Power supply device and ablation system

Abstract

The power supply device includes: a power supply section that supplies power P for ablation between two electrodes out ; and a control section that controls a supply operation of the power P out in the power supply section. The control section controls the supply operation in such a manner that the supplied power P out between the two electrodes is continuously or intermittently increased, in the case where the impedance Z between the two electrodes rises, the supplied power P out is reduced before becoming a breakdown state and is again continuously or intermittently increased.

Description

Technical Field

[0001] This disclosure relates to power supply devices and ablation systems. Background Technology

[0002] Patients with heart failure, pulmonary hypertension, etc., sometimes experience elevated atrial blood pressure. As a treatment method to suppress this rise in atrial pressure, shunt surgery is known to form a shunt (through-hole) in the interatrial septum, which serves as a release channel for atrial pressure. In shunt surgery, sometimes the periphery of the through-hole is ablated (cauterized) by an ablation catheter with an electrode at its tip, in a manner that maintains the through-hole for a prescribed period of time (see, for example, Patent Document 1).

[0003] Patent Document 1: Japanese Patent Application Publication No. 2017-60825

[0004] In ablation procedures, it is essential to reliably ablate body tissues. Summary of the Invention

[0005] This disclosure was made in view of the following circumstances, and its purpose is to provide a technique for improving the reliability of ablation of body tissues in ablation procedures.

[0006] One aspect of this disclosure is a power supply device. The power supply device includes: a power supply unit that supplies ablation power between two electrodes; and a control unit that controls the power supply operation in the power supply unit. The control unit controls the supply operation in such a manner that the power supplied between the two electrodes is continuously or intermittently increased, and when the impedance between the two electrodes increases, the power supply is reduced before a breakdown occurs, and then continuously or intermittently increased again.

[0007] Another aspect of this disclosure is an ablation system. This ablation system comprises: multiple electrodes, a portion disposed in a catheter, and the remainder, all or partly disposed in the catheter or counter electrode; and a power supply device as described above.

[0008] Any combination of the above-mentioned constituent elements, or a scheme transformed from the expression of this disclosure into a method, apparatus, system, etc., is also valid as a scheme of this disclosure.

[0009] Invention Effects

[0010] According to this disclosure, the reliability of ablation of body tissues during ablation procedures can be improved. Attached Figure Description

[0011] Figure 1 This is a schematic diagram of the ablation system implemented in this way.

[0012] Figure 2 This is a top view of the catheter.

[0013] Figure 3 This is an enlarged cross-sectional view of the tip of the catheter.

[0014] Figure 4 This is an enlarged cross-sectional view of the tip of the catheter.

[0015] Figure 5 It is a graph showing the changes in power supply and impedance over time. Detailed Implementation

[0016] Hereinafter, the present disclosure will be described based on preferred embodiments with reference to the accompanying drawings. These embodiments are not intended to limit the present disclosure but are illustrative; not all features described in the embodiments, or combinations thereof, are necessarily essential features of the present disclosure. Identical or equivalent constituent elements, components, and processes shown in the various drawings are labeled with the same reference numerals, and repeated descriptions are omitted where appropriate. Furthermore, for ease of explanation, the scales and shapes of the parts shown in the figures are set in a convenient manner and are not to be interpreted limitingly unless specifically mentioned. In addition, when terms such as "first" or "second" are used in this specification or claims, unless specifically mentioned, these terms are used to distinguish one component from others and do not indicate any order or importance. Furthermore, in the various drawings, based on the description of the embodiments, parts of less important components are omitted.

[0017] Figure 1 This is a schematic diagram of the ablation system 100 according to the embodiment. Figure 1 In this text, some of the constituent elements of the ablation system 100 are described as functional blocks. At least a portion of these functional blocks can be implemented as hardware components using elements and circuits, such as a computer's CPU (Central Processing Unit) and memory, and as software components using computer programs, etc. Those skilled in the art will understand that these functional blocks can be implemented in various forms through a combination of hardware and software. Furthermore, in... Figure 1 Only a portion of catheter 1 is shown in the diagram.

