Electroactive polymer actuator and actuation method thereof

Abstract

An instrument suitable for use in surgical procedures may include (a) a body having a distal end and a proximal end, the body having a catheter between the distal end and the proximal end allowing fluid to flow through the catheter under suction; and (b) one or more actuators attached or embedded in the body, each actuator comprising one or more electroactive polymer layers providing mechanical movement at the distal end in response to simulation of an associated electrical control signal, where the electrical control signal is provided in a predetermined coordinated pattern. The predetermined coordination pattern may include two or more sets of actuators that are activated sequentially, simultaneously, or in a combination thereof.

Description

Technical Field

[0001] This invention relates to medical devices made of electroactive polymers (“EAPs”, such as piezoelectric polymers). In particular, this invention relates to surgical instruments comprising EAP-based actuators or other mechanical components capable of axial, radial, torsional, or helical motion. Summary of the Invention

[0002] According to one embodiment of the invention, an instrument for use in medical procedures is electrically connected to a controller that provides electrical control signals and controls mechanical aspiration. The instrument includes (a) a body having a distal and a proximal end, the body having a conduit between the distal and proximal ends allowing fluid to flow through the conduit under aspiration; and (b) one or more actuators attached to or embedded in the body, each actuator providing mechanical movement at the distal end in response to stimulation by the electrical control signals. The actuators may be EAP-based. The stimulation may be an electrical control signal of a predetermined coordination pattern. The predetermined coordination pattern may involve the sequential, simultaneous, or combined activation of two or more sets of actuators. For example, in one embodiment, the predetermined coordination pattern involves the sequential activation of two or more sets of actuators, one set after another, wherein within each set, two or more actuators are simultaneously actuated. In one embodiment, each actuator extends along the longitudinal direction of the body, and at least two or more sets of actuators are each located at a substantially equidistant radial distance from the longitudinal axis of the conduit.

[0003] According to one embodiment of the invention, the mechanical movement of the actuator is coordinated with the suction pressure. For example, when one of the mechanical movements causes the distal end of the body to move forward, the suction pressure can be reduced.

[0004] According to one embodiment of the invention, the distal end of the body of the aspiration device has an opening for exposing a catheter, and the portion of the body at the opening has a funnel shape.

[0005] According to one embodiment of the invention, a first actuator in the actuator of the suction device is helically wound around the body. In another embodiment, a second actuator in the actuator is also helically wound around the body, but with a different chirality than the first actuator.

[0006] According to one embodiment of the invention, a first actuator in the actuator of the device is wound substantially circumferentially around the body relative to the longitudinal axis of the body. The two ends of the actuator may be abutted against each other during mechanical movement of the actuator. Alternatively, the two ends of the actuator may be separated from each other by a gap, and wherein the actuator includes reinforcing material spanning the gap.

[0007] According to one embodiment of the invention, the suction catheter includes a mass block placed on one of the actuators to modify the resonant frequency of the actuator's mechanical motion. The mass block may include a radiopaque material that can be used to guide the catheter's direction. The mass block may also include tungsten to provide a tunable effect on the actuator's mechanical motion, such as its resonant frequency.

[0008] According to one embodiment of the invention, each actuator of the device may include one or more portions reinforced to constrain the mechanical movement of the actuator. The reinforced portions of the body may be provided with a high-modulus or compliant material, the high modulus or compliance being relative to the EAP layer in the actuator or the material used as a substrate.

[0009] According to one embodiment of the invention, the body may include a patterned or textured material layer exposed to the conduit. The patterned or textured material layer may be formed of polyvinylidene fluoride (PVDF). The patterned or textured layer may include grooves or protrusions, wherein adjacent grooves or protrusions are separated from each other by channels. In this embodiment, each protrusion may include a smooth surface or a textured surface. Alternatively, the patterned or textured layer may include etched recesses. Such etched recesses may be provided in the form of a rifling helical pattern extending longitudinally along the body. The patterned or textured layer may also be formed in a helical pattern extending longitudinally along the body.

[0010] According to one embodiment of the invention, one or more sensors can be provided in conjunction with an EAP actuator. For example, one or more portions of a patterned or textured layer (e.g., at the distal end) can be used as an electroactive sensor. The sensor can be located anywhere within the cannula body or outside the cannula body (e.g., in tubing attached to the cannula). The sensor can be used to detect the presence of blood clots and provide an electrical signal as a sensing output. The sensing output of the electroactive sensor or other sensor can be fed back to a controller to adjust the aspiration pressure, the frequency or amplitude of the EAP actuator oscillation, or any combination thereof.

[0011] According to one embodiment of the invention, a patterned or textured layer may be combined with an axially movable element to induce proximal movement of an ingested blood clot. In one embodiment, the patterned or textured layer includes a flexural beam that constrains the actuator to primarily achieve axial movement. In one embodiment, the patterned and textured layer also includes a compliant region. One embodiment of the compliant region includes a flexural beam interconnected with an elongation element. In another embodiment of the compliant region, an EAP actuator is provided to attach to a material region having a lower modulus than a higher modulus region.

[0012] Various embodiments of the invention also include a mechanical structure at the opening of the conduit that provides a soft flaring opening to the aspiration structure when in the open position, but the mechanical structure is designed to have a strict closure constraint to prevent the opening of the aspiration conduit from collapsing.

[0013] The invention can be better understood by considering the following detailed description in conjunction with the accompanying drawings. Attached Figure Description

[0014] Figure 1A This is a top view according to an embodiment of the present invention, showing a cross-section through the distal end 101 and the cannula shaft 104 at the distal end of the instrument 100.

[0015] Figure 1B It is the cross-section of the distal end 101, which is transverse to Figure 1A The cross-section shows the electrode layer 108 and the EAP layer 109.

[0016] Figure 2A-1 and 2A-2 Side views and cross-sections of the distal end 200 of a plurality of individually controlled actuators (e.g., actuators 201a-201c) according to an embodiment of the present invention are shown respectively; Figure 2A-1 and 2A-2 In the middle, the actuator is in its relaxed state.

[0017] Figure 2A-3 It is shown that when activated, the actuator provides circumferential bending (i.e., radial) of the compliant layer 203, which is concentrated by the action of the base layer 202.

[0018] Figures 2A-4(i) to 2A-4(iii) An example of radial bending is provided.

[0019] Figure 2A-5(i) and 2A-5(ii) The torsional response is shown.

[0020] Figure 2A-6(i) and 2A-6(ii) The axial response is shown.

[0021] Figure 2A-7 The helical response (i.e., a combination of torsional and axial responses) is shown.

[0022] Figure 2A-8(i) and 2A-8(ii) It shows Figure 2A-1 Simultaneous or consistent response in the distal end 200.

[0023] Figure 2A-9(i) and 2A-9(ii) It shows Figure 2A-1Grouping or coordinated response in the distal end 200.

[0024] Figures 2B to 2D Each is shown as one of three activation modes (sequential, simultaneous, or grouped); in each activation mode, four activation control signals (labeled 201a-201d respectively) correspond to the control signals sent to actuators 201a-201b.

[0025] Figure 2E This illustrates how, according to an embodiment of the invention, the activation of an EAP actuator is coordinated with a suction mode.

[0026] Figure 3A-1 A funnel-shaped distal end 300 according to an embodiment of the invention is shown, which includes actuators (e.g., actuators 301a-301c) disposed around the distal end of the device 300.

[0027] Figures 3A-2 to 3A-4 Another configuration of the funnel-shaped distal end according to an embodiment of the present invention is shown.

[0028] Figure 3B An actuator 321 is shown that is helically wound around a distal end 300 according to an embodiment of the present invention.

[0029] Figure 3C A high-modulus material 322 is shown, spirally wound in the opposite direction (i.e., with opposite chirality) by a spiral actuator 321 abutting the distal end 300 according to an embodiment of the present invention.

[0030] Figure 3C A tubular device 350 according to a second embodiment of the present invention is shown, wherein an EAP actuator 326 is circumferentially wound around the body of the tubular device 150 between the distal end 300 and the proximal portion 305.

[0031] Figure 3D The distal end 300 of a tubular device 350 according to a second embodiment of the present invention is shown, wherein an EAP actuator 326 is circumferentially wound around the body of the tubular device 350 between the distal portion of the distal end 300 and the proximal portion 305 of the distal end 300.

[0032] Figure 3E A tubular device 370 with circumferentially wound EAP actuators 326-1, 326-2, 326-3 and 326-4 is shown according to an embodiment of the present invention.

