Method and system for determining the position of an ultrasonic bone cutter

Abstract

A method, system, computer-readable storage medium, and computer program product for determining the position of an ultrasonic bone cutter (10) are disclosed. The method includes obtaining an acoustic impedance signal of the ultrasonic bone cutter (10) and determining a current position of the ultrasonic bone cutter (10) in the bone tissue to be cut based on the acoustic impedance signal. In this method, an operator (50) can easily obtain the position of the ultrasonic bone cutter (10) in real time, so that the movement path of the ultrasonic bone cutter (10) does not substantially deviate from the target path, and damage to soft tissue during surgery can be reduced.

Description

Technical Field

[0001]

[0001] This application incorporates the content of Chinese Patent Application No. 202210507538.6, titled "Method and System for Determining the Position of an Ultrasonic Osteotome", filed on May 10, 2022.

[0002]

[0002] This application relates to the technical field of medical devices, and more particularly, to a method, a system, a computer-readable storage medium, and a computer program product for determining the position of an ultrasonic osteotome.

Background Art

[0003]

[0003] Ultrasonic osteotomes have been widely used to cut and destroy bone tissue. Ultrasonic osteotomes have the characteristic of not damaging soft tissue, but when a certain pressure is applied to the soft tissue, there is a risk of damaging the soft tissue. In particular, during spinal surgery or neurosurgery, after the inner cortical bone is cut, if further cutting is not stopped, the ultrasonic osteotome may still damage nerve tissue such as the spinal cord or the brain within the bone cavity. Therefore, how to reduce damage to soft tissue during surgery is a major problem.

Summary of the Invention

[0004]

[0004] This application aims to solve at least one of the technical problems in the related art. To this end, the object of this application is to provide a method, a system, a computer-readable storage medium, and a computer program product for determining the position of an ultrasonic osteotome to reduce damage to soft tissue during surgery.

[0005]

[0005] According to an embodiment of the first aspect of this application, a method for determining the position of an ultrasonic osteotome is provided. The method includes obtaining an acoustic impedance signal of the ultrasonic osteotome and determining the current position of the ultrasonic osteotome in the bone tissue to be cut based on the acoustic impedance signal.

[0006]

[0006] In some embodiments, the step of determining the current position of the ultrasonic osteotome in the bone tissue to be cut based on the acoustic impedance signal includes determining that the current position is at the interface between other tissue and cortical bone based on determining that the acoustic impedance signal is at a first rising edge within a preset time and the average slope of the first rising edge is within a first slope range.

[0007]

[0007] In some embodiments, the step of determining that the current position is at the interface between other tissue and cortical bone includes determining that the current position is at the interface between air and cortical bone in response to determining that the acoustic impedance amplitude at the starting point of the first rising edge is within a first preset range.

[0008]

[0008] In some embodiments, the step of determining that the current position is at the interface between other tissue and cortical bone includes determining that the current position is at the interface between soft tissue and cortical bone in response to determining that the acoustic impedance amplitude at the starting point of the first rising edge is within a second preset range.

[0009]

[0009] In some embodiments, the step of determining that the current position is at the interface between other tissue and cortical bone includes determining that the current position is at the interface between cancellous bone and cortical bone in response to determining that the acoustic impedance amplitude at the starting point of the first rising edge is within a third preset range.

[0010]

[0010] In some embodiments, the step of determining the current position of the ultrasonic osteotome in the bone tissue to be cut based on the acoustic impedance signal includes determining that the current position is at the interface between cortical bone and other tissue in response to determining that the acoustic impedance signal is at a first falling edge within a preset time and the average slope of the first falling edge is within a second slope range.

[0011]

[0011] In some embodiments, the step of determining that the current position is the interface between cortical bone and other tissue includes, in response to determining that the acoustic impedance amplitude at the endpoint of the first downward edge is within a third preset range, the step of determining that the current position is the interface between cortical bone and cancellous bone.

[0012]

[0012] In some embodiments, the step of determining that the current position is the interface between cortical bone and other tissue includes, in response to determining that the acoustic impedance amplitude at the endpoint of the first downward edge is within a second preset range, the step of determining that the current position is the interface between cortical bone and soft tissue.

[0013]

[0013] In some embodiments, the step of determining that the current position is the interface between cortical bone and other tissue includes, in response to determining that the acoustic impedance signal is consistently within a fourth preset range throughout the preset time, the step of determining that the current position is within the cortical bone.

[0014]

[0014] In some embodiments, the step of determining that the current position is the interface between cortical bone and other tissue includes, in response to determining that the acoustic impedance signal is consistently within a third preset range throughout the preset time, the step of determining that the current position is within the cancellous bone.

[0015]

[0015] In some embodiments, the bone tissue to be cut includes outer cortical bone, cancellous bone, and inner cortical bone sequentially arranged from the outside to the inside. The method further includes the step of sending first prompt information in response to determining that the current position is the interface between the inner cortical bone and soft tissue.

[0016]

[0016] In some embodiments, determining that the current position is the interface between the inner cortical bone and soft tissue includes determining that the current position is the interface between the cortical bone and other tissue twice, and in response, determining that the current position is the interface between the inner cortical bone and soft tissue.

[0017]

[0017] In some embodiments, the bone tissue to be cut includes cortical bone and cancellous bone arranged sequentially from the outside to the inside. The method further includes sending second prompt information in response to determining that the displacement of the ultrasonic osteotome is within a preset size and that the current position is the interface between the cancellous bone and the cortical bone.

[0018]

[0018] In some embodiments, the bone tissue to be cut includes cortical bone. The method further includes sending third prompt information in response to determining that the current position is the interface between the cortical bone and soft tissue.

[0019]

[0019] According to an embodiment of the second aspect of the present application, an ultrasonic surgical system is provided, the system including an ultrasonic osteotome configured to cut bone tissue to be cut, and a processor configured to implement the method described above.

[0020]

[0020] In some embodiments, the ultrasonic surgical system further includes a surgical robot connected to the ultrasonic osteotome and a display device configured to display an acoustic impedance signal of the ultrasonic osteotome. The processor is further configured to operate the ultrasonic osteotome by controlling the surgical robot.

[0021]

[0021] According to an embodiment of the third aspect of the present application, a non-transitory computer-readable storage medium storing computer instructions is provided, the computer instructions being used to cause a computer to implement the method described in any of the above.

[0022] According to an embodiment of the fourth aspect of the present application, there is provided a computer program product including a computer program, which, when executed by a processor, causes the method described in any of the above to be implemented.

[0023] According to a method, a system, a computer-readable storage medium, and a computer program product for determining the position of an ultrasonic osteotome provided by an embodiment of the present application, the current position of the ultrasonic osteotome in the bone tissue to be cut is determined based on an acoustic impedance signal. Therefore, an operator can easily obtain the position of the ultrasonic osteotome in real time, and can effectively prevent the movement path of the ultrasonic osteotome from deviating from the target path, so as to reduce damage to soft tissue during surgery.

