Electrosurgical apparatus with automatic shut-off

Abstract

A puncture device configured to create a puncture in tissue includes an elongate member including a proximal portion defining a longitudinal axis along a length of the elongate member. The elongate member further includes a flexible distal portion curved away from the longitudinal axis and a distal tip configured to deliver energy to the tissue. A sensing element placed on the flexible distal portion of the elongate member detects a curvature of the distal portion such that when the flexible distal portion of the elongate member is straightened, energy is delivered to the distal tip, and when the flexible distal portion of the elongate member is curved, energy is not delivered to the distal tip.

Description

Technical Field

[0001] This disclosure relates to a surgical perforation device configured to deliver energy to living tissue, wherein the energy delivery is controlled by the curvature of a distal portion of the device. More specifically, the invention relates to an apparatus and method for creating a perforation in the atrial septum while automatically stopping the delivery of energy to the atrial septum upon completion of the puncture using the curvature of the distal portion of the device. Background Technology

[0002] Some medical procedures require the use of medical devices that can create a puncture or passage through the heart's tissue. Specifically, puncturing the septum of the heart creates a pathway to the left atrium, where various cardiological procedures are performed. One device that assists in accessing the left atrium is a radiofrequency (RF) transseptal puncture device. In this device, RF energy from a generator is delivered to the target tissue to create a perforation. During the procedure, the user positions the puncture device at the target location on the foramen ovale, located on the heart's septum, and turns on the generator to begin delivering energy to the target location. Delivering RF energy to the tissue causes the intracellular fluid in the cells in contact with the device to evaporate. Ultimately, this results in a gap, hole, or passage at the target tissue site.

[0003] Currently, the parameters surrounding energy delivery involve 1) the duration of energy delivery and 2) pulsed or constant energy delivery. Typically, the user selects the parameters before performing the puncture, such as a constant energy delivery lasting two seconds. The user activates delivery by pressing a button on the generator or via a foot pedal. Once the energy delivery duration has elapsed, the user checks using various means (e.g., fluoroscopy, pressure readings, ultrasound, or contrast agent injection) to determine if the puncture was successful. If unsuccessful, the user manually reactivates energy delivery. Once the duration has elapsed, the user checks again to see if the puncture was successful. The user has the ability to turn off energy delivery before the duration elapses using a button or foot pedal on the generator, but there is still no way to confirm the success of the puncture during energy delivery. This lack of knowledge about the success of the puncture during energy delivery can lead to unintentional damage to surrounding tissues. For example, if the duration has been set to two seconds, but the puncture is completed within one second, the puncture device continues to deliver energy for an extra time after entering the left atrium, which could lead to an unintended perforation within the left atrium. Accidental perforation of other heart tissues can lead to general tissue damage within the left atrium, damage to assistive devices (i.e., damage to the pacemaker leads located in the atrium), or potentially serious complications such as cardiac tamponade or accidental aortic perforation. Cardiac tamponade is a life-threatening complication of transseptal puncture, which occurs when a perforation occurs in the left atrial wall, the roof of the left atrium, or the left atrial appendage. This perforation of the atrial wall can cause fluid to accumulate in the pericardial cavity surrounding your heart. This accumulated fluid compresses your heart, which in turn reduces the amount of blood that can enter your heart. Accidental aortic perforation is a rare but life-threatening complication in which a puncture device enters and perforates the aorta, which may require surgical repair.

[0004] Given these potential complications associated with accidental damage to surrounding tissues, there is a need to provide novel radiofrequency puncture devices in which the delivery of radiofrequency energy is automatically deactivated after the puncture device has completed the puncture and entered the left atrium. Attached Figure Description

[0005] To facilitate understanding of the present invention, embodiments of the invention are illustrated by way of examples in the accompanying drawings, wherein:

[0006] Figure 1 This is a diagram of the system used when creating a transseptal puncture to access the patient's left atrium.

[0007] Figure 2a is a schematic diagram of the construction of a puncture device with a strain gauge.

[0008] Figure 2b is a diagram of a J-shaped tip guidewire with a strain gauge.

[0009] Figure 2c is a diagram of a pigtail guidewire with a strain gauge.

