Laparoscopic instrument control

Abstract

A method for controlling a laparoscopic instrument. The method includes grasping a target with the laparoscopic instrument by applying an initial trigger force to a trigger of the laparoscopic instrument, obtaining a variable trigger force based on a first clamping force, a second clamping force, and a state of the laparoscopic instrument, and applying the variable trigger force to the laparoscopic instrument to grasp the target with the laparoscopic instrument. The first clamping force is applied to the target by an upper jaw of the laparoscopic instrument, and the second clamping force is applied to the target by a lower jaw of the laparoscopic instrument.

Description

Technical Field

[0001] The present disclosure relates generally to minimally invasive medical procedures and, more particularly, to a method and system for controlling laparoscopic instruments. Background Art

[0002] Compared with open surgery and laparoscopic surgery, robot-assisted minimally invasive surgery has many advantages, such as improved dexterity and better ergonomics. Specifically, surgical robots can eliminate surgeons' hand tremors and reduce the range of hand movements, thereby enabling precise manipulation at the tip of surgical instruments. However, compared with open surgery, surgeons cannot directly contact tissues with robotic and laparoscopic systems, and therefore cannot sense the interaction forces between tissues and surgical instruments. In addition, the patient side of commercially available surgical robots may not have force sensing units for capturing interaction forces. Therefore, the lack of tactile feedback may affect surgeons' safe grasping and manipulation of delicate tissues and organs, and may also increase the risk of tissue damage or slippage during surgery.

[0003] Currently, there are two approaches to improve the grasping capabilities of surgical robots. The first is non-automatic grasping, and the second is automatic grasping. For surgical robots that use non-automatic grasping methods, the surgeon can directly control the position of the instrument jaws, and the interaction forces between tissue and instrument can be captured by a proximal or distal force / torque sensor. However, the forces at the jaws of the surgical instrument may not be accurately transmitted to the surgeon's hands, which may cause tissue damage or slippage during surgery.

[0004] In the automated grasping method, an auxiliary control system can automatically adjust the clamping force based on the tension applied to the tissue to prevent tissue damage and slippage. For both methods, it may be necessary to measure the magnitude of the clamping force and the tension applied to the tissue or organ, and the measurement is usually based on distal or proximal force sensing technology. In the distal force sensing technology, a six-degree-of-freedom micro force / torque sensor can be installed at the distal end of the surgical instrument to measure the tension, and one or two micro force sensors located on the clamp can measure the clamping force. However, this technology also has some disadvantages. For example, this technology can be challenging to implement because the force / torque sensor needs to fit into a limited space and meet durability and biocompatibility requirements. In the proximal force sensing technology, a six-degree-of-freedom force / torque sensor can be installed at the end of the surgical instrument near the trigger rod to measure the tension, and a single-degree-of-freedom force sensor can be installed on the trigger rod to measure the clamping force. This technology does not have the limitations of distal force sensing technology (such as being challenging to implement) and is less expensive. The automatic grasping method is based on the assumption that the clamping force on both sides of the jaws is equal during the process of grasping tissue. Under this assumption, the pulling force direction is the same as the direction of the trigger rod of the surgical instrument. However, this situation is very rare because in general three-dimensional operations, the clamping force on both sides of the jaws is usually not equal.

[0005] Therefore, there is a need for an automatic grasping method and system that can take into account the clamping force on both sides of the jaws during the process of changing the pulling force direction. In addition, there is a need for an automatic grasping method and system that can reduce the risk of damage and slippage of tissues and sensitive organs during surgery. Summary of the invention

[0006] This summary is intended to provide an overview of the subject matter of the present disclosure and is not intended to identify essential or critical elements of the subject matter nor to determine the scope of the claimed embodiments. The proper scope of the present disclosure can be determined from the claims set forth below in conjunction with the detailed description and accompanying drawings.

[0007] In one general aspect, the present disclosure describes an exemplary method for controlling a laparoscopic instrument. An exemplary method may include grasping a target with a laparoscopic instrument by applying an initial trigger force to a trigger of the laparoscopic instrument, obtaining a varying trigger force based on a first clamping force, a second clamping force, and a state of the laparoscopic instrument, and applying the varying trigger force to the laparoscopic instrument to grasp the target with the laparoscopic instrument.

[0008] In an exemplary embodiment, the first clamping force may be applied to the target by an upper jaw of the laparoscopic instrument, and the second clamping force may be applied to the target by a lower jaw of the laparoscopic instrument. In an exemplary embodiment, the first clamping force may be equal to or greater than the second clamping force.

[0009] In an exemplary embodiment, obtaining the changing trigger force based on the first clamping force, the second clamping force and the state of the laparoscopic instrument includes: using a force sensor to measure a pulling force applied to a target in response to the applied initial trigger force, wherein the pulling force is associated with an object connected to the target; using one or more processors to determine a lower limit of the second clamping force and an upper limit of the first clamping force based on a three-zone grasping model associated with the magnitude and direction of the pulling force; using one or more processors to set the magnitude of the second clamping force equal to the lower limit; using one or more processors to calculate the magnitude of the first clamping force based on the second clamping force and the pulling force; using one or more processors to generate a warning alarm in response to the magnitude of the first clamping force being equal to or greater than the upper limit; using one or more processors to calculate the magnitude of an average clamping force based on the first clamping force and the second clamping force in response to the magnitude of the first clamping force being less than the upper limit; and using one or more processors to calculate the magnitude of the changing trigger force based on a reaction force model associated with the average clamping force and the state of the laparoscopic instrument.

[0010] In an exemplary embodiment, measuring the pulling force may include measuring the magnitude and pulling angle of the pulling force, wherein the pulling angle is the angle between the direction of the pulling force and the bisector of the clamp angle. In an exemplary embodiment, the clamp angle may be the angle between the upper clamp direction and the lower clamp direction.

[0011] In an exemplary embodiment, finding the lower limit and the upper limit may include generating the three-region gripping model for a specific pulling direction by generating a clamping and pulling plane and dividing the clamping and pulling plane into three separate regions.

[0012] In an exemplary embodiment, the clamping plane in a specific pulling force direction may include a horizontal axis associated with the magnitude of the pulling force and a vertical axis associated with the magnitudes of the first clamping force and the second clamping force. In an exemplary embodiment, the vertical axis may be perpendicular to the horizontal axis.

