CN111631811A - Method and device for obtaining contact force of head end of flexible magnetic conduit - Google Patents
Method and device for obtaining contact force of head end of flexible magnetic conduit Download PDFInfo
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Abstract
The invention provides a method and a device for acquiring contact force of a head end of a flexible magnetic catheter, wherein the method is used for acquiring the contact force between the flexible magnetic catheter and an endocardium when the flexible magnetic catheter is used for repairing and treating a heart part, and the method comprises the following steps: pre-establishing a relation comparison table of contact force and contact type between the head end of the flexible magnetic catheter and the endocardium; obtaining the contact type between the head end of the current flexible magnetic catheter and the endocardium; and searching a relation comparison table according to the contact type to obtain the contact force between the flexible magnetic catheter and the endocardium. According to the method for acquiring the contact force of the head end of the flexible magnetic catheter, in the process of performing an operation through the flexible magnetic catheter, the contact force between the head end of the flexible magnetic catheter and an endocardium can be searched for under the corresponding contact type by contrasting the relation contrast table only by acquiring the contact type between the head end of the flexible magnetic catheter and the endocardium, so that the instantaneous contact force of the head end of the flexible magnetic catheter can be monitored in real time, and the treatment effect is improved.
Description
Technical Field
The invention relates to the technical field of medical equipment, in particular to a method and a device for acquiring contact force of a head end of a flexible magnetic catheter.
Background
In the existing magnetic navigation technology, only the head end contact pressure of a hard manual catheter is measured and calculated, but when a flexible magnetic catheter is adopted for operation, the contact force between the flexible magnetic catheter and an endocardial component cannot be measured and calculated. Therefore, the contact pressure between the catheter tip and the endocardial surface cannot be determined in real time. In the radio frequency ablation operation of the catheter, the measurement of the contact pressure of the head end of the catheter is important for controlling the safety and the near-term and long-term curative effects of the operation. If the instantaneous tension of the catheter tip is too high, complications such as cardiac perforation are easily induced. If the tension of the catheter head is too low, ablation damage is easy to occur to an insufficient degree, which causes the arrhythmia to recur recently or in a long term.
Disclosure of Invention
The invention provides a method and a device for acquiring contact force of a head end of a flexible magnetic catheter, aiming at solving the technical problem of how to acquire the contact force between the head end of the flexible magnetic catheter and an endocardium.
According to the embodiment of the invention, the method for obtaining the contact force of the head end of the flexible magnetic catheter is used for obtaining the contact force between the flexible magnetic catheter and the endocardium when the flexible magnetic catheter is used for repairing treatment of a heart site, and comprises the following steps:
pre-establishing a relation comparison table of contact force and contact type between the head end of the flexible magnetic catheter and the endocardium;
obtaining the current contact type between the head end of the flexible magnetic catheter and the endocardium;
and searching the relation comparison table according to the contact type to obtain the contact force between the flexible magnetic catheter and the endocardium.
According to the method for obtaining the contact force of the head end of the flexible magnetic catheter, provided by the embodiment of the invention, the relation comparison table between the contact force and the contact type between the head end of the flexible magnetic catheter and the endocardium is established in advance, and in the process of performing an operation through the flexible magnetic catheter, the contact force between the flexible magnetic catheter and the endocardium under the corresponding contact type can be searched by comparing the relation comparison table only by obtaining the contact type between the head end of the flexible magnetic catheter and the endocardium, so that the instantaneous contact force of the head end of the flexible magnetic catheter can be monitored in real time, the effective contact force of the head end of the flexible magnetic catheter is ensured, and. In addition, the method is simple and reliable, and can ensure the safety of the operation of the beginner.
According to some embodiments of the present invention, the pre-established table of relationship between contact force and contact type between the head end of the flexible magnetic catheter and the endocardium comprises:
establishing a test environment which is the same as the endocardium, wherein the test environment comprises a test membrane, and a pressure detection device is arranged on the test membrane;
setting a plurality of groups of condition testing parameters, and acquiring the corresponding contact type between the flexible magnetic conduit and the testing film under each group of condition testing parameters;
and detecting the contact force between the head end of the flexible magnetic catheter and the test membrane under each contact type through the pressure detection device, and establishing a relation comparison table of the contact force between the head end of the flexible magnetic catheter and the endocardium and the contact type.