[0010] Figure 3a is a diagram of the strain gauge attached to the core conductor, with the J-shaped tip wire under the insulation.

[0011] Figure 3b is a diagram of the J-shaped tip guidewire to which the strain gauge is attached to the outside of the insulation.

[0012] Figure 4a is a diagram of a puncture device constrained by a sheath and a dilator.

[0013] Figure 4b is an illustration of a puncture device that is not constrained by a sheath and dilator.

[0014] Figure 5 This is a diagram of an example computer algorithm used to control the cutting off of energy delivery.

[0015] Figure 6a is an illustration of a cross-sectional view of a puncture device in which the distal portion includes a conductive wire surrounded by a conductive coil.

[0016] Figure 6b is a cross-sectional view of a puncture device in which the distal portion has been constrained, resulting in contact between the conductive coil and the conductive wire. Detailed Implementation

[0017] Various minimally invasive surgeries involve creating perforations in living tissue. One such procedure is transseptal puncture, which allows surgeons to access the left side of the heart by creating a puncture through the septum from the right side. More recently, medical devices have been configured to perform punctures by delivering energy, specifically radiofrequency energy, to the tissue. Delivering radiofrequency energy to the tissue causes the intracellular fluid in the cells in contact with the energy delivery device to evaporate. This results in a perforation at the target tissue site. One of the complications that can occur during transseptal puncture is accidental puncture of the left atrial wall or aorta. These potentially life-threatening complications can lead to damage to surrounding tissues or assistive devices, or perforation of the left atrial wall or aorta.

[0018] The problem of accidental left atrial puncture can be addressed by providing an electrosurgical puncture device with a mechanism to cut off energy delivery after septal puncture has been completed.

[0019] In a broad aspect, embodiments of the invention include a puncture device configured to create a puncture in tissue. The puncture device has an elongating member including a proximal portion defining a longitudinal axis along the length of the elongating member. The elongating member also includes a flexible distal portion curved away from the longitudinal axis and a distal tip configured to deliver energy to the tissue. A sensing element is positioned on the flexible distal portion of the elongating member such that the sensing element detects the curvature of the distal portion. When the flexible distal portion is straightened, energy is delivered to the distal tip, and when the flexible distal portion is bent, energy is not delivered to the distal tip.

[0020] As a feature of this broad aspect, the sensing element is a strain gauge.

[0021] As another feature of this broad aspect, the elongating member is composed of a conductive material. In some embodiments, the elongating member includes an insulating layer over the conductive material. In some embodiments, a sensing element is positioned above the insulating layer. In an alternative embodiment, the sensing element is positioned below the insulating layer.

[0022] As a feature of this aspect, the sensing element is positioned on one side of the flexible distal portion that is subjected to compression when bent. In an alternative embodiment, the sensing element is positioned on one side of the flexible distal portion that is subjected to tension when bent.

[0023] As another feature of this broad aspect, the puncture device is a guidewire. In some embodiments, the guidewire is a J-tip guidewire. In alternative embodiments, the guidewire is a pigtail guidewire.

[0024] In another broad aspect, embodiments of the invention include a puncture device configured to create a puncture in tissue, the device comprising an elongated member consisting of a conductive core wire. The elongated member includes a proximal portion defining a longitudinal axis along its length. The elongated member also includes a flexible distal portion that bends away from the longitudinal axis. The flexible distal portion includes a conductive coil surrounding the conductive core wire. The flexible distal portion terminates at a distal end configured to deliver energy to tissue, wherein when the flexible distal portion of the elongated member is straightened, the conductive coil contacts the conductive core wire, enabling energy delivery to the distal tip. When the flexible distal portion of the elongated member is bent, the conductive coil does not contact the conductive core wire, disabling energy delivery to the distal tip.

[0025] In another broad aspect, embodiments of the invention include a puncture assembly for puncturing tissue. The puncture assembly includes a puncture device. The puncture device includes an elongation member having a proximal portion defining a longitudinal axis along the length of the elongation member. The puncture device also includes a flexible distal portion and a sensing element disposed on the flexible distal portion such that the sensing element detects the curvature of the flexible distal portion. The flexible distal portion terminates at a distal tip and is configured to deliver energy to the tissue. The puncture assembly also includes a support member including a lumen configured to receive the puncture device such that the flexible distal portion of the puncture device is constrained into a straightened configuration when received within the lumen of the support member.