[0018] The ablation system 100 is used to ablate a treatment site 102 on a patient. The treatment site 102 is, for example, the atrial septum. It should be noted that the treatment site 102 can also be the wall of a blood vessel, etc. The ablation system 100 includes a catheter 1, a counter electrode 104, and a power supply 106. The tip of the catheter 1 is inserted into the treatment site 102 during ablation. Furthermore, the catheter 1 is electrically connected to the power supply 106. Power for ablation is supplied to the electrode 46 of the catheter 1 via the power supply 106. The structure of the catheter 1 will be described in detail later.

[0019] The counter electrode 104 is worn on the patient's body surface during ablation. Furthermore, the counter electrode 104 is electrically connected to a power supply device 106. Ablation power is supplied to the electrodes 46 of the counter electrode 104 via the power supply device 106. Hereinafter, the power supplied between the two electrodes 46 will be appropriately referred to as the supply power P. out It should be noted that when the conduit 1 has multiple electrodes 46 and power is supplied to these electrodes 46, the counter plate 104 can be omitted. That is, a portion of the multiple electrodes 46 that are supplied with power from the power supply device 106 are disposed in the conduit 1, and the remainder are disposed entirely or partially in the conduit 1 or the counter plate 104. In other words, the multiple electrodes 46 may be disposed entirely in the conduit 1, or they may be distributed between the conduit 1 and the counter plate 104. Even when the electrodes 46 are disposed in both the conduit 1 and the counter plate 104, multiple electrodes 46 can still be disposed in the conduit 1.

[0020] The power supply unit 106 includes an input unit 108, a power supply unit 110, a control unit 112, and a display unit 114. The input unit 108, for example, consists of a dial, buttons, or a touch panel, and is operated by the operator of the ablation system 100. The operator can input various setting values ​​and signals indicating actions into the power supply unit 106 via the input unit 108. It should be noted that various setting values ​​can also be preset at the factory and stored in the power supply unit 106. Signals indicating setting values, etc., are sent from the input unit 108 to the control unit 112.

[0021] The power supply unit 110 supplies power for ablation of the treatment site 102 to the space between the two electrodes 46 according to the control signal CTL sent from the control unit 112. Power supply P out For example, high-frequency (RF) power. The two electrodes 46 are sometimes composed of electrodes 46 of the conduit 1 and electrodes 46 of the counter plate 104, and sometimes of multiple electrodes 46 of the conduit 1. The power supply unit 110 is, for example, a power supply circuit defined by a switching regulator. Furthermore, the power supply unit 110 sends information related to the impedance Z between the two electrodes 46 to the control unit 112. The information related to impedance Z can be the value of impedance Z itself, or information required for calculating impedance Z, such as current or voltage values. When the value of impedance Z itself is sent to the control unit 112, the power supply unit 110 calculates impedance Z. When information required for calculating impedance Z is sent to the control unit 112, the control unit 112 calculates impedance Z.

[0022] The control unit 112 controls the overall operation of the power supply unit 106 and performs prescribed calculations. The control unit 112 may be, for example, a microcomputer. The control unit 112 controls the power supply operation in the power supply unit 110 by sending a control signal CTL generated based on impedance Z to the power supply unit 110. The control operation of the control unit 112 will be described in detail later. The display unit 114 displays various information to the outside. The display unit 114 may be composed of a liquid crystal display, a CRT (Cathode Ray Tube) display, an organic EL (Electroluminescence) display, or the like.

[0023] Next, the structure of catheter 1 will be described. Figure 2 This is a top view of catheter 1. As an example, catheter 1 includes a catheter shaft 2, a balloon 4, and a handle 6. The catheter shaft 2 is a flexible, elongated tubular member. The length of the catheter shaft 2 is, for example, 600 mm to 1800 mm. The balloon 4 is located at the tip of the catheter shaft 2. Figure 1 The middle image shows the balloon 4 in its inflated state. A handle 6 is located at the base of the catheter shaft 2. The catheter shaft 2 is inserted into the body from the tip side. Thus, the balloon 4 is advanced into the body. The handle 6 is positioned externally for operation by the therapist.

