JP2005296430A - Ultrasonic surgical system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent a problem from occurring that may occur when the insulation of the ultrasonic oscillator provided in the hand piece drops in the ultrasonic surgical system. <P>SOLUTION: Prior to the ultrasonic surgery, a value of resistance between both edges of the ultrasonic oscillator 14 is detected by the insulating detection part 36. The control part 38 alarms user of a slight drop in the insulation of the ultrasonic oscillator 14, and allows the ultrasonic surgery to be performed only after obtaining confirmation from the user. On the other hand, when the insulation drops considerably, it does not allow the ultrasonic surgery to be performed. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an ultrasonic surgical instrument, and more particularly to a technique for ensuring proper operation of an ultrasonic transducer.

  The ultrasonic surgical instrument includes a surgical instrument such as a horn, an ultrasonic vibrator that transmits ultrasonic vibration to the surgical tool, a drive circuit that supplies a drive signal to the ultrasonic vibrator, and the like. When a surgical tool that vibrates ultrasonically is applied to a living tissue, the tissue is crushed and ultrasonic surgery is performed. As an ultrasonic transducer, a Langevin type ultrasonic transducer (typically a bolted ultrasonic transducer) is well known. Such an ultrasonic vibrator includes a plurality of piezoelectric plates, electrode plates provided between and on both sides thereof, a bolt member that penetrates a laminated body including a plurality of piezoelectric plates and a plurality of electrode plates, and fastens them. Have. For a plurality of electrode plates, a positive electrode and a negative electrode are alternately set, and the same electrode is electrically connected. That is, the ultrasonic vibrator is provided with a positive terminal and a negative terminal, and a high-voltage drive signal is applied between these terminals.

  Patent Document 1 below describes that the frequency of a drive signal is changed in order to determine whether or not the ultrasonic surgical instrument is in a normal use state, and the resonance state at that time is detected. However, there is a problem that the state cannot be determined unless the drive signal is supplied, that is, unless the ultrasonic transducer is actually vibrated.

JP 2000-271140 A

  By the way, in the ultrasonic vibrator built in the ultrasonic surgical instrument, the resistance value of the piezoelectric body included therein is inherently very large, approximately infinite. However, liquids such as water and disinfectant liquid enter the ultrasonic surgical instrument due to the sterilization and sterilization processes of the ultrasonic surgical instrument, thereby reducing the insulation between the electrodes of the ultrasonic transducer. The possibility cannot be denied. In the conventional apparatus, if the insulation is lowered and the supply state of the drive signal changes (changes in current value, voltage value, admittance value, etc.), the safety circuit operates and the ultrasonic surgical instrument operates. Although it will stop, it is required to further improve safety. In particular, it is desirable to confirm the insulation of the ultrasonic transducer before supplying the drive signal.

  An object of the present invention is to further improve safety in an ultrasonic surgical instrument.

  Another object of the present invention is to enable appropriate control for ensuring safety according to the degree of insulation of an ultrasonic transducer.

  The present invention, prior to ultrasonic surgery, an ultrasonic transducer that transmits ultrasonic vibration to a surgical instrument, a drive circuit that supplies a drive signal to the ultrasonic transducer during ultrasonic surgery, A detection unit that detects a resistance value between terminals in the ultrasonic transducer, and a control unit that executes control for improving the operational safety of the ultrasonic surgical device based on the resistance value. To do.

  According to the above configuration, the resistance value between the terminals of the ultrasonic transducer is actually detected by the detection unit before the drive signal is supplied to the ultrasonic transducer, and control is performed from the viewpoint of safety based on the resistance value. Is executed.

  The resistance value between the terminals can be detected as a voltage when a constant voltage is applied or as other information. Preferably, the magnitude of the resistance value is compared with one or more reference values, thereby determining the degree of insulation. If the insulation is greatly deteriorated, it is desirable to notify the user and prohibit the operation of the ultrasonic surgical instrument. In the case where the insulation is deteriorated but can be used, it is desirable to notify the user of the fact and wait for the user's confirmation input before allowing the operation of the ultrasonic surgical instrument. Of course, the control content for ensuring safety can include the output power limit, the operation time limit, and other restrictions of the ultrasonic surgical instrument in addition to the above notification and operation prohibition.

  Preferably, the control unit causes the ultrasonic surgical device to normally operate when the resistance value is in a normal range, and a first alarm when the resistance value is in an operation prohibition range lower than the normal range. And the supply of the drive signal to the ultrasonic transducer is prohibited. According to this configuration, since the fact that the insulation performance has greatly deteriorated is transmitted to the user side, the user can be made aware of the necessity of handpiece replacement and the use is forcibly prohibited. It is.