In some embodiments of the invention, establishing the same testing environment as the endocardium comprises:
and determining the temperature of the test environment and the concentration of the solution in which the test membrane is positioned according to the current body temperature and blood concentration of the patient.
According to some embodiments of the invention, the conditional test parameters comprise: the magnetic field strength of the test environment and a driving force applied to the flexible magnetic conduit.
In some embodiments of the present invention, the obtaining the corresponding contact type between the flexible magnetic conduit and the test film for each set of the conditional test parameters includes:
under each set of the condition test parameters, calculating a tension angle of the flexible magnetic conduit;
dividing the tension angle into a plurality of intervals according to the size of the angle, wherein each interval corresponds to a corresponding contact type;
and determining the contact type according to the calculated interval of the tension angle under each set of the condition test parameters.
According to some embodiments of the invention, the calculating the tension angle of the flexible magnetic conduit comprises:
taking a central point of a head end of the flexible magnetic conduit as a first point, taking a position, which is 20mm away from the first point, of the flexible magnetic conduit along the axial direction of the flexible magnetic conduit in a straightened state as a second point, and taking a straight line where the first point and the second point are located as a reference line;
when the flexible magnetic conduit is in contact with the test film to cause deformation of the flexible magnetic conduit, taking a point on the flexible magnetic conduit between the first point and the second point, which is farthest from the reference line, as a third point, and taking a straight line where the first point and the third point are located as an included angle line;
and calculating an angle between the reference line and the included angle line, namely a tension angle of the flexible magnetic guide pipe.
In some embodiments of the present invention, said dividing the tension angle into a plurality of intervals by angular size, each interval corresponding to a respective contact type, comprises:
when the tension angle is 0 °, the contact type is zero contact;
when the tension angle is in the range of 1 ° to 45 °, the contact type is direct contact;
when the tension angle is in the range of 46 ° to 80 °, the contact type is a side contact;
when the tension angle ranges from 81 ° to 90 °, the contact type is a lateral contact.
According to some embodiments of the invention, the obtaining a type of contact of the flexible magnetic catheter tip with the endocardium comprises:
calculating a tension angle of the flexible magnetic conduit, and determining the contact type according to an interval where the tension angle is located;
wherein calculating a tension angle of the flexible magnetic conduit comprises:
when the flexible magnetic guide pipe is in a straightened state, a midpoint of a connecting line of the first point and the second point is a third point, positioning electrodes used for acquiring position coordinates are arranged at the first point, the second point and the third point, a straight line where the first point and the third point are located is a calculation line, and an included angle between the calculation line and the reference line is calculated to serve as the tension angle.
In some embodiments of the invention, the test membrane is a mammalian endocardium.
The device for acquiring the contact force of the head end of the flexible magnetic conduit according to the embodiment of the invention comprises:
the position acquisition assembly acquires position coordinates of a plurality of corresponding points on the flexible magnetic pipe through a positioning electrode arranged on the flexible magnetic pipe;
the calculation module is used for calculating a tension angle of the flexible magnetic guide pipe according to the acquired position coordinates of the plurality of points;
a contact type determination module that determines a contact type of the flexible magnetic conduit according to the calculated tension angle;
and the contact force acquisition module is used for acquiring the contact force of the head end of the flexible magnetic catheter by searching a pre-established relation comparison table of the contact force and the contact type between the head end of the flexible magnetic catheter and the endocardium.
According to the device for acquiring the contact force of the head end of the flexible magnetic catheter, provided by the embodiment of the invention, the position coordinates of a plurality of points on the flexible magnetic catheter are acquired through the position acquisition assembly, the tension angle of the catheter can be calculated through the calculation module according to the position coordinates of the plurality of points, the contact type of the flexible magnetic catheter can be determined through the contact type determination module according to the tension angle, and the contact force of the head end of the flexible magnetic catheter can be acquired by searching a pre-established relation comparison table of the contact force and the contact type between the head end of the flexible magnetic catheter and an endocardium through the contact force acquisition module. Therefore, the instantaneous contact force of the head end of the flexible magnetic conduit can be monitored in real time, the effective contact force of the head end of the flexible magnetic conduit is guaranteed, and the treatment effect is improved. In addition, the method is simple and reliable, and can ensure the safety of the beginner operation
Drawings
FIG. 1 is a flowchart of a method for obtaining a contact force at a head end of a flexible magnetic conduit according to an embodiment of the invention;
FIG. 2 is a flowchart of a method for establishing a table of relationships between contact force and contact type between a tip of a flexible magnetic catheter and an endocardium, in accordance with an embodiment of the present invention;
FIG. 3 is a flow chart of a method of obtaining a corresponding type of contact between a flexible conduit and a test membrane according to an embodiment of the present invention;
FIG. 4 is a schematic illustration of the corresponding contact type between a flexible conduit and a test membrane according to an embodiment of the present invention;
FIG. 5 is a schematic illustration of the contact area between a flexible magnetic conduit and a test membrane for different contact types according to an embodiment of the invention;
FIG. 6 is a flow chart of a method of calculating a tension angle of a flexible conduit according to an embodiment of the present invention.
