Ultrasonic knife system and constant current driving method, device and host thereof

Abstract

The present application discloses an ultrasonic knife system and its constant current driving method, device and host, the method comprising: obtaining the actual current value currently output by the ultrasonic transducer in each sampling cycle; when the current difference between the actual current value and the target current value is greater than a preset threshold, adjusting the working voltage of the ultrasonic transducer in combination with the speed parameter, and entering the next sampling cycle; the speed parameter is negatively correlated with the current cumulative sampling time; after the current difference between the actual current value and the target current value is not greater than the preset threshold, entering the steady-state adjustment stage, calling the preset steady-state fine-tuning algorithm to adjust the working voltage of the ultrasonic transducer, and entering the next sampling cycle, so that the actual current value reaches the target current value and remains stable. The present application can make the working current of the transducer rise to the target current value quickly and smoothly without overshoot, avoid the problem of overshoot in the entire constant current driving process, and ensure the continuity and stability of the mechanical amplitude of the ultrasonic knife head.

Description

Technical Field

[0001] The present application relates to the field of ultrasonic knife technology, and in particular to an ultrasonic knife system and a constant current driving method, device and host thereof. Background Art

[0002] In recent years, ultrasonic scalpels have been widely used and developed rapidly in the fields of medical treatment, medical aesthetics, etc. In particular, in minimally invasive surgical treatment applications, ultrasonic scalpels cause little thermal damage to surrounding tissues and do not produce smoke. During the operation, no current passes through the human body, the tissue eschar is small, and the damage to the patient is small. Therefore, ultrasonic scalpels are often used in endoscopic minimally invasive surgery and open surgery.

[0003] The ultrasonic transducer is an important component in the ultrasonic scalpel system. Under the stimulation of the ultrasonic excitation signal, it can realize the conversion of electrical energy into mechanical energy (i.e., ultrasonic vibration) based on the piezoelectric element, and transmit the ultrasonic vibration to the ultrasonic scalpel, so that the ultrasonic scalpel head performs high-frequency reciprocating motion to perform operations such as cutting tissues and / or closing small blood vessels. Therefore, the driving control of the ultrasonic transducer will directly affect the use and operation effect of the ultrasonic scalpel.

[0004] In the related art, constant current control is often used to excite the ultrasonic transducer. However, the inventor of the present application found that in practical applications, the existing constant current control method often has a serious current overshoot problem, which leads to instability of the mechanical energy transmitted to the ultrasonic scalpel head.

[0005] In view of this, providing a solution to the above-mentioned technical problems has become an urgent concern for those skilled in the art. Summary of the invention

[0006] The purpose of the present application is to provide an ultrasonic scalpel system and a constant current driving method, device and host thereof, so as to effectively solve the current overshoot problem and improve the continuity and stability of the mechanical amplitude of the ultrasonic scalpel head.

[0007] In order to solve the above technical problems, on the one hand, the present application discloses a constant current driving method of an ultrasonic knife system, comprising:

[0008] In each sampling period, the actual current value currently output by the ultrasonic transducer is obtained;

[0009] When the current difference between the actual current value and the target current value is greater than a preset threshold, the working voltage of the ultrasonic transducer is adjusted in combination with the speed parameter, and the next sampling cycle is entered; wherein the speed parameter is negatively correlated with the current cumulative sampling time, and the longer the current cumulative sampling time is, the smaller the speed parameter is;

[0010] After the current difference between the actual current value and the target current value is less than or equal to the preset threshold value, the steady-state regulation stage is entered, the preset steady-state fine-tuning algorithm is called to adjust the working voltage of the ultrasonic transducer, and the next sampling cycle is entered to make the actual current value reach the target current value and remain stable.

[0011] Optionally, the speed parameter is the reciprocal of the current sampling cycle number.

[0012] Optionally, the adjusting the operating voltage of the ultrasonic transducer in combination with the speed parameter comprises:

[0013] Based on the current difference in the current sampling period, the operating voltage of the ultrasonic transducer is adjusted according to the first voltage calculation formula:

[0014] V n =E n *T n *V para ;

[0015] Among them, V n is the working voltage after the nth adjustment; E n =I targ -I n is the current difference in the nth sampling period; I n is the actual current value in the nth sampling period; I targ is the target current value; T n is the speed parameter in the nth sampling period; V para is the preset voltage conversion parameter.

[0016] Optionally, calling a preset steady-state fine-tuning algorithm to adjust the operating voltage of the ultrasonic transducer includes:

[0017] Obtaining a current difference between the actual current value and the target current value in each sampling period after entering the steady-state regulation stage;

[0018] Based on each of the current differences after entering the steady-state regulation stage, the operating voltage of the ultrasonic transducer is adjusted according to the second voltage calculation formula:

[0019] V m+1 =V m +E m *P+EI m *I+ED m *D;

[0020] Among them, V m+1 is the working voltage value after the mth adjustment since entering the steady-state regulation stage; V mis the working voltage value after the m-1th adjustment since entering the steady-state regulation stage and the working voltage value before the mth adjustment; E m =I targ -I m is the current difference within the mth sampling period since entering the steady-state regulation stage; I m is the actual current value in the mth sampling period since entering the steady-state regulation phase; I targ is the target current value; P is the preset proportional parameter; I is the preset integral parameter; D is the preset differential parameter; ED m =E m -E m-1 ;

[0021] Optionally, after adjusting the operating voltage of the ultrasonic transducer according to the second voltage calculation formula, the method further includes:

[0022] Determine whether the operating voltage value calculated based on the second voltage calculation formula is greater than a preset maximum voltage value;

[0023] If yes, adjusting the working voltage of the ultrasonic transducer according to the preset maximum voltage value;

[0024] If not, the operating voltage of the ultrasonic transducer is adjusted according to the calculated operating voltage value.