[0013] In an exemplary embodiment, the division of the clamping plane into three separate regions may include a slip zone bounded by a slip curve, a damage zone bounded by a damage curve, and a safety zone bounded by the slip curve and the damage curve. In an exemplary embodiment, the safety zone may be associated with the lower limit and the upper limit.

[0014] In an exemplary embodiment, dividing the clamping and pulling plane into three separate areas may include: deriving a slip curve in a specific pulling direction by replacing the target with a test object; setting the magnitude of the second clamping force to multiple clamping force levels in ascending order; obtaining slip thresholds corresponding to each clamping force level; and obtaining a slip curve by fitting the change in the slip threshold that occurs relative to the change in the clamping force level into a curve.

[0015] In an exemplary embodiment, dividing the clamping plane into three separate areas may also include: deriving a damage curve in a specific tension direction by setting the magnitude of the tension to multiple tension levels in ascending order; obtaining damage thresholds corresponding to each tension level; and obtaining a damage curve by fitting the change in the damage threshold that occurs relative to the change in the tension level into a curve.

[0016] In an exemplary embodiment, obtaining the damage thresholds corresponding to the respective tension levels may include: setting the magnitude of the first clamping force to zero; continuously increasing the magnitude of the first clamping force until a damaged area is generated on the test object; and measuring the magnitude of the first clamping force that causes the damaged area to begin to be generated, so as to obtain the corresponding damage threshold. The corresponding damage threshold may be associated with a given tension direction and magnitude.

[0017] In an exemplary embodiment, calculating the magnitude of the first clamping force based on the second clamping force and the pulling force may include solving the following static rotational equilibrium equation:

[0018] F g1 -F g2 =F′ pull

[0019] in:

[0020] F g1 represents the magnitude of the first clamping force,

[0021] F g2 represents the magnitude of the second clamping force, and

[0022] F′ pull It indicates the magnitude of the pulling force along the axis perpendicular to the bisector of the clamp angle.

[0023] In an exemplary embodiment, calculating the magnitude of the average clamping force based on the first clamping force and the second clamping force may include averaging the magnitude of the first clamping force and the magnitude of the second clamping force.

[0024] In an exemplary embodiment, calculating the magnitude of the changing trigger force may include: obtaining the state of the laparoscopic instrument by measuring a clamp angle, i.e., an angle between an upper clamp direction and a lower clamp direction, and by measuring a toggle angle, i.e., an angle between a direction of a trigger rod of the laparoscopic instrument and a bisector of the clamp angle. In an exemplary embodiment, the toggle angle may be calculated according to the following formula:

[0025]

[0026] in:

[0027] represents the elbow angle,

[0028] ψ represents the rotation of the laparoscopic instrument around the Y axis, and

[0029] α represents the rotation amount of the laparoscopic instrument around the Z axis.

[0030] In an exemplary embodiment, calculating the magnitude of the changed trigger force may further include calculating the changed trigger force according to the following formula:

[0031]

[0032] in:

[0033] F g represents the average clamping force,

[0034] F t represents the triggering force of the change,

[0035] θ represents the clamp angle,

[0036] represents the elbow angle, and

[0037] g * (·,·,·) represents the reverse instrument force model (reaction force model) of the laparoscopic instrument.

[0038] In an exemplary embodiment, calculating the magnitude of the changing trigger force may further include: pivoting the upper jaw and the lower jaw through a pivot; applying the initial trigger force to an actuation cable associated with the laparoscopic instrument to apply the initial trigger force to the laparoscopic instrument; applying the initial trigger force to the laparoscopic instrument to grasp the target at a contact point with the target; and deriving the reaction force model according to the following set of equations:

[0039]

[0040]

[0041] μ′=0.5μ 1 +μ 2

[0042] in:

[0043] represents the magnitude of the average clamping force,

[0044] represents the magnitude of the triggering force of the change,

[0045] f k0 represents the static friction force of the laparoscopic instrument,

[0046] L, α 0 and D represent the geometric parameters of the laparoscopic instrument,

[0047] μ represents the friction coefficient between the shaft pin of the laparoscopic instrument and the cam grooves of the lower clamp and the upper clamp,

[0048] r represents the radius of the axle pin,

[0049] d represents the distance between the pivot and the contact point,

[0050] K inst represents the stiffness of the laparoscopic instrument,

[0051] μ 1 represents the coefficient of friction between the actuation cable and the inside of the instrument trigger rod, and

[0052] μ 2 represents the coefficient of friction between the actuation cable and the inside of the instrument elbow.

[0053] In another aspect of the present disclosure, a system for controlling a laparoscopic instrument is disclosed. An exemplary system may include an actuator including an actuation cable configured to apply a trigger force to the laparoscopic instrument. In an exemplary embodiment, the laparoscopic instrument may be configured to grasp an object at a contact point with the object in response to application of the trigger force.

[0054] In an exemplary embodiment, the laparoscopic instrument may include a lower clamp, an upper clamp, a clamp angle, and a toggle angle. In an exemplary embodiment, the upper clamp may be pivotally connected to the lower clamp via a pivot. In an exemplary embodiment, the clamp angle may be an angle between the direction of the upper clamp and the direction of the lower clamp. In an exemplary embodiment, the toggle angle may be an angle between the direction of the instrument trigger rod and the bisector of the clamp angle. In an exemplary embodiment, the toggle angle may be calculated according to the following formula:

[0055]

[0056] in:

[0057] represents the elbow angle,

[0058] ψ represents the rotation of the laparoscopic instrument around the Y axis, and

[0059] α represents the rotation amount of the laparoscopic instrument around the Z axis.

[0060] In an exemplary embodiment, the system may further include: a memory having processor-readable instructions stored therein, and one or more processors configured to access the memory and execute the processor-readable instructions, and when executed by the processor, the instructions configure the processor to perform a method. In an exemplary embodiment, the method may further include obtaining the changed trigger force based on the first clamping force, the second clamping force, and the state of the laparoscopic instrument.

[0061] In an exemplary embodiment, the system may further include a six-degree-of-freedom force / torque sensor mounted on an end of the laparoscopic instrument in the system near the trigger. The six-degree-of-freedom force / torque sensor may be configured to measure the magnitude and direction of the pulling force. In an exemplary embodiment, the pulling force may be applied to the target in response to the applied trigger force. In an exemplary embodiment, the pulling force is associated with an object connected to the target. In an exemplary embodiment, the system may further include a single-degree-of-freedom force sensor, which may be mounted on the trigger rod of the laparoscopic instrument. In an exemplary embodiment, the single-degree-of-freedom force sensor may be configured to measure the clamping force based on proximal force sensing technology. In an exemplary embodiment, the system may further include a spherical mechanism configured to measure the elbow angle of the laparoscopic instrument.