[0024] Figure 3 and Figure 4 This is an enlarged cross-sectional view of the tip side of catheter 1. Figure 3 and Figure 4 The middle figure shows the balloon 4 in its expanded state. The catheter shaft 2 has an outer shaft 8 and an inner shaft 10. The outer shaft 8 and the inner shaft 10 are made of known flexible materials such as resins such as polyolefins and polyamides. The outer shaft 8 is tubular and houses the inner shaft 10 inside. The inner shaft 10 is housed within the outer shaft 8 in a state that allows for relative displacement with respect to the outer shaft 8 in its axial direction.

[0025] The outer shaft 8 of this embodiment has: a main cavity 12 extending along a region overlapping with the central axis of the outer shaft 8; and a plurality of secondary cavities disposed around the main cavity 12. A portion of the plurality of secondary cavities constitutes a supply cavity 14a, another portion constitutes a discharge cavity 14b, and another portion constitutes a wire-carrying cavity 14c. The main cavity 12 and each secondary cavity extend from the top end side to the base end side of the outer shaft 8.

[0026] The inner shaft 10 is housed within the main cavity 12. The tip of the inner shaft 10 protrudes from the outer shaft 8. A tip 16 covers this tip. The tip 16, like the conduit shaft 2, is made of a known resin material. As an example, the tip 16 and the inner shaft 10 are joined together by welding. An annular connecting member 18 is embedded in a portion of the outer peripheral surface of the tip 16. The connecting member 18 is made of a conductive material such as metal.

[0027] A groove 16a extending from the base end of the tip 16 toward the tip side is provided on the inner circumferential surface of the tip 16. Furthermore, a wire through hole 16b extending from the tip of the groove 16a toward the connecting member 18 is provided on the tip 16. The conduit 1 includes a wire 20 extending from the base end side of the conduit shaft 2 toward the tip side. The wire 20 passes through the wire cavity 14c from the base end side of the conduit shaft 2 and reaches the tip 16. The wire 20 reaching the tip 16 passes through the groove 16a and the wire through hole 16b and is electrically connected to the connecting member 18. As an example, the connecting member 18 and the wire 20 are joined together by welding. The base end side of the wire 20 is connected to the power supply unit 110 via the handle 6.

[0028] In this embodiment, the inner shaft 10 has a wire cavity 22. When viewed axially from the guide shaft 2, the tip 16 has a wire through hole 16c at a position overlapping with the wire cavity 22. A guide wire (not shown) passes through the wire cavity 22 and the wire through hole 16c.

[0029] The balloon 4 can be expanded by fluid supplied from the base of the catheter shaft 2. The fluid is, for example, physiological saline. The balloon 4 is made of a known flexible material containing resins such as polyolefins and polyamides. The balloon 4 has a dumbbell shape with a central portion in the axial direction of the catheter shaft 2 that is radially concave throughout the entire region of the catheter shaft 2 in the axial direction.

[0030] The base end of the balloon 4 covers the outer peripheral surface of the region of the outer shaft 8 adjacent to the balloon 4. The tip end of the balloon 4 covers the outer peripheral surface of the tip tip 16 that is closer to the base end than the connecting member 18. The balloon 4 is joined to the outer shaft 8 and the tip tip 16, for example, by welding. Furthermore, the balloon 4 has a through hole (not shown). The through hole connects the inside and outside of the balloon 4 and is used to drain fluid from inside the balloon 4 to the outside. This through hole functions as an infusion mechanism.

[0031] Inside the balloon 4, a supply chamber 14a and a discharge chamber 14b are connected to an outer shaft 8. The supply chamber 14a is a cavity through which fluid flows into the balloon 4. The opening at the top of the supply chamber 14a is located inside the balloon 4. The base of the supply chamber 14a is connected to an external fluid supply and discharge device (not shown) via a handle 6. Fluid supplied from the fluid supply and discharge device passes through the supply chamber 14a and is discharged into the balloon 4. This allows the balloon 4 to inflate.