  Preferably, the control unit further outputs a second alarm when the resistance value is in an operation selection range set between the normal range and the operation prohibition range, and the user's confirmation input thereafter. If there is, supply of the drive signal to the ultrasonic transducer is allowed. According to this configuration, in a case where the insulation is slightly deteriorated (when it is usable but the insulation is lower than usual), the situation is notified to the user. Use, handpiece replacement, and abandonment of handpiece use can be determined by the user according to various situations (biological condition, operation content, time, etc.). Even when the current handpiece is used as it is, its use is allowed for the first time after waiting for the user's confirmation input, so the safety can be improved.

  Preferably, a first switch circuit provided between the ultrasonic transducer and the drive circuit and performing an on / off operation, and a second switch circuit provided between the ultrasonic transducer and the detection unit. The control unit turns off the first switch and turns on the second switch when the resistance value is detected prior to the ultrasonic surgery, and turns on the ultrasonic switch. During the operation, the first switch is turned on and the second switch is turned off.

  According to the above configuration, the first switch circuit can switch the presence / absence of electrical connection between the ultrasonic transducer and the drive circuit, and the second switch circuit can electrically switch between the ultrasonic transducer and the detection unit. The presence or absence of a simple connection can be switched. Therefore, when detecting the resistance value, the drive circuit can be electrically separated from the ultrasonic transducer for accurate detection, and during ultrasonic surgery, the detection unit can be electrically separated from the ultrasonic transducer. To improve biosafety.

  Preferably, the detection unit is configured to determine a resistance value between the terminals of the ultrasonic transducer in a state where the DC voltage is applied and a DC power source for applying a DC voltage between the terminals of the ultrasonic transducer. And a voltage detection circuit that detects the voltage.

  Preferably, the ultrasonic surgical instrument includes a surgical instrument main body and a handpiece that includes the ultrasonic transducer and is connected to the surgical instrument main body, and the handpiece is connected to the surgical instrument main body. When connected, the resistance value between the terminals is detected.

  As described above, according to the present invention, since the resistance value between the terminals is actually measured before the ultrasonic operation, the safety in the ultrasonic surgical instrument can be further improved. According to the present invention, appropriate control for ensuring safety can be performed according to the degree of insulation of the ultrasonic transducer.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, preferred embodiments of the invention will be described with reference to the drawings.

  FIG. 1 shows a preferred embodiment of an ultrasonic surgical instrument according to the present invention, and FIG. 1 is a block diagram showing the overall configuration thereof. This ultrasonic surgical device transmits ultrasonic vibrations to a living tissue, thereby performing a treatment such as tissue crushing. Since this is an instrument for performing a surgical operation on a living body, high safety is required for an ultrasonic surgical instrument.

  The ultrasonic surgical instrument includes a main body 10 and a hand piece 12. The handpiece 12 is detachably connected to the main body 10 via a cable (not shown). The handpiece 12 is gripped by a user such as a doctor. The handpiece 12 has an ultrasonic transducer 14 as shown. In this example, the ultrasonic transducer 14 is a so-called bolted ultrasonic transducer. That is, the ultrasonic transducer 14 includes a plurality of laminated piezoelectric plates 16 and a plurality of electrode plates 18 provided between and at both ends of the piezoelectric plates, and a laminated body configured by laminating them. It has a structure sandwiched between a pair of metal blocks 19A and 19B provided before and after that. The pair of metal blocks 19A and 19B are fastened to each other by bolts not shown. This configuration is known per se. The ultrasonic vibration generated by the ultrasonic transducer 14 is transmitted to a horn 17 as a surgical instrument, and ultrasonic surgery is performed by the tip portion 17A.

  More specifically, a plurality of electrode plates 18 are arranged in the axial direction of the handpiece, and these electrode plates are composed of a plurality of positive electrode plates and a plurality of negative electrode plates arranged alternately. The plurality of positive electrode plates are connected to a positive terminal (positive side line), which is represented by reference numeral 20. The plurality of minus electrode plates are connected to minus terminals (minus side lines), which are represented by reference numeral 22. With such a connection relationship, when a drive signal is supplied between the terminals, ultrasonic vibrations are generated in the same phase in each piezoelectric plate, and a large amplitude is obtained as a whole ultrasonic transducer. Incidentally, the handpiece 12 includes a mechanism for pouring the cleaning liquid into the surgical site and a mechanism for sucking the cleaning liquid and the like from the surgical site, but these configurations are not shown in FIG. The handpiece 12 is provided with various switches, which are also not shown.

