Ultrasonic cutting device and method of controlling the same

Abstract

The present application relates to an ultrasonic cutting device and a control method thereof. The device comprises at least a control mechanism, a cutting sensing assembly for monitoring the cutting force when the blade end cuts the patient's tissue, and a pumping assembly. When the cutting sensing assembly monitors the change of the cutting force on the blade end and sends the change to the control mechanism, the control mechanism determines the position of the cutting tool and controls the pumping assembly to perform the one-way pumping action or the reverse suction action. The ultrasonic cutting device with cooling holes is designed to cool the blade end of the ultrasonic cutting device when cutting thicker bone tissue, and to simultaneously suck the cutting debris and / or excessive liquid accumulated during the ultrasonic cutting process, thereby accelerating the healing of the patient's bone tissue after surgery and avoiding overheating damage to the patient's bone tissue.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of ultrasonic cutting, in particular to an ultrasonic cutting device and a control method thereof. BACKGROUND

[0002] The application of ultrasonic waves in medical surgery is mainly based on three effects of ultrasonic waves: fragmentation effect, cavitation effect and thermal effect. The cutting ability of ultrasonic waves is different for different tissue structures and water contents of the objects to be cut. Generally speaking, for hard materials or fibrous tissues, the cutting effect of ultrasonic waves mainly manifests as fragmentation effect. When ultrasonic waves with a certain vibration acceleration are transmitted to biological tissues by a sound radiation head, the biological tissues will vibrate elastically. When the vibration acceleration reaches a cutting threshold of 50000g (g is the acceleration of gravity, about 9.8m / s 2 ), a large number of micro acoustic flows emitted by the radiation head will cause violent vibration of the biological tissues, so that the biological tissues are broken and separated from the surrounding tissues. For soft tissues or tissues with high water content, the main manifestation is cavitation effect. Under the action of ultrasonic waves, the biological tissues and the working head rub against each other violently, and a large amount of heat is generated locally. When the heat accumulates to a certain extent, the biological tissues will denature. The existing ultrasonic bone cutter utilizes the fragmentation effect of ultrasonic waves and is mainly used in orthopedic or oral surgery open surgery to achieve the functions of cutting and grinding bones for small bone blocks, such as spinal surgery laminectomy or dental bone surgery.

[0003] There are ultrasonic cutting devices using cooling liquid to cool the cutting tool in the prior art. However, most of the existing ultrasonic cutting devices use the technical scheme of using water flow or spraying to the ultrasonic cutter head to perform cooling treatment. However, due to the auxiliary intervention of water flow, after the cooling operation, water will remain in the cutting part of the patient and mix with cutting debris, which will limit the surgical field of view and affect the smooth development of the surgery. Therefore, the implementation or improvement of such technical scheme is to design an ultrasonic cutting device with sufficient surgical field of view after cooling operation. The sufficient surgical field of view is the limitation condition of the cooling operation. Therefore, while requiring to cool the ultrasonic cutter head, the surgical field of view range will also be reduced synchronously, and there are still cutting debris remaining, which cannot meet the cooling demand of the ultrasonic cutting device and also affects the healing of the bone tissue of the patient during the long-term cutting process.

[0004] The Chinese patent CN111904533B discloses an ultrasonic bone knife for spine surgery, comprising a shell, a liquid cooling mechanism, an ultrasonic bone knife body, a power supply structure and a storage mechanism. The liquid cooling mechanism is fixedly installed inside the shell, the ultrasonic bone knife body is arranged outside the shell and is in communication with the liquid cooling mechanism, the power supply structure is fixedly installed inside the shell and is electrically connected with the ultrasonic bone knife body and the liquid cooling mechanism respectively. The patent can prevent the cooling liquid from flowing in the incision on the patient's body, thereby effectively ensuring a clear surgical field, and further ensuring that the doctor can smoothly perform surgery on the patient. It is not directly powered by mains electricity, which can effectively ensure that the ultrasonic bone knife can still be used normally when the power is off, and it is convenient to store, thereby making the use more convenient, and it can also effectively avoid damage to the tool bit due to touching or impact. However, the defect of this patent is that the flow channel of the cooling liquid is designed inside the tool tip, which causes the stress of the tool to easily concentrate on the flow channel, so that the flow channel is prone to rupture during long-term surgery, and even the tool tip is prone to rupture, thereby causing harm to the patient. The design of the flow channel weakens the energy concentration effect, reduces the cutting efficiency, and reduces the service life. Moreover, the patent does not consider the influence of cutting debris on the healing of the patient's bone tissue, and also does not consider the problem of reduced cooling effect of the cooling liquid after absorbing a large amount of heat energy.

[0005] In addition, on the one hand, there are differences in the understanding of those skilled in the art; on the other hand, due to the limited space, the applicant did not list all the details and contents when he researched a large number of literatures and patents when he made the invention, but this does not mean that the invention does not have these characteristics of the prior art. On the contrary, the invention already has all the characteristics of the prior art, and the applicant reserves the right to add relevant prior art in the background art. SUMMARY

[0006] In view of the deficiencies of the prior art, the present application provides an ultrasonic cutting device, which at least comprises a control mechanism, a cutting sensing assembly and a pumping assembly. The cutting sensing assembly is used to monitor the cutting force of the distal end of the tool when cutting the patient's tissue. The control mechanism is configured to determine the position of the tool when the cutting sensing assembly detects a change in the cutting force of the distal end of the tool and sends the change to the control mechanism, and the pumping assembly is linked to sequentially perform a one-way pumping action or a reverse suction action. The technical solution is different from the prior art. The present application provides a solution to the cooling and debris residue problem based on the one-way pumping action or reverse suction action of the pumping assembly. At the same time of the one-way pumping action or reverse suction action, the pumping rate and suction frequency of the cooling liquid can be controlled based on the different positions of the patient cut by the ultrasonic cutting device.