[0033] Figure 3F The illustration shows a mass 345, according to an embodiment of the present invention, placed longitudinally at the distal end of the distal end 300.

[0034] Figure 3G A plurality of enhanced actuators, for example according to one embodiment, are shown, including actuators 341-1 and 341-2 integrated in the configuration of FIG2A.

[0035] Figures 3H-1 to 3H-3 Each shows a configuration in which motion in actuator 360, according to an embodiment of the invention, is amplified by its substrate 351.

[0036] Figure 3I-1 and 3I-3 Passive action in the distal end 300 of a device 380 according to an embodiment of the present invention is shown.

[0037] Figures 3J-1 to 3J-4 This illustrates the incorporation of a second passive mechanical action into the distal end 300 according to another embodiment of the invention.

[0038] Figure 4A-1 A textured surface 410 is shown on the wall of a lumen 120 disposed in the distal end 300 of a cannula according to an embodiment of the present invention.

[0039] Figure 4A-2 and 4A-3 A side view and a perspective view of an exemplary textured surface 410 are shown, the textured surface 410 being configured as a step cut into the inner wall of the lumen 120.

[0040] Figure 4A-4 and 4A-5 A transverse cross-sectional view of the textured surface 410 is shown. The textured surface 410 is provided in the form of patterned stepped protrusions, viewed from the inside of the distal tip toward the opening of the lumen 120 and viewed from the opening of the lumen 120 outwards.

[0041] Figure 4A-6 Figures 4A-8 show (a) a side view and a perspective cross-sectional view of the textured surface 410, which is provided in the form of another patterned stepped protrusion.

[0042] Figure 4B The wall of a lumen 120 having a protrusion 411 separated by a channel 412 is shown according to an embodiment of the present invention.

[0043] Figure 4C-1 and 4C-2 A cross-sectional view and a perspective view of the spiral groove 422 on the wall of the lumen 120 are shown.

[0044] Figure 4D-1 and Figure 4D-2 Cross-sectional and perspective views of a spiral protrusion structure 423 on the enclosing wall of a lumen 120 according to an embodiment of the present invention are shown.

[0045] Figures 5A-1 to 5A-3 The operation of a textured structure 500 disposed on a closed sidewall of a lumen 120 according to an embodiment of the present invention is shown.

[0046] Figures 5B-1 to 5B-3 illustrate the operation of a second textured structure 550 disposed on the sidewall of a lumen 120 according to an embodiment of the present invention.

[0047] Figure 6A-1 and 6A-2 A clamshell structure 610 for controlling an opening to a lumen 120 according to an embodiment of the present invention is shown; the clamshell structure 610 has soft opening and rigid closing restrictions.

[0048] Figures 6B-1 and 6B-2 illustrate a support-like mechanical structure 650 for controlling an opening to a lumen 120 according to an embodiment of the present invention; similar to Figure 6A-1 and 6A-2 The clamshell structure 610 and the support-like mechanical structure 650 also allow for soft opening but maintain rigid closure restrictions for the opening to the lumen 120.

[0049] Figures 6C-1 to 6C-3 Operation of a tubular compliant structure 680 for controlling a lumen 120 using a foldable membrane material, according to an embodiment of the present invention, is shown.

[0050] Figure 7A An integrated thrombectomy device 700 according to an embodiment of the present invention is shown.

[0051] Figure 7B This is an enlarged view of the integrated EAP actuator 725 at the distal end 724 of an integrated thrombectomy device 700 according to an embodiment of the present invention.

[0052] Figure 7C The formation of a Tecoflex package in an integrated EAP actuator 725 according to an embodiment of the present invention is shown. Detailed Implementation

[0053] This application discloses various embodiments of aspiration cannulas or other surgical devices including a distal end that can be actuated to vibrate violently, thereby achieving desired mechanical effects suitable for various surgical applications (e.g., thrombectomy). In thrombectomy, for example, vibration can apply desired forces to a blood clot, thereby agitating, disrupting, breaking, compressing, or fragmenting the clot for removal. For example, it may be necessary to disrupt the blood clot to prevent “clogging,” thus allowing the clot to be directly aspirated into the cannula or surgical instrument. Unlike devices in minimally invasive surgery, where access to the tissue being operated on is made through a small, easily locateable incision, typically through a long, flexible cannula (usually 100 cm or longer) into a location within a blood vessel. However, while this detailed description provides examples of implementing the invention in conjunction with a cannula, the invention can also be implemented even in minimally invasive surgical devices. Therefore, in this detailed description, the term “instrument” should be considered to refer to a device associated with a cannula or any suitable surgical device.

[0054] One or more electroactive polymer (EAP) actuators may be disposed at the distal end (“distal end”) of the device. Each EAP actuator may be actuated (e.g., configured to move or vibrate) by an electrical signal transmitted from the proximal end of the device. In this arrangement, mechanical movement at the distal end may be restricted and not transmitted to any substantial length of the device. In some embodiments, the actuation of the EAP actuators need not be linear. Linear movement may be supplemented by other mechanical movements at the distal end. For example, in some embodiments, the range of mechanical movements at the distal end may include any radial, axial, torsional, and helical movements, or combinations thereof. In this context, torsional movement refers to rotational movement about an axial direction, and helical movement refers to a combination of torsional and axial movements. Suitable electroactive polymers include various combinations of vinylidene fluoride (VDF), vinyl trifluoroethylene (TrFE), 1,1-chlorofluoroethylene (CFE), and chlorotrifluoroethylene (CTFE). For example, terpolymers P(VDF-TrFE-CTFE) and P(VDF-TrFE-CFE) are commercially available from Piezotech (a subsidiary of Arkema SA in Paris, France). These terpolymers, with different electroactive properties, exhibit large electrostrictive strains (e.g., greater than 0.5%, preferably greater than 3.0%) under electric fields of 20-200 V / µm (e.g., 20-100 V / µm, preferably about 50 V / µm).

[0055] Figure 1AThis is a top view according to an embodiment of the invention, showing a distal end 101 and an instrument shaft 104 at the distal end of the device 100. The distal end 101 may be an actuator itself or include one or more actuators, each capable of electrically controlled movement. The device 100 includes a proximal end 105 (not shown) having a watertight connection to electronic drive circuitry to receive electrical signals (e.g., 20-200 Hz; preferably, 50-150 Hz) optimized to the resonant frequency of the distal end 101, such that the device is adapted to rupture blood clots and extract fragments of the blood clot by aspiration (“aspiration action”). Better blood clot extraction performance is considered advantageous at the higher end of the frequency range. For the intended operation, each electrical signal may have an amplitude of, for example, 50.0-300.0 volts, with or without DC offset.

[0056] The device shaft 104 may have a conventional mechanical design, such as an inner layer or liner of polytetrafluoroethylene (PTFE), Pebax, or thermoplastic polyurethane (TPU). The PTFE inner layer may be surrounded by an outer layer of reflowable material (e.g., Pebax with varying stiffness along the length of the device shaft 104). Furthermore, the device shaft 104 houses both an active electrode 106a and a return electrode 106b, electrically insulated from each other, each electrode extending along the entire length of the device shaft 104. These electrodes may be formed from any suitable conductive wire. The inner layer or conductive wire may be provided with suitable mechanical strength, or in the form of braids or coils, to provide mechanical integrity and kink resistance to the device shaft 104. The conductive wire may be embedded in a non-conductive braid or coil (e.g., made of polyetheretherketone (PEEK)) extending along the entire length of the device 100. These braids or coils may be available from, for example, Steeger USA, Biodesign Inc., and Admedes Inc., in various patterns. Alternatively, an all-metal braid or coil with electrically insulated wires is also possible for the active electrode 106a and the return electrode 106b. However, it is preferable to embed the electrodes in a non-conductive braid or coil to avoid short circuits. Although purely for illustrative purposes, Figure 1A Only the active electrode 106a and the return electrode 106b are shown; any suitable number of active and return electrodes can be used.

