CN114209417A - Visual depth ablation catheter - Google Patents

Abstract

The invention relates to the field of medical electrophysiology catheter technology and cardiac electrophysiology ablation, in particular to a visual deep ablation catheter which comprises a sheath catheter and a catheter, and also comprises a handle assembly and an axial movement driving part arranged in the handle assembly, wherein the axial movement driving part can do spiral movement in the handle assembly and drive the catheter to move.

Description

Visual depth ablation catheter

Technical Field

The invention relates to the field of medical electrophysiology catheter technology and cardiac electrophysiology ablation, in particular to a visual deep ablation catheter.

Background

Radio frequency ablation and pulsed electric field ablation can be applied to tissue ablation, which is a common safety means, but when applied to the inside of closed tissue, the problems of tissue scabbing, carbonization and the like are easily formed, so that a cooling electrode needs to be irrigated. The pulsed electric field is always researched by scholars at home and abroad as an efficient and safe ablation energy source, and the pulsed electric field technology has made a great progress in recent years, especially in the field of tumor ablation, and the application of the pulsed electric field ablation principle to the field of cardiac ablation is a direction of research at home and abroad at present. Pulsed electric field techniques are techniques in which a brief high voltage applied to the tissue can produce a local high electric field of several hundred volts per centimeter that disrupts the cell membrane by creating pores in the cell membrane. The application of an electric field at the membrane above the cell threshold causes the pores not to close, and this electroporation is irreversible, thereby allowing the exchange of biomolecular material across the membrane, resulting in cell necrosis or apoptosis.

However, for a deeper lesion site in the tissue, no matter the radio frequency technology, the freezing technology and the pulse electric field can not achieve deep ablation at present, and normal tissue can be ablated during ablation, so the invention provides the ablation catheter which can accurately and safely deliver the electrode to the target tissue area for ablation under the positioning navigation and the adhesion detection, and can realize the functions of deep ablation of cardiac muscle, shape detection, positioning, adhesion detection and the like of the ablation catheter.

Currently, the design of catheters presents the following problems:

1. in the traditional ablation catheter, the catheter and the sheath tube are separately and independently used, so that the operation of an operator is not facilitated, the catheter is flexible relative to the movement of the sheath tube, the inside and deep focus of a tissue is treated, and the precision of the relative position between the catheter and the sheath tube is insufficient.

2. At present, the sheath tube is only used as a catheter channel, and the positioning and the shape detection of the sheath tube and the catheter can be realized only by means of a large amount of X rays, so that the ray exposure of an operator and a patient is increased, and the catheter and the detection method which can realize the positioning and the shape detection more accurately and conveniently are needed.

3. In the inside and darker focus of eccentric adventitia and tissue, it is difficult for its degree of depth position to reach in traditional mode of melting, influences the effect of melting, and can harm healthy tissue around, under the prerequisite of obtaining pipe sheath pipe location and form, need realize that pipe and tissue paste detection component and method. At present, the condition that the electrode is attached to the tissue in the tissue or blood is judged by adopting an electrophysiology waveform, and the electrophysiology signal is easy to interfere in the transmission process, so that the method has inaccuracy. The pressure that detects pipe and tissue and paste in addition among the prior art, the degree of pasting between pipe and the tissue is judged to the pressure that pastes through detecting pipe and tissue, but adopt the pressure detection mode to need to obtain comparatively accurate pressure value and calculate based on this pressure value, and the cost of realization is extremely high, and when the pipe had a plurality of electrodes, the pipe was spatial structure usually, and the pressure value between electrode and the tissue can't reflect the degree of pasting of pipe and tissue completely. And the possibility cannot be provided by means of pressure detection.

4. The energy selection of the current ablation mode is single, only one ablation energy mode can be used by one catheter, and the catheter which can simultaneously carry out radiofrequency ablation and high-voltage pulse ablation needs to be provided.

Disclosure of Invention

The invention provides a visual deep ablation catheter, which aims to overcome the problems and improve a sheath tube and a catheter.

In order to achieve the above purpose, the invention provides the following technical scheme:

the utility model provides a visual degree of depth ablation catheter, includes the pipe and installs sheath outside the pipe, still includes handle assembly and installs axial displacement drive unit in the handle assembly, axial displacement drive unit can be helical motion in handle assembly, and the drive the pipe motion.

In the prior art, although the catheter moves along the length direction of the sheath in the sheath, the catheter freely moves under manual control, the catheter moves relative to the sheath completely depending on the hand feeling of an operator, and the control precision is limited.

Preferably, the catheter is further provided with a bending control part, the head end of the sheath tube is provided with a traction part, the bending control part is fixedly connected with the traction part, and the bending control part moves in the length direction of the sheath tube, so that the traction part drives the sheath tube to bend.