  The main body 10 will be described. The main body 10 has an ultrasonic drive circuit 30. The ultrasonic drive circuit 30 generates a drive signal having a predetermined frequency. The drive signal is boosted by the transformer 32 and supplied to the ultrasonic transducer 14 via the first switch circuit 34. The transformer 32 is a circuit that boosts the primary side voltage with a predetermined magnification to obtain a secondary side voltage. Here, the voltage of the drive signal supplied to the ultrasonic transducer 14 is, for example, 300V. Incidentally, the frequency and periodic pattern of the drive signal can be appropriately changed depending on the operation mode and the like.

  The first switch circuit 34 is turned on only during the execution of ultrasonic surgery. That is, when an operation execution switch (not shown) provided on the handpiece 12 is operated, the control unit 38 detects it, and a signal output command is issued from the control unit 38 to the ultrasonic drive circuit 30. At the same time, an ON operation signal is output to the first switch circuit 34.

  The ultrasonic surgical instrument according to the present embodiment is provided with an insulating detector 36. The insulation detection unit 36 detects an insulation resistance value between both terminals of the ultrasonic transducer 14 prior to ultrasonic surgery. That is, this is a circuit for measuring the degree of insulation (good or bad) of the ultrasonic transducer 14.

  The direct current voltage generation circuit 40 generates a constant direct current (DC) voltage. The DC voltage is applied to the pair of terminals 20 and 22 of the ultrasonic transducer 14 via the resistance bridge circuit 42 and the second switch circuit 44.

  The second switch circuit 44 is a switch circuit that is turned on only when a resistance value is detected. The resistance bridge circuit 42 is configured as a known Wheatstone bridge circuit for detecting the resistance value of the ultrasonic transducer 14 as a voltage. The voltage across the specific resistor in the resistance bridge circuit 42 is voltage-converted at a constant ratio by the isolation amplifier 46 that operates differentially, and the voltage of the detection signal output from the isolation amplifier 46 is input to the determination circuit 48. The determination circuit 48 compares the voltage value corresponding to the resistance value between both terminals with a plurality of threshold values, thereby determining the degree of insulation of the ultrasonic transducer 14. The determination result is output to the control unit 38.

  The control unit 38 controls the operation of each component shown in FIG. 1, and in particular for enhancing the safety of the operation of the ultrasonic surgical instrument based on the determination signal output from the insulation detection unit 36. Control is being executed. If the degree of insulation is above a certain value (if the resistance value is in the normal range described later), normal ultrasonic surgical operation is allowed, and if the degree of insulation is lower than that (resistance value will be described later) When the selected operation range or operation prohibition range is entered, appropriate safety control is executed in accordance with the degree of decrease. For example, control such as prohibition of ultrasonic surgery itself or warning to the user is executed. A display unit 51 and a speaker 53 are connected to the control unit 38. An alarm is notified to the user using the display 51 and the speaker 53.

  As will be described later, the control unit 38, when the handpiece 12 is connected to the main body 10 or at the time of starting up the power supply of the apparatus, that is, at the timing when the transducer inspection before performing ultrasonic surgery is necessary. The insulation detecting unit 36 is operated, and in this case, the second switch circuit 44 is turned on. When the detection of such a resistance value is completed, the second switch circuit 44 is turned off. That is, the first switch circuit 34 is turned on only when ultrasonic surgery is performed, and the second switch circuit 44 is turned on only when the resistance value is detected. It is prohibited by the control unit 38 that both the switch circuits are simultaneously turned on.

  Next, a specific configuration example of the insulation detection unit 36 shown in FIG. 1 will be described with reference to FIG. As described above, the resistance bridge circuit 42 and the second switch circuit 44 are provided between the DC voltage generation circuit 40 and the ultrasonic transducer 14. The resistance bridge circuit 42 includes five resistors R1 to R5 as illustrated. Here, the voltage across the resistor R5 is detected by the isolation amplifier 46. The detection signal output from the isolation amplifier 46 is input to the determination circuit 48.