[0057] The distal end 101 of the device 100 is configured for thrombus occlusion. The distal end 101 preferably has a flush or angled tip to maximize the use of an opening through which the blood clot can be extracted. Layers of the EAP are embedded within the distal end 101. Each EAP layer strains when an electric field is applied to it. (Note that although greater strain is achieved at larger electric fields, the strain-electric field relationship is generally nonlinear.) Figure 1AAs shown, each EAP layer is provided between thin and flexible electrode layers, for example, between electrode 102 and electrode 103 located below electrode 102. Electrodes 102 and 103 are each electrically connected to either active electrode 106a or return electrode 106b. In this way, movement occurs only at the distal end 101 at the distal end of the device 100, and there is no energy loss when moving the active electrode 106a and return electrode 106b in the device axis 104. In one embodiment, each EAP layer can be between 2 and 20 μm thick. The distal end 100 can move in both the longitudinal and lateral directions.

[0058] According to one embodiment of the invention, each EAP layer can be formed by dip coating. For example, the distal end 101 located at the distal end of the device 100 can be immersed in a solution of the EAP in a polar solvent (such as diethylformamide (DMF) or methyl ethyl ketone (MEK)). In this way, a coaxial 20-200 μm thick EAP layer can be formed in the distal end 101 in a continuous dip. After forming each EAP layer, an electrode layer is formed on the exposed surface of the EAP layer by, for example, sputtering (e.g., gold or aluminum), intercalation (e.g., urethane with embedded silver), pad printing, or spraying, using conductive electro-ink or particle-free metal composite conductive ink (e.g., conductive ink available from Electroninks or LiquidX). The EAP layer-electrode layer combination formation step can be repeated multiple times. The electrode layer thus formed can be connected to an active electrode 106a or a return electrode 106b, such that electrodes of opposite polarity are formed on opposite sides of the EAP layer, thereby effectively creating a capacitor. Figure 1B It is the cross-section of the distal end 101, which is transverse to Figure 1A The cross-section shows electrode layer 108 and EAP layer 109. Each EAP layer can have any different thickness depending on the desired mechanical properties. Additional non-EAP layers (not shown) may also be included.

[0059] Fragmented or compressed blood clots generated by the movement of the distal end of the device 100 can be removed from blood vessels using suction. The efficiency of clot uptake depends on many factors (e.g., actuator activation parameters, combined with any cyclic or variable suction mode). The inventors believe that the movement of the distal end can compress the blood clot. This compression can remove serum from the blood clot, thereby reducing the volume of the blood clot and thus promoting clot uptake.

[0060] Aspiration patterns are generated by opening and closing the aspiration mechanism according to a predetermined waveform pattern. Existing aspiration pressure patterns use very low frequency variations (e.g., 6-12 Hz) because the pressure pattern is driven from the proximal end of the device 100. When the EAP actuator is integrated into the device, the inventors have discovered that very strong aspiration can generate a force that resists the outward component of the longitudinal or axial movement of the distal end 100. According to one embodiment of the invention, the aspiration pattern and vibration pattern are electronically controlled in a cooperative manner to optimize both device end-effector movement and clot uptake. For example, when the longitudinal component of the movement of the distal end 100 is outward, the suction force decreases. Conversely, when the longitudinal component of the movement of the distal end 100 is inward, the suction force increases. With coordinated distal end movement and aspiration pressure, a much faster response time can be achieved, and a wider frequency response range—up to 1 kHz—can be utilized.

[0061] A lumen 120, extending substantially along the entire length of the axis in the device 100, provides a conduit for aspiration in and out. A polyvinylidene fluoride (PVDF) copolymer sensor, positioned distally and elsewhere within the lumen 120, detects when the device 100 becomes “clogged” or blocked. A suitable tactile pressure sensor can be, for example, any pressure-sensing guidewire disclosed in, for example, U.S. Patent Application Serial No. 17 / 510,257, filed October 25, 2021, entitled “Pressure-Sensing Guidewire.” Sensing a clogging or blockage condition triggers a controller that alters its aspiration and vibration modes to “pull out” the device.

[0062] In the above embodiments, the electrodes of one or more EAP layers of the actuator are provided separately. Multiple actuators can be integrated as linear segments into the end effector and actuated independently. For example, Figure 2A-1 and 2A-2 Each of the following embodiments of the invention is illustrated: a plurality of individually controlled actuators (e.g., actuators 201a-201d; wherein actuator 201d is located on opposite sides, thus in...) Figure 2A-1 Side view and transverse sectional view of the distal end 200 (not visible in the image). In this configuration, each actuator can be an axially or longitudinally aligned cantilever beam encapsulated at its proximal end to a circumferentially wound base layer 202. Figure 2A-1 As shown, an inner layer 203 of compliant polymer material may be provided to line the lumen 120. A circumferentially wound base layer 202 covers both the proximal end of the actuator and the inner compliant layer 203. The base layer 202 may be formed of a high-modulus material relative to the material in the immediate vicinity (e.g., the compliant layer 203) 1C. Figure 2A-1The actuators are shown in a relaxed state. When activated, each actuator extends in either the axial or longitudinal direction. When the circumferentially wound base layer 202 reinforces the proximal portion of the distal end 200, the preferential circumferential bending (i.e., radial bending) of the compliant layer 203 caused by the actuators provides a flare (i.e., an increase in diameter) at the opening of the lumen 120 at the distal end of the device 200, as shown. Figure 2A-3 As shown.

[0063] By using combinations of actuation modes, medical professionals can individually and collaboratively drive actuators 201a-201d to achieve a variety of effects. For example, Figures 2A-4(i) to 2A-4(iii) Examples of radial bending are provided. Figure 2A-4(i) shows radial expansion at the distal end and the middle segment of the distal end, providing an opening response (Figure 2A-4(ii)) and a radial bulging response (Figure 2A-4(iii)), respectively. Similarly, Figure 2A-5(i) and 2A-5(ii) The torsional response is shown; Figure 2A-6(i) and 2A-6(ii) The axial response is shown; Figure 2A-7 The helical response (i.e., a combination of torsional and axial responses) is shown.

[0064] Figure 2B-2D Control signals for actuators 201a to 201c are shown in sequential activation mode, simultaneous or concurrent actuation mode, and coordinated or group actuation mode, respectively. Figure 2B For example, in sequential actuation mode, actuators 201a-201b are each actuated in a predetermined sequence. Figure 2C In the concurrent or simultaneous actuation mode, actuators 201a-201b are actuated simultaneously. Figure 2A-8(i) and 2A-8(ii) It shows Figure 2A-1 Simultaneous or consistent response in the distal end 200. Figure 2D In the coordinated actuation mode, actuators 201a and 201c, as well as actuators 201b and 201d, form two groups that actuate sequentially. However, within each group, the actuators are actuated simultaneously. Figure 2A-9(i) and 2A-9(ii) It shows Figure 2A-1 Grouping or coordinated response in the distal end 200. Figure 2D In the actuation mode, actuators 201a and 201c, as well as actuators 201b and 201d, form two opposing actuator groups. In embodiments with even more actuators, even more complex but suitable actuation modes can be constructed. Importantly, actuators can be activated by combining actuation modes into a sequence to customize a specific desired result.

[0065] Figure 2EThis illustrates how, according to an embodiment of the invention, the activation of an EAP actuator is coordinated with a suction mode. For example... Figure 2E As shown, at the end of the time period between time points A and B, the suction pump signal ASP slightly preempts the activation signal EAP, which activates one or more EAP actuators at time point C, to deactivate (i.e., reduce) the suction force. At time point D, just slightly earlier than the activation signal EAP deactivates the EAP actuator at time point E, the suction pump signal ASP is reactivated (i.e., increase) the suction force. This activation pattern can be repeated (e.g., ...). Figure 2E (as shown) or may be varied in any suitable manner. Figure 2E In the middle, the mechanical response at the distal end is shown as a displacement waveform DIS.

[0066] However, according to one embodiment of the invention, the EAP actuator can be integrated into an actuator (“integrated EAP actuator”) along with other mechanical or electrical components, which can serve as a building block for constructing a device. The integrated EAP actuator can have characteristic electromechanical properties and can be formed with any desired geometry for deployment in a device (e.g., the distal end 101 at the distal end of device 100). Thus, one or more integrated EAP actuators can be incorporated into the distal end 100 at the distal end of device 100 (e.g., as a three-dimensional array of integrated actuators).

[0067] Each embodiment described herein can be driven by drive electronics. If the distal end 101 is designed with multiple independently controlled actuators, more than one waveform can be provided to each active electrode. In most of the embodiments described above, the drive circuit can provide a drive waveform, for example, between 50.0 and 250.0 volts (peak-to-peak). The drive waveform can be sinusoidal, triangular, square, or any desired waveform (preferably, such as...). Figure 2B-2D (as shown in the square wave) to provide maximum acceleration or vibration. Suitable drive circuitry can be provided, for example, using Microchip HV56020 or Microchip HV 56022.