[0026] As a feature of this broad aspect, the flexible distal portion is constrained within the support member, energy is enabled, and energy delivery is disabled when the flexible distal portion is unconstrained.

[0027] As another feature of this broad aspect, the support members include expanders.

[0028] As a feature of this broad aspect, the puncture device includes a puncture guidewire. In some embodiments, the puncture guidewire includes a J-tip guidewire. In alternative embodiments, the puncture guidewire includes a pigtail guidewire.

[0029] As another feature of this broad aspect, the sensing element is a strain gauge.

[0030] As another feature of this broad aspect, the elongating member is composed of a conductive material. In some embodiments, the elongating member includes an insulating layer over the conductive material. In some embodiments, a sensing element is positioned above the insulating layer. In an alternative embodiment, the sensing element is positioned below the insulating layer.

[0031] As a feature of this aspect, the sensing element is positioned on the side of the flexible distal portion that experiences compression when bent. In an alternative embodiment, the sensing element is positioned on the side of the flexible distal portion that experiences tension when bent.

[0032] In another broad aspect, embodiments of the invention include a method for puncturing the cardiac septum using a puncture assembly comprising a puncture device contained within a lumen of a support member. The method includes the steps of: (i) accessing the patient's vascular system; (ii) advancing the puncture assembly to a target location on the septum such that the distal tip of the puncture device, configured to deliver energy, is exposed beyond the distal tip of the support member, while a flexible, curved, distal portion of the puncture device remains constrained within the lumen of the support member; wherein the flexible, curved, distal portion of the puncture device includes a sensing element to detect the curvature of the distal portion; (iii) delivering energy to the distal tip of the puncture device to create a puncture at the target location; and (iv) advancing the puncture device such that the flexible, curved, distal portion of the puncture device is no longer constrained within the lumen of the support member. The sensing element detects the unconstrained curvature of the flexible, curved, distal portion of the puncture device and prevents energy delivery to the distal tip of the puncture device.

[0033] Referring now to the detailed accompanying drawings, it should be emphasized that the details shown are merely illustrative and for the purpose of discussing certain embodiments of the invention in an illustrative manner. Before explaining at least one embodiment of the invention in detail, it should be understood that the invention is not limited in its application to the details of the structures and arrangements of components set forth in the following description or illustrated in the drawings. The invention can have other embodiments or can be practiced or performed in various ways. Furthermore, it should be understood that the wording and terminology used herein are for descriptive purposes and should not be considered limiting.

[0034] Figure 1An embodiment of an exemplary system 100 that can be used for access to the left atrium via transseptal puncture is shown. System 100 includes a puncture device 110, a sheath 120, a dilator 130, and an energy generator 140 connected to the puncture device via a connection device 150. The puncture device 110, such as a pigtail guidewire (not shown) or a J-tip guidewire, is configured to deliver energy to tissue (such as the atrial septum of a patient's heart). Energy is delivered from the generator 140 to an energy delivery device located at the distal tip of the puncture device 110. In this embodiment, the puncture device 110 includes a sensing element located at a distal portion 240. The sensing element is configured to detect the curvature of the distal portion 240 to which it is attached and to send a signal to the generator 140. The signal from the sensing element varies with the curvature of the distal portion. When the distal portion is in an unconstrained state (i.e., the curved distal portion 240), the generator 140 is configured to process the signal and take a corresponding action. For example, in some embodiments, when generator 140 receives a signal corresponding to the unconstrained remote portion 240, the generator will automatically cut off energy delivery.

[0035] An exemplary method for accessing a patient's left atrium using the present invention may include the following steps:

[0036] (i) Entering the vascular system, for example, through the groin into the femoral vein.

[0037] (ii) The puncture device 110 and its components (i.e., the sheath 120 and the dilator 130) are advanced to a target location, in this embodiment, the fossa ovalis of the patient's heart. During this stage, the distal portion 240 of the puncture device 110 is straightened and constrained by the dilator 130 and sheath 120 components. The distal portion 240, when unconstrained, comprises a predetermined non-linear shape.