The bending control member on the catheter moves in the longitudinal direction of the sheath tube to shorten the relative position between the bending control member and the traction member at the tip end of the sheath tube, but the bending control member is fixedly connected to the traction member, so that the sheath tube bends under a pressure of the shortened relative distance.

Preferably, the sheath comprises a sheath adjustablebending pipe section 15, abending sliding block 103 and arotary bending knob 101, thebending sliding block 103 is connected with atraction assembly 14 through atraction steel wire 141, thetraction assembly 14 is fixed on the inner wall of the distal end of the sheath, the bending slidingblock 103 is engaged with therotary bending knob 101 through external threads and internal threads,

the bending sliding block (103) is driven by the rotary bending knob (101) to be close to the traction assembly (14) along a traction steel wire (141), so that the sheath adjustable bent pipe section (15) is bent.

The curved slidingblock 103 is engaged with the rotarycurved knob 101 through the external thread and the internal thread, so that when the rotarycurved knob 101 rotates around the axis of the sheath, the curvedsliding block 103 does not rotate but moves in the longitudinal direction of the sheath under the limit action of the thread.

Preferably, magnetic positioning sensors are disposed at two ends of the sheath adjustable-bend pipe segment 15, and a plurality of electrodes are disposed in the axial direction of the sheath adjustable-bend pipe segment 15, and the bending form of the sheath adjustable-bend pipe segment 15 is determined by coordinates of the magnetic positioning sensors and coordinates of the electrodes.

Preferably, the axial movement driving part comprises a screw-inmoving mechanism 104, the catheter is fixed on the screw-inmoving mechanism 104, and further comprises a screw-infixing structure 105 fixed in the sheath, and the screw-inmoving mechanism 104 performs screw movement relative to the screw-infixing structure 105 through the engagement of threads and thread grooves.

Because the meshing relation of the threads and the thread grooves is determined, when thescrewing motion mechanism 104 stops moving, thescrewing fixing structure 105 has a locking effect on thescrewing motion mechanism 104, free sliding of thescrewing motion mechanism 104 cannot be caused, in addition, one circle of rotation of thescrewing motion mechanism 104 can be accurately calculated, thescrewing motion mechanism 104 drives the catheter to move in the length direction of the sheath, and the accuracy of controlling the relative position relation between the catheter and the sheath is improved.

Preferably, the medical device further comprises aspiral lead 6, wherein thespiral lead 6 is in a spiral shape and is engaged with thescrewing fixing structure 105 for providing power supply and/or transmitting signals for the positioning sensor and the electrode on the catheter.

Because data on the pipe need be gathered, consequently, need set up the wire on the pipe, set up the wire into the heliciform, on the one hand, the spiral wire is according to the track of screw in fixedknot structure 105 and screw inmotion 104 synchronous revolution, can not make the wire take place to twine or even twist off the wire in the sheath pipe because of the rotation of screw inmotion 104, on the other hand, the heliciform wire ductility is better, along with the propulsion of screw inmotion 104 and stretch, along with the withdrawal of screw inmotion 104 and compress, be convenient for accomodating of wire.

Preferably, the method can judge the contact state of the electrode and the tissue by acquiring the impedance value of the electrode on the catheter, and comprises the following specific steps:

s1, acquiring impedance values between the catheter upper electrode and an external reference electrode outside the human body under different frequencies, and calculating the difference of the impedance values under different frequencies;

s2, if the difference is within a first threshold range, the electrode is in contact with or inside the tissue, and if the difference is within a second threshold range, the electrode is in blood.

As a preferred specific embodiment, step S1 specifically includes the following steps: measuring the impedance value between the catheter upper electrode and anexternal reference electrode 171 outside the human body by using a high-frequency acquisition signal to obtain an impedance value Rb under high frequency; and measuring an impedance value between the same electrode and anexternal reference electrode 171 outside the human body by using a low-frequency acquisition signal to obtain an impedance value Ra at a low frequency, wherein a difference value between the impedance value Ra at the low frequency and the impedance value Rb at a high frequency is alpha;

correspondingly, in step S2, if alpha is more than or equal to 0 and less than or equal to 10 omega, the electrode is in blood; if alpha is more than 10 and less than or equal to 100 omega, the electrode is attached to or in the tissue.

Preferably, a plurality of electrodes including an ablation head electrode are arranged on the catheter, and the plurality of electrodes are used for outputting radio frequency energy or high voltage pulse signals.

Preferably, the ablation head electrode is in a tip shape and is used for leading the catheter electrode to enter the tissue and fixing, a plurality of electrodes are arranged on the axial direction of the catheter, and the distance between the ablation head electrode and the first electrode is in the range of 0.5-3 mm.

Compared with the prior art, the invention has the beneficial effects that:

1. according to the ablation catheter, the sheath tube and the catheter are integrally designed, and the relative motion of the catheter in the sheath tube is limited by the axial movement driving part in the handle assembly, so that the motion of the catheter relative to the sheath tube can be more accurately controlled, the relative position between the catheter and the sheath tube can be accurately controlled aiming at treating a deeper lesion in a tissue, and the precise treatment of the lesion is realized.