[0068] The shape of the distal end can be any of a variety of suitable shapes. For example, Figure 3A-1 A funnel-shaped distal end 300 according to an embodiment of the invention is shown, comprising actuators (e.g., actuators 301a-301c) disposed around the distal end 300. The actuators may be provided as cantilever beams, each cantilever beam being supported at one end by a higher modulus substrate 302, as described above regarding... Figures 2A-1 to 2A-3 As shown. The actuators 301a-301c on the distal end 300 of the funnel shape are merely illustrative. Any suitable number of actuators in any suitable placement can be used. For example, Figures 2A-1 to 2A-3The actuator arrangement and its actuation mode (e.g., such as) Figure 2B-2D The configuration of actuator 4 shown in the diagram is also suitable. Furthermore, actuators 301a-301c do not need to operate in the longitudinal direction. As explained in further detail below, different configurations of the actuators can achieve specific desired results. The funnel construction allows for greater end displacement and allows the clots to be "combed" into a preferred geometry for easy ingestion.

[0069] exist Figure 3A-1 In each of actuators 301a-301c, the proximal end (i.e., farther from the funnel opening) can preferentially be reinforced by a relatively more rigid actuator material (i.e., with a higher modulus), which restricts bending at the proximal end and allows the distal end to have increased degrees of freedom and greater displacement in both the forward and lateral axial directions. In this detailed description, the "forward" or "outward" direction refers to the direction of increasing distance from the proximal end. Greater displacement is considered beneficial for clot uptake.

[0070] Figures 3A-2 to 3A-4 Another configuration of the funnel-shaped distal end according to an embodiment of the present invention is shown. For example... Figure 3A-2 As shown, the distal end 350 is not an independently actuable cantilever beam, but includes a base layer formed as a circumferential portion 322 and a plurality of cantilever beam portions (e.g., cantilever beam portions 323a-323c). Figures 3A-2 to 3A-4 For clarity, the compliance layer lining the cavity 120 is omitted. A cantilever beam is positioned around an annular EAP actuator 321, which expands radially when activated. The base layer can be formed of a material with a higher modulus than, for example, the compliance layer below. However, each cantilever beam portion can be made flexible by performing localized thickness removal at a pivot point. The pivot point can be located, for example, where the cantilever beam extends from the circumferential portion 322. Localized thickness removal can be achieved, for example, by laser ablation. Figure 3A-2 and 3A-3 The relaxed and activated states of the distal end 350 are shown. In the activated state, the expansion of the EAP actuator 321 causes the cantilever beam to open to expand the diameter of the distal end 350.

[0071] Figure 3A-4 The diagram illustrates the extended mechanical action of the EAP actuator 321. (As shown...) Figure 3A-4 As shown, the extended EAP actuator 321 has an outer radius R1, which is amplified by the cantilever beam to create an expanded radius R2 at the opening leading to the lumen 120. In this configuration, the EAP actuator 321 is spaced L1 from the pivot point, while the outwardly flared opening at the distal end 350 is spaced L2 from the pivot point. According to the relationship R1 / R2 = L1 / L2, the finite strain of the EAP actuator 321 is amplified in this configuration.

[0072] The actuator of the present invention can also be integrated into the distal end as one or more strips by being wound in a spiral pattern around the distal end, the spiral pattern extending further toward the proximal end of the device in the longitudinal direction. Figure 3B An actuator 321 is shown helically wound around a distal end 300 according to an embodiment of the invention. In fact, the desired action can be achieved using a passive (i.e., not actively controllable) strip wound around the distal end. For example, additional polymeric material (whether active or passive) can be used to wind the distal end 300 in the same helical direction as the actuator 321 (e.g., clockwise, as viewed from the distal end 300 toward the proximal end of the device) or in the opposite helical direction (e.g., counterclockwise, as viewed from the distal end 300 toward the proximal end of the device). Figure 3C A high modulus material 322 is shown to be spirally wound in the opposite direction (i.e., with opposite chirality or direction) by a helical actuator 321 abutting the distal end 300 according to an embodiment of the present invention.

[0073] The high-modulus material 322 itself can be an EAP actuator. In one embodiment, the high-modulus material 322 can be formed using a polymer material with a higher modulus than the relatively compliant substrate to which it is wound. Reverse winding (i.e., two strips with opposite chirality, such as...) Figure 3C (As shown) allows the actuator 321 to extend to combine axial and rotational motion in the distal end 300. (As shown) Figure 3C As shown, the actuator 321 can be formed using an elastomer liner (e.g., PTFE, Pebax, or TPU). (Pebax belongs to a class of block copolymers composed of rigid polyamide blocks and soft polyether blocks in a hardness range.) The elastomer liner can be supported by a high-modulus material 322 (e.g., higher-hardness Pebax), which is coiled with the opposite chirality to the actuator 321, thereby allowing energy to be directed away from the actuator 321, resulting in axial elongation of the distal end 300.

[0074] Alternatively, the actuator of the present invention can be wound individually, primarily around the distal end of the device, i.e., circumferentially wound. Figure 3DThe distal end 300 of a tubular device 350 according to a second embodiment of the invention is shown, wherein an EAP actuator 326 is circumferentially wound around the body of the tubular device 350 between the distal portion and the proximal portion 305 of the distal end 300. When activated, the EAP actuator 326 circumferentially expands and relaxes around the distal end 300 of the device 350, thereby providing radial movement that dynamically changes the inner diameter of the distal end 300 below the EAP actuator 326 (and thus the diameter of the lumen 120). Using a material construction with a higher modulus than the compliant material below, the EAP actuator 326 provides both mechanical support and resistance to collapse during suction. In one embodiment, the single-wound EAP actuator 326 may be configured such that its two ends abut each other when actuated. In this embodiment, in its inactive state, the single-wound EAP actuator 326 may have a gap between its ends. Reinforcing material can be provided in the gap to reinforce the single-wound actuator 326 when it is in its activated state. Alternatively, the single-wound actuator 326 can be formed with one end of the EAP strip folded over the other end.

[0075] An additional EAP actuator may be provided along the proximal portion 155 to facilitate the downward delivery of ingested blood clots or blood clot fragments along the lumen 120. Figure 3E A tubular device 370 with circumferentially wound EAP actuators 326-1, 326-2, 326-3, and 326-4 is illustrated according to an embodiment of the invention. In some embodiments, the circumferentially wound actuators 326-1 to 326-3 are actuated interdependently and in a coordinated manner to generate peristaltic motion, thereby aiding in the passage of ingested blood clots in a predetermined activation mode. Movement of the actuators can also contribute to propelling the device 370 as it navigates to a target location within the vascular system, ureter, gallbladder, or any other suitable target location. Integrating reinforcing material within or around the actuators can also direct energy from the actuator movement toward optimized motion in a preferred direction.

[0076] In summary, integrating one or more actuators into the distal end of the device provides tunable mechanical energy for optimizing device movement. To further tune its performance, the device can be further integrated with a mass, thereby increasing energy output at a selected resonant frequency. In some embodiments, the integrated material can be a radiopaque material, which can be used for the additional purpose of providing visibility under fluoroscopy, guiding the device during navigation within the patient's body. Alternatively, a tungsten mass can be used. Tungsten is a common material in device construction, and its associated safety, manufacturability, and cost characteristics are well-known. Figure 3FA mass block 345 according to an embodiment of the invention is shown positioned longitudinally at the distal end of the distal end 300. Alternatively or additionally, one or more mass blocks may be positioned further toward the proximal end (e.g., at the middle portion of the distal end 300), and the resonant frequency of the maximum action in the mass block 345 can be optimized by adjusting the size of the mass block 345 and its center of gravity along the length of the mechanical action of the distal end 300.

[0077] Furthermore, the displacement of the actuator can also be optimized by constraining its movement at one or more locations, which can result in increased motion or effectiveness at other locations. In some embodiments, the constraint can be achieved by attaching or encapsulating a more rigid material at the constrained location and incorporating a less rigid material at the desired location with a larger displacement. Figure 3G A plurality of enhanced actuators, including actuators 341-1 and 341-2, are shown integrated into the configuration of FIG. 2A, for example, according to one embodiment. Figure 3G As shown, the proximal and distal ends of each of actuators 341-1 and 341-2 can be used as their respective actuators, which can be constrained or made compliant to allow adjustment of their displacement. For example, constraining actuator 341-1 by rigidifying the proximal end 347-1 can force an increasing displacement along the length of actuator 341-1. The effect is further enhanced if the distal end 346-1 is also constrained. If actuator 341-1 is constrained only at the proximal end 347-1, and the distal end 346-1 is made relatively unconstrained or compliant, actuator 341-1 will provide the maximum displacement at its distal end.