[0038] (iii) Energy is delivered from generator 140 through puncture device 110 and to fossa ovalis to create a puncture in the septum.

[0039] (iv) The puncture device 110 is advanced through the puncture and into the left atrium; upon exiting the assembly, the distal portion 240, no longer constrained by the sheath 120 and dilator 130, returns to its predetermined nonlinear shape. The sensing element detects this change in geometry and signals the generator 140 to cut off the delivery of energy.

[0040] In an alternative approach, access to the heart can be via the superior vena cava, with the puncture device 110 entering the vascular system via the subclavian vein. Those skilled in the art will understand that the dimensions of the components and the puncture device can vary depending on the location of the vascular system accessed (e.g., subclavian vein) and the anatomy (e.g., the right atrium of the heart).

[0041] Various embodiments of the invention used in the system 100 and method described above can be seen in Figures 2a-2c. Referring to Figure 2a, the puncture device 110 comprises an elongated member 250 (such as a wire) coated in an electrically insulating material 210 that substantially covers the conductive elongated member, exposing a portion of the distal tip to form an electrode 220. The elongated member 250 may also include a flexible cone 270 in a distal portion 240. In addition to the cone 270, the distal portion 240 of the elongated member 250 may include a coil 260 to provide support. Both the elongated member 250 and the coil 270 may be composed of electrically conductive materials, such as nitinol or stainless steel, to allow energy to be delivered from the generator along the elongated member 250 to the electrode 220. The coating 210 is composed of an electrically insulating material, such as a PTFE (polytetrafluoroethylene) coating, to ensure that the delivery of radio frequency energy travels along the length of the puncture device 110 to the exposed electrode tip 220. Alternatively, the elongation member 250 may not have an insulating coating applied thereto; instead, the sheath or expander may be composed of a non-electrically conductive material to ensure energy is delivered through the distal tip of the puncture device 110. In an alternative embodiment, the elongation member 250 may be composed of a non-electrically conductive material, such as polyetheretherketone (PEEK) or polyimide. In this alternative embodiment, a conductive element (e.g., an insulated wire) would be required to deliver energy to the distal tip. The distal region 240 may be formed during manufacturing, typically exposed to heat while being held in the desired shape, resulting in a curve that curls away from the central axis. Electrode 220 may be coupled to a conductive wire that carries energy from the generator to the distal tip of the puncture device 110. Sensing element 230 is attached to the distal portion 240 of puncture device 110 such that it is subjected to changes in geometry as puncture device 110 moves from a constrained state (i.e., straightened within a sheath and / or dilator, as shown in FIG2a) to an unconstrained state (e.g., a bent state, as shown in FIG2b or 2c). Sensing element 230 may include a strain gauge; those skilled in the art will understand that other sensing devices may be used to detect changes in the geometry of distal portion 240.

[0042] Referring now to FIG. 2b, the puncture device 110 has a distal portion 240 that has been shaped in a J-tip configuration when unconstrained. A sensing element 230 is attached such that when the distal portion 240 is in its unconstrained configuration (e.g., J-tip configuration), the sensing element 220 bends or twists along the curve.

[0043] As shown in Figure 2c, the puncture device 110 may include a distal portion 240 having a pigtail structure when unconstrained. A sensing element 230 is preferably positioned along the most curved portion of the distal end of the distal portion 240, such that the sensing element 220 bends immediately when the puncture device 110 begins to curl. The shape change of the sensing element 230 is detected when the distal portion 240 becomes unconstrained. In response to the detected shape change, the generator can operate in an "automatic cut-off" mode and automatically stop delivering RF energy. This configuration allows energy delivery to be cut off as soon as the puncture device 110 enters the left atrium, reducing the possibility that the puncture device 110 may damage surrounding tissue by unintentionally delivering RF.