[0025] Optionally, adjusting the operating voltage of the ultrasonic transducer according to the calculated operating voltage value includes:

[0026] Determine whether the difference between the calculated working voltage value and the working voltage value calculated in the previous sampling period is greater than a preset maximum voltage adjustment amount;

[0027] If yes, adjusting the working voltage of the ultrasonic transducer according to the working voltage value calculated in the previous sampling period and the preset maximum voltage adjustment amount;

[0028] If not, the currently calculated working voltage value is used as the working voltage of the ultrasonic transducer.

[0029] Optionally, the constant current driving method further includes:

[0030] According to the input current range setting information, the target current value corresponding to the set current range is determined.

[0031] On the other hand, the present application also discloses a constant current driving device of an ultrasonic knife system, comprising:

[0032] An acquisition module is used to obtain the actual current value currently output by the ultrasonic transducer in each sampling period;

[0033] A first adjustment module, configured to adjust the working voltage of the ultrasonic transducer in combination with a speed parameter when the current difference between the actual current value and the target current value is greater than a preset threshold; wherein the speed parameter is negatively correlated with the current cumulative sampling time, and the longer the current cumulative sampling time is, the smaller the speed parameter is;

[0034] The second adjustment module is used to call a preset steady-state fine-tuning algorithm to adjust the working voltage of the ultrasonic transducer after the current difference between the actual current value and the target current value is less than or equal to the preset threshold and enters the steady-state adjustment stage, so that the actual current value reaches the target current value and remains stable.

[0035] On the other hand, the present application also discloses a host of an ultrasonic knife system, comprising:

[0036] a processor electrically connected to the ultrasonic transducer; and,

[0037] A memory is communicatively connected to the processor, the memory stores instructions executable by the processor, and the instructions are used to implement any of the constant current driving methods described above when executed.

[0038] On the other hand, the present application also discloses an ultrasonic knife system, comprising:

[0039] Ultrasonic scalpel;

[0040] an ultrasonic transducer connected to the ultrasonic scalpel and configured to convert a received ultrasonic excitation signal into ultrasonic vibration and transmit the ultrasonic vibration to the ultrasonic scalpel; and

[0041] The host as described above is electrically connected to the ultrasonic transducer and is used to provide the ultrasonic excitation signal to the ultrasonic transducer.

[0042] The ultrasonic knife system and its constant current driving method, device and host provided by the present application have the following beneficial effects: the present application adopts a two-stage adjustment method to control the current stability of the ultrasonic transducer, wherein, in the rapid current rising stage when the working current of the ultrasonic transducer gradually rises to the target current value, the working voltage of the transducer is regulated in combination with the speed parameter that is negatively correlated with the current cumulative sampling time, so that the working current of the transducer can rise quickly and smoothly to the target current value without overshoot, providing a more stable and accurate initial current value for entering the steady-state adjustment stage, thereby avoiding the problem of overshoot in the entire constant current driving process, and ensuring the continuity and stability of the mechanical amplitude of the ultrasonic knife head. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] In order to more clearly illustrate the technical solutions in the prior art and the embodiments of the present application, the drawings required for use in the description of the prior art and the embodiments of the present application are briefly introduced below. Of course, the drawings described below in relation to the embodiments of the present application are only part of the embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without creative work, and the obtained other drawings also belong to the protection scope of the present application.

[0044] Figure 1 A schematic diagram of current and voltage characteristics output by an ultrasonic knife system disclosed in an embodiment of the present application;

[0045] Figure 2 An equivalent circuit diagram of an ultrasonic transducer disclosed in an embodiment of the present application;

[0046] Figure 3 This is a flow chart of a constant current driving method for an ultrasonic knife system disclosed in an embodiment of the present application;

[0047] Figure 4 This is a flow chart of another constant current driving method for an ultrasonic knife system disclosed in an embodiment of the present application;

[0048] Figure 5 A structural block diagram of a constant current driving device of an ultrasonic knife system disclosed in an embodiment of the present application;

[0049] Figure 6 This is a structural block diagram of an ultrasonic knife system disclosed in an embodiment of the present application. DETAILED DESCRIPTION

[0050] The core of this application is to provide an ultrasonic knife system and its constant current driving method, device and host, so as to solve the current overshoot problem and improve the continuity and stability of the mechanical amplitude of the ultrasonic knife head.