[0032] The discharge chamber 14b is a chamber for venting gas from the balloon 4. The opening at the top of the discharge chamber 14b is located inside the balloon 4. The base of the discharge chamber 14b is connected to the outside via a handle 6. The discharge chamber 14b is used, for example, when venting gas before using the catheter 1. That is, fluid is supplied to the balloon 4 from the fluid supply and discharge device via the supply chamber 14a. The fluid supplied to the balloon 4, along with the gas inside the balloon 4, flows into the discharge chamber 14b and is discharged to the outside via the discharge chamber 14b. When the balloon 4 is contracted during the use of the catheter 1, fluid is discharged from the balloon 4 via the supply chamber 14a.

[0033] The catheter 1 has an electrode 46 disposed on the surface of the balloon 4. As an example, the electrode 46 is made of a thin metal film laminated on the surface of the balloon 4. The electrode 46 extends from the connecting member 18 to the narrowed portion of the balloon 4. The end of the electrode 46 at the tip of the catheter shaft 2 is connected to the connecting member 18. Thus, the wire 20 is electrically connected to the electrode 46 via the connecting member 18. In this embodiment, the tip of the electrode 46 is cylindrical, and multiple rectangular portions extend radially from the base of the cylindrical portion. The portion of the electrode 46, except for the portion overlapping the narrowed portion of the balloon 4, is covered by an insulating film (not shown). The peripheral portion of the shunt is embedded in the narrowed portion of the balloon 4. Thus, the electrode 46 exposed in the narrowed portion abuts against the peripheral portion of the shunt. In this state, by supplying power to each electrode 46 of the catheter 1 and the counter electrode 104, the peripheral portion of the shunt is ablated.

[0034] It should be noted that the structure of catheter 1 is not limited to the structure described above. For example, catheter 1 may also have a basket structure with multiple ribs instead of balloon 4. Each rib is a flexible linear body extending axially along the catheter shaft 2 and arranged at intervals from each other in the direction around the catheter shaft 2. An electrode 46 is provided on each rib. Furthermore, the base end of each rib is fixed to the outer shaft 8, and the tip end is fixed to the inner shaft 10. Through the relative displacement of the outer shaft 8 and the inner shaft 10, each rib can switch between a straight state and a bent state, that is, a folded state and an unfolded state.

[0035] Next, the power supply control performed by the power supply device 106 will be explained. Figure 5 This indicates the supply of electricity P. out A graph showing the time-dependent change in impedance Z. Figure 5 The power supply P shown out The values ​​of impedance Z and time are just one example.

[0036] The contact state between the electrode 46, positioned at the tip of catheter 1, and the body tissue is sometimes unstable. Therefore, the contact area between the electrode 46 and the body tissue may change during ablation. Furthermore, the thickness and shape of the body tissue contacted by the electrode 46 typically vary from patient to patient. Consequently, the contact angle between the electrode 46 and the body tissue differs for each patient, and the contact area between the electrode 46 and the body tissue is not always the same. Additionally, the conductivity of blood may also vary from patient to patient. Higher blood conductivity results in a reduced amount of current flowing through the body tissue.

[0037] Due to variations in ablation conditions, the amount of current flowing through body tissues can change during the ablation process or vary from patient to patient. When the amount of current flowing through body tissues changes, the resistive heating generated within the tissues changes. Therefore, when the supplied power P... out When ablation is performed while the tissue is fixed, reliable ablation of body tissues may be difficult.

[0038] That is, under ablation conditions where current can easily flow through body tissue, the power P supplied between the two electrodes is... out It can become excessively high. In this case, the moisture on the surface of the body tissue evaporates and it is charred, causing the impedance Z to rise sharply. The state of a sharp rise in impedance Z is called the breakdown state, which becomes an indicator of whether the body tissue has fallen into an excessively heated state. When it falls into the breakdown state, current has difficulty flowing within the body tissue. Therefore, sufficient resistive heat is not generated within the body tissue, and the body tissue is difficult to ablate. In addition, if there is blood around the body tissue, the blood is prone to coagulation, resulting in thrombosis.