2. The magnetic positioning sensors at the head end and the tail end of the sheath tube adjustable bending section are used for acquiring the head position information of the sheath tube adjustable bending section, and the bending forms of the sheath tube and the catheter are determined through a plurality of electrodes on the catheter. The shape and the position of the catheter are accurately acquired in real time in a mode of combining the positioning of the magnetic positioning sensor and the positioning of the electrode.

3. In the scheme of the invention, the impedance values of the electrodes are obtained through the electrodes on the catheter, and the impedance values are judged through the threshold value, so that the sticking degree of the electrodes and the tissue is accurately judged.

4. A plurality of electrodes are distributed on the catheter, the space between the electrodes is considered, and under high-voltage pulse, the space between the electrodes is reasonably arranged, so that ionization phenomenon cannot be caused, and the electrodes on the catheter can carry out radio frequency ablation and can also realize high-voltage pulse ablation.

Description of the drawings:

fig. 1 is an overall schematic view of a visual deep ablation catheter in embodiment 1 of the present invention;

FIG. 2 is a schematic view of an adjustable bending section of a sheath tube according to embodiment 1 of the present invention;

FIG. 3 is a sectional view of an adjustable bending section of a sheath tube according to embodiment 1 of the present invention;

FIG. 4 is an enlarged partial cross-sectional view of an adjustable bending section of a sheath tube according to example 1 of the present invention;

FIG. 5 is an overall view of an inner tube in example 1 of the present invention;

FIG. 6 is a schematic sectional view of an inner tube in example 1 of the present invention;

FIG. 7 is a schematic view showing an internal circulation function of an internal pipe in example 1 of the present invention;

FIG. 8 is a schematic view of a catheter in a sheath according to example 1 of the present invention;

FIG. 9 is a schematic view of the catheter extension sheath according to embodiment 1 of the present invention;

FIG. 10 is a schematic view showing the inside of a handle assembly in embodiment 1 of the present invention;

FIG. 11 is an enlarged view of a part of the interior of the handle assembly in accordance with embodiment 1 of the present invention;

FIG. 12 is a schematic view of an external reference electrode in example 1 of the present invention;

FIG. 13 is a schematic diagram showing the relationship between impedance and frequency in embodiment 1 of the present invention;

fig. 14 is a first schematic view of a first application of a visual deep ablation catheter in embodiment 1 of the present invention;

fig. 15 is a schematic view of a visual deep ablation catheter in accordance with embodiment 1 of the present invention;

fig. 16 is a schematic view of a third application of a visual deep ablation catheter in embodiment 1 of the present invention;

fig. 17 is a flowchart of a visualization depth ablation catheter application in embodiment 1 of the present invention.

Reference numerals: 1. sheath electrode, 2, 3 sheath electrode, 3, 4, 5, 6, sheath head end positioning sensor, 7, sheath rear end positioning sensor, 8, adjustable bent sheath tube body, 9, catheter, 91, ablation head electrode, 92, catheter positioning sensor, 93, ablation electrode a, 94, ablation electrode b, 95, braided spiral wire, 96, support tube body, 97, outer tube body, 98, end tube body, 99, coolant channel, 10, handle assembly, 101, bent knob, 102, screw mechanism knob, 103, bent sliding block, 104, screw movement mechanism, 105, screw fixing mechanism, 106, spiral wire, 107, handle mandrel, 11, tissue, 12, connector, 13, tee joint, 14, traction assembly, 141, traction steel wire, 142, traction channel tube, 15, sheath adjustable body section bent tube, 15, and, 16. Sheath lumen, 17, human body, 171, external reference electrode, A, electrode spacing, B, positioning sensor spacing, 18, resistance of electrode against or inside tissue measured at different frequencies, 19, resistance of electrode measured at different frequencies in blood.

Detailed Description

The present invention will be described in further detail with reference to test examples and specific embodiments. It should be understood that the scope of the above-described subject matter is not limited to the following examples, and any techniques implemented based on the disclosure of the present invention are within the scope of the present invention.

Example 1

As shown in fig. 1 and 2, a visual deep ablation catheter is composed of an adjustable bending sheath, asheath 8, ahandle assembly 10, aconnector 12, and atee 13, wherein a proper amount of heparinized saline is injected into the tee at the handle end of the sheath, so that the inner catheter can freely pass through the sheath and prevent thrombus, the adjustablebending sheath segment 15 is arranged at the distal end of the sheath, the adjustablebending sheath segment 15 can realize bending under the control of thehandle assembly 10, the bendingsheath segment 15 can realize bending principle, as shown in fig. 1, 7 and 9, thebending sliding block 103 is connected with atraction assembly 14, internal threads are arranged inside the bendingknob 101, the internal threads inside the bendingknob 101 are matched with the external threads of thebending sliding block 103, when therotating bending knob 101 is controlled, the bending sliding block is driven to move axially (the axial moving finger moves along the length direction of the sheath, the same applies below) to axially move the pullingassembly 14 to bend the sheathadjustable elbow section 15.