Brief Description of the Drawings

[0024] In the accompanying drawings, unless otherwise specified, the same reference numerals indicate the same or similar components or elements throughout the plurality of accompanying drawings. These accompanying drawings are not necessarily drawn to scale. It should be understood that these accompanying drawings only show some embodiments disclosed in accordance with the present application and should not be construed as limiting the scope of the present application.

[0025]

Figure 1A

[0026]

Figure 1B

[0027]

Figure 2

[0028]

Figure 3A

[0028] Figure 3A is a diagram of the operating principle of an ultrasonic surgical system according to some embodiments of the present application.

[0029]

Figure 3B

[0029] Figure 3B is a graph of the change in acoustic impedance of the ultrasonic osteotome of Figure 3A.

[0030]

Figure 3C

[0030] Figure 3C is a flowchart of a method for determining the position of the ultrasonic osteotome applied to the ultrasonic surgical system of Figure 3A.

[0031]

Figure 4A

[0031] Figure 4A is a diagram of the operating principle of an ultrasonic surgical system according to some embodiments of the present application.

[0032]

Figure 4B

[0032] Figure 4B is a graph of the change in acoustic impedance of the ultrasonic osteotome of Figure 4A.

[0033]

Figure 4C

[0033] Figure 4C is a flowchart of a method for determining the position of the ultrasonic osteotome applied to the ultrasonic surgical system of Figure 4A.

[0034]

Figure 5A

[0034] Figure 5A is a diagram of the operating principle of an ultrasonic surgical system according to some embodiments of the present application.

[0035]

Figure 5B

[0035] Figure 5B is a graph of the change in acoustic impedance of the ultrasonic osteotome of Figure 5A.

[0036]

Figure 5C

[0036] Figure 5C is a flowchart of a method for determining the position of the ultrasonic osteotome applied to the ultrasonic surgical system of Figure 5A.

[0037]

Figure 6

[0037] FIG. 6 is a structural diagram of an ultrasonic surgical system according to some embodiments of the present application.

[0038]

Figure 7

[0038] FIG. 7 is a partial enlarged view of the ultrasonic osteotome of FIG. 6.

[0039]

[0039] List of reference symbols 10 Ultrasonic osteotome 11 Transducer 20 Bone tissue to be cut 21 Cortical bone 21a Outer cortical bone 21b Inner cortical bone 22 Cancellous bone 30 Processor 40 Display device 50 Operator 51 Surgical robot 60 Detailed description of the ultrasonic drive power supply embodiment

[0040]

[0040] Only some exemplary embodiments will be briefly described below. As will be understood by those skilled in the art, the described embodiments can be modified in various ways without departing from the spirit or scope of the present application. Therefore, the accompanying drawings and description are considered to be of an illustrative nature and not restrictive.

[0041]

[0041] In related art, during ultrasonic surgery, the cutting position is usually detected by an image position detection method. However, due to the movement related to the patient's breathing and the deformation of the bone position during the cutting process, the image position detection method may cause a position detection error and tend to damage soft tissue. In particular, during spinal surgery or neurosurgery, the soft tissue is usually nerve tissue such as the spinal cord or the brain in the bone cavity. If the soft tissue is damaged, the patient will be severely affected.

[0042]

[0042] To solve at least one of the above problems, the present application provides a method and a system for determining the position of an ultrasonic bone cutter. The current position of the ultrasonic bone cutter in the bone tissue to be cut is determined based on an acoustic impedance signal, so that the operator can easily obtain the position of the ultrasonic bone cutter in real time. This has higher accuracy compared to image position detection, which can reduce damage to soft tissue during surgery by ensuring that the movement path of the ultrasonic bone cutter does not substantially deviate from the target path.

[0043]

[0043] Embodiments of the present application are described below with reference to the accompanying drawings. FIG. 1A is a flowchart of a method for determining the position of an ultrasonic bone cutter according to some embodiments of the present application, and FIG. 1B is a diagram of the operating principle of an ultrasonic surgical system according to some embodiments of the present application. Referring to FIGS. 1A and 1B, this embodiment provides a method 100 for determining the position of an ultrasonic bone cutter, which can be used in open surgery or minimally invasive surgery using an ultrasonic bone cutter, particularly in surgeries related to bone tissue. Method 100 includes steps S101 and S102.

[0044]

[0044] Step S101: Obtain the acoustic impedance signal of the ultrasonic bone cutter 10.

[0045]

[0045] Step S102: Determine the current position of the ultrasonic bone cutter 10 in the bone tissue 20 to be cut based on the acoustic impedance signal.

[0046]

[0046] As shown in FIG. 1B, the ultrasonic osteotome 10 can have a general structure in the related art that can cut bone tissue using ultrasonic energy. The ultrasonic osteotome can include a main body and a transducer 11. The main body has a tip that contacts the patient, and the tip can be used as a cutting implement. The tip can have various shapes including various tips for cutting, polishing, drilling, etc. The transducer 11 is connected to the ultrasonic drive power source 60 and the tip, can convert electrical energy into ultrasonic vibrations, and can be connected to a feedback circuit that sends the acquired acoustic impedance information. The ultrasonic drive power source 60 is a power device that can generate an ultrasonic drive signal.

[0047]

[0047] The acoustic impedance signal can be used to reflect the attenuation characteristics of particles at a certain position in the medium caused by mechanical perturbation. The acoustic impedance signal can be represented as an acoustic impedance curve, a data table, etc. In the case of the ultrasonic osteotome 10, it will be understood that the acoustic impedance changes when the tip contacts various media such as air, soft tissue, and bone tissue. Bone tissue can be structurally divided into cortical bone and cancellous bone, and the acoustic impedance also changes when the tip contacts cortical bone and cancellous bone. The acoustic impedance signal can be acquired in real time at a specific sampling frequency.

[0048]

[0048] The bone tissue 20 to be cut is the bone tissue that needs to be cut using the ultrasonic osteotome 10. There can be multiple types of bone tissue 20 to be cut. For example, the bone tissue to be cut can be cortical bone, or can have a structure that combines cortical bone and cancellous bone, and can specifically vary depending on the type of surgery or the location of the surgery.

[0049]

[0049] The current position can be information regarding the current position of the tip of the ultrasonic osteotome 10 in the bone tissue to be cut. The operator 50 can be a doctor or a surgical robot that operates the ultrasonic osteotome 10, but is not limited thereto.