[0044] In some embodiments, the sensing element 230 may be directly attached to the elongation member 250, as shown in FIG3a. For example, the sensing element 230 may be soldered or glued to the elongation member 250. Those skilled in the art will understand that other means may be used to attach the sensing element 230 to the elongation member 250. The insulating coating 210 may cover both the sensing element 230 and the insulating internal wiring 610. In an alternative embodiment, the sensing element 230 may be directly attached to the insulating coating 210, as shown in FIG3b. For example, the sensing element 230 may be attached to the insulating coating 210 by soldering or gluing. The insulating internal wiring 610 may extend along the length of the puncture device 110. In an alternative embodiment, the insulating internal wiring 610 may be attached to the outside of the insulating coating 210 and extend along the outside of the insulating coating 210 (not shown). The insulating internal wiring exits the puncture device 110 at its proximal end, which in turn connects to the generator. The sensing element 230 is capable of detecting changes in the geometry of the distal portion 240 of the puncture device 110. In some embodiments, the sensing element 230 may be placed in the distal portion 240, on the inner or outer portion of the curvature, such that the sensing element 220 bends or twists with the curve of the distal portion 240. In an embodiment, internal insulating wiring 610 delivers signals from the sensing element 230 to the generator.

[0045] In one embodiment, sensing element 230 may include a strain gauge attached to the inner portion of the curve, as shown in Figures 3a and 3b. In an alternative embodiment, the strain gauge may be positioned on the outer portion of the curve. Those skilled in the art will understand that the strain gauge can be positioned anywhere along the curved portion, such that there is a difference in strain gauge readings from a straightened state versus a bent state. The strain gauge twists with the curvature of the distal portion 240. The twisting of the strain gauge will cause a change in its resistance; for example, compression of the strain gauge will cause a decrease in resistance, while tension will cause an increase in resistance. This change in resistance is used to determine whether the distal portion is in its constrained configuration (i.e., conforming to the shape of the sheath and / or expander) or in its unconstrained configuration (i.e., in its predetermined shape). The detection signal from the strain gauge can be used to enable or disable the delivery of energy to the puncture device 110. For example, the measurement can be implemented into an algorithm that compares a baseline strain with a measured strain. The baseline strain can be an unconstrained measurement of strain, such as the strain on the strain gauge when the distal portion 240 of the puncture device 110 is bent or shaped; this measurement can be performed during manufacturing. The algorithm then compares the measured strain to the baseline to determine whether the distal portion 240 is straightened (i.e., constrained) or bent (i.e., unconstrained), thus enabling or disabling energy delivery. For example, if the detected strain is more positive than the baseline should change (i.e., the change in resistance is positive, meaning the strain gauge is under tension), this corresponds to the distal portion 240 of the puncture device 110 being straightened or constrained; therefore, energy delivery is enabled. If the detected strain is the same as the baseline strain, it indicates that the distal portion 240 of the puncture device 110 is bent or unconstrained. When the current strain of the device is detected to be equal to the baseline strain, the generator can be configured to disable energy delivery to the puncture device.

[0046] The constrained and unconstrained states of the puncture device 110 are shown in Figures 4a and 4b, respectively. In this embodiment, the puncture device 110 is constrained by the dilator 130 when inserted into the lumen of the auxiliary device. The flexibility of the distal portion 240 of the puncture device 110 causes the normally bent distal portion 240 to straighten. This causes the sensing element 230 to also straighten. In some embodiments, this configuration of the puncture device 110 (as seen in Figure 4a) is ready to perform a puncture. The configuration of the sensing element 230 indicates that the puncture device 110 is in a position to deliver energy to the electrode 220. For example, if the sensing element 230 is a strain gauge, the detected strain will be greater than the baseline strain (i.e., the detected strain is the strain of the puncture device in an unconstrained configuration). The generator will receive this information and enable energy delivery. In some embodiments, energy delivery can be initiated by the user. For example, the generator can alert the user to begin energy delivery via sound, user interface prompts, optical alarms (i.e., lights being turned on), or any other alarm means. In an alternative embodiment, energy delivery can be automatic, such that energy is delivered once the sensing element is in a constrained configuration. Upon completion of the puncture, the puncture device 110 is pushed through a hole in the septum and into the left atrium. The distal portion 240 of the puncture device 110 is pushed out of the dilator 130 and into the left atrium. As the puncture device 110 enters the left atrium, the distal portion 240 is no longer constrained and returns to its original shape (FIG. 4b). The bending of the distal portion 240 causes the sensing element 230 to bend; the sensing element 230 detects the change in the configuration of the distal portion. In an embodiment, the detected signal is interpreted as the puncture device 110 having completed the puncture, and energy delivery should be cut off. For example, if the sensing element 230 is a strain gauge, the detected strain will be approximately equal to the baseline strain (obtained when the device is unconstrained). In response to detecting this state, the generator can be configured to disable energy delivery. Additionally, the generator can alert the user, informing them that energy delivery has been disabled. The alarm can take the form of sound, user interface prompts, optical alarms (i.e., lights off), or any other alarm means.