[0051] In order to describe the technical solutions in the embodiments of the present application more clearly and completely, the technical solutions in the embodiments of the present application will be introduced below in conjunction with the drawings in the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application.

[0052] In the ultrasonic scalpel system, the mechanical energy transmitted to the ultrasonic scalpel changes continuously with the output power of the ultrasonic transducer. Ensuring the stability of the ultrasonic transducer working current helps to ensure the stability of the output power, which in turn helps to ensure the stability of the mechanical amplitude of the ultrasonic scalpel head and prevent the cutting process of the ultrasonic scalpel from being fast or slow during the surgical operation.

[0053] Generally, the working current of an ultrasonic transducer is adjusted by adjusting a given working voltage, and the change of the working current lags behind the working voltage. Figure 1 The current and voltage characteristic curve of the ultrasonic transducer output is shown in Figure 1 It can be seen that the maximum current obviously lags behind the maximum voltage. This lag of current relative to voltage directly leads to the overshoot of the working current of the ultrasonic transducer during the adjustment process, resulting in the instability of the amplitude output of the cutter head.

[0054] The reason why the current lags behind the voltage is that the load of the ultrasonic transducer is not a pure resistive load and is constantly changing. Figure 2 The equivalent circuit diagram of the ultrasonic transducer is shown.

[0055] The equivalent circuit of the ultrasonic transducer includes two parallel branches. One of the branches is the static branch, including the static capacitor Co, which is mostly piezoelectric ceramics. The capacitance is determined by the electrode area and thickness of the piezoelectric ceramic vibrator, and is generally around 2nF-4nF. The other branch is the dynamic branch, including the dynamic inductance Ls, dynamic capacitance Cs and dynamic resistance Rs in series, which are used to equalize the load clamped by the ultrasonic scalpel head. Therefore, the parameter values ​​of these three will change with the change of load conditions (the continuous cutting of the ultrasonic scalpel makes the cut tissue thinner and the load smaller).

[0056] Due to the complexity of the load in the ultrasonic scalpel system, the output voltage and output current of the ultrasonic transducer are out of phase. The constant current drive of the ultrasonic transducer is to adjust the voltage to maintain a constant current, so it is very easy to produce current overshoot. In view of this, the present application provides a constant current drive solution for an ultrasonic scalpel system, which can effectively solve the above problems.

[0057] See also Figure 3 As shown, the embodiment of the present application discloses a constant current driving method for an ultrasonic knife system, which mainly includes:

[0058] S101: In each sampling period, the actual current value currently output by the ultrasonic transducer is obtained.

[0059] S102: When the current difference between the actual current value and the target current value is greater than a preset threshold, the operating voltage of the ultrasonic transducer is adjusted in combination with the speed parameter, and the next sampling cycle is entered; wherein the speed parameter is negatively correlated with the current cumulative sampling time, and the longer the current cumulative sampling time is, the smaller the speed parameter is.

[0060] S103: After the current difference between the actual current value and the target current value is less than or equal to the preset threshold, the steady-state regulation phase is entered, the preset steady-state fine-tuning algorithm is called to adjust the working voltage of the ultrasonic transducer, and the next sampling cycle is entered to make the actual current value reach the target current value and remain stable.

[0061] Specifically, the ultrasonic excitation signal output by the host of the ultrasonic knife system for stimulating the ultrasonic transducer is a signal with adjustable frequency and voltage amplitude. By adjusting the frequency of the ultrasonic excitation signal, the ultrasonic transducer can be operated in a resonant state as much as possible to obtain the maximum energy conversion efficiency. The voltage amplitude of the ultrasonic excitation signal determines the input energy of the ultrasonic transducer and the maximum output energy; when the energy conversion efficiency remains unchanged, by adjusting the voltage amplitude of the ultrasonic excitation signal, that is, the working voltage of the ultrasonic transducer, the working current of the ultrasonic transducer can be effectively adjusted, thereby affecting the output power of the ultrasonic transducer.

[0062] Therefore, in order to achieve constant current control of the ultrasonic transducer, the present application can periodically sample and obtain the actual current value of the ultrasonic transducer, so as to adjust the operating voltage of the ultrasonic transducer in real time based on the current difference between the actual current value and the target current value.

[0063] Among them, in order to ensure the speed of current regulation and avoid current overshoot, this application adopts a two-stage regulation to effectively balance the performance of regulation speed and regulation stability. In the first stage, since the system has just started, the current actual current value is much smaller than the target current value, and the current difference from the target current value is greater than the preset threshold. Therefore, the actual current value can be quickly increased in this stage to reach near the target current value. Therefore, this stage is also called the fast regulation stage, or the current rapid rise stage.

[0064] As the actual current value rises rapidly in the rapid adjustment stage, when the current difference between the actual current value and the target current value is no longer greater than the preset threshold, the second stage can be entered. In the second stage, the current can be fine-tuned in a steady state so that the working current of the ultrasonic transducer reaches the target current value and remains stable. Therefore, this stage is also called the steady-state adjustment stage. It should be emphasized that in the rapid current rise stage and the steady-state adjustment stage, although the problem of current overshoot is faced due to the characteristic that the ultrasonic transducer current lags behind the voltage, since the goal in the rapid current rise stage is to quickly approach the target current value, the amplitude of voltage regulation is relatively larger than that in the steady-state adjustment stage, and the possibility and amplitude of current overshoot are also greater, which can further affect the entire constant current driving process.