[0007] Since the blade of the ultrasonic cutting device and the corresponding connection need to be kept tough to avoid blade breakage, the cooling liquid cannot be directly introduced into the blade. Based on the deficiencies or shortcomings of the prior art, the combination structure between the blade and the cooling hole is designed to ensure the energy concentration effect and improve the cutting efficiency, reduce the stress concentration caused by the setting of the cooling hole, avoid the breakage of the ultrasonic bone cutter during long-time work, prolong the service life, and the cooling of the cooling liquid no longer affects the surgical field, which maximizes the smooth progress of the operation. Therefore, the ultrasonic cutting device provided by the present application meets the cooling demand of the ultrasonic cutting device, reduces the cost required for cooling, and avoids the residue of the cutting device in the patient's body.

[0008] According to a preferred embodiment, the control mechanism generates a real-time cutting model related to the cutting site signal based on the cutting force on the distal end of the cutter during the cutting work collected by the cutting sensing assembly, through the coupling relationship between the cutting force and the charge distribution, and the control mechanism compares the real-time cutting model with the reference cutting model established by collecting the cutting force variation characteristics of different tissues to classify and judge the cutting site signal. The control mechanism of the present application identifies the tissue boundary of the cutting position based on the cutting force generated during the contact of the distal end of the cutter with the cutting position of the ultrasonic cutting device, so as to perform corresponding cooling liquid pumping and cutting debris suction under different tissues.

[0009] According to a preferred embodiment, the control mechanism compares the previous clock data of the cutting force on the distal end of the cutter collected by the cutting sensing assembly with the reference cutting model to analyze the boundary of the patient tissue cut by the cutter, and the relevant judgment result is reminded to the medical staff through the display, so as to facilitate the medical staff to control the operation progress, avoid cutting the patient's soft tissue or other normal tissue due to misoperation, and avoid accidents in advance.

[0010] According to a preferred embodiment, the control mechanism responds to the judgment of the cutting position of the cutter and responds to the way of actively triggering the control mechanism to retrieve the previous clock data of the cutting force on the distal end of the cutter collected by the cutting sensing assembly for correction judgment. Since unpredictable changes may occur in the patient's body, i.e., the cutting force variation characteristics of different tissues may be different, which may cause errors in the judgment process of the control mechanism, so that the control mechanism is mistakenly opened. To this end, the present application improves the identification accuracy of the cutting site during the operation process through the active triggering of the medical staff.

[0011] According to a preferred embodiment, the control mechanism establishes a trigger cutting model according to a trigger time point based on the active trigger action, so as to judge whether the cutting force borne by the distal end of the knife at the trigger time point conforms to different tissue cutting force variation characteristics in a manner of comparing the trigger cutting model with a reference cutting model, wherein, when it is able to match at least one cutting force variation characteristic, it is judged that a fault occurs, so as to issue a warning information; when it is unable to match at least one cutting force variation characteristic, it is judged that the reference cutting model is not applicable to the tissue condition in the current patient, and the control mechanism iterates the pre-established reference cutting model, so that the reference cutting model after iteration is able to classify and judge when similar cutting site signals occur. The ultrasonic cutting device of the present application optimizes the structural characteristics of the knife itself, solves the problem of stress concentration caused by the setting of cooling holes and shortens the service life, and on the other hand, is used for actively judging the cutting site and adjusting the pumping of cooling liquid and the suction of debris. Especially, it combines the secondary judgment of the cutting site including monitoring the cutting force and the active trigger of medical staff. The existing ultrasonic cutting device lacks accurate judgment of the cutting site and control of the related parameters of the pumping of cooling liquid and the suction of debris. With the continuous progress of the operation, long-time repeated work is easy to cause the medical staff to cut the normal tissue of the patient due to misoperation, and the medical staff is also difficult to make corresponding response and countermeasures in a short time. In this case, through the active reminder and modification of the control mechanism, the accurate judgment of the cutting site is realized.

[0012] According to a preferred embodiment, the control mechanism regulates the pumping rate of the cooling liquid based on the working time of the knife after cutting into the boundary of different tissues, wherein the control mechanism non-linearly regulates the pumping rate of the cooling liquid based on the increase of the working time.

[0013] The existing cooling liquid pump relies on the start-stop control of medical staff, so that the pump rate of cooling liquid per unit time varies depending on the speed of the medical staff's knob or slide or press operation. In actual surgical procedures, medical staff usually want to control the pump of cooling liquid through the least operation, without considering the change of the pump rate of cooling liquid during the operation, that is, the pump rate of cooling liquid is uncontrollable to achieve the cooling operation, which undoubtedly reduces the reliability of the cooling operation, and too much pump of cooling liquid will cause damage to the patient's tissue and affect the surgical field, and even cause unpredictable accidents. The present application improves the solution of using different cooling liquid pump rates based on different cutting sites, wherein the control mechanism provided by the present application first determines the cutting site by cutting force, and then adjusts the cooling liquid pump rate based on the determined cutting site. The adjustment mode is that the ultrasonic cutting device uses different cooling liquid pump rates in different tissues for different working times, which can be adjusted by the preset cooling mechanism to save the cost of cooling liquid pump and prevent accidents caused by too much liquid.

[0014] According to a preferred embodiment, by pre-setting between the control signal and the response of the pumping assembly, when the pump of cooling liquid is completed, the pumping direction of the pumping assembly is instantaneously switched from one-way pump to reverse suction; the control mechanism transmits the control signal to the pumping assembly based on the obtained cutting site, and the pumping assembly responds to the received control signal to instantaneously switch; the control mechanism removes the transmitted control signal, and the pumping direction of the pumping assembly is instantaneously reversed again from reverse suction to one-way pump. The present application uses one-way pump and reverse suction to remove the used cooling liquid from the patient's body, and at the same time, the cutting debris generated by cutting is also removed from the patient's body, solving the problems of heat damage caused by residual cooling liquid and healing difficulty caused by residual debris.

[0015] According to a preferred embodiment, the control mechanism adjusts the switching frequency of the pumping assembly based on the working time of the cutter after cutting into different tissue boundaries and the pump rate of cooling liquid, wherein the control mechanism linearly adjusts the switching frequency of the pumping assembly based on the increase of the working time and the pump rate of cooling liquid.