[0047] In some embodiments, the sensing element 230 may be positioned along the elongation member 250 at the proximal end of the distal portion 240. As an example, the sensing element 230 may be positioned along the elongation member 250 such that when the puncture device 110 is in the optimal puncture position, the sensing element 230 is located within a curved portion of the dilator 130. In this configuration, the sensing element 230 detects a change from a straight configuration (i.e., when the sensing element 230 is close to the curve of the dilator) to a curved configuration (e.g., when the sensing element 230 is sensed to be contained within the curve of the dilator). In this embodiment, when the sensing element 230 is in the straight configuration, no energy is delivered to the electrode 220. When the sensing element 230 is in the curved configuration, energy can be delivered; in other words, when the sensing element 230 is positioned within the curved portion of the dilator 130 (when the puncture device 110 is in the optimal position for puncturing tissue), energy can be delivered to the electrode 220, enabling the device 110 to perform a puncture. Once the puncture is complete, the puncture device 110 can be advanced, and the sensing element 230 moves from a curved configuration (e.g., positioned within a curved portion of the dilator 130) to a straight configuration (e.g., positioned within a straight portion of the dilator 130 away from the curved portion), which in turn inhibits energy delivery. In an alternative embodiment, the sensing element 230 can be configured to enable energy delivery while in a straight configuration. As an example of this embodiment, the sensing element 230 can be positioned on the elongation member 250 such that when the puncture device 110 is in the optimal position for puncturing tissue, the sensing element 230 is close to the curved portion of the auxiliary device (e.g., the dilator 130) and in a straight configuration, ready to deliver energy to the tissue. After the puncture is complete, the puncture device 110 is advanced through the dilator 130 and into the curved portion of the dilator. In the curved configuration, the sensing element 230 is configured to inhibit energy delivery. In other words, energy delivery is inhibited when the sensing element 230 reaches the curved portion of the dilator 130. In some embodiments, the sensing element 230 may be positioned on top of the insulating layer 210 of the puncture device 110. In another embodiment, the sensing element 230 may be positioned below the insulating layer 210 of the puncture device 110. In some embodiments, the sensing element 230 may be positioned on an inner portion of the puncture device; in other words, the sensing element 230 will be subjected to compression when constrained by the curved portion of the dilator 130. In an alternative embodiment, the sensing element 230 may be positioned on an outer portion of the puncture device such that it is subjected to tension when constrained by the curved portion of the dilator 130.

[0048] As previously discussed, software algorithms can be implemented to control energy delivery from the generator to the puncture device. This algorithm can use signals from a sensing element to determine the geometry of the distal portion; this, in turn, will be used to control energy delivery. For example, if the sensing element is a strain gauge placed on a curve of the distal portion, it can use strain measurements, as previously described, to signal the generator to enable or disable energy delivery.

[0049] In an alternative embodiment, the generator can apply a known voltage to the strain gauge. As the strain gauge deforms, its resistance changes, ultimately altering the current returning to the generator. A baseline for this current can be determined during manufacturing and set to a value when the puncture device is unconstrained. This baseline will be used to cut off energy delivery, as this value will indicate when the puncture device has entered the left atrium after the puncture is complete. For example, now refer to... Figure 5 The generator applies a known voltage to the strain gauge throughout the process 510. Using the known voltage and resistance of the strain gauge, the current of the electrical signal 520 can be calculated. The algorithm compares the current of the electrical signal to see if it matches a baseline current value (i.e., the unconstrained distal portion of the puncture device) 530. When the strain gauge is under tension, the resistance increases; therefore, the current will decrease when the distal portion of the puncture device is constrained compared to when it is unconstrained. Therefore, if the measured current is less than the baseline current value, energy delivery is enabled 540, and the measured current continues to be compared 530. If the measured current matches the baseline current, energy delivery is disabled 550, a signal is sent that the puncture is complete and the puncture device has entered the left atrium. Those skilled in the art will understand that other electrical signal properties can be used and implemented in the algorithm to control energy delivery.

