. The sealing device (1) according to claim 6, characterized in that, The adjustable capacitor (C1) is arranged in a circuit path that is electrically parallel to the electrode device.

19. The sealing device (1) according to claim 7, characterized in that, The adjustable capacitor (C1) is arranged in a circuit path that is electrically parallel to the electrode device.

20. The sealing device (1) according to claim 1 or 2, characterized in that, The control circuit system (11) includes an inductor (L1) electrically connected to the adjustable capacitor (C1).

21. The sealing device (1) according to claim 3, characterized in that, The control circuit system (11) includes an inductor (L1) electrically connected to the adjustable capacitor (C1).

22. The sealing device (1) according to claim 4, characterized in that, The control circuit system (11) includes an inductor (L1) electrically connected to the adjustable capacitor (C1).

23. The sealing device (1) according to claim 5, characterized in that, The control circuit system (11) includes an inductor (L1) electrically connected to the adjustable capacitor (C1).

24. The sealing device (1) according to claim 6, characterized in that, The control circuit system (11) includes an inductor (L1) electrically connected to the adjustable capacitor (C1).

25. The sealing device (1) according to claim 7, characterized in that, The control circuit system (11) includes an inductor (L1) electrically connected to the adjustable capacitor (C1).

26. The sealing device (1) according to claim 8, characterized in that, The control circuit system (11) includes an inductor (L1) electrically connected to the adjustable capacitor (C1).

27. The sealing device (1) according to claim 1 or 2, characterized in that, The generator unit (110) is configured to supply AC current to the electrode unit.

28. The sealing device (1) according to claim 3, characterized in that, The generator unit (110) is configured to supply AC current to the electrode unit.

29. The sealing device (1) according to claim 4, characterized in that, The generator unit (110) is configured to supply AC current to the electrode unit.

30. The sealing device (1) according to claim 5, characterized in that, The generator unit (110) is configured to supply AC current to the electrode unit.

31. The sealing device (1) according to claim 6, characterized in that, The generator unit (110) is configured to supply AC current to the electrode unit.

32. The sealing device (1) according to claim 7, characterized in that, The generator unit (110) is configured to supply AC current to the electrode unit.

33. The sealing device (1) according to claim 8, characterized in that, The generator unit (110) is configured to supply AC current to the electrode unit.

34. The sealing device (1) according to claim 9, characterized in that, The generator unit (110) is configured to supply AC current to the electrode unit.

35. The sealing device (1) according to claim 1 or 2, characterized in that, The medical tube (2) is a PVC tube.

36. The sealing device (1) according to claim 3, characterized in that, The medical tube (2) is a PVC tube.

37. The sealing device (1) according to claim 4, characterized in that, The medical tube (2) is a PVC tube.

38. The sealing device (1) according to claim 5, characterized in that, The medical tube (2) is a PVC tube.

39. The sealing device (1) according to claim 6, characterized in that, The medical tube (2) is a PVC tube.

40. The sealing device (1) according to claim 7, characterized in that, The medical tube (2) is a PVC tube.

41. The sealing device (1) according to claim 8, characterized in that, The medical tube (2) is a PVC tube.

42. The sealing device (1) according to claim 9, characterized in that, The medical tube (2) is a PVC tube.

43. The sealing device (1) according to claim 10, characterized in that, The medical tube (2) is a PVC tube.

44. A method for operating a sealing device (1) to seal a medical tube (2), the method comprising: The medical tube (2) is received in a receiver (100), the receiver (100) including an electrode device for inducing a welding action on the medical tube (2), and A control circuit system (11) is used to supply current to the electrode device, the control circuit system (11) being operatively connected to the electrode device of the receiver (100), the control circuit system (11) including an adjustable capacitor (C1) and a generator device (110). The feature is that a bias voltage (V2) is applied to the adjustable capacitor (C1) using the bias source (111) of the control circuit system (11) to adjust the capacitance value of the adjustable capacitor (C1).

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