[0016] Most of the existing ultrasonic cutting devices adopt the technical solution of cooling treatment by using water flow or spray to the ultrasonic knife head, which utilizes the high specific heat capacity of the cooling liquid for cooling treatment. However, due to the high specific heat capacity of the cooling liquid, it is difficult to dissipate the heat absorbed by the cooling liquid after the cooling treatment, resulting in that the used cooling liquid also causes thermal damage to the patient's tissue. Especially the cooling liquid remaining in the patient's body, which absorbs a large amount of heat, is equivalent to leaving "hot water" in the patient's body. The present application periodically discharges the excess cooling liquid, heated cooling liquid and cutting debris from the patient's body by controlling the switching frequency of the pumping assembly, thereby preventing secondary damage to the patient's bone tissue.

[0017] The present application also relates to a control method of an ultrasonic cutting device, which at least includes a control mechanism, a cutting sensing assembly and a pumping assembly. The cutting sensing assembly is used to monitor the cutting force of the distal end of the knife when cutting the patient's tissue. The control method at least includes one or more of the following steps:

[0018] When the cutting sensing assembly monitors the change of the cutting force of the distal end of the knife, and sends the change to the control mechanism, the control mechanism judges the cutting position of the knife and links the pumping assembly to successively perform the one-way pumping action or the reverse suction action.

[0019] According to a preferred embodiment, the control mechanism generates a real-time cutting model related to the cutting position signal based on the coupling relationship between the cutting force of the distal end of the knife when the knife is cutting and the charge distribution collected by the cutting sensing assembly. The control mechanism compares the real-time cutting model with the reference cutting model established by the different tissue cutting force change characteristics collected in advance to classify and judge the cutting position signal. BRIEF DESCRIPTION OF DRAWINGS

[0020] Figure 1 is a simplified module connection relationship diagram of an ultrasonic cutting device according to a preferred embodiment of the present application;

[0021] Figure 2 is a cross-sectional view of the axial surface of the knife body extending along the blade according to a preferred embodiment of the present application;

[0022] Figure 3 is a cross-sectional view of the axial surface of the knife body perpendicular to the blade according to a preferred embodiment of the present application;

[0023] Figure 4 is a side view of the blade of an ultrasonic cutting device according to a preferred embodiment of the present application;

[0024] Figure 5 is a schematic view of a blade root and connecting portion of an ultrasonic cutting device according to a preferred embodiment of the present application;

[0025] Figure 6 is a simplified structural schematic view of a blade clearance angle of an ultrasonic cutting device according to a preferred embodiment of the present application.

[0026] List of Reference Signs

[0027] 1: cutter; 2: shank end; 3: blade end; 4: blade connecting portion; 5: cooling hole; 6: connecting cam; 7: cutting portion; 81: first blade; 82: second blade; 83: first blade clearance; 84: second blade clearance; 91: first circular arc radius; 92: second circular arc radius; 93: third circular arc radius; 94: fourth circular arc radius; 10: blade clearance angle; 11: tooth circular arc; 12: blade face; 13: control mechanism; 14: cutting sensor assembly; 15: pumping assembly; 16: shape steep change zone. DETAILED DESCRIPTION

[0028] The application will be described in detail below with reference to the drawings.

[0029] Example 1

[0030] The present application relates to an ultrasonic cutting device, at least comprising a cutter 1 which is transitioned from a shank end 2 to a blade end 3. The shank end 2 is provided with an opening for connecting a pumping assembly 15. There is a shape steep change zone 16 in the transition area between the shank end 2 and the blade end 3. A cooling hole 5 is opened at the shape steep change zone 16 for guiding the outflow of cooling liquid. Preferably, the cooling hole is in communication with the pumping assembly 15 to deliver the cooling liquid through the internal cavity of the cutter 1 to the cutter head. In surgery, the temperature of such a cutter cannot exceed 60℃, preferably no more than 65℃ or at most 70℃. Excessive temperature can cause damage to the patient's tissue. The present application changes the perfusion outlet for cooling the cooling liquid from the outside to the internal opening of the cutter 1. The cooling liquid is sprayed out of the shape steep change zone 16 to complete the perfusion cooling, so that the blade end 3 is effectively cooled when working in the human bone tissue, avoiding excessive temperature causing damage to the human bone tissue and other surrounding tissues. It should be noted that the opening is not shown in the drawings because it is at the shank. The prior art lacks the design of the transition structure and structural parameters of the ultrasonic cutting device, resulting in the problem of excessive temperature of the blade of the ultrasonic cutting device. The prior art uses the flow or spray of cooling liquid to cool the blade, which has high efficiency, but because too much attention is paid to the cooling operation, the structural design of the cutter itself can also bring the effect of preventing local high temperature and improving cutting efficiency. Especially for the design of the transmission structure at the connection between the cutter and the blade, which can further reduce local high temperature and improve cutting efficiency. The shape steep change zone 16 designed by the present application is from thick to thin as a whole, and the radius and step design in it reduces the stress concentration caused by the change of shape and improves the energy concentration of ultrasonic waves, while meeting the cutting requirements and reducing local friction.

[0031] According to a preferred embodiment, the shape steep change zone 16 is a monotonically decreasing change form (as shown in Figure 2 and Figure 3 ) along the axial direction of the cutter 1 from the shank end 2 to the blade end 3, wherein it starts from the cylindrical shape of the shank end 2, transitions to the connecting arc table 6 of the transition area, and then transitions to the blade end 3. Preferably, in the shape steep change zone 16, the overall material thickness decreases by more than 60%, preferably by 85% to 90% from the round shape of the shank end 2. Since the change in thickness will cause stress changes, which in turn will cause vibration wave transmission to be blocked, forming a heating node. The above monotonically decreasing refers to the overall trend of the radial diameter of the shape steep change zone 16 being gradually decreasing.

[0032] According to a preferred embodiment, as shown in Figure 3As shown, the blade end 3 close to one end of the connecting arc platform 6 is connected to the connecting arc platform 6 by the blade connecting part 4 with the same curvature radius but opposite arc surface directions, wherein the size of the circular arc of the blade connecting part 4 is a first circular arc radius 91. Preferably, the first circular arc radius 91 of the blade connecting part 4 is in the range of 3mm to 7mm, preferably 5mm, and the advantage of the connecting arc platform 6 narrowing to the blade connecting part 4 by the circular arc surface is to generate the energy gathering characteristics of ultrasonic waves, improve the amplitude ratio of the tool, and increase the amplitude of the cutting edge. The blade connecting part 4 is an arc-shaped transition section connected by two arc surfaces, which is used to transition the cutting edge and the cutting back of the blade end 3 to the connecting arc platform 6. The arc-shaped narrowing connecting arc platform 6 can on the one hand gather the ultrasonic waves transmitted from the shank to the blade end 3 by the change from thick to thin, and on the other hand can avoid the stress concentration caused by the sudden change of the change from thick to thin, and prevent the damage to the internal structure of the tool after the stress concentration.