Detailed Description
To further explain the technical means and effects of the present invention adopted to achieve the intended purpose, the present invention will be described in detail with reference to the accompanying drawings and preferred embodiments.
In the related art, the contact force between the catheter and the endocardium is obtained by two methods:
the first method is as follows: the contact pressure from the positive end and the head end side margin of the conduit within 360 degrees is sensed by arranging a three-coordinate pressure sensor at the head end of the conduit. The principle is as follows: the degree of the deformation of the piezoelectric crystal spring by the external force is in direct proportion to the force, and the instantaneous pressure and the change thereof can be rapidly calculated by empirically correcting parameters.
The second method comprises the following steps: the contact force between the catheter and the endocardium was measured using a light diffraction catheter. The principle is as follows: the external force makes the catheter head end deform, influences the conduction of catheter inner core diffraction light, and the influence degree is directly proportional with the external force size, through empirical parameter, can calculate the pressure in twinkling of an eye and its change fast.
Both of the above methods are directed to obtaining the contact force between the rigid manual catheter and the endocardium. At present, in a permanent magnet navigation system used clinically, because the magnetic field intensity is fixed and unchanged, the influence of changes of other factors on the contact pressure is considered to be small. When the flexible magnetic catheter is driven by electromagnetism, the strength of a magnetic field in which the flexible magnetic catheter is located can be controlled and changed, and no effective acquisition method exists for the contact force between the flexible magnetic catheter and the endocardium in the operation environment. However, in the catheter radiofrequency ablation operation, the contact force of the flexible magnetic catheter head end is determined to be important for controlling the safety and the near-term and long-term curative effects of the operation. If the contact force of the head end of the flexible magnetic catheter is too large, complications such as cardiac perforation and the like are easily induced. If the contact force of the head end of the flexible magnetic catheter is too small, ablation damage is easy to occur to an insufficient degree, so that the arrhythmia is easy to relapse recently or in a long term.
The invention provides a method and a device for acquiring contact force of a head end of a flexible magnetic catheter, aiming at the problem of how to acquire the contact force between the flexible magnetic catheter and an endocardium.
According to the method for obtaining the contact force of the head end of the flexible magnetic catheter, disclosed by the embodiment of the invention, when the flexible magnetic catheter is used for repairing and treating a cardiac site, the contact force between the flexible magnetic catheter and an endocardium is obtained, and as shown in fig. 1, the method comprises the following steps:
s100, establishing a relation comparison table of contact force and contact type between the head end of the flexible magnetic catheter and an endocardium in advance;
that is, a table of the relationship between contact force and type of contact between the flexible-magnetic-catheter tip and the endocardium may be established prior to obtaining the contact force between the flexible-magnetic-catheter tip and the endocardium. For example, a table of relationships between flexible magnetic catheter tips and endocardium can be obtained experimentally.
S200, acquiring the contact type between the head end of the current flexible magnetic catheter and an endocardium;
s300, searching a relation comparison table according to the contact type to obtain the contact force between the flexible magnetic catheter and the endocardium.
According to the method for obtaining the contact force of the head end of the flexible magnetic catheter, provided by the embodiment of the invention, the relation comparison table between the contact force and the contact type between the head end of the flexible magnetic catheter and the endocardium is established in advance, and in the process of performing an operation through the flexible magnetic catheter, the contact force between the flexible magnetic catheter and the endocardium under the corresponding contact type can be searched by comparing the relation comparison table only by obtaining the contact type between the head end of the flexible magnetic catheter and the endocardium, so that the instantaneous contact force of the head end of the flexible magnetic catheter can be monitored in real time, the effective contact force of the head end of the flexible magnetic catheter is ensured, and. In addition, the method is simple and reliable, and can ensure the safety of the operation of the beginner.