[0039] On the other hand, under ablation conditions where current is difficult to flow through body tissue, the supply of power P between the two electrodes... out It may be too small. In this case, the insufficient current flowing within the body tissue is the reason why enough resistance heat is not generated, making it difficult for the body tissue to be dissolved.

[0040] In contrast, the power supply device 106 of this embodiment performs the power supply control described below. That is, the control unit 112 first supplies power P to the area between the two electrodes. out The power supply P between the two electrodes increases continuously or in stages. In other words, the control unit 112 increases the power supply P continuously or in stages. out Gradually increase. Furthermore, as the impedance Z between the two electrodes increases, reduce the supplied power P before reaching a breakdown state. out Then, control unit 112 supplies power P. out The supply will gradually increase again. Control unit 112 will control the power supply P. outThe increase from the start to the end is defined as a cycle, and multiple cycles are repeated during one ablation procedure. That is, the control unit 112 controls the supply of power P between the two electrodes. out It changes periodically.

[0041] More specifically, in the first cycle C1, the control unit 112 supplies power P out From the specified first starting power P s1 The starting power gradually increases. The initial starting power P... s1 For example, around 10W. This allows the power supply P to... out The rate of increase during gradual increase is, for example, less than 10 W / s, preferably less than 1 W / s. Typically, the impedance Z gradually decreases from the start of power supply, reaching an inflection point Z at a certain time. i Then it begins to rise sharply. When the control unit 112 detects that the impedance Z has changed from decreasing to increasing, it stops supplying power P before it falls into a breakdown state. out The power supply gradually increases. Thus, the first cycle C1 ends. Then, the power supply P is reduced. out Then the second cycle C2 begins.

[0042] The nth cycle C n The initial value of (n being a natural number greater than 1) is the minimum supply power P that is output in this cycle. out At that time. Furthermore, in the nth loop C... n Finally, the maximum supply power P is output in this cycle. out hour.

[0043] For example, control unit 112 at inflection point Z i The rise in impedance Z reaches the specified threshold ΔZ. th When the first loop C1 ends, the threshold ΔZ is set. th Set to start from inflection point Z i The threshold ΔZ increased. th The impedance Z is the breakdown impedance Z under the breakdown state. bk Low. That is to say, the "breakdown state" in this disclosure refers to the impedance value Z reaching the breakdown impedance Z. bk The state of breakdown impedance Z. bk At least more than the initial starting power P supplied in the first cycle C1. s1 The reference impedance Z measured at time st A high value. Therefore, as an example, the control unit 112 will adjust the impedance Z when it exceeds the reference impedance Z. st It is judged to be in a breakdown state at that time.

[0044] The control unit 112 can determine the reference impedance Z during the first cycle C1. st and inflection point Z iThen, the threshold ΔZ can be set based on the values ​​obtained. th For example, the threshold ΔZ th Set to start from inflection point Z i Rising threshold ΔZ th The impedance Z is the reference impedance Z. st the following.

[0045] Furthermore, the control unit 112 stops the power supply at the same time as the first cycle C1 ends. Then, after a predetermined time T, the power supply P that was supplied at the end of the first cycle C1 is resumed. out The second starting power P is reduced by the specified amount ΔP. s2 This initiates the second cycle C2. As an example, control unit 112 will supply the second starting power P. s2 Set to be higher than the first start-up power P s1 Larger values.

[0046] Control unit 112 also supplies power P in the second cycle C2. out From the second startup power P s2 The impedance Z increases continuously or in stages. Control unit 112 reaches the threshold ΔZ when the impedance Z changes from decreasing to increasing. th When the time is up, the second cycle C2 ends. Then, after a predetermined time T, the power supply P is increased at a rate higher than the time at the end of the second cycle C2. out Small power supply P out The third cycle C3 begins. In this embodiment, the control unit 112 also uses the second start power P after the third cycle C3. s2 Initiate each cycle. That is, control unit 112 ensures that the power supply P at the beginning of the second cycle C2 and subsequent cycles is activated. out The power supply P at the beginning of the first cycle C1 is greater than the power supply P at the beginning of the first cycle. out That is, the first starting power P s1 The same control is repeated thereafter, from the fourth cycle C4 to the nth cycle C. n This completes one ablation procedure.