[0050] Alternatively, energy delivery can be implemented through hardware means. In one embodiment, a sensing element can control a switch in a generator that controls the delivery of energy to the puncture device. In some embodiments, the sensing element may include a strain gauge that may have a current-gated switch to control energy delivery. The current-gated switch can be switched on or off based on the inflection point of the strain gauge. For example, when the strain gauge is bent (i.e., the puncture device is unconstrained), the current-gated switch can switch to cut off energy delivery.

[0051] As previously described, the puncture device 110 includes an electrode 220 at a distal tip, which can be used to deliver energy for puncturing tissue. The puncture device 110 also includes an elongation member 250, which tapers 270 at a distal portion 240 (as shown in Figures 6a and 6b). A coil 260 is used to provide support to the distal portion 240. In an alternative embodiment of the invention, the coil 260 and the elongation member 250 may be made of a conductive material, and an insulating layer 210 is applied to the device. In an unconstrained state, as shown in Figure 6a, the coil 260 and the elongation member 250 do not contact each other. However, in a constrained state, as shown in Figure 6b, the elongation member 250 may have a tendency to kink, resulting in contact between the coil 260 and the elongation member 250. In some embodiments, the coil 260 may be connected to a generator such that when the puncture device 110 is constrained (i.e., the elongation member 250 is kinked), contact between the coil 260 and the elongation member 250 results in the delivery of energy; thus, energy is delivered from the generator to the coil 260, which in turn is delivered to the elongation member 250, and finally to the electrode 220 at the distal tip. Upon completion of the puncture, the puncture device 110 is pushed through, resulting in an unconstrained state (FIG. 6a), in which case the elongation member 250 and the coil 260 are no longer in contact; thereby stopping the delivery of energy to the electrode 220.

[0052] In an alternative embodiment of the invention, the puncture device 110 includes an electrode 220 at a distal tip, configured to deliver energy to puncture tissue. In some embodiments, energy may be delivered to the electrode 220 via a conductive wire. In some embodiments, the conductive wire may be an insulated wire 610. The insulated wire 610 may be positioned on the puncture device 110 such that it extends along the outside of the curved distal portion 240; that is, when the puncture device 110 is unconstrained, the insulated wire 610 will be under tension. The insulated wire 610 may consist of two separate portions: a distal portion and a proximal portion. The insulated wire 610 may be positioned along the puncture device 110 such that when the curved distal portion 240 is constrained by an auxiliary device (e.g., dilator 130), the two separate portions of the insulated wire 610 are in contact with each other, allowing energy delivery. In other words, when the puncture device 110 is in a ready or optimal position for puncture, the curved distal portion 240 of the puncture device is straightened. The straightening of the curved distal portion 240 causes the distal and proximal portions of the insulated wire 610 to be compressed together, thereby enabling energy delivery. Upon completion of the puncture, the puncture device 110 is advanced beyond the expander 130, causing the curved distal portion 240 to be no longer constrained and to return to its curved configuration. As a result, the distal and proximal portions of the insulated wire 610 are pulled apart due to the elongation of the distal ends on the outer periphery of the curved distal portion 240. Therefore, an interruption occurs in the circuit, and energy delivery is disabled.

[0053] Further examples

[0054] 1) A puncture device configured to create a puncture in tissue, comprising:

[0055] An elongating member, including a proximal portion that defines a longitudinal axis along the length of the elongating member;

[0056] The flexible distal portion of the elongated member bends away from the longitudinal axis;

[0057] The distal tip is configured to deliver energy to the tissue; and

[0058] A sensing element is placed on the flexible distal portion of the elongated member, such that the sensing element detects the curvature of the distal portion;

[0059] Specifically, when the flexible distal portion of the elongated member is straightened, energy is delivered to the distal tip, and when the flexible distal portion of the elongated member is bent, energy is not delivered to the distal tip.

[0060] 2) The puncture device according to Example 1, wherein the sensing element is a strain gauge.