[0062] In an exemplary embodiment, obtaining the changing trigger force based on the first clamping force, the second clamping force and the state of the laparoscopic instrument may include: finding a lower limit of the second clamping force and an upper limit of the second clamping force based on a three-zone grasping model associated with the pulling force; setting the magnitude of the second clamping force to be equal to the lower limit; calculating the magnitude of the first clamping force based on the second clamping force and the magnitude and direction of the pulling force; generating a warning alarm in response to the magnitude of the first clamping force being equal to or greater than the upper limit; calculating the magnitude of the average clamping force based on the first clamping force and the second clamping force; and calculating the magnitude of the changing trigger force based on a reaction force model associated with the average clamping force and the state of the laparoscopic instrument.

[0063] In an exemplary embodiment, finding the lower limit and the upper limit may include generating the three-region gripping model for a specific pulling force direction by generating a clamping and pulling plane including a plurality of curve pairs and dividing the clamping and pulling plane into three separate regions. In an exemplary embodiment, in a specific pulling force direction, each curve pair may include a first value associated with the magnitude of the pulling force and a second value associated with the magnitude of the first clamping force and the magnitude of the second clamping force.

[0064] In an exemplary embodiment, the clamping plane may include a slip zone limited by a slip curve, a damage zone limited by a damage curve, and a safety zone limited by the slip curve and the damage curve. In an exemplary embodiment, the safety zone may be associated with the lower limit and the upper limit.

[0065] In an exemplary embodiment, dividing the clamping and pulling plane into three separate areas may include: deriving a slip curve in a specific pulling direction by replacing the target with a test object; setting the magnitude of the second clamping force to multiple clamping force levels in ascending order; obtaining slip thresholds corresponding to each clamping force level; and obtaining a slip curve by fitting the change in the slip threshold that occurs relative to the change in the clamping force level into a curve.

[0066] In an exemplary embodiment, obtaining the slip threshold values ​​corresponding to each clamping force level may include: setting the magnitude of the pulling force to zero; continuously increasing the magnitude of the pulling force until the test object slips on the laparoscopic instrument; and measuring the magnitude of the pulling force that causes the test object to begin to slip, so as to obtain the corresponding slip threshold values.

[0067] In an exemplary embodiment, dividing the clamping plane into three independent areas may also include: deriving a damage curve in a specific tension direction by setting the magnitude of the tension to multiple tension levels in ascending order; obtaining damage thresholds corresponding to each tension level; and obtaining a damage curve by fitting the change in the damage threshold that occurs relative to the change in the tension level into a curve.

[0068] In an exemplary embodiment, obtaining the damage thresholds corresponding to the respective tension levels may include: setting the magnitude of the first clamping force to zero; continuously increasing the magnitude of the first clamping force until a damaged area is generated on the test object; and measuring the magnitude of the first clamping force that causes the damaged area to begin to be generated, so as to obtain the corresponding damage threshold. The corresponding damage threshold may be associated with a given tension magnitude and direction.

[0069] In an exemplary embodiment, calculating the magnitude of the first clamping force includes solving the following static rotational equilibrium equation:

[0070] Fg1 -F g2 =F′ pull

[0071] in:

[0072] F g1 represents the magnitude of the first clamping force,

[0073] F g2 represents the magnitude of the second clamping force, and

[0074] F′ pull It indicates the magnitude of the pulling force along the axis perpendicular to the bisector of the clamp angle.

[0075] In an exemplary embodiment, calculating the magnitude of the average clamping force may include finding an average of the magnitude of the first clamping force and the magnitude of the second clamping force. In an exemplary embodiment, calculating the magnitude of the variable trigger force based on the reaction force model may include deriving the reaction force model based on the following set of equations about the instrument force model:

[0076]

[0077]

[0078] μ′=0.5μ 1 +μ 2

[0079] in:

[0080] represents the magnitude of the average clamping force,

[0081] represents the magnitude of the triggering force of the change,

[0082] f k0 represents the static friction force of the laparoscopic instrument,

[0083] θ represents the clamp angle,

[0084] represents the elbow angle,

[0085] L, α 0 and D represent the geometric parameters of the laparoscopic instrument,

[0086] μ represents the friction coefficient between the shaft pin of the laparoscopic instrument and the cam grooves of the lower clamp and the upper clamp,

[0087] r represents the radius of the axle pin,

[0088] d represents the distance between the pivot and the contact point,

[0089] K inst represents the stiffness of the laparoscopic instrument,

[0090] μ 1 represents the coefficient of friction between the actuation cable and the inside of the instrument trigger rod, and

[0091] μ 2 represents the coefficient of friction between the actuation cable and the inside of the instrument elbow. BRIEF DESCRIPTION OF THE DRAWINGS

[0093] By way of example and not limitation, the accompanying drawings depict one or more embodiments that may be employed in accordance with the present solution. In the accompanying drawings, the same reference numerals refer to the same or similar elements.

[0094] Figure 1A A flow chart of a method for controlling a laparoscopic instrument is shown, consistent with one or more exemplary embodiments of the present disclosure.

[0095] Figure 1B A flow chart for obtaining a varying trigger force is shown, consistent with one or more exemplary embodiments of the present disclosure.

[0096] Figure 2A A schematic diagram of a laparoscopic instrument is shown, consistent with one or more exemplary embodiments of the present disclosure.

[0097] Figure 2B Another schematic diagram of a laparoscopic instrument is shown, consistent with one or more exemplary embodiments of the present disclosure.

[0098] Figure 3 A three-zone grasping model is shown, consistent with one or more exemplary embodiments of the present disclosure.

[0099] Figure 4 A system for controlling a laparoscopic instrument is shown, consistent with one or more exemplary embodiments of the present disclosure.

[0100] Figure 5 An exemplary computer system is shown in which embodiments of the present invention or portions thereof may be implemented as computer-readable code, consistent with one or more exemplary embodiments of the present disclosure. Specific embodiments

[0101] In the following detailed description, many specific details are set forth by way of example to provide a thorough understanding of the relevant scheme. However, it is apparent that the scheme can be practiced without these specific details. In other cases, well-known methods, steps, components and / or circuits are not described in detail to avoid unnecessary confusion of various aspects of the scheme.