[0065] In this regard, considering that in the first stage, as time goes by, the rising actual current value is getting closer and closer to the target current value, and the possibility of current overshoot is also increasing, the present application utilizes the speed parameter to adjust the working voltage of the ultrasonic transducer, intending to gradually weaken the single adjustment amplitude of the working voltage based on smaller and smaller speed parameters, thereby slowing down the adjustment speed of the working voltage of the ultrasonic transducer.

[0066] To this end, the present application specifically sets a relevant parameter, the speed parameter, in order to control the adjustment speed of the working voltage. Among them, the speed parameter is negatively correlated with the current cumulative sampling time, that is, the longer the current cumulative sampling time, the smaller the speed parameter. For example, as a specific embodiment, the speed parameter can be specifically the reciprocal of the current sampling cycle number, that is, the speed parameter value is inversely proportional to the current sampling cycle number. For another example, as another specific embodiment, the speed parameter can be specifically the reciprocal of the square root of the current cumulative sampling time. In short, the speed parameter is a decreasing function of the current cumulative sampling time.

[0067] It should also be noted that when calculating the speed parameters, the "current cumulative sampling time" used is specifically the sampling time accumulated during the rapid current rise stage, and the "current sampling cycle number" used is specifically the sampling cycle number accumulated during the rapid current rise stage, and neither of them involves the steady-state regulation stage. Specifically, it is easy for those skilled in the art to understand that, for reasons such as the safety of equipment use, ultrasonic knife systems generally start from a shutdown state, so the regulation process of the working current generally first goes through a rapid current rise stage, and then transitions from the rapid current rise stage to a steady-state regulation stage, without switching back and forth between the rapid current rise stage and the steady-state regulation stage.

[0068] It is easy to understand that controlling the actual current value to the target current value is a real-time and continuous process. Therefore, in each sampling period, the current current difference needs to be recalculated and the working voltage of the ultrasonic transducer needs to be readjusted so that the actual current value of the ultrasonic transducer always remains at the target current value.

[0069] It can be seen that the constant current driving method of the ultrasonic knife system provided in the present application adopts a two-stage adjustment method to control the current stability of the ultrasonic transducer, wherein, in the rapid current rising stage when the working current of the ultrasonic transducer gradually rises to the target current value, the working voltage of the transducer is regulated in combination with the speed parameter that is negatively correlated with the current cumulative sampling time. The working current of the transducer can be made to rise quickly and smoothly to the target current value without overshoot, providing a more stable and accurate initial current value for entering the steady-state adjustment stage, thereby avoiding the problem of overshoot in the entire constant current driving process, and ensuring the continuity and stability of the mechanical amplitude of the ultrasonic knife head.

[0070] As a specific embodiment, the constant current driving method of the ultrasonic knife system provided in the embodiment of the present application is based on the above content and adjusts the working voltage of the ultrasonic transducer in combination with the speed parameter, including:

[0071] Based on the current difference in the current sampling period, the operating voltage of the ultrasonic transducer is adjusted according to the first voltage calculation formula:

[0072] V n =E n *T n *V para ;

[0073] Among them, V n is the working voltage after the nth adjustment; E n =I targ -I n is the current difference in the nth sampling period; I n is the actual current value in the nth sampling period; I targ is the target current value; T n is the speed parameter in the nth sampling period; V para is the preset voltage conversion parameter.

[0074] Specifically, during the first stage of rapid adjustment, the actual current value I n Although it is rising, it has not yet reached the target current value I targ Nearby, distance to target current value I targ The current difference E n Greater than the preset threshold I th , that is, E n =I targ -I n >I th At this time, the focus is on accelerating the current rise, so the current difference E n And the voltage conversion parameter V para The adjusted operating voltage is calculated by multiplying the product of . At the same time, in order to avoid overshoot in the later stage, the speed parameter T introduced in the above content is also used n To gradually reduce the regulation speed of the operating voltage.

[0075] As a specific embodiment, the constant current driving method of the ultrasonic knife system provided in the embodiment of the present application, based on the above content, calls a preset steady-state fine-tuning algorithm to adjust the working voltage of the ultrasonic transducer, including:

[0076] Obtain the current difference between the actual current value and the target current value in each sampling period after entering the steady-state regulation stage;

[0077] Based on the current differences after entering the steady-state regulation stage, the operating voltage of the ultrasonic transducer is adjusted according to the second voltage calculation formula:

[0078] V m+1 =V m +E m *P+EI m *I+ED m *D;

[0079] Among them, V m+1 is the working voltage value after the mth adjustment since entering the steady-state regulation stage; V m is the working voltage value after the m-1th adjustment since entering the steady-state regulation stage and the working voltage value before the mth adjustment; E m =I targ -I m is the current difference within the mth sampling period since entering the steady-state regulation stage; I m is the actual current value in the mth sampling period since entering the steady-state regulation stage; I targ is the target current value; P is the preset proportional parameter; I is the preset integral parameter; D is the preset differential parameter; ED m =E m -E m-1 ;