According to some embodiments of the present invention, as shown in FIG. 2, a table of relationship between contact force and contact type between a tip of a flexible magnetic catheter and an endocardium is pre-established, comprising:
s110, establishing a test environment the same as the endocardium, wherein the test environment comprises a test membrane, and a pressure detection device is arranged on the test membrane;
it should be noted that, when a relation comparison table of the contact force and the contact type of the flexible magnetic catheter and the endocardium is established, the test membrane can be used for carrying out experimental determination instead of the endocardium. The pressure detection device is arranged on the test membrane, and when the flexible magnetic conduit is contacted with the test membrane, the contact force between the flexible magnetic conduit and the test membrane can be measured through the pressure detection device.
S120, setting a plurality of groups of condition testing parameters, and acquiring the corresponding contact type between the flexible magnetic conduit and the testing film under each group of condition testing parameters;
that is, under multiple sets of conditional test parameters, the corresponding contact type between the flexible conduit and the test membrane for each set of conditional test parameters is obtained.
S130, detecting the contact force between the head end of the flexible magnetic catheter and the test membrane under each contact type through a pressure detection device, and establishing a relation comparison table of the contact force between the head end of the flexible magnetic catheter and the endocardium and the contact type.
In some embodiments of the invention, establishing the same testing environment as the endocardium comprises:
and determining the temperature of the test environment and the concentration of the solution in which the test membrane is positioned according to the current body temperature and blood concentration of the patient. For example, the temperature of the test environment may be set to the current body temperature of the patient, and the concentration of the solution in which the test membrane is located may be set to the blood concentration of the patient. Therefore, corresponding test environments can be constructed for different individual patients, and the accuracy of the relation comparison table data is improved. It should be noted that the temperature of the test environment can also be set to 37 ℃ directly, and the solution of the test membrane can be isotonic colloid solution.
According to some embodiments of the invention, the conditional test parameters comprise: the magnetic field strength of the test environment and the driving force applied to the flexible magnetic conduit. It should be noted that, since the flexible magnetic catheter is located in the effective working magnetic field covering the heart chamber of the human body, the main factors influencing the contact force between the head end of the flexible magnetic catheter and the endocardium include: the magnetic field intensity, the traction degree of the catheter driver, the angle of the catheter tip in contact with the endocardial surface, and the stability of the catheter tip in contact with the endocardial surface. When a relation comparison table of contact force and contact type is established, the relation comparison table of the contact force and the contact type under the action of different magnetic field strengths and different driving forces can be obtained by changing different magnetic field strengths of a test environment and the driving force applied to the flexible magnetic guide pipe.
For example, a comparison table of the relationship between the contact force and the contact type of the magnetic field strength in the range of 800-1000 gauss can be determined, and the difference value of the magnetic field strength of two adjacent sets of condition test parameters is 10 gauss.
In some embodiments of the present invention, as shown in fig. 3 and 4, obtaining a corresponding type of contact between the flexible magnetic conduit and the test membrane for each set of conditional test parameters includes:
s121, calculating a tension angle of the flexible magnetic guide pipe under each set of condition test parameters;
s122, dividing the tension angle into a plurality of intervals according to the angle, wherein each interval corresponds to a corresponding contact type;
and S123, determining the contact type according to the calculated interval where the tension angle under each set of condition test parameters is located.
Wherein, as shown in fig. 6, calculating the tension angle of the flexible magnetic conduit comprises:
a100, taking a central point of a head end of a flexible magnetic conduit as a first point, taking a position, which is 20mm away from the first point, of the flexible magnetic conduit along the axial direction of the flexible magnetic conduit in a straightened state as a second point, and taking a straight line where the first point and the second point are located as a reference line;
a200, when the flexible magnetic conduit is deformed due to the contact of the flexible magnetic conduit and the test film, taking a point on the flexible magnetic conduit between the first point and the second point, which is the largest distance from the reference line, as a third point, and taking a straight line where the first point and the third point are located as an included angle line;
and A300, calculating an angle between the reference line and the included angle line, namely a tension angle of the flexible magnetic guide pipe.