[0050]

[0050] During the operation, the acoustic impedance signal of the ultrasonic osteotome 10 is acquired in real time, and the current position of the tip of the ultrasonic osteotome 10 is determined based on various types of acoustic impedance signals fed back from various types of bone tissues and their interfaces to determine whether the cutting position meets the surgical requirements for simultaneous cutting and detection. Compared with the image position detection in the related art, this method has high accuracy, and the movement path of the ultrasonic osteotome can be easily prevented from deviating from the target path. Therefore, during the operation, damage to nerve tissues such as the spinal cord or brain can be reduced, and the safety and efficiency of the operation can be improved.

[0051]

[0051] FIG. 2 shows the implementation of step S102 in FIG. 1. Referring to FIG. 2, determining the current position of the ultrasonic osteotome 10 in the bone tissue 20 to be cut based on the acoustic impedance signal can include the following steps. Step S201: In response to determining that the acoustic impedance signal is at the first rising edge within the preset time and the average slope of the first rising edge is within the first slope range, determine that the current position is the interface between other tissues and cortical bone.

[0052]

[0052] To facilitate the description of step S201, FIG. 3A is a diagram of the operating principle of an ultrasonic surgical system according to some embodiments of the present application. FIG. 3B is a graph of the acoustic impedance change of the ultrasonic osteotome in FIG. 3A. Referring to FIGS. 3A and 3B, in some embodiments, the bone tissue 20 to be cut includes an outer cortical bone 21a, a cancellous bone 22, and an inner cortical bone 21b sequentially arranged from the side close to the ultrasonic osteotome 10 to the side away from the ultrasonic osteotome 10. Both the inner cortical bone 21b and the outer cortical bone 21a are cortical bone 21, and the inner and outer sides represent their positional relationships with the cancellous bone 22, respectively. The outer side can be the position to be cut first during the operation, and the inner side can be the position to be cut later during the operation.

[0053]

[0053] Figure 3B shows the acoustic impedance signal represented as the acoustic impedance curve of the ultrasonic osteotome 10 that sequentially cuts through the outer cortical bone 21a, cancellous bone 22, and inner cortical bone 21b. The horizontal coordinate axis is time, and the vertical coordinate axis is the amplitude of the acoustic impedance. In Figure 3B, the solid line represents the acoustic impedance change curve during the experiment, and the dashed line represents the ideal acoustic impedance change curve. Due to the presence of interference, it can be understood that the acoustic impedance change curve during the experiment has a certain degree of minute fluctuation and displacement compared to the ideal acoustic impedance change curve.

[0053] It will be understood that the acoustic impedance change curve during the experiment has a certain degree of minute fluctuation and displacement compared to the ideal acoustic impedance change curve.

[0054]

[0054] In step S201, the first rising edge is a process in which the amplitude of the acoustic impedance signal increases with time. The dashed line in Figure 3B is used as an example, and both 41a and 41b represent the first rising edge.

[0055]

[0055] The preset time can be set for a plurality of sampling periods based on the actual situation. By determining whether the amplitude of the acoustic impedance signal gradually increases with time within the preset time, it can be determined whether the acoustic impedance signal is on the first rising edge. In addition, by appropriately setting the preset time, the interference of minute fluctuations of the signal to the determination of the first rising edge can be avoided.

[0056]

[0056] The inclination of the first rising edge can be the included angle between the first falling edge and the horizontal coordinate axis, and the average inclination of the first rising edge is the average value of the inclination of the first rising edge at the preset time. The first inclination range is a numerical interval that can be specifically set based on the actual cutting speed. For example, when the cutting speed of the ultrasonic bone cutter 10 is 0.5 millimeter per second (mm / s) or more, using seconds as the unit of the horizontal coordinate axis of the acoustic impedance signal and ohms as the unit of the vertical axis of the acoustic impedance signal, the first inclination range is 45 degrees, 50 degrees, 55 degrees, 60 degrees, 65 degrees, 70 degrees, 75 degrees, 80 degrees, 85 degrees, or 90 degrees, etc., which is from 45 degrees (°) to 90 degrees. In a preferred embodiment, the first inclination range is from 60 degrees to 90 degrees, that is, the first inclination range can be 60 degrees or more and 90 degrees or less. Therefore, the current position of the tip can be accurately determined.

[0057]

[0057] Other tissues can be tissues other than cortical bone, such as cancellous bone, soft tissue, or air. The interface between the other tissue and the cortical bone 21 indicates that the other tissue is on the outer side surface of the cortical bone 21 and the cutting direction of the tip is directed from the other tissue towards the cortical bone 21.

[0058]

[0058] Referring to the first rising edges 41a and 41b in FIG. 3B, when the acoustic impedance signal is at the first rising edge and its average inclination is within the first inclination range, the current position can be accurately determined to be the interface between the other tissue and the cortical bone 21. Therefore, the operator 50 can easily know the current position of the ultrasonic bone cutter 10.

[0059]

[0059] In some embodiments, in step S201, determining that the current position is the interface between the other tissue and the cortical bone includes determining that the current position is the interface between the air and the cortical bone in response to determining that the acoustic impedance amplitude at the starting point of the first rising edge is within the first preset range.

[0060]

[0060] It will be appreciated that the acoustic impedance changes when the ultrasonic osteotome 10 is in various types of tissue. Accordingly, the interface between the specific tissue in which the ultrasonic osteotome 10 is present and the cortical bone 21 can be determined by the acoustic impedance amplitude at the starting point of the entire first rising edge 41a.

[0061]

[0061] The first preset range is the acoustic impedance amplitude range of the ultrasonic osteotome 10 in air. By determining whether the acoustic impedance amplitude at the starting point of the first inclined edge 41a is within the first preset range, it is possible to accurately determine whether the current position is the interface between air and the cortical bone 21.

[0062]

[0062] In addition, in step S201, determining that the current position is the interface between another tissue and the cortical bone can further include the following steps.

[0063]

[0063] That is, in response to determining that the acoustic impedance amplitude at the starting point of the first rising edge is within the second preset range, a step of determining that the current position is the interface between the soft tissue and the cortical bone.

[0064]

[0064] The second preset range is the acoustic impedance amplitude range of the ultrasonic osteotome 10 in soft tissue. Similarly, by determining whether the acoustic impedance amplitude at the starting point of the first rising edge 41a is within the second preset range, it is possible to accurately determine whether the current position is the interface between the soft tissue and the cortical bone 21.

[0065]

[0065] In fact, in step S201, determining that the current position is at the interface between another tissue and the cortical bone can further include, in response to determining that the acoustic impedance amplitude at the starting point of the first rising edge is within the third preset range, determining that the current position is the interface between the cancellous bone and the cortical bone.

[0066]

[0066] The third preset range is the acoustic impedance amplitude range of the ultrasonic osteotome 10 in cancellous bone. Similarly, by determining whether the acoustic impedance amplitude at the starting point of the first rising edge 41b is within the third preset range, it is possible to accurately determine whether the current position is the boundary surface between the cancellous bone 22 and the cortical bone 21.