[0047] In the aforementioned power supply control, the following situation may occur: Generally, the output voltage of the power supply unit 110 has an upper limit. Therefore, when the impedance is Z, sometimes the actual supplied power (hereinafter referred to as actual supplied power) will not rise to the intended supplied power (hereinafter referred to as set supply power) before reaching its maximum. In other words, there is a situation where the actual supplied power deviates from the set supply power. When the actual supplied power has reached its maximum, the voltage reaches its upper limit, and the actual supplied power becomes maximum.

[0048] The control unit 112 determines the power supply P at the start of the next cycle based on the set power supply. outIn the case of P, the determined power supply out The supply power P becomes more than the supply power determined based on the actual supply power at the peak state. out A high value. Therefore, assuming that the actual power supply has reached its peak, the impedance Z reaches the threshold ΔZ. th In the case of the next startup, the power supply P out The actual supply power P that becomes the supply power P when the state of near-peak is approached, i.e., the supply power P that shows signs of breakdown. out The value of this is such that signs of a breakdown state will be seen shortly in the next cycle, potentially preventing sufficient ablation from being performed.

[0049] Therefore, the control unit 112 repeatedly obtains information related to the actual power supply from the power supply unit 110, and when executing the power supply P... out When the actual power supply is detected to have reached its limit under gradually increasing control conditions, the execution cycle terminates regardless of the impedance Z. Then, the power supply P is reduced by a predetermined amount ΔP from the actual power supply. out Start the next loop.

[0050] It should be noted that the information related to the actual power supply can be the value of the actual power supply itself, or information required for calculating the actual power supply, such as current and voltage values. In this disclosure, "reaching the peak" refers to a state where the actual power supply remains fixed for a specified time. This specified time can be appropriately set based on the designer's experience or through experiments and simulations. Furthermore, the specified amount ΔP used to calculate the starting power for the next cycle can differ depending on whether the next cycle begins based on a rise in impedance Z or based on the peak state of the actual power supply.

[0051] As described above, the control unit 112 of this embodiment supplies power P out The supply of power P is increased continuously or in stages, and when a small increase in impedance Z corresponding to the causation state of body tissue is detected, the power is applied before reaching the breakdown state. out The increase stops. Then, the power supply P is reduced from the point where the increase stopped. out Small power supply P out The ablation process can then resume with continuous or intermittent increases. Therefore, under various ablation conditions, it can prevent body tissues from entering an excessively heated state while ensuring a sufficient amount of current flows through the tissues. This improves the reliability of tissue ablation. Furthermore, it can inhibit thrombus formation.

[0052] In particular, the power supply unit 110 of this embodiment supplies power to the electrode 46 disposed on the conduit 1. The electrode 46 disposed on the conduit 1 tends to have its position and posture easily change relative to body tissue. Therefore, when power P is supplied...out When ablation is performed in a fixed position, the amount of current flowing through the body tissue is prone to variation. Therefore, when electrode 46 is positioned in catheter 1, the power supply control performed by control unit 112 can function more effectively.

[0053] In addition, the control unit 112 will supply power P at the beginning of the second cycle C2. out Let P be the initial starting power at the beginning of the first cycle C1. s1 Large second start-up power P s2 Therefore, in the first cycle C1, the power supply P can be expanded. out The range of variation allows for a more reliable grasp of the effective supply of electricity P for ablation. out The range and impedance Z reach an inflection point Z i Electricity supply P out Furthermore, after the second cycle C2, electricity P will be supplied. out By narrowing the frequency range to a higher supply band, the need to generate effective resistance heat for ablation in body tissues can be avoided or shortened. Therefore, the reliability of ablation of body tissues can be improved. Furthermore, it is easier to shorten the time required for ablation procedures.