[0078] In some embodiments, the constraints in the actuator may work in conjunction with the substrate to which the actuator is embedded or attached to apply a desired action (e.g., maximum displacement) at the distal end of the actuator. According to one embodiment of the invention, Figures 3H-1 to 3H-3 Each shows a configuration where the motion in actuator 360 is amplified by its base 351. Figure 3H-1 For example, actuator 300 is embedded in substrate 351, which has a varying thickness along the longitudinal length of actuator 360. Therefore, depending on the modulus of the material of substrate 351 and whether constraints are placed along the length of actuator 360, the position of the desired action (e.g., maximum displacement) can be controlled. Figure 3H-2 The diagram shows an actuator 360 attached to a substrate 351, the substrate 351 having a reduced thickness near or at the mid-length of the actuator 360. In this configuration, maximum displacement can be achieved near or at the mid-length of the actuator 360. Figure 3H-3One configuration is shown in which actuator 360 is attached to substrate 351, with constraint applied at the proximal end. In this configuration, maximum displacement can be achieved at the free distal end of actuator 360. Therefore, the desired action of actuator 360 can be achieved, thereby adjusting the flexibility of the substrate (e.g., by appropriately selecting the width, thickness, or other dimensions of the substrate).

[0079] In some embodiments, the opening of the lumen 120 at the distal end of the device may be combined with passive mechanical movement. Figure 3I-1 and 3I-3 A passive action is illustrated in the distal end 300 of the device 380 according to an embodiment of the present invention. For example... Figure 3I-1 As shown, at the opening of the lumen 120, the distal end 300 may include a diamond-patterned structure 390 formed of braided wire (e.g., round or flat braided wire) or mesh components (e.g., laser-cut tubing). (As known to those skilled in the art, laser-cut tubing has been used in support structures.) Figures 3I-1 to 3I-3 In this design, a polymer overlay may be provided on the rhomboid patterned structure 390, but this polymer layer is omitted to allow the rhomboid patterned structure 390 to be clearly shown. The rhomboid patterned structure 390 consists of rows of rhomboid elements. The angle in each rhomboid element of the row at the distal end of the rhomboid patterned structure 390 decreases as the row approaches its proximal end, such as... Figure 3I-2 As shown. In this configuration, when a blood clot is bound, the opening of the lumen 120 at the distal end 300 is blocked, and the aspiration pressure within the lumen 120 decreases. This decrease in aspiration pressure axially compresses the tubular structure at the distal end 300, causing the rhomboid patterned structure 390 to expand radially outward from its proximal portion to its distal portion, thereby increasing the size of the opening to the lumen 120, as shown. Figure 3I-3 As shown.

[0080] Figures 3J-1 to 3J-4 This illustrates the incorporation of a second passive mechanical action into the distal end 300 according to another embodiment of the invention. Figure 3J-1 The distal end 300 in a stationary state is shown. The distal end 300 includes a tubular flexible region 395 defined by rings 397-1 and 397-2 behind the opening of the lumen 120. Rings 397-1 and 397-2 may be formed of a material with a modulus higher than that of the tubular flexible region 395. A plurality of flexible cantilever beams oriented along the axial direction may be attached to both rings 397-1 and 397-2. (Although...) Figures 3J-1 to 3J-4Each is shown as a single cantilever beam 396, but it should be understood that cantilever beams such as cantilever beam 396 are arranged around the flexible region 395 at regular or variable angular intervals, and each cantilever beam is attached to rings 397-1 and 397-2. Although rings 397-1 and 397-2 have a relatively higher modulus than the flexible region 395, they are also compliant enough to allow their respective inner radii to expand to allow the blood clot to pass through when the blood clot is pushed against the rings.

[0081] Initially, upon encountering a blood clot at the opening of lumen 120, the suction pressure within lumen 120 decreases, causing the tubular flexible region 395 to compress radially and elongate axially. This causes the tubular flexible region 395 to move towards the blood clot. The force propelling the flexible region 395 forward is transmitted through a cantilever beam (e.g., cantilever beam 396) to open the distal end 300 at the opening of lumen 120. Figure 3J-2 and Figure 3J-3 This situation is illustrated in perspective and side views. The enlarged, outwardly flared opening leading to lumen 120 allows blood clots to be drawn in and pulled inward by suction pressure. Figure 3J-4 The ingested blood clot 399 is shown pressed against the ring 397-1, which enlarges the inner radius of the ring 397-1, thereby increasing the chance that the blood clot 399 can be pulled into the tubular flexible region 395 by suction pressure.

[0082] It is known to provide a liner to the surface of the aspiration catheter in an aspiration device. The conventional distal end of the device is provided as slightly rounded or angled (i.e., angled or tilted forward). This distal end is non-invasive to surrounding tissues when navigating through a blood vessel. The angled end can increase the cross-sectional area of ​​the opening to the aspiration catheter into which clots can be drawn. In such a aspiration device, the innermost tubular layer (e.g., the wall of the aspiration catheter through which the aspirated blood clot passes) can be, for example, an etched PTFE layer, Pebax, or another material. Surrounding one or more inner layers can be a coil or braided layer, with urethane or Pebax material flowing back onto the coil or braid to form a consistent structure. Because the etched PTFE inner layer is not a melt-processable material, it is geometrically limited to a straight tubular construction. However, according to one embodiment of the invention, the inner layer of the device can be provided with Pebax (e.g., nylon) or PVDF, PVDF being a melt-processable fluoropolymer. Both Pebax and PVDF can be used to produce geometries at preferred dimensions suitable for removing clotted linings.

[0083] According to one embodiment of the invention, a patterned or textured lining (e.g., the surface of a PVDF layer) may be provided along a segment or the entire length of the device's suction cannula, particularly at the distal end of the device. Figure 4A-1A textured surface 410 is shown on the wall of the lumen 120 disposed in the distal end 300 of the device. This liner can facilitate additional movement and can apply additional stress to the ingested blood clot or clot fragments, thereby further promoting the breaking down of the ingested clot or clot fragments into even more digestible fragments. Such a liner can also induce movement of the ingested clot or clot fragments in a manner that promotes its ingestion. Healthcare professionals can further enhance these movements by manipulating the device in forward and backward axial vibrational movements, wherein an actuator, with or without, vibrates simultaneously at the distal end of the device and with or without providing suction pressure.

[0084] According to one embodiment of the invention, one or more sensors or transducers can be provided in conjunction with an EAP actuator. For example, one or more portions of a patterned or textured layer (e.g., at the distal end) can be used as an electroactive sensor. The sensor can be located anywhere within the cannula body or outside the cannula body (e.g., in tubing attached to the cannula). The sensor can be used to detect the presence of blood clots and provide an electrical signal as a sensing output. The sensing output of the electroactive sensor or other sensor can be fed back to a controller to adjust the aspiration pressure, the frequency or amplitude of the EAP actuator's vibration, or any combination thereof, to aid in performing thrombectomy.

[0085] Figure 4A-2 and 4A-3 A side view and a perspective view of an exemplary textured surface 410 are shown, the textured surface 410 being configured as a step cut into the inner wall of the lumen 120.

[0086] Figure 4A-4 and 4A-5 A cross-sectional view of the textured surface 410 is shown. The textured surface 410 is provided in the form of patterned stepped protrusions, viewed from the inside of the distal end toward the opening of the lumen 120 and viewed from the opening of the lumen 120 outwards, respectively.

[0087] Figure 4A-6 Figures 4A-8 show (a) a side view and a perspective cross-sectional view of the textured surface 410, which is provided in the form of another patterned stepped protrusion.

[0088] According to another embodiment of the invention, the inner layer may be etched to provide a "grooved" surface on the wall of the suction catheter. The grooved surface is a surface with a raised structure that extends axially and is separated from each other by gaps or channels that also extend axially. Figure 4B The wall of a lumen 120 is shown, having protrusions 411 separated by channels 412. The protrusions 411 may have a textured or patterned surface (e.g., formed using PVDF), or may have a smooth surface using a suitable material.