[0033] According to a preferred embodiment, the first cutting edge 81 close to one end of the connecting arc platform 6 of the blade end 3 is connected to the first cutting back 83 close to one end of the connecting arc platform 6 of the blade end 3 to transition to the blade connecting part 4, wherein the first cutting back 83 is smoothly connected to the blade connecting part 4. The arc surface of the first cutting edge 81 and the blade connecting part 4 forms a circular arc on the projection plane perpendicular to the extension plane of the blade end 3 and passing through the axis of the tool 1, and the size of the circular arc is a second circular arc radius 92. Preferably, the second circular arc radius 92 of the arc surface of the first cutting edge 81 and the blade connecting part 4 is in the range of 0.3mm to 0.7mm, preferably 0.5mm. As shown in the front view of the above projection plane. Figure 4 The front view of the above projection plane. Since the tool will generate a larger stress concentration at the position of the sudden change of the cross-sectional area when it vibrates at a high frequency, and damage the internal structure of the tool, as many circular arcs as possible are arranged at the position of the change of the cross-sectional area to reduce the sudden change rate and reduce the stress concentration.

[0034] According to a preferred embodiment, as shown in Figure 2 The cutting part 7 is formed at the arc-shaped distal end of the blade end 3 away from the shank end 2, wherein the cutting part 7 includes a plurality of cutting teeth arcuately distributed along the cutting head edge of the blade end 3, and the plurality of cutting teeth are identical in shape and spaced apart from each other; wherein the cutting part 7 forms a quarter circular arc on the extension plane of the blade end 3, and the size of the circular arc of the cutting part 7 is a third circular arc radius 93. Each adjacent cutting tooth has the same tooth spacing, and the circular arc size of the tooth circular arc 11 between each adjacent cutting tooth is a fourth circular arc radius 94. Preferably, the spacing between each cutting tooth is set as follows, i.e. the linear tooth spacing at the center axis point of each adjacent cutting tooth is in the range of 0.9mm to 2.1mm, preferably 1.5mm. As shown in Figure 1As shown, the tooth circular arc 11 refers to the chip space between each adjacent cutting tooth of the cutting portion. The tooth circular arc 11 is in the shape of a circular arc, and the circular arc size of the tooth circular arc 11 is a fourth circular arc radius 94. The fourth circular arc radius 94 of the tooth circular arc 11 between each adjacent cutting tooth is 0.3mm-0.7mm, and preferably 0.5mm, so as to leave a larger chip space to facilitate chip removal by the pumping assembly. Preferably, the cutting portion 7 is preferably a quarter circle. Since the tool movement trajectory is reciprocating motion, the tool is prone to fatigue fracture, so it is necessary to concentrate as little stress as possible, and therefore the cutting portion 7 is selected to be a quarter circle. Preferably, the third circular arc radius 93 of the quarter circular arc formed on the cutting blade end 3 extension surface of the cutting portion 7 is in the range of 5mm-7mm, and preferably 6mm. Since the application scenario of the ultrasonic bone knife of the present application is orthopedic surgery, in the case of a blade width of 6mm, the curvature radius of the third circular arc radius 93 is set to 6mm, which can avoid the problem of the formation of an acute angle at the tip of the cutting blade end 3 and avoid causing harm to the patient in surgical applications. At the same time, since a larger cutting area is required in surgical cutting applications, the prior art usually uses an acute angle tip to increase the cutting ability of the tool, but as a result, the ultrasonic waves from the ultrasonic vibration module of the handle are highly concentrated on the acute angle tip, thereby increasing the amplitude at the acute angle tip. The increase in amplitude at the acute angle tip further increases the local friction of the tip, causing the tip temperature to rise too quickly, and even reaching a high temperature that the patient's body tissue cannot withstand. The quarter circular arc with a curvature radius of 6mm of the present application also avoids the high temperature caused by the high concentration (acute angle) of amplitude and the resulting local friction.

[0035] Preferably, the length of the sawtooth portion of the cutting portion 7 is 13mm. Preferably, the sawtooth portion of the cutting portion 7 is uniformly spaced by 11 cutting teeth. Preferably, the projection length of the uniformly spaced cutting teeth on the cutting portion 7 in the extension direction of the cutting blade end 3 is the sawtooth length. Preferably, the sawtooth length of the cutting teeth is in the range of 12mm-15mm, and preferably 13mm. The above projection length refers to the length of the straight line projected in the extension direction of the cutting blade end 3, with the 11 cutting teeth arranged in a circular arc shape. Preferably, the sawtooth length of the cutting teeth enables the cutting amplitude of the cutting portion 7 to reach 50μm during operation, thereby meeting the cutting requirements of human bones. The thickest part of human bones is about 12mm, and the sawtooth length of the present application is designed to be 13mm, leaving a 1mm margin.

[0036] According to a preferred embodiment, as Figure 6As shown, the second cutting edge 82 of the blade end 3 distal to one end of the connecting arc platform 6 and the second cutting back 84 of the blade end 3 distal to one end of the connecting arc platform 6 form a blade-back angle 10 in a cross section perpendicular to the blade end 3. The blade-back angle 10 is an included angle formed by the extension of the at least two inclined blade faces 12. The blade face 12 refers to at least two inclined faces formed by the second cutting back 84 to the second cutting edge 82. The blade-back angle 10 ranges from 1° to 4°, preferably 2°. As shown, Figure 5 As shown, a simplified schematic diagram of the blade-back angle 10, Figure 5 is a structural schematic diagram from the blade end 3 towards the handle end 2. The included angle of the extension of the two blade faces 12 of the blade end 3 is 2°, facilitating the matching of the machining tool, and the structure from wide to narrow can also enable the ultrasonic vibration module to produce a focusing effect, and transmit energy to the front cutting edge, so as to achieve a better cutting effect. That is, the ultrasonic waves from the ultrasonic vibration module of the handle will be highly concentrated on the thinner side (the cutting edge) due to the difference in thickness of the cutting back and the cutting edge, and the setting range of the blade-back angle of the present application can ensure the focusing effect while reducing the local friction of the cutting edge, balancing between improving the cutting effect and temperature rise, so as to improve the cutting force and control the temperature within a proper range.