As shown in fig. 2, the head end and the rear end of the adjustable bending sheath are respectively provided with a positioning sensor, the head end of the adjustable bending sheath is provided with apositioning sensor 6, the rear end of the adjustable bending sheath is provided with a positioning sensor 7, thepositioning sensors 6 and 7 are magnetic positioning sensors, the coordinates of thepositioning sensors 6 and 7 can be obtained in real time in the magnetic field region, the bending form of the adjustable bending sheath can be fitted according to the curve characteristics after the coordinates of thepositioning sensors 6 and 7 are determined, and then the bending form of the adjustable bending sheath can be displayed on the device in real time.

Another method for acquiring the bending form of the adjustable bent sheath tube is that coordinates of thepositioning sensors 6 and 7 are acquired in real time in a magnetic field area, and the head and tail positions of the adjustable bent sheath tube are acquired, because the adjustable bent sheath tube is also provided with the sheath tube electrode 2, the sheath tube electrode 3, thesheath tube electrode 4 and the sheath tube electrode 5, and the electrodes are arranged along the axial direction of the adjustable bent sheath tube and are distributed between the head and the tail ends of the adjustable bent sheath tube, the positions of the electrodes can be acquired through electric field positioning of the sheath tube electrode 2, the sheath tube electrode 3, thesheath tube electrode 4 and the sheath tube electrode 5, the coordinates of thepositioning sensors 6 and 7 acquired by the magnetic positioning sensor and the coordinates of the sheath tube electrode positioned by the electric field are combined, and the bending form of the adjustable bent sheath tube is acquired through multi-point positioning. Thepositioning sensor 6 and the positioning sensor 7 are respectively provided with the sheath head electrode 1 and the sheath electrode 5, because thepositioning sensor 6 and the positioning sensor 7 can respectively determine absolute coordinates T1(x1, y1, z1) and T5(x5, y5, z5) in real time, because the sheath head electrode 1 and thepositioning sensor 6 are fixed in position and the sheath electrode 5 and the positioning sensor 7 are fixed in position, the absolute coordinates of thepositioning sensor 6 and the positioning sensor 7 are also the absolute position coordinates of the sheath head electrode 1 and the sheath electrode 5, and the absolute position coordinates of the sheath head electrode 1 and the sheath electrode 5 are respectively T1 '(x 1, y1, z1) and T5' (x5, y5, z 5). Because the sheath electrode 1 and the sheath electrode 2, the sheath electrode 3, the sheath electrode 4 and the sheath electrode 5 can display relative position coordinates thereof in real time under an electric field, which are respectively Q1(X, Y, Z), Q2(X, Y, Z), Q3(X, Y, Z), Q4(X, Y, Z) and Q5(X, Y, Z), the basic principle of the relative position coordinates under the action of the electric field is that a voltage is loaded between at least one pair of external reference electrodes arranged on a human body, the position of the electrode (the sheath electrode) in the electric field formed by the external reference electrodes can be determined according to the relation between potential difference and distance position, the external reference electrodes are 3 pairs in space and respectively correspond to the X axis, the Y axis and the Z axis, so the position coordinates of the electrode in the electric field can be determined, and therefore the relative position relation between the electrodes on the sheath can be determined, because the positioning sensor on the sheath can determine the absolute positions of the sheath electrode 1 and the sheath electrode 5, the relative position relation of the electrodes on the sheath is determined, so that the absolute coordinates of all the electrodes on the sheath can be deduced, and the connecting lines of all the coordinate points are the bending form of the sheath. Theoretically, the denser the electrode distribution on the sheath tube, the more accurate the bending form.

Further, as shown in fig. 2, a hollow head electrode is disposed at the sheath head end of the adjustable bending sheath, a plurality of ring electrodes are sequentially disposed along the axial direction of the adjustable bending sheath, and particularly, the distance a between the sheath electrode 2 and the sheath head electrode 1 is set within a range of 0.5-1.5mm, and the intra-cavity electrophysiology map can be detected in real time in the heart through the sheath electrode 2 and the sheath head electrode 1 to determine the specific position reached by the sheath head end.