[0102] By providing the following detailed description, it is possible for those skilled in the art to make and use the methods and devices disclosed in the exemplary embodiments of the present disclosure. For the purpose of explanation, specific nomenclature is set forth to provide a thorough understanding of the present disclosure. However, it is obvious that the disclosed exemplary embodiments can also be practiced without these specific details for those skilled in the art. The description of specific exemplary embodiments is provided only as a representative example. It will be readily apparent to those skilled in the art that various modifications to these exemplary implementations will be apparent, and the general principles defined herein may be applicable to other examples and applications without departing from the scope of the present disclosure. The present disclosure is not intended to be limited to the described embodiments, but is intended to conform to the broadest possible scope consistent with the principles and features disclosed herein.

[0103] An exemplary method and system for controlling a laparoscopic instrument is disclosed herein. According to an exemplary method, human tissue can be grasped by applying an initial trigger force to a trigger of a laparoscopic instrument. When the tissue is grasped by the clamp of the laparoscopic instrument, the force applied from the tissue to the upper clamp of the laparoscopic instrument and the force applied from the tissue to the lower clamp of the laparoscopic instrument may not be the same. Therefore, a varying trigger force of the laparoscopic instrument can be obtained based on different magnitudes of force applied from the tissue to the clamp of the laparoscopic instrument. Thereafter, the tissue can be grasped by applying the varying trigger force to the trigger of the laparoscopic instrument.

[0104] Figure 1A A flow chart of a method for controlling a laparoscopic instrument is shown, consistent with one or more exemplary embodiments of the present disclosure. Exemplary method 100 may include grasping a target with a laparoscopic instrument by applying an initial trigger force to a trigger of the laparoscopic instrument (step 102), obtaining a varying trigger force based on a first clamping force, a second clamping force, and a state of the laparoscopic instrument (step 104), and applying the varying trigger force to the laparoscopic instrument to grasp the target with the laparoscopic instrument (step 106).

[0105] Figure 2A A schematic diagram of a laparoscopic instrument is shown, consistent with one or more exemplary embodiments of the present disclosure. Figure 2BAnother schematic diagram of a laparoscopic instrument is shown, consistent with one or more exemplary embodiments of the present disclosure. In an exemplary embodiment, the different steps of method 100 can be implemented by utilizing an exemplary laparoscopic instrument 200. In an exemplary embodiment, the laparoscopic instrument 200 can also include an actuation cable 202 and a trigger lever 203. In an exemplary embodiment, a target 210 can be grasped by applying a force to the actuation cable 202. In an exemplary embodiment, a force can be applied to the actuation cable 202. In an exemplary embodiment, a surgeon can manually apply a force to a trigger of the laparoscopic instrument. However, in an exemplary embodiment, a force can be applied to a trigger of the laparoscopic instrument by using an actuator. In an exemplary embodiment, the target 210 can include tissue or an organ in a human body. In an exemplary embodiment, with the laparoscopic instrument 200, the target 210 can be grasped by pulling the actuation cable 202 in a direction 222.

[0106] In an exemplary embodiment, it is understood that since the target 210 is connected to some objects near it, by applying the initial trigger force to the actuation cable 202, a pulling force can be applied to the target 210. In an exemplary embodiment, it is understood that the direction of the pulling force can be any direction in space. In an exemplary embodiment, it is understood that the target 210 can be connected to some tissues and / or organs in the human body. For example, the target 210 can be connected to bones and / or muscles of the human body. When the initial trigger force is applied to the actuation cable 202, the object connected to the target 210 can resist the initial trigger force, so a pulling force can be applied to the target 210. In an exemplary embodiment, the direction of the applied pulling force can be any direction in space. In an exemplary embodiment, the laparoscopic instrument 200 may also include a lower clamp 204 and an upper clamp 206. In an exemplary embodiment, the lower clamp 204 and the upper clamp 206 may be pivotally connected by a shaft pin 234. In an exemplary embodiment, when the target 210 is grasped by the laparoscopic instrument 200, a first clamping force 242 may be applied to the target 210 from the upper jaw 206, and a second clamping force 262 may be applied to the target 210 from the lower jaw 204. In an exemplary embodiment, it can be understood that when the target 210 is grasped by the laparoscopic instrument 200, the lower jaw 204 and the upper jaw 206 may prevent the target 210 from slipping, thereby holding the target 210 between the lower jaw 204 and the upper jaw 206. In an exemplary embodiment, the first clamping force 242 may refer to the force applied to the target 210 by the upper jaw 206 when the target 210 is grasped by the laparoscopic instrument 200. In an exemplary embodiment, the second clamping force 262 may refer to the force applied to the target 210 by the lower jaw 204 when the target 210 is grasped by the laparoscopic instrument 200. In an exemplary embodiment, since the second clamping force 262 may be different from the first clamping force 242, it may be assumed that the first clamping force 242 is equal to or greater than the second clamping force 262. In an exemplary embodiment, the jaw angle 205 may be defined as the angle between the main axis 243 of the lower jaw 204 and the main axis 263 of the upper jaw 206. In addition, the toggle angle 235 may be defined as the angle between the main axis 232 of the trigger lever 203 and the bisector 252 of the jaw angle 205. In an exemplary embodiment, the toggle angle 235 may be calculated according to the following formula:

[0107]

[0108] in:

[0109] represents the elbow angle,

[0110] ψ represents the amount of rotation of the laparoscopic instrument 200 about the Y-axis 237, and

[0111] α represents the amount of rotation of the laparoscopic instrument around the Z-axis 238 .

[0112] In an exemplary embodiment, the state of the laparoscopic instrument 200 may refer to the state of the forceps angle 205 and the elbow angle 235. In an exemplary embodiment, different measurements of the forceps angle 205 and the elbow angle 235 may cause the laparoscopic instrument 200 to present different states. For example, when the forceps angle 205 and / or the elbow angle 235 are increased and / or decreased, the state of the laparoscopic instrument 200 may also change. In other words, a specific state of the laparoscopic instrument 200 may refer to a specific measurement of the forceps angle 205 and the elbow angle 235.