[0080] Specifically, after several adjustment cycles in the first stage, the actual current value I n Has risen to the target current value I targ Nearby, distance to target current value I targ The current difference E n No longer greater than the preset threshold I th , that is, E n =I targ -I n ≤I th , at this time, the second stage of steady-state regulation will begin. This stage focuses on the stability and accuracy of the current, so the PID control algorithm can be used to accurately adjust the working voltage of the ultrasonic transducer within a small range. Those skilled in the art can adjust the reasonable values ​​of the preset proportional parameter P, the preset integral parameter I, and the preset differential parameter D by themselves, so as to achieve a better control effect, so that the actual current value transitions smoothly and remains stable at the target current value.

[0081] It should be noted that the current rapid rise stage and the steady-state regulation stage use independent regulation algorithms respectively. The two stages should use the current difference in this stage to calculate the voltage respectively, and the number of sampling cycles and the number of adjustments in this stage should be counted independently. As a specific embodiment, the constant current driving method of the ultrasonic knife system provided in the embodiment of the present application is based on the above content, and after adjusting the working voltage of the ultrasonic transducer according to the second voltage calculation formula, it also includes:

[0082] Determine whether the operating voltage value calculated based on the second voltage calculation formula is greater than a preset maximum voltage value;

[0083] If yes, adjusting the working voltage of the ultrasonic transducer according to the preset maximum voltage value;

[0084] If not, the working voltage of the ultrasonic transducer is adjusted according to the calculated working voltage value.

[0085] Specifically, further, in order to avoid overshoot caused by excessive working voltage calculated by the second voltage calculation formula, the embodiment of the present application also limits the calculated working voltage. Specifically, the present application pre-sets a maximum voltage value. Once the calculated working voltage exceeds the preset maximum voltage value, the ultrasonic transducer is driven based on the preset maximum voltage value, thereby further effectively preventing the occurrence of current overshoot. When the calculated working voltage does not exceed the preset maximum voltage value, the working voltage of the ultrasonic transducer can be adjusted according to the calculated working voltage value.

[0086] As a specific embodiment, the embodiment of the present application adjusts the working voltage of the ultrasonic transducer according to the calculated working voltage value, which may include:

[0087] Determine whether the difference between the calculated working voltage value and the working voltage value calculated in the previous sampling period is greater than a preset maximum voltage adjustment amount;

[0088] If yes, adjusting the working voltage of the ultrasonic transducer according to the working voltage value calculated in the previous sampling period and the preset maximum voltage adjustment amount;

[0089] If not, the currently calculated working voltage value is used as the working voltage of the ultrasonic transducer.

[0090] Specifically, in order to avoid overshooting caused by excessive single voltage adjustment in the second stage, the embodiment of the present application also limits the single adjustment amplitude of the working voltage. That is, the present application pre-sets the maximum voltage adjustment amount. Once the currently calculated working voltage is significantly different from the last calculated working voltage, specifically exceeding the preset maximum voltage adjustment amount, the new working voltage is calculated based on the last calculated working voltage with the preset maximum voltage adjustment amount as the adjustment amplitude, thereby further effectively preventing the occurrence of current overshoot.

[0091] As a specific embodiment, the constant current driving method of the ultrasonic knife system provided in the embodiment of the present application further includes, based on the above content:

[0092] According to the input current range setting information, a target current value corresponding to the set current range is determined.

[0093] Specifically, the target current value can be set by the user according to the actual operation situation. As a specific embodiment, the host of the ultrasonic knife system is provided with a human-machine interaction interface, which can provide the user with the option to input commands such as power on / off, and can also provide the user with the option to input operation information such as current gear. The present application pre-establishes a one-to-one correspondence between each current gear (e.g., low gear, mid-range, high gear) and the target current value, so that the corresponding target current value can be determined according to the current gear setting information input by the user, and then the ultrasonic knife transducer is driven and controlled with constant current to achieve the target with the target current value.

[0094] Combined with the above description of the two-stage adjustment process, the complete startup process of the ultrasonic knife system can be specifically referred to Figure 4 , mainly including the following steps:

[0095] S201: Determine the target current value I corresponding to the set current gear according to the input current gear setting information targ .

[0096] S202: Start driving the ultrasonic transducer with a preset small signal working voltage V0.

[0097] S203: In each sampling period, the actual current value I currently output by the ultrasonic transducer is obtained. n .

[0098] S204: Judgment I targ -I n ≤I th Is it established? If not, proceed to S205; if so, proceed to S206.

[0099] S205: According to V n =E n *Tn *V para Adjust the operating voltage of the ultrasonic transducer; return to S203.

[0100] S206: In each sampling period, the actual current value I currently output by the ultrasonic transducer is obtained. m ; Enter S207.

[0101] S207: Calculate E m =I targ -I m , ED m =E m -E m-1 , Enter S208.

[0102] S208: According to V m+1 =V m +E m *P+EI m *I+ED m *D adjust the operating voltage of the ultrasonic transducer; return to S206.