[0089] According to another embodiment of the invention, the wall of the aspiration catheter is etched to provide etched recesses. For example, the etched recesses may form a "rifled" channel (i.e., a continuous spiral groove) extending along a portion of the entire length of the distal end or even along a considerable length or the entire length of the device. Figure 4C-1 and Figure 4C-2 Cross-sectional and perspective views of the helical groove 422 on the enclosing wall of lumen 120 are shown, respectively. In other embodiments, the patterned surface may even be formed as a helical structure, such that, in conjunction with the movement of one or more actuators, the ingested clot rotates and presses against the internal patterned surface as it passes through the instrument. The size of the ingested clot can be reduced due to wear along the aspiration catheter. Figure 4D-1 and Figure 4D-2 Cross-sectional and perspective views of a spiral protrusion structure 423 on the enclosing wall of a lumen 120 according to an embodiment of the present invention are shown.

[0090] In other embodiments, the patterned surface may be in the form of scales (e.g., in a configuration of a familiar pattern similar to the pattern provided on the bottom of a cross-country ski, snakeskin, or wood file).

[0091] The textured surface on the sidewall of lumen 120 may include actuators or movable or extendable elements to facilitate the preferential proximal migration of ingested blood clots. Figures 5A-1 to 5A-3 The operation of a textured structure 500 disposed on a closed sidewall of a lumen 120 according to an embodiment of the present invention is shown. Figure 5A-1 As shown, structure 500 includes a high-modulus moving element 501, which can itself be an EAP actuator, axially movable or extended relative to a fixed flexural beam 502, providing the fixed flexural beam 502 to constrain the lateral (i.e., radial) movement of the high-modulus moving element 501. The textured structure 500 also includes a compliant region formed by a reinforced flexural beam 504, which is laterally connected by an elongation member 503. The elongation member 503 acts as a compressible spring that resists pressure from the axial movement of the high-modulus moving element 501, pushing towards the proximal portion of the distal end 300 while laterally stretching the compliant region. An EAP actuator 506, extending axially along the entire length of the compliant region, is attached at one end to the high-modulus moving element 501 and at the other end to the proximal portion of the distal end 300 beyond the compliant region. In this embodiment, since the actuator 506 is attached to the lumen 120 on the outside of the liner, it does not... Figure 5A-1 As shown in the image.

[0092] Figure 5A-2This is a perspective view of the distal end 300, which has two copies of a textured structure 500 disposed on opposite sidewalls of the lumen 120. For clarity of reference in the following description, the actuator 506 is also not shown. Figure 5A-2 As shown in the image. Figure 5A-3 An actuator 506 is shown disposed on an elongated member 503 in the compliant region of structure 500. When a blood clot is engaged and pushed proximally within lumen 120 by aspiration pressure, obstruction may occur, causing a drop in aspiration pressure within lumen 120. Actuator 506 can be activated in a vibratory manner to cause axial back-and-forth movement of the high-modulus movable element 501. Simultaneously, the elongated member 503 in the compliant region also engages during movement. While providing a restoring force to push the high-modulus movable element 501 backward during the relaxation phase of actuator 506, the lateral movement of the elongated member 503 increases the diameter of lumen 120 during the activation phase of actuator 506. This radial expansion of lumen 120 facilitates movement of the ingested clot or clot fragment towards the proximal end of texturized structure 500. A reinforcing flexural beam 504 constrains the bending of the elongated member 503 to maintain the structural integrity of the distal end 503. The combined effect of the axial and radial movement of the textured structure 500 can be very effective in clearing the lumen 120 and promoting the movement of ingested blood clots or clot fragments along the preferred direction.

[0093] Figures 5B-1 to 5B-2 illustrate the operation of a second textured structure 550 disposed on the sidewall of a lumen 120 according to an embodiment of the present invention. The textured structure 550 is configured according to... Figures 5A-1 to 5A-3 The principle of the textured structure 500 is essentially the same. However, the elongated member 503 in the compliant region is replaced by a membrane 553, which is formed of a material with a lower modulus than the high-modulus moving element 551. As shown in FIG5B-1, the textured structure 550 includes a higher-modulus moving element 551, which can move axially relative to the fixed flexural beam 552 when the EAP actuator 556 (not shown) is activated. The membrane 553 in the compliant region is attached to the high-modulus moving element 551 at end 557a and to the proximal portion of the distal end 300 at end 557b. The EAP actuator 503 is fixed to the textured structure 550 outside the lumen 120, as shown in FIG5B-1. Figure 5B-2As shown. Membrane 553 is connected to a reinforcing flexure beam 554, which, when actuator 556 is activated, constrains the movement of membrane 553 within its plane. When activated, EAP actuator 556 causes high-modulus moving element 551 to move towards the proximal end of textured structure 550 and laterally stretch the region of low-modulus material, increasing the size of lumen 120. Reinforcing flexure beam 554 constrains the region of bending lower-modulus material to maintain structural integrity. Therefore, the movement of high-modulus moving element 551 and membrane 553 is essentially similar to the above description regarding their movement within the plane. Figures 5A-1 to 5A-3 The counterparts described in [the text]. In some embodiments, the EAP actuator 553 may also be embedded in a membrane 553, in which case the membrane 553 may be formed of two laminated layers of a lower modulus material. Figure 5B-2 As shown, two copies of the textured structure 550 can be disposed on opposite sidewalls of the lumen 120. The combined movement of the high-modulus moving element 551 and the membrane 553 effectively clears the lumen 120 and causes ingested blood clots or clot fragments to preferentially move toward the proximal end of the distal end 300.

[0094] Various other embodiments are designed to improve the flexibility of the funnel-shaped opening leading to the lumen 120 when in the flared open position, while maintaining the opening at a fixed size in the collapsed position. Figure 6A-1 and 6A-2 A clamshell structure 610 for controlling an opening to a lumen 120 according to an embodiment of the present invention is shown; the clamshell structure 610 has soft-opening and rigid-closing restrictions. Figure 6A-1 As shown, the clamshell structure 600 at the distal end 300 of the device includes a first structural half 600a and a second structural half 600b connected by elastic elements 601a and 601b. A compliant polymer cover (not shown in the following description for clarity) is provided on the clamshell structure 610. The first structural half 600a and the second structural half 600b are hinged at planar hinge flexures 602a and 602b, which are integrally formed on the proximal portion of the distal end 300. The planar hinge flexure 602b is positioned at 180 degrees on opposite sides of the distal end 300. Figure 6A-1 The clamshell structure 610 is shown in its collapsed position, maintaining a strict closure constraint for opening the lumen 120. Elastic elements 601a and 601b can each be operated by an EAP actuator (not shown) that stretches the polymer cover to open the first structural half 600a and the second structural half 600b, as shown. Figure 6A-2As shown. In some embodiments, the tension in the polymer cover may be sufficient to allow the elastic elements 601a and 601b to position the clamshell structure 610 in its open position. This configuration provides large displacement at the opening of the lumen 120, but provides strict closure restriction at the collapsed position of the clamshell structure.

[0095] Figures 6B-1 and 6B-2 illustrate a support-like mechanical structure 650 for controlling an opening to a lumen 120 according to an embodiment of the present invention; similar to Figure 6A-1 and 6A-2 The clamshell structure 610 and the scaffold-like mechanical structure 650 also allow for flexible openings, but maintain rigid closure constraints for openings leading to the lumen 120. As shown in Figure 6B-1, the scaffold-like mechanical structure 650 is disposed on a compliant (i.e., low-modulus) polymer layer 651, which forms the inner wall of the lumen 120. The scaffold-like mechanical structure 650 can be a connected laser-cut mechanical frame formed of NiTi or any other suitable material. Figure 6B-1 shows the relaxed or collapsed state of the scaffold-like mechanical structure 650. Figure 6B-2 The open state of the compliant structure 650 is shown. Therefore, the support-like mechanical structure 650 has the advantage of low stiffness during its open state, while maintaining high stiffness during its collapsed position to maintain a tight closure constraint that prevents the opening of the suction conduit from collapsing.