[0113] In conjunction with the further detailed description of step 104, Figure 1B A flow chart for obtaining the changed trigger force is shown, consistent with one or more exemplary embodiments of the present disclosure. In an exemplary embodiment, obtaining the changed trigger force may include: measuring the magnitude and direction of the pulling force applied to the target 210 (step 108); finding a lower limit of the second clamping force 262 and an upper limit of the first clamping force 242 (step 110); setting the magnitude of the second clamping force 262 to be equal to the lower limit (step 112); calculating the magnitude of the first clamping force 242 based on the second clamping force 262 and the magnitude and direction of the pulling force (step 114); generating a warning alarm in response to the magnitude of the first clamping force 242 being equal to or greater than the upper limit (step 116); calculating the magnitude of the average clamping force based on the first clamping force 242 and the second clamping force 262 in response to the magnitude of the first clamping force 242 being less than the upper limit (step 118); and calculating the magnitude of the changed trigger force based on a reaction force model associated with the first clamping force, the second clamping force, and the state of the laparoscopic instrument (step 120).

[0114] In an exemplary embodiment, the pulling force applied to the target 210 may include a pulling force magnitude and a pulling force angle. In an exemplary embodiment, the pulling force angle may be changed by changing the direction of the pulling force in space. In an exemplary embodiment, the pulling force magnitude and the pulling force angle may be measured by a six-degree-of-freedom force / torque sensor mounted at the end of the laparoscopic instrument 200 and adjacent to the trigger. In an exemplary embodiment, the pulling force angle may be defined as the angle between the direction of the pulling force and the bisector 252 of the forceps angle 205.

[0115] In an exemplary embodiment, a lower limit of second clamping force 262 and an upper limit of first clamping force 242 may be found based on a three-zone gripping model associated with the pulling force (step 110 ). Figure 3 A three-zone gripping model 300 is shown, consistent with one or more exemplary embodiments of the present disclosure. In exemplary embodiments, it can be understood that the three-zone gripping model 300 can be associated with a specific direction of the pulling force. In fact, for each different pulling force direction, a corresponding three-zone gripping model can be obtained.

[0116] like Figure 3 As shown, in an exemplary embodiment, the three-zone grip model 300 for a specific pulling force direction can be defined in a clamping and pulling plane 307, wherein the clamping and pulling plane 307 has a horizontal axis 372 associated with the pulling force magnitude. In an exemplary embodiment, the clamping and pulling plane 307 can also have a vertical axis 374 associated with the first clamping force 242 and the second clamping force 262. In an exemplary embodiment, the clamping and pulling plane 307 is divided into three separate areas, which can include a slip zone 302, a damage zone 304, and a safe zone 306. In an exemplary embodiment, the slip zone 302 can be limited by a slip curve 303, the damage zone 304 can be limited by a damage curve 305, and the safe zone 306 can be limited by both the slip curve 303 and the damage curve 305. In an exemplary embodiment, the lower limit can be associated with the slip curve 303 and the upper limit can be associated with the damage curve 305.

[0117] like Figure 3 As further shown, in an exemplary embodiment, an actual slip curve 308 may be obtained by shifting the slip curve 303 up by a first amount 332. Additionally, in an exemplary embodiment, an actual injury curve 309 may be obtained by shifting the injury curve 305 down by a second amount 352. In an exemplary embodiment, an actual safety zone may be defined between the slip curve 308 and the actual injury curve 309. In an exemplary embodiment, the actual safety zone helps ensure safe grasping during the implementation of the automatic grasping algorithm. In an exemplary embodiment, the lower limit may be obtained by utilizing the actual slip curve 308. In an exemplary embodiment, the upper limit may be obtained by utilizing the actual injury curve 309. In an exemplary embodiment, the first amount 332 and the second amount 352 may be calculated based on the laparoscopic surgery conditions. In an exemplary embodiment, the first amount 332 may be the same as the second amount 352.

[0118] In an exemplary embodiment, a test object may be used to replace the target 210 in order to derive the slip curve 303. In an exemplary embodiment, the test object may be similar to the target 210 in terms of shape, size, and mechanical properties. Then, the magnitude of the second clamping force 262 may be set to a plurality of clamping force levels starting from zero and in ascending order. Then, for each different clamping force level, the magnitude of the pulling force in a specific direction may be continuously increased until the test object slips on the laparoscopic instrument 200. In an exemplary embodiment, the test object slipping on the laparoscopic instrument 200 may refer to the test object being detached from the laparoscopic instrument 200 when being grasped by the laparoscopic instrument 200 due to insufficient gripping force. Then, the pulling force when the test object starts to slip between the lower clamp 204 and the upper clamp 206 may be recorded as a slip data point associated with a given clamping force magnitude and pulling force direction. Then, in response to the slipping of the test object, a corresponding slip threshold may be measured. Finally, the slip curve 303 for a specific pulling force direction is obtained by fitting the change of the slip threshold value occurring with respect to the change of the clamping force level into a curve.

[0119] In an exemplary embodiment, in order to obtain the damage curve 305, the magnitude of the pulling force in a specific direction can be set to multiple pulling levels starting from zero in ascending order. Then, for each different pulling level, the magnitude of the first clamping force 242 can be continuously increased until a damaged area is generated on the test object. In an exemplary embodiment, the clamping force can be recorded as a damage data point associated with a given pulling force magnitude and a corresponding pulling direction. Then, the corresponding damage threshold can be obtained by measuring the magnitude of the first clamping force 242 that causes the damage area to begin to be generated. Finally, the damage curve 305 for a specific pulling direction is obtained by fitting the change in the damage threshold relative to the change in the pulling level into a curve. In an exemplary embodiment, it can be understood that the damage curve 305 and the slip curve 303 can be associated with a specific pulling direction. In an exemplary embodiment, corresponding damage curves 305 and slip curves 303 can be obtained for different pulling directions.