[0054] Furthermore, in this embodiment, the power supply P at the beginning of the second cycle C2 is... out Fixed as the second starting power P s2 This simplifies control. It should be noted that this configuration is not particularly limited; for example, the control unit 112 could also supply power P at a later time than the last power supply in the previous cycle (i.e., the nth cycle). out The power supply P is lower than the pre-set specified amount ΔP. out Begin the next iteration (that is, the (n+1)th iteration). This means that the power supply P at the beginning of the second iteration (C2 and later) can also be adjusted. out Based on the last power supply P of the previous cycle out And this change. Therefore, it can improve the responsiveness to changes in ablation conditions. Thus, it can further improve the reliability of ablation of body tissues.

[0055] In addition, control unit 112 performs power supply P out When the actual power supply reaches its limit during the gradual increase of control, the next cycle begins with a power supply ΔP lower than the actual power supply, independent of the impedance Z. This further improves the reliability of ablation of body tissue.

[0056] Furthermore, in this embodiment, the control unit 112 stops the power supply for a predetermined time T after the end of the previous cycle, and then starts the next cycle. In this way, with intervals between cycles, the blood around the ablation site is replaced with colder blood during the intervals. Therefore, the formation of thrombi caused by ablation can be suppressed. Furthermore, during these intervals, water moves from the body tissue around the ablation site to the ablation site. Therefore, the inflection point Z of the resistance Z can be delayed in the next cycle. i The time until then. Therefore, it can improve the reliability of ablation.

[0057] It should be noted that the control unit 112 may also continue supplying power without setting an interval between each cycle. However, in this case, it is preferable to supply power P at the beginning of the next cycle. out Become the first to start the power P s1 or the size of its vicinity is at least smaller than the second starting power P. s2 Therefore, a period of insufficient power supply for ablation can be set at the beginning of the next cycle. This period serves the same purpose as the interval. The phrase "reducing the power supply before reaching a breakdown state and then continuously or intermittently increasing it again" in this disclosure, unless otherwise specifically mentioned, includes situations where the power supply is temporarily stopped from the end of the previous cycle to the beginning of the next cycle, and situations where the power supply continues from the end of the previous cycle to the beginning of the next cycle.

[0058] Furthermore, in this embodiment, the measurement is performed from the inflection point Z in each cycle. i The impedance Z is increased, and each cycle ends. This improves the responsiveness to changes in ablation conditions and enhances the reliability of ablation of body tissue. It should be noted that this configuration is not particularly limited; for example, if the impedance Z at the end is determined in the first cycle C1, each cycle can be ended with the same impedance Z after the second cycle C2. This simplifies control.

[0059] First start-up power P s1 Power supply P out Rise rate, breakdown impedance Z bk (e.g., the reference impedance Z) st (Amount), specified time T, specified quantity ΔP, second starting power P s2 The number of cycles in a single ablation procedure can be appropriately set based on the designer's experience and insights, or through the designer's experiments and simulations.

[0060] The embodiments of this disclosure have been described in detail above. These embodiments are merely examples illustrating specific practices of this disclosure. The content of the embodiments does not limit the technical scope of this disclosure, and various design changes, such as alterations, additions, and deletions of constituent elements, can be made without departing from the spirit of this disclosure as defined in the claims. New embodiments with applied design changes possess the effects of both combined embodiments and variations. In the embodiments, the phrases "in this embodiment" and "in this embodiment" are used to emphasize the possibility of such design changes, but design changes are permitted even without such phrases. Any combination of constituent elements included in each embodiment is valid as a solution of this disclosure. The shading lines in the cross-sectional drawings do not limit the material of the objects marked with shading lines.

[0061] The implementation method can also be determined by the items described below.