In some embodiments of the present invention, as shown in connection with fig. 4, dividing the tension angle into a plurality of intervals by angular size, each interval corresponding to a respective contact type, includes:
when the tension angle is 0 degrees, the contact type is zero contact;
when the tension angle ranges from 1 ° to 45 °, the contact type is direct contact;
when the tension angle ranges from 46 ° to 80 °, the contact type is a side contact;
when the tension angle ranges from 81 ° to 90 °, the contact type is a lateral contact.
For each contact type, a further sub-grouping according to the angular range can be made as follows:
direct contact (1-45 ℃) is divided into 5 groups: 1 degree to 9 degrees, 10 degrees to 19 degrees, 20 degrees to 29 degrees, 30 degrees to 39 degrees, 40 degrees to 45 degrees;
side contact (46 ° to 80 °) into 4 groups: 46 degrees to 54 degrees, 55 degrees to 64 degrees, 65 degrees to 74 degrees and 75 degrees to 80 degrees.
The transverse contact (81-90 deg.) is divided into 1 group.
According to some embodiments of the invention, obtaining a type of contact of a flexible magnetic catheter tip with an endocardium comprises:
calculating a tension angle of the flexible magnetic guide pipe, and determining a contact type according to an interval where the tension angle is located;
wherein calculating the tension angle of the flexible magnetic conduit comprises:
when the flexible magnetic guide pipe is in a stretched state, the middle point of the connecting line of the first point and the second point is a third point, positioning electrodes used for acquiring position coordinates are arranged at the first point, the second point and the third point, a straight line where the first point and the third point are located is a calculation line, and an included angle between the calculation line and the reference line is calculated and used as a tension angle.
It should be noted that obtaining the position coordinates at the corresponding position through the positioning electrodes on the flexible magnetic conduit is a means of a mature technology in the field and is not described herein again. After the position coordinates of the three points are obtained, the side length of a triangle formed by the first point, the second point and the third point can be calculated according to the coordinates of the three angles, and then the tension angle can be calculated according to the corner relation of the triangle.
It should be noted that, after the comparison table of the contact force and the contact type is obtained, the contact pressure between the flexible magnetic catheter and the endocardium can be calculated according to the contact force and the contact type:
according to the relation among pressure, pressure and contact area: f ═ PS. After the contact force is measured in the test, the contact area between the flexible magnetic catheter and the test membrane can be calculated according to the contact type, and then the contact pressure between the flexible magnetic catheter and the endocardium is calculated. The method for calculating the contact area between the flexible magnetic guide pipe and the test membrane under different contact types comprises the following steps:
as shown in fig. 5, the contact area between the flexible magnetic conduit and the test membrane is shown by the shaded area in the figure for different contact types:
when the contact type is zero contact, the contact area is 0;
when the contact type is direct contact, the contact area is equal to the area of the head circle of the flexible conduit;
when the contact type is side contact, the contact area is 1/2 flexible catheter head end circle area +1/4 cylinder area;
when the contact type is a lateral contact, the contact area is 1/2 cylinder area.
The method for calculating the head end circle area and the column area of the flexible magnetic guide pipe comprises the following steps:
the calculation formula of the head end circle area of the flexible magnetic guide pipe is as follows: at ═ pi r2And r is the radius of the cross section of the flexible magnetic conduit. The calculation formula of the area of the 5mm column at the head end of the flexible magnetic conduit is as follows: as is 10 pi r, r is the radius of the cross section of the flexible magnetic conduit.
Therefore, the contact area between the flexible magnetic guide pipe and the test membrane under the corresponding contact type can be calculated, and then the contact area and the pressure can be obtained according to the relation among the contact force, the contact area and the pressure: and F/S, and calculating the contact pressure between the flexible magnetic pipe and the test film.