[0120] In an exemplary embodiment, a force sensor may be used to measure the pulling force applied to the target 210 in response to the initial trigger force applied. In an exemplary embodiment, the force sensor may refer to a device capable of measuring the force applied to an object. In an exemplary embodiment, the force sensor may include a dynamometer. In an exemplary embodiment, the force sensor may include a six-degree-of-freedom force / torque sensor, which is mounted at one end of the laparoscopic instrument 200 and is configured to measure the magnitude and direction of the pulling force. Then, using the three-zone grasping model 300, for a given magnitude and direction of the pulling force, a lower limit and an upper limit of the clamping force that are actually safe may be derived. In an exemplary embodiment, to derive the lower limit and upper limit of the clamping force that are actually safe, an assumed line (not shown) parallel to the second axis 374 and intersecting the first axis 372 may be used, wherein the first axis is associated with the pulling force measured in a specific direction. In an exemplary embodiment, for a specific magnitude and direction of the pulling force, the value of the intersection of the assumed line with the actual damage curve 309 may represent the upper limit, and the value of the intersection of the assumed line with the actual slip curve 308 may represent the lower limit. Then, the magnitude of the second clamping force 262 may be set to the derived lower limit, and the magnitude of the first clamping force 242 may be calculated based on the second clamping force 262 and the magnitude and direction of the pulling force.

[0121] In an exemplary embodiment, the magnitude of the first clamping force may be calculated based on the second clamping force and the pulling force by solving the following static rotational equilibrium equation (step 114):

[0122] F g1 -F g2 =F′ pull

[0123] Among them, F g1 represents the magnitude of the first clamping force 242, F g2 represents the magnitude of the second clamping force 262, F′ pull Represents the magnitude of the pulling force along the direction of the axis perpendicular to the bisector 252 of the clamp angle 205, which can be measured using a force sensor / dynamometer. In an exemplary embodiment, if the calculated first clamping force 242 is equal to or greater than the upper limit, a warning alarm will be generated, indicating that the total force applied to the target 210 may exceed the allowed value. If the first clamping force 242 is less than the upper limit, the average clamping force can be calculated based on the first clamping force 242 and the second clamping force 262. In an exemplary embodiment, the average clamping force can be calculated by finding the average value of the first clamping force 242 and the second clamping force 262. In an exemplary embodiment, the magnitude of the changing trigger force can be calculated based on the reaction force model of the instrument force model. In an exemplary embodiment, the instrument force model can be derived according to the following formula:

[0124]

[0125]

[0126] μ′=0.5μ 1 +μ 2

[0127] Indicates the magnitude of the average clamping force. Indicates the magnitude of the triggering force of the change. k0 represents the static friction force of the laparoscopic instrument. L, α 0 and D represent the geometric parameters of the laparoscopic instrument, μ represents the friction coefficient between the shaft pin 234 of the laparoscopic instrument 200 and the cam grooves of the lower clamp 204 and the upper clamp 206, r represents the radius of the shaft pin 234, and d represents the distance between the pivot and the contact point. In an exemplary embodiment, the contact point may refer to the point where the target 210 contacts the lower clamp 204 and the upper clamp 206. inst represents the stiffness of the laparoscopic instrument 200, μ 1 represents the friction coefficient between the actuation cable and the inner side of the instrument trigger rod, and μ 2 represents the coefficient of friction between the actuation cable and the inside of the instrument elbow.

[0128] Also disclosed herein is an exemplary system for controlling a laparoscopic instrument, such as laparoscopic instrument 200 . Figure 4A system 400 for controlling a laparoscopic instrument 200 is shown, consistent with one or more exemplary embodiments of the present disclosure. In an exemplary embodiment, the system 400 may include an actuator 402, wherein the actuator 402 includes an actuation cable 202. In an exemplary embodiment, the actuation cable 202 may be configured to apply a trigger force to the laparoscopic instrument 200. In an exemplary embodiment, the system 400 may also include a memory 404 in which processor-readable instructions are stored. In an exemplary embodiment, the system 400 may also include one or more processors 406, which are configured to access the memory 404 and execute the processor-readable instructions, and when executed by the processor, the instructions configure the processor to perform the method 100. In an exemplary embodiment, the system 400 may also include a force sensor 405, which may be configured to measure the magnitude and direction of the pulling force. In an exemplary embodiment, the system 400 may also include a six-degree-of-freedom force / torque sensor, which may be mounted on the trigger rod of the laparoscopic instrument 200. In an exemplary embodiment, the six-degree-of-freedom force / torque sensor may be configured to measure the magnitude and direction of the pulling force. In an exemplary embodiment, the system 400 may further include a single degree of freedom force sensor, which may be mounted on the trigger rod of the laparoscopic instrument 200. In an exemplary embodiment, the single degree of freedom force sensor may be configured to measure the clamping force based on a proximal force sensing technique. In an exemplary embodiment, the proximal force sensing technique may refer to a technique for calculating the clamping force based on an instrument force model and a force applied to the trigger rod. In an exemplary embodiment, the system 400 may further include a spherical mechanism, wherein the spherical mechanism includes encoders of a plurality of actuators. In an exemplary embodiment, the encoders of the actuators of the spherical mechanism may be configured to measure the elbow angle.

[0129] Figure 5 An exemplary computer system 500 is shown in which embodiments of the present invention or portions thereof may be implemented as computer readable code, consistent with one or more exemplary embodiments of the present disclosure. For example, method 100 may be implemented in computer system 500 using hardware, software, firmware, a tangible computer readable medium storing instructions, or a combination thereof, and may be implemented in one or more computer systems or other processing systems. In an exemplary embodiment, system 500 may be similar to processor 406. Hardware, software, or any combination thereof may embody Figure 4 Any modules and components in .

[0130] If programmable logic is used, the logic can be executed on a commercial processing platform or a dedicated device. It should be understood by those skilled in the art that embodiments of the disclosed subject matter can be practiced on a variety of computer system configurations, including multi-core multi-processor systems, minicomputers, mainframe computers, computers connected or grouped to have distributed functionality, and general-purpose or microcomputers that can be embedded in almost any device.

[0131] For example, the above embodiments may be implemented using a computing device having at least one processor device and a memory. The processor device may be a single processor, multiple processors, or a combination thereof. The processor device may have one or more processor "cores".

[0132] Embodiments of the present invention are described with respect to an exemplary computer system 500. After reading this description, it will be apparent to those skilled in the relevant art how to implement the present invention using other computer systems and / or computer architectures. Although various operations may be described as sequential processes, portions of the operations may actually be performed in parallel, simultaneously, and / or in a distributed environment, and have program code that may be stored locally or remotely for access by a single processor or a multi-processor machine. Furthermore, in some embodiments, the order of operations may be rearranged without departing from the spirit of the disclosed subject matter.

[0133] Processor device 504 can be a dedicated or general purpose processor device. Those skilled in the relevant art will appreciate that processor device 504 can be a single processor in a multi-core / multi-processor system running alone, or a single processor in a cluster of computing devices running in a cluster or server group. Processor device 504 can be connected to a communication infrastructure 506, such as a bus, a message queue, a network, or a multi-core message passing scheme.