[0067]

[0067] In addition, the minimum value of the third preset range is greater than the maximum value of the first preset range, and the minimum value of the third preset range is greater than the maximum value of the second preset range.

[0068]

[0068] In order to cut the three-layer bone tissue, when the cutting speed of the ultrasonic osteotome 10 is 0.5 mm / s or more, the average inclination of the first rising edge 41a of the boundary surface between the air or soft tissue and the outer cortical bone 21a is in the range of 45 degrees to 90 degrees, and the average inclination of the first inclined edge 41b of the boundary surface between the cancellous bone 22 and the inner cortical bone 21b is in the range of 45 degrees to 90 degrees.

[0069]

[0069] As shown in FIG. 2, in some embodiments, in step S102, determining the current position of the ultrasonic osteotome 10 in the bone tissue 20 to be cut based on the acoustic impedance signal may further include the following steps. Step S202: In response to determining that the acoustic impedance signal is at the first falling edge within the preset time and the average inclination of the first falling edge is within the second inclination range, determine that the current position is the boundary surface between the cortical bone and other tissues.

[0070]

[0070] Still referring to FIG. 3B, in step S202, the first falling edge is a process in which the amplitude of the acoustic impedance signal decreases with time. The dashed line in FIG. 3B is used as an example, and both 42a and 42b represent the first falling edge.

[0071]

[0071] The preset time can be set for a plurality of sampling periods based on the actual situation. By determining whether the amplitude of the acoustic impedance signal gradually decreases with time within the preset time, it is possible to determine whether the acoustic impedance signal is at the first falling edge. In addition, by appropriately setting the preset time, interference from minute fluctuations in the signal with respect to the determination of the first falling edge can be avoided.

[0072]

[0072] The slope of the first falling edge can be the angle between the first falling edge and the horizontal coordinate axis, and the average slope of the first falling edge is the average value of the slopes of the first falling edge at the preset time. The second slope range is a numerical interval that can be specifically set based on the actual cutting speed. For example, when the cutting speed of the ultrasonic osteotome 10 is 0.5 millimeters per second or more, using seconds as the unit of the horizontal coordinate axis of the acoustic impedance signal and ohms as the unit of the vertical axis of the acoustic impedance signal, the second slope range is from 45 degrees to 90 degrees, such as 45 degrees, 50 degrees, 55 degrees, 60 degrees, 65 degrees, 70 degrees, 75 degrees, 80 degrees, 85 degrees, or 90 degrees. In a preferred embodiment, the second slope range is from 60 degrees to 90 degrees. That is, the second slope range can be 60 degrees or more and 90 degrees or less, and thus the current position of the tip can be accurately determined.

[0073]

[0073] Other tissues can be tissues other than cortical bone, such as cancellous bone, soft tissue, or air. The interface between the cortical bone 21 and other tissues indicates that the cortical bone 21 is on the outer surface of the other tissue, and the cutting direction of the tip is directed from the cortical bone 21 to the other tissue.

[0074]

[0074] Referring to the first falling edges 42a and 42b in FIG. 3B, when the acoustic impedance signal is on the first falling edge and its average slope is within the second slope range, the current position can be accurately determined to be the interface between the cortical bone 21 and other tissues, and the operator 50 can easily know the current position of the ultrasonic osteotome 10.

[0075]

[0075] In some embodiments, in step S202, determining that the current position is the interface between the cortical bone and other tissues may include, in response to determining that the acoustic impedance amplitude at the end point of the first descending edge is within the third preset range, determining that the current position is the interface between the cortical bone 21 and the cancellous bone 22.

[0076]

[0076] It should be understood that the acoustic impedance also changes when the ultrasonic osteotome 10 is in different types of tissues. Therefore, the interface between the cortical bone 21 where the ultrasonic osteotome 10 is present and a specific tissue can be determined by the acoustic impedance amplitude at the end points of the entire first descending edge 42a.

[0077]

[0077] The third preset range is the range of the acoustic impedance amplitude of the ultrasonic osteotome 10 in the cancellous bone 22. By determining whether the acoustic impedance amplitude at the end point of the first descending edge 42a is within the third preset range, it is possible to accurately determine whether the current position is at the interface between the cortical bone 21 and the cancellous bone 22.

[0078]

[0078] In some embodiments, in step S202, determining that the current position is the interface between the cortical bone and other tissues may further include, in response to determining that the acoustic impedance amplitude at the end point of the first descending edge is within the second preset range, determining that the current position is the interface between the cortical bone and the soft tissue.

[0079]

[0079] The second preset range is the range of the acoustic impedance amplitude of the ultrasonic osteotome 10 in the soft tissue. Similarly, by determining whether the acoustic impedance amplitude at the end point of the first descending edge 42b is within the second preset range, it is possible to accurately determine whether the current position is at the interface between the cortical bone 21 and the soft tissue.

[0080]

[0080] In fact, in step S202, determining that the current position is the interface between the cortical bone and other tissues may further include determining that the current position is the interface between the cortical bone and air in response to determining that the acoustic impedance amplitude at the endpoint of the first descending edge is within the first preset range.

[0081]

[0081] Referring further to FIG. 2, in step S102, determining the current position of the ultrasonic osteotome 10 in the bone tissue 20 to be cut based on the acoustic impedance signal may include the following steps. Step S203: In response to determining that the acoustic impedance signal is consistently within the fourth preset range throughout the preset time, determine that the current position is within the cortical bone.

[0082]

[0082] The fourth preset range can be the acoustic impedance amplitude range of the ultrasonic osteotome 10 in the cortical bone 21 that can have a minimum value. When the acoustic impedance amplitude is greater than the minimum value, it can be considered that the tip is present within the cortical bone 21. Similarly, by determining whether the acoustic impedance signal is within the fourth preset range, it is possible to accurately determine whether the current position is the cortical bone 21.

[0083]

[0083] The preset time can be set for a plurality of sampling periods based on the actual situation. By determining whether the amplitude of the acoustic impedance signal consistently exists within the fourth preset range throughout the preset time, it is possible to determine whether the acoustic impedance signal is in the cortical bone impedance level portion. As shown in FIG. 3B, the acoustic impedance signal consistently exists within the fourth preset range throughout the preset time, that is, the acoustic impedance signal is in the cortical bone impedance level portion 43b. The cortical bone impedance level portion 43b indicates that the tip is within the cortical bone 21 passing through the interface between the other tissue and the cortical bone 21. The length of the cortical bone impedance level portion 43b on the horizontal coordinate axis can vary according to the thickness of the cortical bone 21.