[0037] According to a preferred embodiment, the thickness ratio of the first cutting edge 81 and the first cutting back 83 is a first ratio; the thickness ratio of the second cutting edge 82 and the second cutting back 84 is a second ratio. The above-mentioned first ratio refers to the ratio of the first cutting edge 81 to the first cutting back 83, which ranges from 1:2 to 3:5, preferably 0.58:0.99. The above-mentioned second ratio refers to the ratio of the second cutting edge 82 to the second cutting back 84, which ranges from 1:3 to 1:2, preferably 0.26:0.61.

[0038] According to a preferred embodiment, as shown, Figure 2 As shown, the extension of the inclined face of the connecting arc platform 6 forms a step angle with the axis of the tool 1 in the axial face of the tool 1 coinciding with the extension face of the blade end 3. Preferably, the step angle ranges from 30° to 60°, preferably 45°. The connecting arc platform 6 is used to fix the blade end 3, and the step angle improves the focusing effect of the ultrasonic waves, thereby increasing the amplitude of the first cutting edge 81 and the second cutting edge 82, and enhancing the cutting effect. The ultrasonic waves from the ultrasonic vibration module of the handle increase the amplitude of the blade end 3 due to the existence of the step angle, that is, the ultrasonic waves are transmitted from the longer diameter to the shorter diameter, so that the ultrasonic waves are concentrated on the blade end 3, thereby enhancing the cutting effect of the cutting edge.

[0039] According to a preferred embodiment, the shank end 2 is provided with an ultrasonic vibration module to provide ultrasonic vibration to the blade end 3 for cutting. The end of the shank end 2 away from the blade end 3 is provided with a pumping assembly for suction while the blade end 3 is working for cutting. The present application provides the pumping assembly on the shank end 2 to perform suction while the blade end 3 is working for cutting, and to timely extract the perfusion of cooling liquid and cutting bone tissue debris out of the body, to avoid the cooling liquid from gathering too much in the local area and overheating to damage the bone tissue, and to avoid the cutting debris from affecting the healing of the bone tissue after the operation of the patient. Preferably, the ultrasonic vibration module comprises a transducer and a horn. Preferably, the ultrasonic vibration module generates ultrasonic waves with a wave form of longitudinal waves at 20 kHz to 40 kHz, or at 15 kHz to 45 kHz. The amplitude of the ultrasonic waves is 70 to 110 μm, preferably 75 to 100 μm, and particularly preferably 80 to 95 μm.

[0040] According to a preferred embodiment, the cooling hole 5 is closer to the connecting arc 6 than the position where the ultrasonic vibration module is provided. The cooling hole 5 is provided in the form of a through hole in the radial direction of the cutter 1. Preferably, the cooling hole 5 can also be provided in the form of an outlet hole in the axial direction of the cutter 1. Preferably, the cooling hole can be provided in other orientations. The present application is brief and does not repeat the orientations of the remaining cooling holes, but does not mean that the remaining orientations are not provided.

[0041] Embodiment 2

[0042] The present embodiment is a further improvement and / or supplement to Embodiment 1, and the repeated contents will not be repeated. The overall and / or part of the preferred embodiments of other embodiments can be supplemented as the present embodiment without causing conflicts or contradictions.

[0043] The present application provides an ultrasonic cutting device for cooling an ultrasonic bone cutter for a cutting site during an ultrasonic cutting stage, and a control method thereof, to reduce the local temperature during ultrasonic cutting. The present application uses an ultrasonic cutting device designed with a cooling hole, so that the cooling liquid can cool the blade end 3 of the ultrasonic cutting device through the cooling hole when the ultrasonic cutting device is cutting thick bone tissue, and can simultaneously suck the cutting debris and / or excessive liquid accumulated during the ultrasonic cutting process, so as to accelerate the healing of the bone tissue of the patient after the operation and avoid overheating to damage the bone tissue of the patient.