[0062] [First item]

[0063] A power supply device (106) comprising:

[0064] The power supply unit (110) supplies ablation power (P) between the two electrodes (46). out );and

[0065] The control unit (112) controls the power (P) in the power supply unit (110). out The supply action of )

[0066] The control unit (112) controls the supply operation in the following manner: it supplies power (P) between the two electrodes (46). out The impedance (Z) between the two electrodes (46) increases continuously or in stages, and the power supply (P) is reduced before breakdown occurs. out And then increase it continuously or in stages again.

[0067] [Second item]

[0068] According to the power supply device (106) described in the first item, wherein,

[0069] In the event that the power supply (P) will be used out When the increment of ) is set to a loop from the start to the end,

[0070] The control unit (112) supplies power (P) at the beginning of the second cycle (C2). out P s2 The power supplied at the beginning of the first cycle (C1) is greater than the power supplied at the beginning of the second cycle (P). out Ps1 ).

[0071] [Third item]

[0072] According to the power supply device (106) described in the first or second item, wherein,

[0073] In the event that the power supply (P) will be used out When the increment of ) is set to a loop from the start to the end,

[0074] Compared to the last power supply of the previous cycle (P) out The power supply (P) is lower than the pre-set predetermined amount (ΔP). out Start the next loop.

[0075] [Item 4]

[0076] The power supply device (106) according to any one of the first to third items, wherein,

[0077] In the event that the power supply (P) will be used out When the increment of ) is set to a loop from the start to the end,

[0078] The control unit (112) is used to supply power (P) out When the supply action is controlled by increasing the supply method, and the actual supply power supplied between the two electrodes (46) has reached its limit, the supply power (P) is supplied at a predetermined amount (ΔP) lower than the actual supply power, independent of the impedance (Z). out Start the next loop.

[0079] [Item 5]

[0080] The power supply device (106) according to any one of the first to fourth items, wherein,

[0081] The power supply unit (110) supplies power (P) to the electrode (46) disposed in the conduit (1). out ).

[0082] [Item 6]

[0083] An ablation system (100) comprising:

[0084] Multiple electrodes (46), some disposed in the conduit (1), and the remainder disposed, either entirely or partially, in the conduit (1) or in the counter electrode (104); and

[0085] The power supply device (106) according to any one of the first to fifth items.

[0086] Industrial availability

[0087] This disclosure can be applied to power supply devices and ablation systems.

[0088] Explanation of reference numerals in the attached figures

[0089] 1: Catheter; 46: Electrode; 100: Ablation system; 104: Counter plate; 106: Power supply; 110: Power supply unit; 112: Control unit; P out Z: Power supply; Impedance.

Claims

1. A power supply device, the power supply device comprising: The power supply unit provides ablation power between the two electrodes; and The control unit controls the power supply operation in the power supply unit. The control unit controls the supply operation in the following manner: continuously or intermittently increasing the power supplied between the two electrodes; reducing the power supplied before a breakdown occurs when the impedance between the two electrodes increases; and then continuously or intermittently increasing the power supplied again.

2. The power supply device according to claim 1, wherein, When a cycle is defined as the increase in the supplied power from the beginning to the end, The control unit ensures that the power supplied at the beginning of the second cycle is greater than the power supplied at the beginning of the first cycle.

3. The power supply device according to claim 1 or 2, wherein, When a cycle is defined as the increase in the supplied power from the beginning to the end, The next cycle begins with a power supply that is a predetermined amount lower than the power supply at the end of the previous cycle.

4. The power supply device according to claim 1 or 2, wherein, When a cycle is defined as the increase in the supplied power from the beginning to the end, When the control unit controls the supply operation in a manner that increases the supply power, and the actual supply power supplied between the two electrodes has reached its limit, the next cycle begins with a supply power that is a predetermined amount lower than the actual supply power, regardless of the impedance.

5. The power supply device according to claim 1 or 2, wherein, The power supply unit supplies power to the electrodes disposed in the conduit.

6. An ablation system, the ablation system comprising: Multiple electrodes, some of which are disposed in the conduit, and the remainder, all or part of which are disposed in the conduit or the counter electrode; and The power supply device according to claim 1 or 2.

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