[0084]

[0084] In addition, the fourth preset range can be different for the cortical bones of different individuals or for the cortical bones at different positions of the same individual. For example, in FIG. 3B, the fourth preset range of the cortical bone impedance level 43b representing the outer cortical bone may be different from the fourth preset range of the cortical bone impedance level 43d representing the inner cortical bone.

[0085]

[0085] In some embodiments, still referring to FIG. 2, in step S102, determining the current position of the ultrasonic osteotome 10 in the bone tissue 20 to be cut based on the acoustic impedance signal can include the following steps. Step S204: In response to determining that the acoustic impedance signal consistently exists within the third preset range throughout the preset time, determine that the current position is within the cancellous bone.

[0086]

[0086] Since the hardness of cortical bone is greater than that of cancellous bone, the maximum value of the third preset range is smaller than the minimum value of the fourth preset range. The acoustic impedance amplitude in cancellous bone should be 60% or less of the acoustic impedance amplitude in cortical bone, that is, the average value of the third preset range is about 60% or less of the average value of the fourth preset range. The third preset range can be the acoustic impedance amplitude range of the ultrasonic osteotome 10 in the cancellous bone 22. As shown in FIG. 3B, when the acoustic impedance amplitude is within this range, the acoustic impedance signal is in the cancellous bone impedance level portion 43c, and it is considered that the tip is within the cancellous bone 22. The cancellous bone impedance level portion 43c indicates that the tip is within the cancellous bone 22 after passing through the interface between other tissues such as the cortical bone 21 and the cancellous bone 22. The length of the cancellous bone impedance level portion 43c on the horizontal coordinate axis can vary according to the thickness of the cancellous bone 22.

[0087]

[0087] In this step S204, the method for determining that the current position is cancellous bone is the same as the method for determining that the current position is cortical bone in step S203. Refer to the above description of step S203. Again, details will not be described.

[0088]

[0088] The above embodiments describe a method for determining the current position. Regarding the application of the present application, it will be described below with reference to an exemplary type of bone tissue 20 to be cut.

[0089]

[0089] FIG. 3C is a flowchart of a method for determining the position of an ultrasonic osteotome applied to the ultrasonic surgical system of FIG. 3A. Referring to FIGS. 3A, 3B, and 3C, the method provided in this embodiment can be applied to a surgery for cutting three layers of bone tissue. For example, the surgery can be a spinal fenestration. As shown in FIG. 3A, the bone tissue 20 to be cut includes an outer cortical bone 21a, a cancellous bone 22, and an inner cortical bone 21b arranged sequentially from the outside to the inside.

[0090]

[0090] A method 300 for determining the position of an ultrasonic bone cutter can include steps S301 to S303.

[0091]

[0091] Step S301: Obtain an acoustic impedance signal of the ultrasonic bone cutter 10.

[0092]

[0092] Step S302: Based on the acoustic impedance signal, determine the current position of the ultrasonic bone cutter 10 in the bone tissue 20 to be cut.

[0093]

[0093] Step S303: In response to determining that the current position is the interface between the inner cortical bone 21b and the soft tissue, send the first prompt information.

[0094]

[0094] Steps S301 and S302 are the same as steps S101 and S102 in the above embodiment, and reference can be made to the description of the above embodiment.

[0095]

[0095] It will be understood that FIG. 3B shows an acoustic impedance curve obtained when the three-layer bone tissue is cut through. The impedance level portion 43a indicates that the tip of the ultrasonic bone cutter 10 is consistently in air or soft tissue. The first rising edge 41a indicates that the tip is at the interface between air or soft tissue and the outer cortical bone 21a. The cortical bone impedance level portion 43b indicates that the tip is within the outer cortical bone 21a. The first falling edge 42a indicates that the tip is at the interface between the outer cortical bone 21a and the cancellous bone 22. The cancellous bone impedance level portion 43c indicates that the tip is within the cancellous bone 22. The first rising edge 41b indicates that the tip is at the interface between the cancellous bone 22 and the inner cortical bone 21b. The cortical bone impedance level portion 43d indicates that the tip is within the inner cortical bone 21b. The first falling edge 42b indicates that the tip is at the interface between the inner cortical bone 21b and the soft tissue. The impedance level portion 43e indicates that the tip has penetrated the structure of the three-layer bone tissue.

[0096]

[0096] In an actual operation, the inner side of the inner cortical bone 21b is usually soft tissue such as the spinal cord or the brain. After the ultrasonic osteotome 10 penetrates the inner cortical bone 21b, there is a tendency to damage nerve tissue.

[0097]

[0097] Therefore, when it is determined that the current position is the interface between the inner cortical bone 21b and the soft tissue, if the operator 50 is a doctor, the first prompt information can be sent to the operator 50 without delay. Here, the first prompt information can be a signal such as sound, light, or vibration, and the doctor can easily stop or lift the ultrasonic osteotome 10. In addition, when the operator 50 is a surgical robot, the first prompt information sent can be directly used to control the ultrasonic osteotome 10 to stop cutting.

[0098]

[0098] In conclusion, according to the above method 300, the current position of the tip can be detected, a prompt can be sent to a dangerous position, the safety of the operation can be further improved, and accidental damage to nerve tissue such as the spinal cord or the brain can be reduced.

[0099]

[0099] In some embodiments, in step S303, determining that the current position is the interface between the inner cortical bone and the soft tissue can include determining that the current position is the interface between the inner cortical bone 21b and the soft tissue in response to determining that the current position is the interface between the cortical bone 21, which is the second time, and other tissues.

[0100]

[0100] In the case of three-layer bone tissue, it will be understood that the cutting order is the outer cortical bone 21a, the cancellous bone 22, and the inner cortical bone 21b. Both the outer cortical bone 21a and the inner cortical bone 21b are the cortical bone 21. For the method for determining the interface between the outer cortical bone or the inner cortical bone and other tissues, refer to the method for determining the interface between the cortical bone and other tissues in the above embodiments.

[0101]

[0101] In this embodiment, the number of times the current position is at the interface between the cortical bone 21 and other tissues can be recorded to determine whether the current position is at the interface between the outer cortical bone 21a and the soft tissue or at the interface between the inner cortical bone 21b and the soft tissue. First, when the current position of the tip is at the interface between the cortical bone 21 and other tissues, the interface is the interface between the outer cortical bone 21a and the cancellous bone 22. When the current position of the tip is at the interface between the cortical bone 21 and other tissues for the second time, the interface is the interface between the inner cortical bone 21b and the soft tissue, and thus it is possible to accurately determine whether the tip is in contact with the outer cortical bone 21a or the inner cortical bone 21b.

[0102]

[0102] FIG. 4A is a diagram of the operating principle of an ultrasonic surgical system according to some embodiments of the present application. FIG. 4B is a graph of the acoustic impedance change of the ultrasonic osteotome in FIG. 4A. FIG. 4C is a flowchart of a method for determining the position of the ultrasonic osteotome applied to the ultrasonic surgical system of FIG. 4A.