[0103] See also Figure 5 As shown, the embodiment of the present application discloses a constant current driving device 300 of an ultrasonic knife system, which mainly includes:

[0104] The acquisition module 301 is used to acquire the actual current value currently output by the ultrasonic transducer in each sampling period;

[0105] The first adjustment module 302 is used to adjust the working voltage of the ultrasonic transducer in combination with the speed parameter when the current difference between the actual current value and the target current value is greater than a preset threshold; wherein the speed parameter is negatively correlated with the current cumulative sampling time, and the longer the current cumulative sampling time is, the smaller the speed parameter is;

[0106] The second adjustment module 303 is used to call a preset steady-state fine-tuning algorithm to adjust the working voltage of the ultrasonic transducer after the current difference between the actual current value and the target current value is less than or equal to a preset threshold and enters the steady-state adjustment stage, so that the actual current value reaches the target current value and remains stable.

[0107] It can be seen that the constant current driving device of the ultrasonic knife system disclosed in the embodiment of the present application adopts a two-stage adjustment method to control the current stability of the ultrasonic transducer, wherein, in the rapid current rising stage when the working current of the ultrasonic transducer gradually rises to the target current value, the working voltage of the transducer is regulated in combination with the speed parameter that is negatively correlated with the current cumulative sampling time. The working current of the transducer can be made to rise quickly and smoothly to the target current value without overshoot, providing a more stable and accurate initial current value for entering the steady-state adjustment stage, thereby avoiding the problem of overshoot in the entire constant current driving process, and ensuring the continuity and stability of the mechanical amplitude of the ultrasonic knife head.

[0108] For specific contents of the constant current driving device of the ultrasonic knife system, please refer to the detailed introduction of the constant current driving method of the ultrasonic knife system mentioned above, which will not be repeated here.

[0109] As a specific embodiment, the constant current driving device of the ultrasonic knife system disclosed in the embodiment of the present application is based on the above content, and the first adjustment module 302 adjusts the working voltage of the ultrasonic transducer in combination with the speed parameter, specifically for:

[0110] Based on the current difference in the current sampling period, the operating voltage of the ultrasonic transducer is adjusted according to the first voltage calculation formula:

[0111] V n =E n *T n *V para ;

[0112] Among them, V n is the working voltage after the nth adjustment; E n =I targ -I n is the current difference in the nth sampling period; I n is the actual current value in the nth sampling period; I targ is the target current value; T n is the speed parameter in the nth sampling period; V para is the preset voltage conversion parameter.

[0113] As a specific embodiment, the constant current driving device of the ultrasonic knife system disclosed in the embodiment of the present application is based on the above content, and the second adjustment module 303 is specifically used to call the preset steady-state fine-tuning algorithm to adjust the working voltage of the ultrasonic transducer:

[0114] Obtain the current difference between the actual current value and the target current value in each sampling period after entering the steady-state regulation stage; based on each current difference after entering the steady-state regulation stage, adjust the operating voltage of the ultrasonic transducer according to the second voltage calculation formula:

[0115] V m+1 =V m +E m *P+EI m *I+ED m *D;

[0116] Among them, V m+1 is the working voltage value after the mth adjustment since entering the steady-state regulation stage; V m is the working voltage value after the m-1th adjustment since entering the steady-state regulation stage and the working voltage value before the mth adjustment; E m =I targ -I m is the current difference within the mth sampling period since entering the steady-state regulation stage; I m is the actual current value in the mth sampling period since entering the steady-state regulation phase; I targ is the target current value; P is the preset proportional parameter; I is the preset integral parameter; D is the preset differential parameter; ED m =E m -E m-1 ;

[0117] As a specific embodiment, the constant current driving device of the ultrasonic knife system disclosed in the embodiment of the present application is based on the above content, and the second adjustment module 303 is further used to:

[0118] Determine whether the working voltage value calculated based on the second voltage calculation formula is greater than the preset maximum voltage value; if so, adjust the working voltage of the ultrasonic transducer according to the preset maximum voltage value; if not, adjust the working voltage of the ultrasonic transducer according to the calculated working voltage value.

[0119] As a specific embodiment, the constant current driving device of the ultrasonic knife system disclosed in the embodiment of the present application is based on the above content, and the second adjustment module 303 adjusts the working voltage of the ultrasonic transducer according to the preset maximum voltage value, specifically including:

[0120] Determine whether the difference between the calculated working voltage value and the working voltage value calculated in the previous sampling period is greater than a preset maximum voltage adjustment amount; if so, adjust the working voltage of the ultrasonic transducer according to the working voltage value calculated in the previous sampling period and the preset maximum voltage adjustment amount; if not, use the currently calculated working voltage value as the working voltage of the ultrasonic transducer.

[0121] As a specific embodiment, the constant current driving device of the ultrasonic knife system disclosed in the embodiment of the present application is based on the above content, and the acquisition module 301 is also used for:

[0122] According to the input current range setting information, a target current value corresponding to the set current range is determined.

[0123] Furthermore, the present application also discloses an ultrasonic knife system 400 and a host 401 thereof.