It should be noted that, in order to further improve the calculation accuracy of the contact pressure, when the contact types are the direct contact and the side contact, the contact types may be further grouped according to different magnitudes of the tension angle, and the corresponding formula is adopted to calculate the contact area, as shown below:
(1) when the contact type is direct contact, the contact area can be calculated by dividing into five groups according to the magnitude of the tension angle: in addition to the electrode tip circular area, the column area gradually increased as the tension angle increased, up to 1/4 electrode column area. The calculation method of the contact area of the five groups under direct contact comprises the following steps:
tension angle 1-9 °: electrode tip circle area +1/20 electrode column area;
tension angle 10-19 °: electrode tip circle area +1/10 electrode column area;
tension angle 20-29 °: electrode tip circle area +3/20 electrode columnar area;
tension angle 30 ° -39 °: electrode tip circle area +1/5 electrode columnar area;
tension angle 40-45 °: electrode tip circle area +1/4 electrode cylinder area.
(2) When the contact type is side contact, the contact area can be calculated by dividing the contact type into four groups according to the magnitude of the tension angle: as the tension angle gradually increased, the electrode tip 1/2 circular area gradually decreased and the electrode cylindrical area gradually increased to 1/2. The method for calculating the contact areas of the four groups under side contact comprises the following steps:
tension angle 46-54 °: 1/2 electrode tip circle area +1/8 electrode cylinder area;
tension angle 55-64 °: 3/8 electrode tip circle area +1/4 electrode cylinder area;
tension angle 65-74 °: 1/4 electrode tip circle area +3/8 electrode cylinder area;
the tension angle is 75-80 degrees: 1/8 electrode tip circle area +1/2 electrode cylinder area.
Therefore, the calculation accuracy of the contact area can be further improved, and a high-precision relation comparison table between the contact pressure and the contact type of the flexible magnetic catheter and the endocardium can be obtained. During operation, the contact pressure between the flexible magnetic catheter and the endocardium can be obtained by obtaining the contact type and searching the relation comparison table.
In some embodiments of the invention, the test membrane is a mammalian endocardium. For example, the endocardium of a pig may be used as a test membrane. The structure of the porcine endocardium is similar to that of the human endocardium, so that the accuracy of the relation comparison table data can be improved.
The device for acquiring the contact force of the head end of the flexible magnetic conduit according to the embodiment of the invention comprises: the device comprises a position acquisition component, a calculation module, a contact type determination module and a contact force acquisition module.
The position acquisition assembly acquires position coordinates of a plurality of points on the flexible magnetic conduit through a positioning electrode arranged on the flexible magnetic conduit; the calculation module calculates a tension angle of the flexible magnetic guide pipe according to the acquired position coordinates of the plurality of points; the contact type determining module determines the contact type of the flexible magnetic guide pipe according to the calculated tension angle; the contact force obtaining module obtains the contact force of the head end of the flexible magnetic catheter by searching a pre-established relation comparison table of the contact force and the contact type between the head end of the flexible magnetic catheter and the endocardium.
According to the device for acquiring the contact force of the head end of the flexible magnetic catheter, provided by the embodiment of the invention, the position coordinates of a plurality of points on the flexible magnetic catheter are acquired for the position acquisition assembly, the tension angle of the catheter can be calculated by the calculation module according to the position coordinates of the plurality of points, the contact type of the flexible magnetic catheter can be determined by the contact type determination module according to the tension angle, and the contact force of the head end of the flexible magnetic catheter can be acquired by searching a pre-established relation comparison table of the contact force and the contact type between the head end of the flexible magnetic catheter and an endocardium through the contact force acquisition module. Therefore, the instantaneous contact force of the head end of the flexible magnetic conduit can be monitored in real time, the effective contact force of the head end of the flexible magnetic conduit is guaranteed, and the treatment effect is improved. In addition, the method is simple and reliable, and can ensure the safety of the operation of the beginner.
While the invention has been described in connection with specific embodiments thereof, it is to be understood that it is intended by the appended drawings and description that the invention may be embodied in other specific forms without departing from the spirit or scope of the invention.
Claims (10)
1. A method for obtaining a contact force between a flexible magnetic catheter and an endocardium when a cardiac site is undergoing a repair treatment using the flexible magnetic catheter, the method comprising:
pre-establishing a relation comparison table of contact force and contact type between the head end of the flexible magnetic catheter and the endocardium;
obtaining the current contact type between the head end of the flexible magnetic catheter and the endocardium;
and searching the relation comparison table according to the contact type to obtain the contact force between the flexible magnetic catheter and the endocardium.