The sheath adjustablebent tube section 15 is a flexible braided tube body, can be freely bent and straightened under the control of thehandle assembly 10, and can be matched with themagnetic positioning sensors 6 and 7 at the head end and the tail end and the ring electrode along the axial direction of the sheath to carry out physical model construction and mapping under a three-dimensional mapping system. As shown in fig. 3, asheath lumen 16 is provided inside the sheath for the catheter to move inside, and the material is preferably polytetrafluoroethylene with high lubricity. The sheath tube wall is also provided with atraction channel tube 142, thetraction assembly 14 is fixedly arranged on the sheath tube wall at the far end of the sheath tube, one end of atraction steel wire 141 is fixedly connected with thetraction assembly 14, the other end of the traction steel wire is fixedly connected with thebending sliding block 103, thetraction steel wire 141 axially moves in thetraction channel tube 142 under the driving of the axial movement of thebending sliding block 103, thetraction assembly 14 is pulled by thetraction steel wire 141, and the sheath tube is bent or straightened under the pulling force of thetraction assembly 14 pulled by thetraction steel wire 141. The drawing of the position relationship of thedrawing wire 141, thedrawing passage tube 142 and the drawingassembly 14 is shown in detail in fig. 4, and the enlarged view of the section of the adjustable bending section of the sheath tube.

As shown in fig. 5-10, the sheathadjustable elbow section 15 has an axially movable catheter that can be ablated using pulsed electric fields or using radio frequency energy.

The tip of the catheter is provided with anablation head electrode 91, theablation head electrode 91 is in a tip shape, when the catheter enters the tissue, the tip of the ablation electrode is fixed inside the tissue through the tip-shapedablation head electrode 91, as shown in fig. 5 and 6, the outer surface of the ablation head electrode can be in a spiral screw form or a spiral wire form, and theablation head electrode 91 is made of stainless steel conforming to medical grade and has enough rigidity. An ablation electrode a93 and an ablation electrode b94 are further sequentially arranged behind theablation head electrode 91 along the axial direction of the catheter, theablation head electrode 91, the ablation electrode a93 and the ablation electrode b94 are connected by independent electrode leads, theablation head electrode 91, the ablation electrode a93 and the ablation electrode b94 are linearly distributed on the catheter, the distance between theablation head electrode 91 and the ablation electrode a93 and the distance between the ablation electrode b 3538 and the catheter are 0.50-3.0mm, when high-voltage pulse discharge is used, a bipolar electric field is formed by theablation head electrode 91, the two rear-end electrodes a93 and the ablation electrode b94 for tissue ablation, a bipolar electric field can be formed between the two rear-end electrodes 93 and 94 for tissue ablation, namely, bipolar discharge can be randomly combined between theablation head electrode 91 and the two rear-end electrodes 93 and 94, and the ablation head electrode length is 1-3 mm. Theablation head electrode 91 and the twoelectrodes 93 and 94 at the rear end can acquire the intracavity electrophysiology waveform, and themagnetic positioning sensor 92 is arranged in the ablation head electrode, so that the position of the ablation head electrode can be displayed in real time under a three-dimensional mapping system. Furthermore, because the position relationship between the ablation head electrode and the rear end electrode is fixed, and the position relationship between the ablation head electrode and the magnetic positioning sensor is fixed, the position and the shape of the head end of the catheter can be obtained in real time through the intracavity electrophysiology waveform acquired by theablation head electrode 91 and the tworear end electrodes 93 and 94 and the coordinates of themagnetic positioning sensor 92, and the position and the shape of theablation head electrode 91 and the tworear end electrodes 93 and 94 can be accurately displayed on system equipment.

In addition, as shown in fig. 9, thepositioning sensor 92 on the catheter and thepositioning sensor 6 on the sheath tube body can determine the position relationship B in real time, so that the physical position relationship between the catheter and the sheath can be displayed on the system equipment in real time, and further, whether the ablation head electrode and other electrodes are out of sheath can be judged.

The catheter is advanced while being rotated inside the sheath under the control of a screw-inmechanism knob 102 on thehandle assembly 10.

As shown in fig. 10, a screw-in fixingstructure 105 is arranged inside the screw-inmechanism knob 102, the screw-in fixingstructure 105 has an internal thread, an external thread is arranged on the screw-in movingmechanism 104, the internal thread of the screw-in fixingstructure 105 is matched with the external thread on the screw-in movingmechanism 104, the screw-in movingmechanism 104 moves under the limit of the screw-in fixingstructure 105, the catheter body of thecatheter 9 is fixed on the axial direction of the screw-in movingmechanism 104, when the screw-inmechanism knob 102 is operated, the screw-inmechanism knob 102 drives the internal screw-in movingmechanism 104 to move spirally on the screw-in fixingstructure 105, and further the catheter is made to perform a spiral feeding motion in the sheath along the length direction of the sheath. When the screwingmotion mechanism 104 stops moving relative to the screwingfixation structure 105, the screwingfixation structure 105 acts as a lock to the screwingmotion mechanism 104 due to the engagement of the screwingmotion mechanism 104 and the screwingfixation structure 105, facilitating accurate control of the progress of the movement of thecatheter 9. The limiting effect of the screw-in fixingstructure 105 on the screw-in movingmechanism 104 is favorable for the ablation head electrode of thecatheter 9 to stably enter the tissue and avoid extensive trauma, the tail end of thecatheter 9 is connected with aspiral wire 106, thespiral wire 106 is used for supplying power to a magnetic positioning sensor and an electrode at the front end of the catheter, and transmitting communication signals, thespiral wire 106 is in a spiral shape, when the catheter rotates in a sheath tube, the wire correspondingly rotates and stretches, the wire is set to be in a spiral shape so that the wire is not twisted off in the rotation, and the spiral shape can be stretched and compressed, and the catheter can be conveniently stored in the handle assembly and fixed.