[0044] The present application relates to an ultrasonic cutting device for cooling an ultrasonic osteotome at a cutting site during an ultrasonic cutting phase, comprising at least a control mechanism 13, a cutting sensing assembly 14 and a pumping assembly 15. The pumping assembly 15 is connected to an opening to send cooling liquid to the blade end 3 through the cooling hole 5. The cutting sensing assembly 14 can be a piezoelectric sensor for monitoring the cutting force on the blade end 3. Preferably, the cutting sensing assembly 14 is arranged in the handle end 2 of the ultrasonic osteotome to monitor the cutting force on the blade end 3 (blade) when cutting patient tissue. Preferably, the control mechanism 13 controls the pumping assembly 15 to pump in cooling liquid or to suck cutting debris and liquid when the cutting sensing assembly 14 detects a change in the cutting force on the blade end 3 and sends the change to the control mechanism 13. Preferably, the control mechanism 13 controls the pumping assembly 15 to sequentially perform a one-way pumping action or a reverse suction action. Preferably, the control mechanism 13 is configured to control the pumping assembly 15 to perform a one-way pumping action or a reverse suction action based on the change in the cutting force on the blade end 3 measured by the cutting sensing assembly 14. The control mechanism 13 of the present application controls the cutting process of the ultrasonic cutting device based on the different functions required at different cutting sites of the patient during a one-way pumping action or a reverse suction action. That is, the heat generated during cutting of muscle groups, thin bone tissue or thick bone tissue is different, and the required cooling liquid and cooling effect are also different. The control mechanism 13 determines the cutting site of the patient where the cutting tool is currently located by at least the change in the cutting force on the blade end 3 measured by the cutting sensing assembly 14, thereby controlling the efficiency of pumping in cooling liquid and the frequency of sucking cutting debris and liquid by the pumping assembly 15. There are ultrasonic cutting devices in the prior art that use cooling liquid to cool the cutting tool. However, most of the existing ultrasonic cutting devices use a technical solution in which water flows through or is sprayed onto the ultrasonic knife head to cool it. However, due to the auxiliary intervention of water flow, water remains in the cutting site of the patient after the cooling operation, and is mixed with cutting debris, which limits the surgical field of view and affects the smooth progress of the operation. Therefore, the implementation or improvement of such a technical solution is to design an ultrasonic cutting device that has a sufficient surgical field of view after the cooling operation. Having a sufficient surgical field of view is a limitation of the cooling operation, so that the ultrasonic knife head must be cooled while the surgical field of view is simultaneously reduced, and cutting debris remains, which cannot meet the cooling requirements of the ultrasonic cutting device and also affects the healing of the patient's bone tissue during a long cutting process. Unlike the above-mentioned technical solution of the prior art, the present application provides a solution based on the one-way pumping action or reverse suction action of the pumping assembly 15 to solve the problems of cooling and debris residue, and the one-way pumping action or reverse suction action can control the pumping rate of cooling liquid and the suction frequency based on different sites of the patient cut by the ultrasonic cutting device.Since the blade of the ultrasonic cutting device and the corresponding connection need to be kept tough to avoid blade breakage, the cooling liquid cannot be directly introduced into the blade. Based on the deficiencies or shortcomings of the prior art, the combination structure between the blade and the cooling hole is designed to ensure the energy concentration effect and improve the cutting efficiency, reduce the stress concentration caused by the setting of the cooling hole, avoid the breakage of the ultrasonic bone cutter during long-time work, prolong the service life, and the cooling of the cooling liquid no longer affects the surgical field, which maximizes the smooth progress of the operation. Therefore, the ultrasonic cutting device provided by the present application meets the cooling demand of the ultrasonic cutting device, reduces the cost required for cooling, and avoids the residue of the ultrasonic cutting device in the patient's body.

[0045] According to a preferred embodiment, the pumping assembly 15 is used to cool the blade during the cutting of bone tissue to reduce thermal damage to the bone tissue. The cutting sensing assembly 14 monitors the cutting force on the blade end 3 when the cutter is cutting, and sends it to the control mechanism 13, which then obtains the cutting site signal based on the coupling relationship between the cutting force and the charge distribution of the cutting sensing assembly 14. Preferably, the control mechanism 13 processes the obtained cutting site signal based on the decoupling transformation matrix, and classifies the cutting site signal based on the cutting force variation characteristics of different tissues of the patient, so as to determine the cutting position of the current ultrasonic cutting device. Specifically, the control mechanism 13 establishes the coupling relationship between the cutting force on the blade end 3 and the charge distribution based on the geometric position of the patient's body where the cutting sensing assembly 14 is located and the geometric size of the resonant system of the ultrasonic cutting device, and based on the charge superposition of the cutting sensing assembly 14. The control mechanism 13 obtains the decoupling transformation matrix after simplifying and transforming the matrix constant through the geometric position of the cutting sensing assembly 14 and the coupling relationship conversion. Preferably, the control mechanism 13 obtains the coupling constant of the ultrasonic cutting device, realizes the calibration and correction of the decoupling parameters of the cutting force to determine the cutting position of the current ultrasonic cutting device. The cutting position of the above ultrasonic cutting device at least includes the outer cortical bone, cancellous bone, inner cortical bone and soft tissue of the bone tissue. The control mechanism 13 of the present application identifies the tissue boundary of the cutting position based on the cutting force generated during the contact between the blade end 3 and the cutting position of the above ultrasonic cutting device, so as to perform corresponding cooling liquid pumping and cutting debris suction under different tissues.

[0046] According to a preferred embodiment, the control mechanism 13 can generate a real-time cutting model related to the cutting site signal according to the cutting force size of the blade end 3 during the cutting work of the cutter collected by the cutting sensing assembly 14, through the coupling relationship between the cutting force size and the charge distribution. Preferably, the control mechanism 13 classifies and judges the cutting site signal by comparing the real-time cutting model with the reference cutting model established by using the cutting force variation characteristics of different tissues collected in advance. Preferably, the control mechanism 13 analyzes the boundary of the tissue cut by the ultrasonic cutting device by comparing the previous clock data of the cutting force size of the blade end 3 collected by the cutting sensing assembly 14 with the reference cutting model. Preferably, the control mechanism 13 also retrieves the previous clock data of the cutting force size of the blade end 3 collected by the cutting sensing assembly 14 and the real-time cutting model according to the classification judgment for different tissues, so as to remind the medical staff of the relevant judgment results through the display, so as to facilitate the medical staff to control the operation progress, avoid cutting the soft tissue or the remaining normal tissue of the patient due to misoperation, and make accident avoidance in advance. The above-mentioned previous clock data refers to the data of the time period before the time point of the abnormal or sudden change of the cutting site signal as the starting time point, and the time period before the time point can be designed by the medical staff. The previous clock data of the present application is preferably the previous one minute data.