[0134] In an exemplary embodiment, the computer system 500 may include a display interface 502, such as a video connector, to transmit data to a display unit 530, such as a monitor. The computer system 500 may also include a main memory 508, such as a random access memory (RAM), and may also include an auxiliary memory 510. The auxiliary memory 510 may include, for example, a hard disk drive 512 and a removable storage drive 514. The removable storage drive 514 may include a floppy disk drive, a tape drive, an optical disk drive, a flash memory, etc. The removable storage drive 514 can read and write to a removable storage unit 518 in a well-known manner. The removable storage unit 518 may include a floppy disk, a tape, an optical disk, etc., which can be read and written by the removable storage drive 514. It should be understood by those skilled in the relevant art that the removable storage unit 518 may include a computer-usable storage medium having computer software and / or data stored therein.

[0135] In alternative embodiments, the secondary memory 510 may include other similar devices to allow computer programs or other instructions to be loaded into the computer system 500. Such devices may include, for example, a removable storage unit 522 and an interface 520. Examples of such devices may include a program cartridge and cartridge interface (such as used in video game devices), a removable memory chip (such as an EPROM or PROM) and an associated slot, and other removable storage units 522 and interfaces 520 that allow software and data to be transferred from the removable storage unit 522 to the computer system 500.

[0136] The computer system 500 may also include a communication interface 524. The communication interface 524 allows software and data to be transferred between the computer system 500 and external devices. The communication interface 524 may include a modem, a network interface (e.g., an Ethernet card), a communication port, a PCMCIA slot and card, etc. The software and data transferred via the communication interface 524 may be in the form of signals, which may be electronic signals, electromagnetic signals, optical signals, or other signals capable of being received by the communication interface 524. These signals may be provided to the communication interface 524 via a communication path 526. The communication path 526 carries the signals and may be implemented using wire or cable, optical fiber, a telephone line, a cellular phone link, an RF link, or other communication channel.

[0137] In this document, the terms "computer program medium" and "computer usable medium" are used to broadly refer to media such as removable storage unit 518, removable storage unit 522, and a hard disk installed in hard disk drive 512. Computer program medium and computer usable medium may also refer to memories, such as main memory 508 and secondary memory 510, which may be memory semiconductors (e.g., DRAM, etc.).

[0138] Computer programs (also referred to as computer control logic) are stored in the main memory 508 and / or the secondary memory 510. In addition, computer programs may be received via the communication interface 524. Such computer programs, when executed, enable the computer system 500 to implement the various embodiments of the present disclosure described herein. In particular, the computer programs, when executed, enable the processor device 504 to implement the processes of the present disclosure, such as the above-mentioned Figure 1A Flowchart 100 and Figure 1B 104. Such a computer program therefore represents a controller of the computer system 500. In an exemplary embodiment where the method 100 is implemented using software, the software may be stored in a computer program product and loaded into the computer system 500 via the removable storage drive 514, the interface 520 and the hard disk drive 512 or the communication interface 524.

[0139] Embodiments of the present disclosure may also be directed to a computer program product comprising software stored on any computer-usable medium. When executed in one or more data processing devices, such software causes the data processing device to operate as described herein. Embodiments of the present disclosure may use any computer-usable or readable medium. Examples of computer-usable media include, but are not limited to, primary storage devices (such as random access memory of any type), auxiliary storage devices (such as hard disk drives, floppy disks, CD ROMs, ZIP disks, magnetic tapes, magnetic storage devices, and optical storage devices, MEMS, nanotechnology storage devices, etc.).

[0140] The embodiments have been described above with the aid of functional building blocks that illustrate implementation of specified functions and relationships thereof. For ease of description, the boundaries of these functional building blocks have been arbitrarily defined herein. Alternative boundaries may be defined as long as the specified functions and relationships thereof are appropriately performed.

[0141] Although the above has described what are considered to be the best modes and / or other examples, it should be understood that various modifications may be made therein and various forms and examples may be adopted to implement the subject matter disclosed herein. In addition, the present solution may be applied to numerous applications, only some of which are described here. The following claims are intended to claim protection for any and all applications, modifications and variations that fall within the true scope of the present solution.

[0142] Unless otherwise indicated, all measurements, values, ratings, positions, amplitudes, dimensions and other specifications outlined in this specification (including the claims that follow) are approximate and not exact. These values ​​are intended to be within a reasonable range and consistent with the functions to which they are related and the customary practices in the art.

[0143] The scope of protection of the present invention is limited only by the appended claims. When interpreted in light of this specification and the attached examination process history, the scope is intended and should be interpreted to be consistent with the ordinary meaning of the language used in the appended claims, and is intended to cover all structural and functional equivalents. Nevertheless, no claim is intended to include subject matter that does not meet the relevant requirements of Sections 101, 102, or 103 of the Patent Act, nor should the claims be interpreted in this manner. Any unexpected inclusion of such subject matter is hereby denied.

[0144] Except as stated above, nothing stated or described is intended or should be construed as conferring any component, step, feature, object, benefit, advantage or equivalent to the public, whether or not recited in the appended claims.

[0145] It should be understood that the terms and expressions used herein have the general meaning of the respective fields of investigation and research in which the terms and expressions are located, unless a special meaning is otherwise specified. Relational terms such as first and second are used only to distinguish one entity or action from another entity or action, without necessarily requiring or implying any actual such relationship or order between these entities or actions. The term "comprises" or any other variant thereof is intended to represent non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only these elements themselves, but also other elements that are not explicitly listed or inherent in such processes, methods, articles or devices. In the absence of further constraints, an element beginning with the expression "one" does not exclude the presence of other identical elements in the process, method, article or device including the element.

[0146] The Abstract of the present disclosure enables the reader to quickly determine the nature of the technical disclosure and is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the appended claims. In addition, it can be seen from the above detailed description that various features are grouped in various embodiments. This is for the purpose of simplifying the present disclosure and should not be interpreted as reflecting the intention that the claimed embodiments require more features than the features explicitly stated in the individual claims. On the contrary, as reflected in the appended claims, the subject matter of the present invention is that it has fewer than all the features of the individual embodiments disclosed above. Therefore, the appended claims are hereby incorporated into the detailed description, with each claim being separately claimed as the subject matter.