Referring to fig. 10 and 11, it can be seen that thetraction wire 141 enters thehandle mandrel 107, thehandle mandrel 107 is fixedly disposed inside the handle, thetraction wire 141 is fixed on the curved slidingblock 103, the curved slidingblock 103 can move axially on thehandle mandrel 107, the curved slidingblock 103 has external threads, and is matched with thecurved knob 101, the internal threads of thecurved knob 101 are meshed with the external threads on the curved slidingblock 103, when thecurved knob 101 rotates, the slidingblock 103 is driven to move axially on thehandle mandrel 107, and thetraction wire 141 is controlled to move, so as to achieve the sheath bending control. Thecatheter 9 moves in the adjustable bendingsheath tube body 8, thecatheter 9 passes through thehandle mandrel 107 and the bendingslide block 103, but is not fixedly connected with thehandle mandrel 107 and the bendingslide block 103, and thecatheter 9 can freely rotate in thehandle mandrel 107 and the bendingslide block 103. Thehandle spindle 107 is fixed inside the handle, so that thehandle spindle 107 and thebending sliding block 103 do not rotate due to the rotation of thecatheter 9, and the movement of thebending sliding block 103 and the rotation of thecatheter 9 do not interfere with each other and do not affect each other. Thecatheter 9 enters the screw-in movingmechanism 104 through thehandle mandrel 107 and is fixed at the tail of the screw-in movingmechanism 104, the screw-in movingmechanism 104 is a cylinder and has external threads, and can axially move on the screw-in fixing mechanism 105 (which has internal threads and is fixed inside the handle), the screw-in movingmechanism 104 is also in gear engagement with the screw-inmechanism knob 102, the screw-inmechanism knob 102 has internal threads, and the screw-inmechanism knob 102 can drive the screw-in movingmechanism 104 to axially move when rotating to control the axial movement of thecatheter 9 relative to the sheath. The sheath is fixed on thehandle mandrel 107 and is independent from thecatheter 9, and thecatheter 9 can move independently in the sheath.

The ablation head electrode and the electrode of the catheter are arranged on the tail end pipe body of the catheter, and in order to enable the pipe body to have enough rigidity and be convenient for supporting the ablation head electrode and the electrode, the material of the catheter can be polyimide or polyether ether ketone. As shown in fig. 5 and 6, for promoting catheter torque and rigidity, be convenient for control catheter and remove along sheath pipe length direction, be provided with on the terminal body near-end and weave thespiral silk 95, it makes for metal stainless steel or nickel titanium alloy silk to weave thespiral silk 95, be used for increasing the body moment of torsion and do not influence body elasticity, inside is provided withsupport body 96,support body 96 can be the plastics body such as polyimide, the inside wire and the wire of magnetism location sensor that is used for passing through the electrode of body, the outside of weavingspiral silk 95 is provided withouter body 97,outer body 97 is used for protecting the body,outer body 97 material can be made for the polyurethane material.

The catheter can perform both radio frequency ablation and high voltage pulsed electric field ablation, where high voltage pulsed electric field ablation applies a brief high voltage to the tissue, creating a local high electric field of several hundred volts per centimeter across the tissue that disrupts the cell membrane by creating pores in the cell membrane. The application of an electric field at the membrane above the cell threshold causes the pores not to close, and this electroporation is irreversible, thereby allowing the exchange of biomolecular material across the membrane, resulting in cell necrosis or apoptosis. The high-voltage pulse electric field ablation is adopted, the electrode diameter, the electrode distance, the field intensity and the effective depth under specific energy need to be considered when the electrodes are designed, and the effective depth can be reached under the condition of ensuring no ionization. The electric field intensity is maximum on the surface of the electrode and gradually attenuates outwards, and meanwhile, the field intensity is gradually attenuated from the electrode to the center of the electrode, so that the distance and the area of the electrode need to be analyzed to determine the optimal parameter value in order to ensure that enough field intensity exists in the depth and the electric field intensity in the middle of the electrode is effective. Too large space can not form continuous ablation zone, too small space field intensity is concentrated and easy to generate ionization phenomenon, and the space is preferably 0.5-3 mm.