[0124] Specifically, see Figure 6 As shown, an ultrasonic knife system 400 disclosed in the present application includes a host 401, an ultrasonic transducer 402 and an ultrasonic knife 403 connected in sequence.

[0125] The host 401 of the ultrasonic knife system 400 is also called an energy generator, which is used to provide an ultrasonic excitation signal (specifically an electrical signal) and other control signals to the ultrasonic transducer 402. The host 401 may specifically include: a processor electrically connected to the ultrasonic transducer 402, and a memory in communication with the processor, wherein the memory stores instructions executable by the processor, and when the instructions are executed by the processor, the processor can execute the constant current driving method described in any of the above embodiments, for example, executing Figure 3 or Figure 4 The constant current driving method shown.

[0126] The ultrasonic transducer 402 is electrically connected to the host 401 , and may specifically include piezoelectric elements such as piezoelectric ceramic sheets, for converting the ultrasonic excitation signal (electrical energy) received from the host 401 into ultrasonic vibration (mechanical energy), and transmitting the ultrasonic vibration to the ultrasonic knife 403 .

[0127] It should be noted that in the host 401 of the ultrasonic knife system disclosed in the present application, its processor and memory can be specifically implemented based on FPGA. At the same time, it is easy to understand that the host 401 of the ultrasonic knife system disclosed in the present application can also include other conventional circuit components for realizing the excitation output function, such as DSP, power amplifier, detection circuit and digital-to-analog converter.

[0128] Among them, the DSP is electrically connected to the FPGA, and is used to output an excitation control signal to the FPGA to control the FPGA to generate an ultrasonic excitation signal; the power amplifier is used to amplify the ultrasonic excitation signal and output it to the ultrasonic transducer; the detection circuit is used to perform waveform sampling detection on the actual current value of the equivalent circuit of the ultrasonic transducer; the digital-to-analog converter is electrically connected to the detection circuit and the FPGA respectively, and is used to output the waveform sampling data of the detection circuit to the FPGA after analog-to-digital conversion, so that the FPGA can determine the current difference between the actual current value and the target current value based on these waveform sampling data, and then adjust the voltage amplitude of the output ultrasonic excitation signal to change the working voltage of the ultrasonic transducer, so that the actual current value of the ultrasonic transducer reaches the target current value and remains stable.

[0129] The ultrasonic knife 403 specifically includes a grippable handle, a knife bar and an end effector. The end effector includes a knife head and a clamping arm that can pivot relative to the knife head, and is used to clamp tissue and cut and / or stop bleeding. The knife head is arranged at the distal end of the knife bar, and the proximal end of the knife bar is connected to the ultrasonic transducer 402, and the knife bar is used to transmit and amplify the ultrasonic vibration generated by the ultrasonic transducer 402.

[0130] When the ultrasonic knife system 400 is working, the host 401 sends out an ultrasonic excitation signal to drive the ultrasonic transducer 402, and the ultrasonic transducer 402 converts the received ultrasonic excitation signal into ultrasonic vibration, and transmits and amplifies the ultrasonic vibration through the knife rod of the ultrasonic knife 403, and finally drives the knife head to perform high-frequency reciprocating motion, so that the tissue clamped between the knife head and the clamping arm is denatured and broken, so as to achieve the function of cutting and / or closing small blood vessels.

[0131] It should be understood that since the ultrasonic knife system 400 and its host 401 provided in the present application can implement the constant current driving method provided in the present application, or run the constant current driving device provided in the present application; therefore, it also has the beneficial effects of the constant current driving method and device provided in the present application, which will not be repeated here.

[0132] In this application, each embodiment is described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the embodiments can be referred to each other. For the device disclosed in the embodiment, since it corresponds to the method disclosed in the embodiment, the description is relatively simple, and the relevant parts can be referred to the method part.

[0133] It should also be noted that, in this application document, relational terms such as "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. In addition, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, an element defined by the statement "comprises a ..." does not exclude the presence of other identical elements in the process, method, article or device including the element.

[0134] The technical solution provided by the present application is described in detail above. The principle and implementation method of the present application are described in detail using specific examples herein, and the description of the above embodiments is only used to help understand the method and core idea of ​​the present application. It should be pointed out that for ordinary technicians in this technical field, without departing from the principle of the present application, several improvements and modifications can be made to the present application, and these improvements and modifications also fall within the scope of protection of the present application.

Claims

1. A constant current driving method for an ultrasonic knife system, characterized in that: include: In each sampling period, the actual current value currently output by the ultrasonic transducer is obtained; When the current difference between the actual current value and the target current value is greater than a preset threshold, the working voltage of the ultrasonic transducer is adjusted in combination with the speed parameter, and the next sampling cycle is entered; wherein the speed parameter is negatively correlated with the current cumulative sampling time, and the longer the current cumulative sampling time is, the smaller the speed parameter is; After the current difference between the actual current value and the target current value is less than or equal to the preset threshold value, the steady-state adjustment stage is entered, the preset steady-state fine-tuning algorithm is called to adjust the working voltage of the ultrasonic transducer, and the next sampling cycle is entered, so that the actual current value reaches the target current value and remains stable; the steady-state fine-tuning algorithm is a PID control algorithm; Wherein, the combining speed parameter to adjust the working voltage of the ultrasonic transducer comprises: Based on the current difference in the current sampling period, the operating voltage of the ultrasonic transducer is adjusted according to the first voltage calculation formula: V n =E n *T n *V para ; Among them, V n is the working voltage after the nth adjustment; E n =I targ -I n is the current difference in the nth sampling period; I n is the actual current value in the nth sampling period; I targ is the target current value; T n is the speed parameter in the nth sampling period; V para is the preset voltage conversion parameter.