[0147] Although various embodiments have been described, the description is intended to provide examples rather than limitations, and it is apparent to those of ordinary skill in the art that more implementations and embodiments are possible within the scope of the embodiments. Although many possible combinations of features are shown in the drawings and discussed in this detailed description, many other combinations of the disclosed features are equally possible. Unless specifically limited, any feature of any embodiment may be used in combination with any other feature or element in any other embodiment, or replace any other feature or element. Therefore, it should be understood that any feature described and / or discussed in this disclosure can be implemented in any appropriate combination. Therefore, the embodiments are limited only by the appended claims and their equivalents. In addition, various modifications and changes may be made within the scope of the appended claims.

Claims

1. A system for controlling a laparoscopic instrument, wherein the system comprises: an actuator comprising an actuation cable configured to apply a trigger force to the laparoscopic instrument, Also included is a force sensor configured to measure a magnitude and direction of a pulling force, wherein the pulling force is applied to the target in response to the applied trigger force, and the pulling force is associated with an object connected to the target; The laparoscopic instrument is configured to grasp a target at a contact point with the target in response to application of a trigger force, and comprises: a lower clamp; an upper clamp, wherein the upper clamp and the lower clamp are pivotally connected via a pivot; The clamp angle, which is the angle between the upper clamp direction and the lower clamp direction; and The elbow angle is the angle between the direction of the trigger rod of the laparoscopic instrument and the bisector of the forceps angle, and can be calculated according to the following formula: in: represents the elbow angle, ψ represents the rotation of the laparoscopic instrument around the Y axis, and α represents the rotation amount of the laparoscopic instrument around the Z axis; a memory having processor-readable instructions stored therein; and one or more processors configured to access the memory and execute the processor-readable instructions, and when executed by the processor, the instructions configure the processor to perform a method, wherein the method includes obtaining the trigger force based on a first clamping force applied by an upper clamp to a target, a second clamping force applied by a lower clamp to a target, and a state of a laparoscopic instrument; The magnitude of the first clamping force is calculated, which includes solving the following static rotational equilibrium equation: F g1 -F g2 =F′ pull in: F g1 represents the magnitude of the first clamping force, F g2 represents the magnitude of the second clamping force, and F′ pull Indicates the magnitude of the pulling force along the direction of the axis perpendicular to the bisector of the clamp angle; A changing trigger force is obtained based on the first clamping force, the second clamping force and the state of the laparoscopic instrument, including: Calculating an average clamping force based on the first clamping force and the second clamping force; and calculating the magnitude of the changed trigger force based on a reaction force model associated with the average clamping force and the state of the laparoscopic instrument; The magnitude of the changing trigger force is calculated based on the reaction force model, which includes deriving the reaction force model according to the following set of equations about the instrument force model: μ′=0.5μ1+μ2 in: represents the magnitude of the average clamping force, represents the magnitude of the triggering force of the change, f k0 represents the static friction force of the laparoscopic instrument, θ represents the clamp angle, represents the elbow angle, L, α0 and D represent the geometric parameters of the laparoscopic instrument, μ represents the friction coefficient between the shaft pin of the laparoscopic instrument and the cam grooves of the lower clamp and the upper clamp, r represents the radius of the axle pin, d represents the distance between the pivot and the contact point, K inst represents the stiffness of the laparoscopic instrument, μ1 represents the friction coefficient between the actuation cable and the inside of the instrument trigger rod, and μ2 represents the friction coefficient between the actuation cable and the inside of the instrument elbow.

2. The system of claim 1, further comprising a spherical mechanism configured to measure the elbow angle of the laparoscopic instrument.

3. The system according to claim 2, characterized in that A changing trigger force is obtained based on the first clamping force, the second clamping force and the state of the laparoscopic instrument, including: Based on a three-zone grasping model associated with the magnitude and direction of a pulling force, a lower limit of the second clamping force and an upper limit of the first clamping force are obtained; the pulling force is a force exerted on the target by a nearby object connected to the target; Setting the magnitude of the second clamping force to be equal to the lower limit; Calculating the magnitude of the first clamping force based on the second clamping force, the magnitude of the pulling force and the pulling angle; generating a warning alarm in response to the magnitude of the first clamping force being equal to or greater than the upper limit; Determining the lower limit and the upper limit includes generating the three-zone grasping model by: generating a clamping plane including a plurality of curve pairs, wherein each curve pair includes a first value associated with the tension magnitude and a second value associated with the first clamping force magnitude and the second clamping force magnitude, and the clamping plane is associated with a specific tension direction; and The clamping plane is divided into three separate regions, including: Slip zone, limited by the slip curve; The damage zone, limited by the damage curve; and a safety zone, limited by the slip curve and the damage curve, and the safety zone is associated with the lower limit and the upper limit; The clamp-pull plane is divided into three separate regions, where the slip curve is derived, including: replacing the target with a test subject; Setting the magnitude of the second clamping force to a plurality of clamping force levels in ascending order, wherein the magnitude of the clamping force of the first clamping force level is zero; The slip threshold corresponding to each clamping force level is obtained in the following way: Setting the magnitude of the pulling force to zero; Continuously increasing the pulling force until the test object slips on the laparoscopic instrument; and measuring the magnitude of the pulling force that causes the test object to begin to slip, to obtain a corresponding slip threshold; and The slip curve is obtained by fitting the change of the slip threshold value occurring with respect to the change of the clamping force level into a curve, wherein the slip curve is associated with a specific direction of the pulling force, and for each different clamping force level, the pulling force in the specific direction can be continuously increased until the test object slips on the laparoscopic instrument; The dividing of the clamping and pulling plane into three separate regions further includes deriving the damage curve, including: Setting the magnitude of the pulling force to a plurality of pulling force levels in ascending order, wherein the magnitude of the pulling force of the first pulling force level is zero; The damage threshold corresponding to each tension level is obtained by the following method: Setting the magnitude of the first clamping force to zero; Continuously increasing the magnitude of the first clamping force until a damaged area is generated on the test object; and measuring the magnitude of the first clamping force that causes the damage area to begin to form to obtain a corresponding damage threshold; and The damage curve is obtained by fitting the change of the damage threshold with respect to the change of the tension level into a curve, wherein the damage curve is associated with a specific direction of the tension.

4. The method according to claim 3, characterized in that The average clamping force is calculated, which includes finding an average value of the first clamping force and the second clamping force.

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