The field intensity analysis of different intervals is carried out under the condition that the voltage, the electrodes and the medium are the same, the field intensity of the center of the electrodes is reduced along with the increase of the intervals, the field intensity of the edges of the electrodes is reduced along with the increase of the intervals, and the field intensity does not change after reaching a certain distance. The field intensity analysis of different electrode sectional areas is carried out under the condition that the voltage, the electrode distance and the medium are the same, the field intensity of the center between the electrodes is increased along with the increase of the sectional area, but the change is obvious, the field intensity of the edge of the electrode is reduced along with the increase of the sectional area, the change is not obvious after reaching a certain value, the smaller the electrode sectional area is, the ionization problem is easy to occur when a strong electric field is concentrated at the edge of the electrode, the larger the electrode sectional area is, the more uniform the field intensity distribution is, the more uniform the electrode diameter of the field intensity distribution is designed and selected, and the electrode diameter is preferably 1-2 mm. The amplitude of the pulse electric field is set to be 500V-4000V, and can be set according to the required effect. The pulse electric field is used for accurately ablating focal tissues and avoiding damaging peripheral blood vessels and conducting tissues.

In addition to the ablation by using the high-voltage pulse electric field, the catheter can also use radio frequency energy, as shown in fig. 7, theablation head electrode 91 and the rear-end electrodes 93 and 94 can both be used as ablation electrodes to perform radio frequency discharge ablation, and in order to realize the high-voltage pulse discharge and also perform the radio frequency ablation discharge, the insulation strength between theablation head electrode 91 and the rear-end electrodes 93 and 94 should be sufficient and sufficient, and at least can bear the dc 4000V voltage. Because the ablation is carried out in the tissue, the open perfusion ablation can not be carried out, so that the ablation needs to be carried out by internally circulating cooling liquid, and because the internally circulating cooling liquid is added, the output of ablation radio frequency energy can be increased, and the problem of tissue carbonization caused by overhigh temperature near the electrode can be avoided. Typically, radiofrequency ablation is selected when large-area destructive ablation is required, and high-voltage pulsed electric field ablation is often used for single-point ablation.

The quality of the ablation effect is greatly related to the sticking degree of the ablation electrode and the tissue, so the detection of the sticking degree in the technical scheme is also improved. As shown in fig. 12 and 13, theexternal reference electrode 171 is applied to the trunk of thehuman body 17, and the impedance value between the electrode on the catheter and theexternal reference electrode 171 can be measured in real time, and the impedance value between the electrode on the ablation head on the catheter and theexternal reference electrode 171 can also be measured in real time. Under the actual measurement condition, the impedance of human muscle tissue is more sensitive to the influence of frequency, the impedance difference is larger under different frequencies, and the impedance of the electrode in blood is less influenced by the frequency, so that the positions of the electrode and the ablation head electrode in the tissue can be determined in real time according to the size difference of the impedance influenced by the frequency, and the position of the electrode in the tissue can be close to the tissue, or inside the tissue, or in the blood. By the method, the reliability and safety of ablation can be improved. In the method, the impedance of the electrode is measured by simultaneously adopting the high-frequency acquisition signal and the low-frequency acquisition signal to obtain an impedance value Ra under low frequency and an impedance value Rb under high frequency, and the position of the measurement electrode of the acquired signal is judged according to the difference value of the impedance value Ra and the impedance value Rb. If the impedance between the measuring electrode and the external reference electrode is simultaneously acquired under the acquisition signals of 1KHZ and 30KHZ respectively, the impedance values Ra and Rb are obtained, and the specific application frequency can be set according to the actual application requirements. The Ra-Rb value in blood is alpha, the alpha value is 0-100 omega, and the specific value is determined according to the practical measurement and statistics of the specific application environment and frequency. If alpha is more than or equal to 0 and less than or equal to 10 omega, the electrode is in blood; if alpha is more than 10 and less than or equal to 100 omega, the electrode is attached to or in the tissue.

When the tail of the electrode at the head end of the sheath tube is attached to the tissue, the electrode can extend out of the ablation electrode to scratch the internal tissue easily, and the tail of the electrode at the head end of the ablation electrode is not supported, so that the electrode can not be smoothly screwed into the tissue. Therefore, before the ablation head electrode is screwed into the tissue, the ablation electrode and the ablation head electrode are judged to be in blood or the tissue so as to judge whether the ablation electrode is screwed in. Because the impedance between all the electrodes and theexternal reference electrode 107 is detected, the same reference electrode is provided, the impedance detection data is accurate, the position condition of each electrode or the ablation head electrode and the tissue can be accurately measured, the electrodes are prevented from discharging in the tissue to form ineffective ablation, and the ablation head electrode can be prevented from passing through the muscle tissue to reach the other side to be ablated to form safety risk.