[0047] Preferably, the medical staff can also determine the cutting position of the ultrasonic cutting device according to the surgical field and / or surgical experience, and the medical staff feeds back the artificial judgment position to the device by actively triggering the control mechanism 13, so that the control mechanism 13 corrects the judgment based on the previous clock data of the cutting force on the blade end 3 collected by the stored cutting sensing assembly 14 according to the active triggering of the medical staff. The control mechanism 13 can establish a trigger cutting model according to the triggering time point according to the active triggering action of the medical staff, so as to judge whether the cutting force on the blade end 3 at the triggering time point meets the different tissue cutting force variation characteristics by comparing the trigger cutting model with the reference cutting model. If it can match a certain cutting force variation characteristic, it is judged that the device has a fault, so as to remind the medical staff, and the pumping assembly 15 is switched to manual control. The above reminding the medical staff can be that the control mechanism 13 sends a warning information, and a prompt module such as an audio module, a display module, a vibration module, etc. receives the warning information to make corresponding reminders. If it cannot match a certain cutting force variation characteristic, it is judged that the reference cutting model is not suitable for the tissue in the current patient, and the control mechanism 13 iterates the pre-established reference cutting model, so that the iterated reference cutting model can classify and judge similar cutting site signals for the patient in the subsequent operation process. Because unpredictable changes may occur in the patient, that is, the cutting force variation characteristics of different tissues may be different, which may cause the judgment process of the control mechanism 13 to be wrong, so that the control mechanism 13 is mistakenly turned on. The pumping assembly 15. For this purpose, the active triggering of the medical staff is used to improve the recognition accuracy of the cutting site during the operation. The ultrasonic cutting device of the present application optimizes the structural characteristics of the cutting tool itself, solves the problem of stress concentration caused by the cooling hole, and prolongs the service life. On the other hand, it is used to actively judge the cutting site and adjust the cooling liquid pumping and debris suction. Especially combined with the secondary judgment of the cutting site including monitoring the cutting force and the active triggering of the medical staff. The existing ultrasonic cutting device lacks accurate judgment of the cutting site and control of the related parameters of the cooling liquid pumping and debris suction. With the continuous operation, long-term repeated work is easy to cause the medical staff to cut the normal tissue of the patient due to misoperation, and the medical staff is also difficult to make corresponding response and countermeasures in a short time. In this case, the active reminding and modification of the control mechanism 13 are used to realize the accurate judgment of the cutting site. Preferably, the control mechanism 13 can also determine the cutting position of the ultrasonic cutting device according to the different acoustic impedance of different tissues of the patient.

[0048] It is to be noted that the active triggering by the medical staff refers to the case where the medical staff finds that the cutting position at the site has changed, but the control mechanism 13 does not remind the medical staff. That is, the premise of the active triggering by the medical staff is that the control mechanism 13 judges that an abnormality occurs but does not make a corresponding feedback. Thus, after the control mechanism 13 re-monitors the cutting force variation characteristic, if the obtained cutting force variation characteristic matches a certain cutting force variation characteristic, it indicates that the judging device is abnormal and does not correctly make a corresponding feedback to the cutting position.

[0049] According to a preferred embodiment, the control mechanism 13 dynamically regulates the pumping rate of the cooling liquid based on the judged cutting position of the tool. Preferably, the control mechanism 13 regulates the pumping rate of the cooling liquid based on the working time of the tool after cutting into different tissue boundaries. Preferably, the control mechanism 13 non-linearly regulates the pumping rate of the cooling liquid based on the increase of the working time. The non-linear regulation refers to the case where the pumping rate of the cooling liquid is gradually increased, i.e., the pumping rate of the cooling liquid is increased from zero to a preset threshold in an accelerated manner. Preferably, the pumping rate of the cooling liquid is also regulated based on the temperature of the tip of the tool. The higher the temperature, the greater the pumping rate of the cooling liquid, so as to keep the temperature of the tool within the range of 38 degrees Celsius, i.e., within the range of the temperature of the patient's body. The existing pumping of the cooling liquid depends on the start-stop control of the medical staff, thus causing the variation of the pumping rate of the cooling liquid per unit time to depend on the speed of the knob or slide or press operation of the medical staff. In actual surgery, the medical staff usually wants to control the pumping of the cooling liquid through the least number of operations, without considering the variation of the pumping rate of the cooling liquid during the operation, i.e., the pumping rate of the cooling liquid for cooling is uncontrollable, which undoubtedly reduces the reliability of the cooling operation, and excessive pumping of the cooling liquid can also cause damage to the patient's tissue and affect the surgical field, and even cause unpredictable accidents. For example, when cutting thin bone tissue, the same pumping of the cooling liquid can cause excessive liquid to enter the patient's body, and the cooling efficiency is too low, and it actually only needs less pumping of the cooling liquid to achieve the same cooling effect. Unlike the prior art, the present application improves the solution of using different pumping rates of the cooling liquid based on different cutting positions, wherein the control mechanism 13 of the present application first judges the cutting position through the cutting force, and then regulates the pumping rate of the cooling liquid based on the determined cutting position. The regulation manner is that the ultrasonic cutting device uses different pumping rates of the cooling liquid in different tissues for different working times, which can be correspondingly regulated through a preset cooling mechanism to save the pumping cost of the cooling liquid and prevent accidents that can be caused by excessive liquid. The present application reduces the use of the cooling liquid as much as possible to prevent secondary damage to the patient's bone tissue.

[0050] According to a preferred embodiment, the control mechanism 13 controls the pumping assembly 15 to sequentially perform the one-way pumping action or the reverse suction action. Preferably, the pumping direction of the pumping assembly 15 is instantaneously switched from the one-way pumping action to the reverse suction action upon completion of the cooling liquid pumping by a pre-setting between the control signal and the response of the pumping assembly 15. Preferably, the control mechanism 13 transmits the control signal to the pumping assembly 15 based on the acquired cutting site, and the pumping assembly 15 responds to the control signal to perform the instantaneous switching. Preferably, the control mechanism 13 cancels the transmitted control signal, and the pumping direction of the pumping assembly 15 is again instantaneously reversed to switch from the reverse suction action to the one-way pumping action. Preferably, the control mechanism 13 dynamically regulates the switching frequency of the pumping assembly 15 based on the cutting site of the tool. Preferably, the control mechanism 13 regulates the switching frequency of the pumping assembly 15 based on the working time after the tool cuts into different tissue boundaries and the pumping rate of the cooling liquid. Preferably, the control mechanism 13 linearly regulates the switching frequency of the pumping assembly 15 based on the increase of the working time and the pumping rate of the cooling liquid. The above-mentioned linear regulation refers to the increase of the switching frequency of the pumping assembly 15 with the increase of the working time at the cutting site and the pumping rate of the cooling liquid, wherein the regulation of the switching frequency of the pumping assembly 15 is mainly regulated by the pumping rate of the cooling liquid. Preferably, the switching frequency of the pumping assembly 15 is linearly increased with the increase of the pumping rate of the cooling liquid. Preferably, the switching frequency of the pumping assembly 15 is regulated within a threshold range at the switching frequency determined by the pumping rate of the cooling liquid with the increase of the working time at the cutting site. For example, the switching frequency of the pumping assembly 15 is the first switching frequency at the current pumping rate of the cooling liquid. With the extension of the working time, the switching frequency of the pumping assembly 15 is limited to the second switching frequency within a pre-set threshold range based on the first switching frequency. Most of the existing ultrasonic cutting devices use the technical solution of cooling by flowing or spraying cooling liquid to the ultrasonic knife head, which uses the high specific heat capacity of the cooling liquid for cooling, but also due to the high specific heat capacity of the cooling liquid, after cooling, the cooling liquid absorbs heat and it is difficult to dissipate the heat, resulting in that the used cooling liquid also causes thermal damage to the patient's tissue. Especially the cooling liquid remaining in the patient's body, after absorbing a large amount of heat, is equivalent to leaving "hot water" in the patient's body. Unlike the above-mentioned prior art, the present application removes the used cooling liquid from the patient's body by switching between the one-way pumping action and the reverse suction action, and at the same time removes the cutting debris generated by cutting from the patient's body, solving the problems of thermal damage caused by residual cooling liquid and healing difficulty caused by residual debris.