  The determination circuit 48 is input to the two determination devices 60 and 62 arranged in parallel in the example shown in FIG. The determination unit 60 compares the voltage of the detection signal (corresponding to the resistance value R) with the first reference voltage (corresponding to the reference resistance value α). If the voltage of the detection signal is higher than the first reference voltage, the Hi signal Is output, otherwise the Lo signal is output. On the other hand, in the determination unit 62, the voltage of the detection signal is compared with the second reference voltage (corresponding to the reference resistance value β), and the determination unit 62 determines that the Hi signal is high when the detection signal voltage is higher than the second reference voltage. A signal is output, and a Lo signal is output in other cases. Here, there is a relationship of α> β, that is, the determination circuit 48 determines which of the three sections (ranges) the detected resistance value belongs to. In this example, there are three ranges: a normal range, a range that can be regarded as slightly deteriorated (selected operation range), and a range that is recognized as being considerably deteriorated (operation prohibited range). As will be described later, when the resistance value is within the normal range, the normal ultrasonic surgical operation is allowed as it is, and when the resistance value is within the selected operation range, the user is informed of the fact. Confirmation input is allowed and ultrasonic surgery is allowed. In this case, the upper limit value such as power is reduced as necessary from the viewpoint of safety. When the resistance value is within the operation prohibition range, execution of ultrasonic surgery is prohibited. Here, the values of the first reference voltage (that is, α) and the second reference voltage (that is, β) can be fixedly set in advance, or appropriate values can be variably set according to various situations. . In any case, it is possible to perform ultrasonic surgery after actually measuring the resistance value in the ultrasonic transducer 14 and confirming the state of the ultrasonic transducer 14.

  As shown in the figure, the second switch circuit 44 includes two photocouplers 56 and 58 provided on the plus line and the minus line, respectively. The photocouplers 56 and 58 are turned on or off according to the signal from the control unit shown in FIG.

  A first switch circuit 34 is provided between the transformer 32 and the ultrasonic transducer 14. The first switch circuit 34 includes two switches 50 and 52 provided on the plus line and the minus line, respectively. Then, when an ON operation signal is given from the control unit shown in FIG. 1, the relay 54 is operated, whereby the switches 50 and 52 are turned ON.

  Incidentally, the code | symbol 102 represents the housing | casing in a main body. Reference numeral 100 denotes an insulated unit portion. That is, a state in which the handpiece 12 and the insulation detecting unit 36 are floated in a direct current is formed including the handpiece 12 and the insulation detection unit 36, and it is possible to prevent a high voltage from being applied to the handpiece for some reason. .

  Incidentally, the resistance bridge circuit 42 outputs a voltage signal that is inversely proportional to the magnitude of the resistance value between the terminals in the ultrasonic transducer 14. The DC voltage is 200 V, for example, and the range of the resistance value that can be detected by the insulating detection unit 36 is, for example, 0 MΩ to 5000 MΩ. Corresponding to the range, the isolation amplifier 46 outputs a detection signal as an analog voltage signal of 0 to 5V, for example. The first reference voltage is a value corresponding to a resistance value of 1000 MΩ, for example, and the second reference voltage is a value corresponding to a resistance value of 10 MΩ, for example. Of course, those numbers are only examples. The resistance bridge circuit 42 is suitable for the above wide resistance value monitoring.

  Next, the operation of the ultrasonic surgical instrument shown in FIG. 1 will be described with reference to FIG. In the initial state, the first switch circuit 34 (hereinafter referred to as SW1) is in an off state, and the second switch circuit 44 (hereinafter referred to as SW2) is also in an off state.

  If it is determined in S101 that the handpiece is connected to the main body, or if the power is turned on while the handpiece is connected to the main body, the electrical circuit is stabilized in S102 as necessary. In order to make it into a standby state, a standby state is maintained until a predetermined time elapses. Thereafter, in S103, the insulation detection unit 36 detects the resistance value R between both terminals of the ultrasonic transducer. In this detection, only SW2 is turned on. After detection, SW2 is turned off.

  In S104, it is determined whether or not the resistance value R is larger than the first reference value α. If the condition is satisfied, S105 is executed. On the other hand, if the condition of S104 is not satisfied, it is further determined in S107 whether or not the resistance value R is greater than the second reference value β. If the condition is satisfied, S108 is executed, and if not satisfied, S110 is executed. That is, in S104 and S107, it is determined whether the resistance value R belongs to the normal range (R> α), the operation selection range (α> R> β), or the operation prohibition range (β> R). However, two ranges of a normal range and an operation prohibition range may be provided, or four or more ranges may be provided.

  Here, when the resistance value R is within the normal range, a cleaning system that supplies and sucks the cleaning liquid is operated prior to the ultrasonic operation in S105. In S106, an ultrasonic operation is performed by turning on an operation switch provided on the handpiece. In this case, SW1 is turned on.