Further, fig. 14-16 show a schematic diagram of the sheath and the catheter in cooperation, first, under three-dimensional navigation, the head end of the sheath is perpendicularly and stably attached to the surface of the expected tissue, and if not, the head end of the sheath is readjusted to the position of the tissue to achieve stable attachment, if stable attachment is achieved, the electrode at the head end of the sheath is used to detect whether the anatomical position is safe, if safe, the catheter in the sheath is controlled to extend out of the sheath and enter the tissue, and simultaneously, whether the electrode on the catheter is completely inside the tissue is detected, if not, the ablation head electrode is adjusted to enter the tissue, if inside the tissue, the electric discharge ablation and the electrophysiological examination are performed, and finally, the catheter withdraws the sheath to complete the ablation. A flowchart of the application of the visual depth ablation catheter is shown in fig. 17.

While there have been shown and described what are at present considered the fundamental principles and essential features of the invention and its advantages, it will be apparent to those skilled in the art that the invention can be embodied in other specific forms without departing from the spirit or essential characteristics thereof. The present embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein. Any reference sign in a claim should not be construed as limiting the claim concerned.

Furthermore, it should be understood that although the present description refers to embodiments, the embodiments do not include only one independent technical solution, and such description is only for clarity, and those skilled in the art should take the description as a whole, and the technical solutions in the embodiments may be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims (10)

1. The utility model provides a visual degree of depth ablation catheter, includes the pipe and installs the sheath outside the pipe, its characterized in that still includes the handle subassembly and installs axial displacement drive part in the handle subassembly, axial displacement drive part can be helical motion in the handle subassembly, and the drive the pipe motion.

2. The visual deep ablation catheter of claim 1, wherein the catheter is further provided with a bending control component, the head end of the sheath is provided with a traction component, the bending control component is fixedly connected with the traction component, and the bending control component moves in the length direction of the sheath, so that the traction component drives the sheath to bend.

3. The visual deep ablation catheter of claim 2, wherein the sheath comprises a sheath adjustable bending tube section (15), a bending sliding block (103) and a rotary bending knob (101), the bending sliding block (103) is connected with a traction assembly (14) through a traction steel wire (141), the traction assembly (14) is fixed on the inner wall of the distal end of the sheath, the bending sliding block (103) is engaged with the rotary bending knob (101) through external threads and internal threads,

the bending sliding block (103) is driven by the rotary bending knob (101) to be close to the traction assembly (14) along a traction steel wire (141), so that the sheath adjustable bent pipe section (15) is bent.

4. The visualization depth ablation catheter as recited in claim 3, wherein both ends of the sheath adjustable elbow section (15) are provided with magnetic positioning sensors, and a plurality of electrodes are provided in the axial direction of the sheath adjustable elbow section (15), and the bending form of the sheath adjustable elbow section (15) is determined by the coordinates of the magnetic positioning sensors and the coordinates of the electrodes.

5. The visual depth ablation catheter of claim 1, wherein the axial movement drive member comprises a screw-in motion mechanism (104), the catheter being fixed to the screw-in motion mechanism (104), and further comprising a screw-in fixation structure (105),

the screwing motion mechanism (104) performs screwing motion relative to the screwing fixing structure (105) through the engagement of threads and thread grooves.

6. The visualization depth ablation catheter of claim 5, further comprising a helical wire (6), the helical wire (6) being helically shaped and engaging the screw-in fixation structure (105) for providing power and/or transmitting signals to the positioning sensor and the electrode on the catheter.

7. The visual deep ablation catheter of any one of claims 1-6, wherein the contact state of the electrode and the tissue is judged by obtaining the impedance value of the electrode on the catheter, and the specific steps are as follows:

s1, acquiring impedance values between the catheter upper electrode and an external reference electrode outside the human body under different frequencies, and calculating the difference of the impedance values under different frequencies;

s2, if the difference is within a first threshold range, the electrode is in contact with or inside the tissue, and if the difference is within a second threshold range, the electrode is in blood.

8. The visual depth ablation catheter of claim 7, wherein the step S1 comprises the steps of: measuring an impedance value between the catheter upper electrode and an external reference electrode (171) outside the human body by using a high-frequency acquisition signal to obtain an impedance value Rb under high frequency; measuring an impedance value between the same electrode and an external reference electrode (171) outside the human body by adopting a low-frequency acquisition signal to obtain an impedance value Ra under low frequency, wherein a difference value between the impedance value Ra under the low frequency and the impedance value Rb under the high frequency is alpha;

correspondingly, in step S2, if alpha is more than or equal to 0 and less than or equal to 10 omega, the electrode is in blood; if alpha is more than 10 and less than or equal to 100 omega, the electrode is attached to or in the tissue.

9. The visual depth ablation catheter of claim 8, wherein a plurality of electrodes including an ablation head electrode are disposed on the catheter, and the plurality of electrodes are configured to output radio frequency energy or high voltage pulse signals.

10. The visual depth ablation catheter of claim 9, wherein the ablation head electrode is tip-shaped for extending and fixing the catheter electrode inside the tissue, and a plurality of electrodes are provided in the axial direction of the catheter, and the distance between the ablation head electrode and the first electrode is in the range of 0.5-3 mm.

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