[0096] Alternatively, the compliant structure used to control the opening to the lumen 120 can also be formed using a foldable membrane. Figures 6C-1 to 6C-3 Operation of a tubular compliant structure 680 for controlling a lumen 120 using a foldable membrane material, according to an embodiment of the present invention, is shown. Figure 6C-1 A distal end 300 is shown, having a tubular compliant structure 680 disposed at the opening of a lumen 120 of the distal end 300. A polymer cover (not shown) may be disposed on the tubular compliant structure 680. The tubular compliant structure 680 is attached to a non-compliant base 681 at a proximal portion 681 of the distal end 300. The tubular compliant structure 680 includes a plurality of rigid sliding plates 693 connected to each other by sheets 692 of a foldable membrane. Figure 6C-1 As shown, the tubular compliant structure 680 is in its collapsed or closed position. Figure 6C-2 The tubular compliant structure 680 is shown in its open position. Figure 6C-3The diagram illustrates the configuration of the tubular compliant structure 680 in its open position (A) and in its closed or collapsed position (B). In position A, stretching of the polymer cover (e.g., by an EAP actuator) causes the foldable diaphragm 692 to relax, and the sliding plate 693 unfolds in its open position (i.e., with minimal overlap), thereby providing a large displacement from the collapsed position of the tubular compliant structure 680. However, in position B, the foldable diaphragm 692 is tightened, which causes the sliding plate 693 to be in its maximum overlap, thereby maintaining a minimum diameter at the opening leading to the lumen 120.

[0097] Figure 7A An integrated thrombectomy device or instrument 700 according to an embodiment of the present invention is shown. Figure 7A As shown, the integrated thrombectomy device 700 includes a distal end 724, a flexible cannula body 726, and a digital controller 728. The distal end 724 includes an integrated EAP actuator 725 and a dilator 721. As described above, the term "integrated EAP actuator" collectively refers to one or more EAP actuators that, together with other electrical and mechanical components, form the components for constructing a functional device. The dilator 721 is shown as having a tapered profile. The flexible cannula body 726 provides a large-bore lumen that extends continuously along its entire length to provide suction and function as a fluid conduit. In one embodiment, the lumen at the distal end 722 of the flexible cannula body 726 may be provided with a larger lumen than the rest of the flexible cannula body 726 to enhance suction pressure at the distal end. The proximal end of the flexible cannula body 726 includes a port 727 adapted to connect to a suction device (not shown) to provide suction pressure and allow fluid handling. The integrated EAP actuator 725 receives electrical signals from the digital controller 728 via electrical conductors or traces embedded in a cylindrical wall along the entire length of the flexible cannula body 726, as shown in insert 723. In one embodiment, the electrical traces comprise at least two copper coils and at least one stainless steel coil. The copper coils are provided to carry electrical control and data signals between the digital controller 728 and the integrated EAP actuator 725. The stainless steel coils provide structural strength to the flexible cannula body 726 to prevent the large-aperture lumen therein from collapsing under suction pressure (i.e., at suction pressures below 30 in.Hg) and to prevent kinking along the flexible cannula body 726. If desired, additional support rings or bands (e.g., metal rings, such as stainless steel rings) may be provided at suitable locations along the flexible cannula body 726 (e.g., near the EAP actuator 725) to constrain inward or longitudinal movement of the EAP actuator 725 and to provide additional structural strength and integrity to the flexible cannula body 726.

[0098] At the distal end 724, one or more radiopaque markers may be provided to guide navigation of the distal end 724 through the vascular system. For example... Figure 7A As shown, a radiopaque marker is provided between the integrated EAP actuator 725 and the dilator 721. The dilator 721 is shaped to facilitate the distal end 724's passage through the vascular system to its destination. The dilator 721 can be configured to expose or open a large-bore lumen using any of the techniques described above to take up clots.

[0099] Figure 7B This is an enlarged view of the integrated EAP actuator 725 at the distal end 724 of an integrated thrombectomy device 700 according to an embodiment of the present invention. Figure 7B An integrated EAP actuator 725 is shown at a later step in its formation. (See diagram.) Figure 7B As shown, the integrated EAP actuator 725 can be circumferentially formed on the outer surface of the mandrel 702. At the end of the formation of the integrated EAP actuator 725, the mandrel 702 is removed to provide a large-bore lumen. The mandrel 702 can be, for example, a PTFE glass-filled cylinder or tube whose outer circumference matches the outer circumference of the desired large-bore lumen in the integrated EAP actuator 725. First, an inner polymer layer 703 of the integrated EAP actuator 725 is formed on the mandrel 702. The inner polymer layer 703 can be a Pebax layer. In some embodiments, multiple layers of Pebax with different hardnesses can be provided for transition.

[0100] A polyimide flexible circuit 704 is disposed on the outer surface of the inner polymer layer 702. The polyimide flexible circuit 704 may have two or more electrodes 707 provided thereon (e.g., using conductive ink) for attaching an EAP actuator. Figure 7B As shown, an EAP actuator 705 is formed above a polyimide flexible circuit 704. The EAP actuator 705 is shown as an electrical contact, for example, at location 706. The EAP actuator 705 can be formed from one or more suitable electroactive polymers described above. In one embodiment, the EAP actuator 705 is formed from a rectangular sheet (e.g., 11.0 mm × 23.5 mm) and then circumferentially wound around an inner polymer layer 720 such that the longer-dimension opposite sides are adjacent. For example, the electrode 707 can be electrically connected to a copper coil embedded in the flexible cannula body 726 using wire bonding techniques. In one embodiment, two copper coils and one stainless steel coil are embedded in the flexible cannula body 726, for example, each coil is provided at 26 turns per inch. In one embodiment, as... Figure 7B As shown, the Pebax outer sheath 710 (with varying stiffness for transition, if desired) is disposed along the outer surface of the flexible cannula body 726, distally extending to or near the polyimide flexible circuitry 704 of the integrated EAP actuator 725. The remainder of the integrated EAP actuator 725 (in...) Figure 7B (Indicated by ovoid 701) Use the following combination Figure 7C The described technology is encapsulated in Tecoflex material. Tecoflex material can be obtained, for example, as an adhesive based on a rapidly crystallizing polyurethane resin.

[0101] Figure 7C The formation of a Tecoflex package in an integrated EAP actuator 725 according to an embodiment of the present invention is shown. A short sheath portion of the Tecoflex is disposed on the integrated EAP actuator 726, its end overlapping the spindle 702 and the outer sheath 710. In one embodiment, the Tecoflex sheath may be, for example, 0.003” thick. Figure 7C As shown, the Tecoflex sheath 732 has a proximal end 731 overlapping with the outer sheath 710 and a distal end 733 overlapping with the spindle 702. Heat is then applied to the proximal end 731 and the distal end 733 to cause them to have an inner polymer layer 703 and a polymer material of the outer sheath 710 (i.e., the Tecoflex melts and flows back into the hydrophilic coating at the distal end 733 and the Pebax at the proximal end 731). In this way, the integrated EAP actuator 725 is hermetically encapsulated without the Tecoflex sheath 732 mixed into the EAP actuator 705.

[0102] A hydrophilic coating can be applied to the integrated thrombectomy device 700 to enhance navigation performance and outer lubrication.

[0103] The above detailed description is provided to illustrate specific embodiments of the invention and is not intended to be restrictive. Many modifications and variations are possible within the scope of the invention. The invention is set forth in the appended claims.

Claims

1. An instrument suitable for use in medical surgery, the instrument being electrically connected to a controller that provides electrical control signals and mechanical suction, the instrument comprising: A main body having a distal end and a proximal end, the main body having a conduit between the distal end and the proximal end, through which fluid moves under suction. and One or more actuators are attached to or embedded in the body, each actuator comprising one or more electroactive polymer layers that provide mechanical movement at the distal end in response to stimulation by the electro-control signal, wherein the electro-control signal is provided according to at least one predetermined pattern.

2. The apparatus of claim 1, wherein the predetermined mode enables two or more sets of the actuators to be activated sequentially.

3. The apparatus of claim 1, wherein the predetermined mode enables two or more sets of the actuators to be activated simultaneously.

4. The apparatus of claim 1, wherein the predetermined mode enables two or more groups of the actuators to be activated sequentially, one group after another, and wherein within each group, two or more actuators are actuated simultaneously.

5. The apparatus of claim 4, wherein each actuator extends along the length of the body in a longitudinal direction.

6. The device of claim 5, wherein each of the two or more sets of actuators is located at a radial distance from the longitudinal axis of the catheter.

7. The device of claim 1, wherein the mechanical suction varies in a manner coordinated with the predetermined pattern.

8. The device of claim 7, wherein the pressure of the mechanical suction decreases when one of the mechanical movements includes longitudinal movement at the distal end of the body.