2. The method of claim 1, wherein the pre-establishing a table of the relationship between the contact force and the contact type between the flexible magnetic catheter tip and the endocardium comprises:
establishing a test environment which is the same as the endocardium, wherein the test environment comprises a test membrane, and a pressure detection device is arranged on the test membrane;
setting a plurality of groups of condition testing parameters, and acquiring the corresponding contact type between the flexible magnetic conduit and the testing film under each group of condition testing parameters;
and detecting the contact force between the head end of the flexible magnetic catheter and the test membrane under each contact type through the pressure detection device, and establishing a relation comparison table of the contact force between the head end of the flexible magnetic catheter and the endocardium and the contact type.
3. The method of claim 2, wherein establishing the same testing environment as the endocardium comprises:
and determining the temperature of the test environment and the concentration of the solution in which the test membrane is positioned according to the current body temperature and blood concentration of the patient.
4. The method of claim 2, wherein the conditional test parameters comprise: the magnetic field strength of the test environment and a driving force applied to the flexible magnetic conduit.
5. The method for obtaining the contact force of the head end of the flexible magnetic pipe according to claim 2, wherein the obtaining of the corresponding contact type between the flexible magnetic pipe and the test film for each set of the condition test parameters comprises:
under each set of the condition test parameters, calculating a tension angle of the flexible magnetic conduit;
dividing the tension angle into a plurality of intervals according to the size of the angle, wherein each interval corresponds to a corresponding contact type;
and determining the contact type according to the calculated interval of the tension angle under each set of the condition test parameters.
6. The method of claim 5, wherein the calculating the tension angle of the flexible magnetic conduit comprises:
taking a central point of a head end of the flexible magnetic conduit as a first point, taking a position, which is 20mm away from the first point, of the flexible magnetic conduit along the axial direction of the flexible magnetic conduit in a straightened state as a second point, and taking a straight line where the first point and the second point are located as a reference line;
when the flexible magnetic conduit is in contact with the test film to cause deformation of the flexible magnetic conduit, taking a point on the flexible magnetic conduit between the first point and the second point, which is farthest from the reference line, as a third point, and taking a straight line where the first point and the third point are located as an included angle line;
and calculating an angle between the reference line and the included angle line, namely a tension angle of the flexible magnetic guide pipe.
7. The method of claim 6, wherein the step of angularly dividing the tension angle into a plurality of intervals, each interval corresponding to a respective contact type comprises:
when the tension angle is 0 °, the contact type is zero contact;
when the tension angle is in the range of 1 ° to 45 °, the contact type is direct contact;
when the tension angle is in the range of 46 ° to 80 °, the contact type is a side contact;
when the tension angle ranges from 81 ° to 90 °, the contact type is a lateral contact.
8. The method of obtaining contact force of a flexible magnetic catheter tip according to claim 7, wherein obtaining the type of contact of the flexible magnetic catheter tip with the endocardium comprises:
calculating a tension angle of the flexible magnetic conduit, and determining the contact type according to an interval where the tension angle is located;
wherein calculating a tension angle of the flexible magnetic conduit comprises:
when the flexible magnetic guide pipe is in a straightened state, a midpoint of a connecting line of the first point and the second point is a third point, positioning electrodes used for acquiring position coordinates are arranged at the first point, the second point and the third point, a straight line where the first point and the third point are located is a calculation line, and an included angle between the calculation line and the reference line is calculated to serve as the tension angle.
9. The method for obtaining the contact force of the head end of a flexible magnetic catheter according to any one of claims 2-8, wherein the test membrane is a mammalian endocardium.
10. An apparatus for obtaining contact force of a head end of a flexible magnetic conduit, comprising:
the position acquisition assembly acquires position coordinates of a plurality of corresponding points on the flexible magnetic pipe through a positioning electrode arranged on the flexible magnetic pipe;
the calculation module is used for calculating a tension angle of the flexible magnetic guide pipe according to the acquired position coordinates of the plurality of points;
a contact type determination module that determines a contact type of the flexible magnetic conduit according to the calculated tension angle;
and the contact force acquisition module is used for acquiring the contact force of the head end of the flexible magnetic catheter by searching a pre-established relation comparison table of the contact force and the contact type between the head end of the flexible magnetic catheter and the endocardium.
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| CN115068106A (en) * | 2022-05-25 | 2022-09-20 | 绍兴梅奥心磁医疗科技有限公司 | Method and device for measuring pressure vector of catheter |
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