2. The constant current driving method of the ultrasonic knife system according to claim 1, characterized in that: The speed parameter is the reciprocal of the current sampling period number.

3. The constant current driving method of the ultrasonic knife system according to claim 1, characterized in that: The calling of a preset steady-state fine-tuning algorithm to adjust the working voltage of the ultrasonic transducer includes: Obtaining a current difference between the actual current value and the target current value in each sampling period after entering the steady-state regulation stage; Based on each of the current differences after entering the steady-state regulation stage, the operating voltage of the ultrasonic transducer is adjusted according to the second voltage calculation formula: V m+1 =V m +E m *P+EI m *I+ED m *D; Among them, V m+1 is the working voltage value after the mth adjustment since entering the steady-state regulation stage; V m is the working voltage value after the m-1th adjustment since entering the steady-state regulation stage and the working voltage value before the mth adjustment; E m =I targ -I m is the current difference within the mth sampling period since entering the steady-state regulation stage; I m is the actual current value in the mth sampling period since entering the steady-state regulation phase; I targ is the target current value; P is the preset proportional parameter; I is the preset integral parameter; D is the preset differential parameter; ED m =E m -E m-1 ; 4. The constant current driving method of the ultrasonic knife system according to claim 3, characterized in that: After adjusting the working voltage of the ultrasonic transducer according to the second voltage calculation formula, the method further includes: Determine whether the operating voltage value calculated based on the second voltage calculation formula is greater than a preset maximum voltage value; If yes, adjusting the working voltage of the ultrasonic transducer according to the preset maximum voltage value; If not, the operating voltage of the ultrasonic transducer is adjusted according to the calculated operating voltage value.

5. The constant current driving method of the ultrasonic knife system according to claim 4, characterized in that: The step of adjusting the working voltage of the ultrasonic transducer according to the calculated working voltage value comprises: Determine whether the difference between the calculated working voltage value and the working voltage value calculated in the previous sampling period is greater than a preset maximum voltage adjustment amount; If yes, adjusting the working voltage of the ultrasonic transducer according to the working voltage value calculated in the previous sampling period and the preset maximum voltage adjustment amount; If not, the calculated working voltage value is used as the working voltage of the ultrasonic transducer.

6. The constant current driving method of the ultrasonic knife system according to any one of claims 1 to 5, characterized in that: Also includes: According to the input current range setting information, the target current value corresponding to the set current range is determined.

7. A constant current driving device for an ultrasonic knife system, characterized in that: include: An acquisition module is used to obtain the actual current value currently output by the ultrasonic transducer in each sampling period; A first adjustment module, configured to adjust the working voltage of the ultrasonic transducer in combination with a speed parameter when the current difference between the actual current value and the target current value is greater than a preset threshold; wherein the speed parameter is negatively correlated with the current cumulative sampling time, and the longer the current cumulative sampling time is, the smaller the speed parameter is; A second adjustment module is used to call a preset steady-state fine-tuning algorithm to adjust the working voltage of the ultrasonic transducer after the current difference between the actual current value and the target current value is less than or equal to the preset threshold and enters the steady-state adjustment stage, so that the actual current value reaches the target current value and remains stable; the steady-state fine-tuning algorithm is a PID control algorithm; Wherein, when the first adjustment module adjusts the working voltage of the ultrasonic transducer in combination with the speed parameter, it is specifically used to: Based on the current difference in the current sampling period, the operating voltage of the ultrasonic transducer is adjusted according to the first voltage calculation formula: V n =E n *T n *V para ; Among them, V n is the working voltage after the nth adjustment; E n =I targ -I n is the current difference in the nth sampling period; I n is the actual current value in the nth sampling period; I targ is the target current value; T n is the speed parameter in the nth sampling period; V para is the preset voltage conversion parameter.

8. A host of an ultrasonic knife system, characterized in that: include: a processor electrically connected to the ultrasonic transducer; as well as, A memory communicatively connected to the processor, the memory storing instructions executable by the processor, the instructions being used to implement the constant current driving method according to any one of claims 1 to 6 when executed.

9. An ultrasonic knife system, characterized in that: include: Ultrasonic scalpel; an ultrasonic transducer connected to the ultrasonic scalpel and configured to convert a received ultrasonic excitation signal into ultrasonic vibration and transmit the ultrasonic vibration to the ultrasonic scalpel; and The host according to claim 8, which is electrically connected to the ultrasonic transducer and is used to provide the ultrasonic excitation signal to the ultrasonic transducer.

Images