9. The device of claim 1, wherein the distal end of the body has an opening exposing the catheter, and wherein the portion of the body at the opening has a funnel shape.

10. The apparatus of claim 9, wherein the actuator is disposed behind the opening.

11. The apparatus of claim 1, wherein the first actuator of the actuator is helically wound around the body.

12. The apparatus of claim 11, wherein the second actuator in the actuator is also spirally wound around the body but with a chirality different from that of the first actuator.

13. The apparatus of claim 1, wherein the first actuator of the actuator is wound substantially circumferentially around the body relative to the longitudinal axis of the body.

14. The apparatus of claim 13, wherein the first actuator has a first end and a second end, and wherein the first end and the second end are adjacent to each other during mechanical movement of the actuator.

15. The device of claim 13, wherein the first actuator has a first end and a second end, wherein the first end and the second end are separated from each other by a gap, and wherein the actuator is attached to a reinforcing material spanning the gap.

16. The device of claim 1, further comprising a flexible circuit on which the actuator is mounted.

17. The apparatus of claim 1, further comprising a mass block placed on one of the actuators to modify the resonant frequency of the mechanical motion of the actuator.

18. The apparatus of claim 17, wherein the mass block comprises a radiopaque material.

19. The apparatus of claim 17, wherein the mass block comprises tungsten.

20. The apparatus of claim 1, wherein each actuator includes a first end and a second end, wherein one or both ends of the actuator are reinforced to constrain the mechanical movement of the actuator.

21. The device of claim 1, wherein each actuator is embedded or attached to a portion of the body comprising a high-modulus material having a modulus higher than that of the electroactive polymer layer of the actuator, the portion of the body serving as a substrate.

22. The apparatus of claim 21, wherein the portion of the high-modulus material is positioned to guide the mechanical movement.

23. The device of claim 21, further comprising (i) a flexible circuit formed on the substrate, and (ii) an electrode disposed on the flexible circuit to provide the electrical signal to the actuator.

24. The device of claim 1, wherein each actuator is embedded or attached to a portion of the body having a low-modulus material having a modulus lower than that of the electroactive polymer layer, the portion of the body serving as a substrate.

25. The device of claim 1, wherein the body comprises a patterned or textured material layer exposed to the catheter.

26. The device of claim 25, wherein the patterned or textured material layer comprises one or more of the following: polyvinylidene fluoride (PVDF), trifluoroethylene (TrFE), 1,1-chlorofluoroethylene (CFE), and trifluorochloroethylene (CTFE).

27. The device of claim 25, wherein the patterned or textured material layer comprises a copolymer of polyvinylidene fluoride (PVDF) and one or more monomers selected from the group consisting of trifluoroethylene (TrFE), 1,1-chlorofluoroethylene (CFE), and trifluorochloroethylene (CTFE).

28. The device of claim 25, wherein the patterned or textured layer has one or more grooves or protrusions, wherein adjacent grooves or protrusions are separated from each other by channels.

29. The device of claim 28, wherein each protrusion further comprises a smooth surface.

30. The device of claim 28, wherein each protrusion further comprises a textured surface.

31. The device of claim 25, wherein the patterned or textured layer comprises etched recesses.

32. The device of claim 31, wherein one of the etched recesses is provided as a rifling spiral pattern extending longitudinally along the body.

33. The device of claim 25, wherein the patterned or textured layer is formed in a spiral pattern extending longitudinally along the body.

34. The apparatus of claim 25, wherein the patterned or textured layer comprises a movable element capable of axial movement.

35. The apparatus of claim 34 further includes a flexural beam that constrains the movable element to perform primary axial movement.

36. The apparatus of claim 35, wherein the patterned or textured layer further comprises a compliant region having greater compliance than the area within which the moving element moves.

37. The device of claim 36, wherein the compliant region comprises flexural beams interconnected by elongating elements.

38. The device of claim 37, wherein the elongation element abuts against the flexural beam of the compliant region, thereby causing radial expansion of the catheter.

39. The device of claim 1, further comprising a mechanical structure leading to the catheter, the mechanical structure providing a flared opening to the catheter in one of two locations, while the mechanical structure maintaining a closed constraint on the size of the catheter in the other of the two locations.

40. The device of claim 39, wherein the mechanical structure is externally covered by a polymer coating.

41. The apparatus of claim 39, wherein the mechanical structure comprises a first portion and a second portion attached to each other by one or more elastic elements.

42. The device of claim 39, wherein the mechanical structure comprises a plurality of movable plates connected to each other by foldable membrane material sheets.

43. The device of claim 1, further comprising one or more non-transmissive elements disposed at the distal end of the body.

44. The device of claim 1, wherein the hydrophilic coating is disposed at the distal end of the body.

45. The device of claim 1, further comprising one or more support straps on the body to provide mechanical support.

46. ​​The device of claim 45, wherein each of the support bands comprises stainless steel.

47. The device of claim 45, wherein the support band keeps the catheter open when the aspiration pressure is at or below 30 inHg.

48. The device of claim 1, further comprising one or more support straps on the body to restrain longitudinal or axial movement of one or more of the actuators.

49. A device suitable for use in medical procedures, the device being configured to operate according to an electrical signal received from a controller, the device comprising a cannula body having a proximal end and a distal end, the distal end including a tapered tip and an integrated electroactive polymer (EAP) actuator disposed between the tapered tip and the proximal end of the body, wherein (i) the cannula body includes a lumen forming a fluid conduit extending continuously through the length of the cannula body to allow fluid to be received from an opening at the tapered tip and flow to the proximal end of the cannula body under aspiration pressure, (ii) the cannula body further includes two or more electrical conductors in the cannula body to transmit the electrical signal between the controller and the integrated EAP actuator, (iii) the EAP actuator is actuated by the electrical signal, and (iv) the electrical signal and the aspiration pressure vary in a coordinated manner according to one or more predetermined patterns.

50. The device of claim 49, wherein the tapered end comprises an expander.

51. The device of claim 49, wherein the catheter has a larger radius at the distal end of the cannula body than at the proximal end of the cannula body.

52. The apparatus of claim 49 further includes a port in the proximal end of the cannula body, the port leading to the catheter and adapted for connection to a suction device.

53. The apparatus of claim 52, wherein each of the electrical conductors is helically embedded in the cannula body.

54. The apparatus of claim 49 further comprises one or more wires helically embedded in the cannula body to provide mechanical support.

55. The apparatus of claim 54, wherein the wire is made of stainless steel.

56. The device of claim 49, wherein the catheter provides mechanical support within the cannula body to remain open at a pressure equal to or less than 30 in.Hg.

57. The apparatus of claim 49 further includes one or more support rings or belts to provide mechanical support.

58. The apparatus according to claim 57, wherein, The support ring or the constrained EAP actuator moves inward or longitudinally.

59. The apparatus of claim 57, wherein one or more of the support rings or bands serve as radiopaque markers for guiding the distal end of the cannula body through navigation of the vascular system.

60. The apparatus according to claim 49, wherein, The integrated EAP actuator includes one or more EAP actuators and an inner polymer layer.

61. The apparatus of claim 60, wherein the inner polymer layer comprises Pebax.

62. The apparatus of claim 60, wherein the inner polymer layer comprises a plurality of layers with different hardnesses.

63. The apparatus of claim 60, wherein the integrated EAP actuator further comprises a flexible circuit having electrodes for attaching and electrically connecting the EAP actuator.

64. The apparatus of claim 63, wherein the flexible circuit further comprises conductive ink configured to electrically connect the conductor in the cannula body to the electrode.

65. The apparatus of claim 60, wherein each of the EAP actuators is formed of a rectangular sheet circumferentially wound around the inner polymer layer, such that opposite sides of the rectangle are adjacent.

66. The apparatus of claim 60, wherein each of the conductors in the cannula body is embedded in the cannula body in the form of a conductive coil.

67. The apparatus of claim 60 further includes an outer sheath disposed along the outer surface of the cannula body, except at the integrated EAP actuator.

68. The device of claim 67, wherein the integrated EAP actuator is encapsulated in a thermoplastic polyurethane (TPU) material.

69. The apparatus of claim 68, wherein a portion of the distal end of the cannula body is provided with a hydrophilic coating.

70. The apparatus according to claim 69, wherein, The TPU material is attached to the inner polymer layer and the outer sheath.

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