[0051] Throughout the specification, "preferably", "particularly preferred", and "preferably" or "particularly preferred" are used to describe a preference for a feature, state, or result. It is to be understood that these terms are not to be taken in an exclusive sense but are descriptive of only one embodiment of the application, and hence, applicants reserve the right to drop or omit any of the described preferred features, states, or results.

[0052] It should be noted that the above-mentioned embodiments illustrate rather than limit the application, and that one skilled in the art will be able to devise modifications and alternatives that are within the scope of the application. The disclosure of the application therefore should not be limited to the described embodiments. It will be understood by those within the art that, in general, terms used herein, and especially, terms of degree such as "comprises", "comprising", "as consisting of" and "consisting essentially of" are used herein to convey the intended meaning of "comprising" unless otherwise indicated by context. Thus, it will be understood by those within the art that, in general, terms used herein, and especially, terms of degree such as "comprises", "comprising", "as consisting of" and "consisting essentially of" are used herein to convey the intended meaning of "comprising" unless otherwise indicated by context. Thus, it will be understood by those within the art that, in general, terms used herein, and especially, terms of degree such as "comprises", "comprising", "as consisting of" and "consisting essentially of" are used herein to convey the intended meaning of "comprising" unless otherwise indicated by context. Thus, it will be understood by those within the art that, in general, terms used herein, and especially, terms of degree such as "comprises", "comprising", "as consisting of" and "consisting essentially of" are used herein to convey the intended meaning of "comprising" unless otherwise indicated by context. Thus, it will be understood by those within the art that, in general, terms used herein, and especially, terms of degree such as "comprises", "com

Claims

1. An ultrasonic cutting device, comprising: At least comprising a control mechanism (13), a cutting sensing assembly (14) for monitoring the cutting force of the blade end (3) when cutting the patient tissue, and a pumping assembly (15), The control mechanism (13) is configured to: When the cutting sensing assembly (14) monitors the change of the cutting force of the blade end (3) and sends the change to the control mechanism (13), the part cut by the cutter (1) is determined and the pumping assembly (15) is linked to sequentially perform the one-way pumping action or the reverse suction action; The control mechanism (13) identifies the tissue boundary of the cutting position based on the cutting force generated during the contact of the blade end (3) and the cutting position of the ultrasonic cutting device, so as to perform corresponding cooling liquid pumping and cutting debris suction under different tissues; The control mechanism (13) establishes a trigger cutting model according to the trigger time point of the active trigger action, so as to determine whether the cutting force of the blade end (3) at the trigger time point matches the cutting force change characteristics of different tissues by comparing the trigger cutting model with a reference cutting model, wherein When it can match at least one cutting force change characteristic, it is determined that a fault occurs, and a warning information is sent out; When it cannot match at least one cutting force change characteristic, it is determined that the reference cutting model is not suitable for the current tissue in the patient's body, and the control mechanism (13) iterates the pre-established reference cutting model, so that the iterated reference cutting model can classify and judge the similar cutting position signal; The control mechanism (13) regulates the pumping rate of the cooling liquid based on the working time of the cutter cutting into different tissue boundaries, wherein The control mechanism (13) non-linearly regulates the pumping rate of the cooling liquid based on the increase of the working time; The control mechanism (13) regulates the switching frequency of the pumping assembly (15) based on the working time of the cutter cutting into different tissue boundaries and the pumping rate of the cooling liquid, wherein The control mechanism (13) linearly regulates the switching frequency of the pumping assembly (15) based on the increase of the working time and the pumping rate of the cooling liquid.

2. The ultrasonic cutting device of claim 1, wherein, The control mechanism (13) generates a real-time cutting model related to the cutting position signal through the coupling relationship between the cutting force of the blade end (3) collected by the cutting sensing assembly (14) when the cutter (1) is cutting and the charge distribution, wherein The control mechanism (13) compares the real-time cutting model with a reference cutting model established by using the pre-collected different tissue cutting force change characteristics to classify and judge the cutting position signal.

3. The ultrasonic cutting device of claim 1 or 2, wherein, The control mechanism (13) compares the previous clock data of the cutting force of the blade end (3) collected by the cutting sensing assembly (14) with the reference cutting model to analyze the boundary of the patient tissue cut by the cutter.

4. The ultrasonic cutting device of claim 1, wherein, In response to the judgment of the cutting position of the tool, and in response to the way of actively triggering the control mechanism (13), the control mechanism (13) calls the previous clock data of the cutting force of the blade end (3) collected by the cutting sensing assembly (14) to make a correction judgment.

5. The ultrasonic cutting device of claim 1, wherein, Through the pre-setting between the control signal and the response of the pumping assembly (15), when the cooling liquid is pumped in, the pumping direction of the pumping assembly (15) is instantaneously switched from one-way pumping action to reverse suction action; The control mechanism (13) transmits the control signal to the pumping assembly (15) based on the obtained cutting position, and the pumping assembly (15) responds at the same time to make an instantaneous switch; the control mechanism (13) removes the control signal, and the pumping direction of the pumping assembly (15) is again instantaneously reversed to switch from reverse suction action to one-way pumping action.

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