  On the other hand, when the resistance value R belongs to the operation selection range, the second error is displayed on the display 51 in S108. That is, a message indicating a state in which the insulation is slightly deteriorated or a symbol indicating the message is displayed. A second alarm sound is output from the speaker 53. The second alarm sound is a sound having a predetermined pattern or tone color. Further, if necessary, limits on operating conditions, such as output power, are set.

  In S109, the user who has recognized the situation by the second error display or the output of the second alarm sound as described above is required to confirm whether or not to perform the ultrasonic operation even in such a state. Here, if there is such an input, the steps after S105 are executed. However, if such an input is not made, or if an input for giving up the ultrasonic operation is made, the steps after S105 are not executed. The confirmation input is made by operating a predetermined switch provided on the handpiece.

  On the other hand, in S110, since the insulation is in a considerably lowered state, execution of ultrasonic surgery is forcibly prohibited. At that time, a first error display is issued and a first alarm sound is output. Here, the first error display includes a message or a symbol representing the state. Both the first error display and the first alarm sound are different from the second error display and the second alarm sound. Therefore, after receiving the notification as described above in S110, the user performs an operation such as exchanging the handpiece. When the handpiece is exchanged, each process from S102 is repeatedly executed.

  According to the ultrasonic surgical instrument described above, the degree of insulation of the ultrasonic transducer is actually measured prior to the execution of the ultrasonic operation, and the safety of the ultrasonic operation is improved according to the degree of insulation. Since the operation | movement for raising is applied, there exists an advantage that the operation | movement reliability of an ultrasonic surgical instrument can be improved and biological safety can be improved.

1 is a block diagram showing a preferred embodiment of an ultrasonic surgical instrument according to the present invention. It is a figure which shows the specific structural example of the insulation detector shown in FIG. It is a flowchart which shows the operation example of the apparatus shown in FIG.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 Main body, 12 Handpiece, 14 Ultrasonic vibrator, 30 Ultrasonic drive circuit, 34 1st switch circuit, 36 Insulation detection part, 38 Control part, 42 Resistance bridge circuit, 44 2nd switch circuit, 48 Determination circuit.

Claims (6)

An ultrasonic transducer that transmits ultrasonic vibrations to the surgical instrument;
A driving circuit for supplying a driving signal to the ultrasonic transducer during ultrasonic surgery;
Prior to ultrasonic surgery, a detection unit for detecting a resistance value between terminals in the ultrasonic transducer,
Based on the resistance value, a control unit that executes control to increase the safety of the operation of the ultrasonic surgical instrument,
An ultrasonic surgical instrument comprising: The ultrasonic surgical instrument according to claim 1, wherein
The control unit normally operates the ultrasonic surgical instrument when the resistance value is in a normal range, and outputs a first alarm when the resistance value is in an operation prohibition range lower than the normal range. An ultrasonic surgical instrument that prohibits the supply of the drive signal to the ultrasonic transducer. The ultrasonic surgical instrument according to claim 2,
The control unit further outputs a second alarm when the resistance value is within an operation selection range set between the normal range and the operation prohibition range, and when there is subsequent user confirmation input. Further, the ultrasonic surgical instrument is allowed to supply the drive signal to the ultrasonic transducer. The ultrasonic surgical instrument according to claim 1, wherein
A first switch circuit which is provided between the ultrasonic transducer and the drive circuit and performs an on / off operation;
A second switch which is provided between the ultrasonic transducer and the detection unit and performs an on / off operation;
Including
The control unit turns off the first switch and turns on the second switch when detecting the resistance value prior to the ultrasonic surgery, and turns on the first switch during the ultrasonic surgery. An ultrasonic surgical instrument characterized in that a switch is turned on and the second switch is turned off. The ultrasonic surgical instrument according to claim 1, wherein
The detector is
A DC power supply for applying a DC voltage between the terminals of the ultrasonic transducer;
In a state where the DC voltage is applied, a voltage detection circuit that detects a resistance value between terminals in the ultrasonic transducer as a voltage;
An ultrasonic surgical instrument comprising: The ultrasonic surgical instrument according to claim 1, wherein
The ultrasonic surgical instrument is composed of a surgical instrument main body and a handpiece that incorporates the ultrasonic transducer and is connected to the surgical instrument main body.
The ultrasonic surgical instrument, wherein a resistance value between the terminals is detected when the handpiece is connected to the surgical instrument body.

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