[0103]

[0103] Referring to FIGS. 4A, 4B, and 4C, this embodiment further provides a method 400 for determining the position of the ultrasonic osteotome, and the method can be applied to surgeries for cutting a two-layer bone tissue structure, such as pedicle screw drilling surgery. As shown in FIG. 4A, the bone tissue 20 to be cut can include a cortical bone 21 and a cancellous bone 22 arranged sequentially from the outside to the inside, where the cortical bone 21 is outside the cancellous bone 22. The method can include steps S401 to S403.

[0104]

[0104] Step S401: Obtain the acoustic impedance signal of the ultrasonic osteotome 10.

[0105]

[0105] Step S402: Determine the current position of the ultrasonic osteotome 10 in the bone tissue 20 to be cut based on the acoustic impedance signal.

[0106]

[0106] Step S403: In response to determining that the displacement of the ultrasonic bone cutter 10 is within the preset size and the current position is at the boundary surface between the cancellous bone 22 and the cortical bone 21, send the second prompt information.

[0107]

[0107] Steps S401 and S402 are the same as steps S101 and S102 in the above embodiment. Please refer to the description of the above embodiment.

[0108]

[0108] It will be understood that FIG. 4B shows the acoustic impedance curve obtained when the two-layer bone tissue is cut through. The impedance level portion 43f indicates that the tip of the ultrasonic bone cutter 10 is consistently in air or soft tissue. The first rising edge 41c indicates that the tip is at the boundary surface between air or soft tissue and the cortical bone 21. The cortical bone impedance level portion 43g indicates that its tip is within the cortical bone 21. The first falling edge 42c indicates that the tip is at the boundary surface between the outer cortical bone 21 and the cancellous bone 22. The cancellous bone impedance level portion 43h indicates that the tip is within the cancellous bone 22.

[0109]

[0109] Regarding the pedicle screw drilling surgery, during the actual surgery, the drilling should penetrate the cortical bone 21 and stop in the cancellous bone 22. It will be understood that there is no such phenomenon that the tip is at the boundary surface between the cancellous bone and the cortical bone during this surgery.

[0110]

[0110] In step S403, the preset size can be the required drilling length, that is, the displacement of the ultrasonic bone cutter 10 should reach the preset size. In addition, if the displacement of the ultrasonic bone cutter 10 does not reach the preset size and the current position is at the boundary surface between the cancellous bone 22 and the cortical bone, it indicates that the cutting direction of the tip, that is, the drilling direction, is incorrect and the ultrasonic bone cutter 10 is in contact with other cortical bones. In this case, it is necessary to adjust the drilling direction. For the method of determining that the current position is at the boundary surface between the cancellous bone 22 and the cortical bone, please refer to the above embodiment.

[0111]

[0111] In addition, when the displacement of the ultrasonic bone cutter 10 is within the preset size and the current position is the interface between the cancellous bone 22 and the cortical bone 21, if the operator 50 is a doctor, the second prompt information can be sent to the operator 50 without delay. Here, the second prompt information can be a signal such as sound, light, or vibration, which prompts the doctor to adjust the cutting direction of the tip. In addition, when the operator 50 is a surgical robot, the sent second prompt information can be directly used to control the ultrasonic bone cutter 10 to adjust the direction of the tip.

[0112]

[0112] In conclusion, according to the above method 400, the current position of the tip can be detected, and when the drilling direction is incorrect for the operator 50, a prompt is issued without delay. Therefore, the drilling position is accurate and the safety of the surgery can be further improved.

[0113]

[0113] FIG. 5A is a diagram of the operating principle of an ultrasonic surgical system according to some embodiments of the present application. FIG. 5B is a graph of the acoustic impedance change of the ultrasonic bone cutter in FIG. 5A. FIG. 5C is a flowchart of a method for determining the position of the ultrasonic bone cutter applied to the ultrasonic surgical system of FIG. 5A.

[0114]

[0114] Referring to FIGS. 5A, 5B, and 5C, this embodiment further provides a method 500 for determining the position of an ultrasonic bone cutter, and the method can be applied to surgeries for cutting a single layer of bone tissue such as the lower limb bone. As shown in FIG. 5A, the bone tissue 20 to be cut can include the cortical bone 21. The method can include steps S501 to S503.

[0115]

[0115] Step S501: Obtain the acoustic impedance signal of the ultrasonic bone cutter 10.

[0116]

[0116] Step S502: Based on the acoustic impedance signal, determine the current position of the ultrasonic osteotome 10 in the bone tissue 20 to be cut.

[0117]

[0117] Step S503: In response to determining that the current position is the interface between the cortical bone and the soft tissue, send the third prompt information.

[0118]

[0118] Steps S501 and S502 are the same as steps S101 and S102 in the above embodiment. Please refer to the description of the above embodiment.

[0119]

[0119] It will be understood that FIG. 5B shows the acoustic impedance curve obtained when a single layer of bone tissue is cut through. The impedance level portion 43i indicates that the tip of the ultrasonic osteotome 10 is consistently in air or soft tissue. The first rising edge 41d indicates that the tip is at the interface between air or soft tissue and the cortical bone 21. The cortical bone impedance level portion 43j indicates that its tip is within the cortical bone 21. The first falling edge 42d indicates that the tip is at the interface between the cortical bone 21 and the soft tissue.

[0120]

[0120] In step S503, when the interface between the cortical bone 21 and the soft tissue appears, it is considered that the ultrasonic osteotome 10 has cut through the bone tissue. In this case, if the operator 50 is a doctor, the third prompt information can be sent to the operator 50 without delay. Here, the third prompt information can be a signal such as sound, light, or vibration, so that the doctor can easily stop or lift the ultrasonic osteotome 10. In addition, if the operator 50 is a surgical robot, the third prompt information sent can be directly used to control the ultrasonic osteotome 10 to stop the cutting.

[0121]

[0121] For the method of determining that the current position is the interface between the cortical bone and the soft tissue, please refer to the description of the above embodiment.

[0122]

[0122] As a conclusion, according to the above method 500, the current position of the tip can be detected. After the ultrasonic osteotome 10 cuts through the bone tissue, a prompt can be provided without delay, the safety of the surgery can be further improved, and damage to soft tissue can be reduced.

[0123]

[0123] As shown in FIG. 1B, the present application further provides an ultrasonic surgical system including an ultrasonic osteotome 10 and a processor 30. The ultrasonic osteotome 10 is configured to cut bone tissue 20 to be cut. The processor 30 is configured to implement a method for determining the position of the ultrasonic osteotome described in the above embodiments.

[0124]

[0124] The ultrasonic osteotome 10 can be controlled by a doctor or a surgical robot, and the processor 30 has a general structure capable of performing data processing. The processor can obtain an acoustic impedance signal of the tip by the transducer 11, process the acoustic impedance signal, and determine the current position of the tip. The method for determining the position of the ultrasonic osteotome is the same as that in the above embodiments, and the above embodiments can be referred to.

[0125]

[0125] According to the ultrasonic surgical system provided in this embodiment, the current position of the ultrasonic osteotome 10 in the bone tissue to be cut is determined based on the acoustic impedance signal. Therefore, the operator 50 can easily obtain the position of the ultrasonic osteotome 10 in real time. This system has high accuracy compared with image position detection, can effectively prevent the movement path of the ultrasonic osteotome from deviating from the target path, reduce damage to soft tissue during surgery, and improve the efficiency of the surgery.

[0126] [

[0126] ]FIG. 6 is a structural diagram of an ultrasonic surgical system according to some embodiments of the present application, and FIG. 7 is a partial enlarged view of the ultrasonic osteotome of FIG. 6. Referring to FIGS. 6 and 7, in some embodiments, the ultrasonic surgical system further includes a surgical robot 51 and a display device 40. The surgical robot 51 is connected to the ultrasonic osteotome 10. The display device 40 is configured to display the acoustic impedance signal of the ultrasonic osteotome 10. The processor 30 is further configured to operate the ultrasonic osteotome 10 by controlling the surgical robot 51.

[0127] [

[0127] ]The surgical robot 51 can be a general robot capable of performing motion control. The display device 40 can be a display structure such as a display, and can be configured to display acoustic impedance information and data feedback in real time, and can be further configured to display prompt information and the like.

[0128] [

[0128] ]The surgical robot 51 can be connected to the ultrasonic osteotome 10, and the processor 30 is communicably connected to the surgical robot 51 to send control commands to the surgical robot 51 and drive the ultrasonic osteotome 10 to move along the target path.

[0129] [

[0129] ]In fact, the ultrasonic surgical system can further include an image device configured to capture images of the ultrasonic osteotome 10 and the bone tissue 20 to be cut. The display device 40 can display the images to assist the operator 50 in intuitively knowing the position of the tip.

[0130] [

[0130] ]According to the embodiments of the present application, a non-transitory computer-readable storage medium storing computer instructions and computer program products is further provided.

[0131]

[0131] Computer instructions are used to cause a computer to perform the methods described above. A computer program product includes a computer program that, when executed by a processor, causes the methods described above to be performed.

[0132]

[0132] The computer can be any machine configured to perform processing and / or calculations, including but not limited to workstations, servers, desktop computers, laptop computers, tablet computers, personal digital assistants, smartphones, in-vehicle computers, wearable devices, or any combination thereof. According to some embodiments, the method for determining the position of the ultrasonic osteotome described above can also be performed, in whole or in part, by a computer or similar device or system.

[0133]

[0133] A computer can include elements connected to or communicating with a bus (possibly via one or more interfaces). For example, a computer can include a bus, one or more processors, one or more input devices, and one or more output devices. The one or more processors can be of any type of processor, and can include, but are not limited to, one or more general-purpose processors and / or one or more dedicated processors (e.g., dedicated processing chips, etc.). An input device can be any type of device that can input information into the computer, and can include, but are not limited to, sensors (e.g., sensors for acquiring images as described above), a mouse, a keyboard, a touch screen, a microphone, and / or a remote controller. An output device can be any type of device that can present information, and can include, but are not limited to, a display, a speaker (e.g., an output device that can be used to output audio data as described above), a video / audio output terminal, a vibrator, and / or a printer. The computer can further include a non-transitory storage medium or can be further connected to a non-transitory storage device. A non-transitory storage device (e.g., one that can be used to implement a computer-readable device as described above) can be non-transitory and can be any storage device that can implement a data storage device, and can include, but are not limited to, a disk drive, an optical storage device, a solid-state element memory, a floppy disk, a flexible disk, a hard disk, a magnetic tape or any other magnetic medium, an optical disk or any other optical medium, a read-only memory (ROM), a random access memory (RAM), a cache memory, and / or any other memory chip or cartridge, and / or any other medium that the computer can read data, instructions, and / or code from. The non-transitory storage device can be separable from the interface. The non-transitory storage device can have data / programs (including instructions) / code for implementing the methods and steps described above.The computer can further include a communication device. The communication device can be any type of device or system capable of communicating with an external device and / or a network, and includes, but is not limited to, for example, a modem, a network card, an infrared communication device, a wireless communication device, and / or a chipset, such as a Bluetooth device, a 1302.11 device, a Wi-Fi device, a WiMax device, a cellular communication device, and / or the like.

[0134]

[0134] The computer can further include a working memory (which can be used to implement the memory of the aforementioned system). The working memory can be any type of working memory capable of storing programs (including instructions) and / or data useful for the operation of the processor, and includes, but is not limited to, random access memory and / or read-only memory.

[0135]

[0135] The software element (program) can be located in the working memory, and includes, but is not limited to, an operating system, one or more application programs, drivers, and / or other data and code. The instructions for executing the methods and steps can be included in one or more applications. The executable code or source code of the instructions of the software element (program) can be stored in a non-transitory computer-readable storage medium (such as the aforementioned storage device), and can also be stored in the working memory when executed (which can be compiled and / or installed). Alternatively, the executable code or source code of the instructions of the software element (program) can also be downloaded from a remote location.

[0136]

[0136] The program code used to implement the method of the present application can be described in any combination of one or more programming languages. The program code can be provided to a processor or a controller of a general-purpose computer, a dedicated computer, or other programmable data processing device, so that when the program code is executed by the processor or the controller, the functions / operations specified in the flowchart and / or block diagram are implemented. The program code can be fully executed by a machine, or can be partially executed by a machine, or as an independent software package, can be partially executed by a machine and partially executed by a remote machine, or can be fully executed by a remote machine or server.

[0137]

[0137] It should be understood that based on the various forms of the procedures shown above, steps can be reordered, added, or deleted again. For example, the steps recorded in the present application can be implemented in parallel, in sequence, or in a different order as long as the desired results of the technical solutions in the present application can be achieved, but it is not limited in this specification.

[0138]

[0138] In this description, directional or positional relationships or dimensions indicated by terms such as "center", "longitudinal direction", "lateral direction", "length", "width", "thickness", "upper side", "lower side", "front", "rear", "left", "right", "vertical", "horizontal", "upper part", "bottom part", "inner side", "outer side", "clockwise", "counterclockwise", "axial direction", "radial direction", and "circumferential direction" are the directional or positional relationships or dimensions shown based on the drawings. These terms are not used to indicate or imply that the referenced device or element needs to have a specific orientation and be configured and operated in a specific orientation, but are simply used to facilitate the description. Therefore, it should be understood that they should not be construed as limiting the scope of protection of the present application.

[0139] In addition, terms such as "first", "second", and "third" are for descriptive purposes only and should not be construed as indicating or suggesting the relative importance of the recited technical features or implicitly indicating the number of such features. Thus, features defined as "first", "second", and "third" can explicitly or implicitly include one or more features. In the description of this application, the term "a plurality of" means two or more unless specifically and otherwise limited.

[0140]

[0140] In this application, terms such as "attach", "connect", "connected", and "fix" should be construed broadly, for example, as a fixed or removable connection, or integration, etc., and can be a mechanical connection or an electrical connection, or communication, and can be a direct connection or an indirect connection through an intermediate medium, or internal communication between two elements, or interaction between two elements, unless explicitly stated otherwise or otherwise limited. A person skilled in the art will interpret the specific meaning of the above terms in this application according to specific circumstances.

[0141]

[0141] In this application, unless explicitly stated otherwise or otherwise limited, the expression that a first feature is "above" or "below" a second feature can include the case where the first feature is in direct contact with the second feature, and can also include the case where the first feature and the second feature are not in direct contact but are in contact through another feature therebetween. Further, the fact that a first feature is "over", "above", or "on" a second feature includes the case where the first feature is directly or diagonally above the second feature, or simply indicates that the first feature is at a higher level than the second feature. The fact that a first feature is "below", "under", or "beneath" a second feature includes the case where the first feature is directly or diagonally below the second feature, or simply indicates that the first feature is at a lower level than the second feature.

[0142]

[0142] This description provides many different embodiments or examples that can be used to implement this application. It should be understood that these various embodiments or examples are purely illustrative and are by no means intended to limit the scope of protection of this application. Based on the disclosure of the description of this application, those skilled in the art may be able to conceive of various changes or alternative forms. Any changes or alternative forms will be included in the scope of protection of this application. Therefore, the scope of protection of this application will follow the scope of protection of the claims.

Claims

1. A method for determining the position of an ultrasonic bone cutter, comprising: acquiring an acoustic impedance signal of the ultrasonic bone cutter; and determining a current position of the ultrasonic bone cutter in bone tissue to be cut based on the acoustic impedance signal. A method as described above.

2. The step of determining the current position of the ultrasonic bone cutter in bone tissue to be cut based on the acoustic impedance signal includes: in response to determining that the acoustic impedance signal is at a first rising edge within a preset time and the average slope of the first rising edge is within a first slope range, determining that the current position is an interface between other tissue and cortical bone. The method according to claim 1, including the above step.

3. The step of determining that the current position is an interface between other tissue and cortical bone includes: in response to determining that the acoustic impedance amplitude at the starting point of the first rising edge is within a first preset range, determining that the current position is an interface between air and the cortical bone. The method according to claim 2, including the above step.

4. The step of determining that the current position is an interface between other tissue and cortical bone includes: in response to determining that the acoustic impedance amplitude at the starting point of the first rising edge is within a second preset range, determining that the current position is an interface between soft tissue and the cortical bone. The method according to claim 2, including the above step.

5. The step of determining that the current position is an interface between other tissue and cortical bone includes: in response to determining that the acoustic impedance amplitude at the starting point of the first rising edge is within a third preset range, determining that the current position is an interface between cancellous bone and the cortical bone. The method according to claim 2, including the above step.

6. The step of determining the current position of the ultrasonic bone cutter in bone tissue to be cut based on the acoustic impedance signal includes: in response to determining that the acoustic impedance signal is at a first falling edge within a preset time and the average slope of the first falling edge is within a second slope range, determining that the current position is an interface between cortical bone and other tissue. The method according to claim 1, including the above step.

7. The step of determining that the current position is an interface between cortical bone and other tissue includes: In response to determining that the acoustic impedance amplitude at the endpoint of the first downward edge is within a third preset range, determining that the current position is the interface between the cortical bone and the cancellous bone The method according to claim 6, comprising: **Claim 8** The step of determining that the current position is the interface between the cortical bone and other tissue In response to determining that the acoustic impedance amplitude at the endpoint of the first downward edge is within a second preset range, determining that the current position is the interface between the cortical bone and the soft tissue The method according to claim 6, comprising: **Claim 9** The step of determining the current position of the ultrasonic osteotome in the bone tissue to be cut based on the acoustic impedance signal In response to determining that the acoustic impedance signal is consistently within a fourth preset range throughout a preset time, determining that the current position is within the cortical bone The method according to claim 1, comprising: **Claim 10** The step of determining the current position of the ultrasonic osteotome in the bone tissue to be cut based on the acoustic impedance signal In response to determining that the acoustic impedance signal is consistently within a third preset range throughout a preset time, determining that the current position is within the cancellous bone The method according to claim 1, comprising: **Claim 11** The bone tissue to be cut comprises an outer cortical bone, the cancellous bone, and an inner cortical bone arranged sequentially from the outside to the inside, and the method Further comprising sending first prompt information in response to determining that the current position is the interface between the inner cortical bone and the soft tissue The method according to any one of claims 1 to 10, further comprising: **Claim 12** Determining that the current position is the interface between the inner cortical bone and the soft tissue In response to determining twice that the current position is the interface between the cortical bone and the other tissue, determining that the current position is the interface between the inner cortical bone and the soft tissue The method according to claim 11, comprising: **Claim 13** The bone tissue to be cut comprises the cortical bone and the cancellous bone arranged sequentially from the outside to the inside, and the method Sending second prompt information in response to determining that the displacement of the ultrasonic osteotome is within a preset size and that the current position is the interface between the cancellous bone and the cortical bone The method according to any one of claims 1 to 10, further comprising this step.

14. The bone tissue to be cut includes the cortical bone, and the method includes Sending third prompt information in response to determining that the current position is the interface between the cortical bone and the soft tissue The method according to any one of claims 1 to 10, further comprising this step.

15. An ultrasonic osteotome configured to cut bone tissue to be cut, A processor configured to implement the method according to any one of claims 1 to 14 An ultrasonic surgical system comprising these components.

16. The system includes A surgical robot connected to the ultrasonic osteotome, A display device configured to display an acoustic impedance signal of the ultrasonic osteotome, The ultrasonic surgical system according to claim 15, further comprising these components, wherein the processor is further configured to operate the ultrasonic osteotome by controlling the surgical robot.

17. A non-transitory computer-readable storage medium storing computer instructions, wherein the computer instructions are used to cause the computer to implement the method according to any one of claims 1 to 14.

18. A computer program product comprising a computer program, wherein when the computer program is executed by a processor, it causes the processor to implement the method according to any one of claims 1 to 14.

Images