[0061] 3) The puncture device according to Example 1, wherein the elongating member is made of a conductive material.

[0062] 4) The puncture device according to Example 3, wherein the elongating member includes an insulating layer on the conductive material.

[0063] 5) The puncture device according to Example 4, wherein the sensing element is positioned on the insulating layer.

[0064] 6) The puncture device according to Example 4, wherein the sensing element is positioned under the insulating layer.

[0065] 7) The puncture device according to Example 1, wherein the sensing element is positioned on the inner portion of the flexible distal portion that is compressed when bent.

[0066] 8) The puncture device according to Example 1, wherein the sensing element is positioned on the outer portion of the flexible distal portion that is subjected to tension when bent.

[0067] 9) The puncture device according to Example 1, wherein the puncture device is a guidewire.

[0068] 10) The puncture device according to Example 9, wherein the guidewire is a J-tip guidewire.

[0069] 11) The puncture device according to Example 9, wherein the guidewire is a pigtail guidewire.

[0070] 12) A puncture device configured to create a puncture in tissue, comprising:

[0071] An elongated member consisting of a conductive core wire includes a proximal portion that defines a longitudinal axis along the length of the elongated member;

[0072] The flexible distal portion of the elongated member bends away from the longitudinal axis;

[0073] The flexible distal portion includes a conductive coil surrounding the conductive core wire; and a distal tip configured to deliver energy to the tissue.

[0074] Specifically, when the flexible distal portion of the elongated member is straightened, the conductive coil contacts the conductive core wire, enabling energy delivery to the distal tip; and when the flexible distal portion of the elongated member is bent, the conductive coil does not contact the conductive core wire, disabling energy delivery to the distal tip.

[0075] 13) A puncture assembly for puncturing tissue, the puncture assembly comprising:

[0076] A puncture device, including an elongation member having a proximal portion defining a longitudinal axis along the length of the elongation member;

[0077] The puncture device further includes a flexible distal portion of the elongated member that bends away from the longitudinal axis and a sensing element placed on the flexible distal portion of the elongated member, such that the sensing element detects the curvature of the flexible distal portion.

[0078] The flexible distal portion terminates at a distal tip, the distal tip being configured to deliver energy to the tissue; and

[0079] A support member, including a lumen configured to accommodate the puncture device;

[0080] The flexible distal portion is constrained into a straightened structure when housed within the cavity of the support member.

[0081] 14) The puncture assembly according to Example 13, wherein energy delivery is enabled when the flexible distal portion is constrained within the support member, and energy delivery is disabled when the flexible distal portion is unconstrained.

[0082] 15) The puncture assembly according to Example 13, wherein the support member includes an expander.

[0083] 16) The puncture assembly according to Example 13, wherein the puncture device includes a puncture guidewire.

[0084] 17) The puncture assembly according to Example 16, wherein the puncture guidewire includes a J-shaped tip guidewire.

[0085] 18) The puncture assembly according to Example 16, wherein the puncture guidewire comprises a pigtail guidewire.

[0086] 19) The puncture assembly according to Example 13, wherein the sensing element is a strain gauge.

[0087] 20) The puncture device according to Example 13, wherein the elongating member is made of a conductive material.

[0088] 21) The puncture device according to Example 20, wherein the elongating member includes an insulating layer over the conductive material.

[0089] 22) The puncture device according to Example 21, wherein the sensing element is positioned on the insulating layer.

[0090] 23) The puncture device according to Example 21, wherein the sensing element is positioned under the insulating layer.

[0091] 24) The puncture device according to Example 13, wherein the sensing element is positioned on the inner portion of the flexible distal portion that is compressed when bent.

[0092] 25) The puncture device according to Example 13, wherein the sensing element is positioned on the outer portion of the flexible distal portion that is subjected to tension when bent.

[0093] 26) A method for puncturing the cardiac septum using a puncture assembly comprising a puncture device contained within a lumen of a support member, the method comprising the steps of:

[0094] (i) Entering the patient's vascular system;

[0095] (ii) Advance the puncture assembly to a target position on the septum such that the distal tip of the puncture device configured to deliver energy is exposed outside the distal tip of the support member, while the flexibility, bending, and distal portion of the puncture device remain constrained within the lumen of the support member.

[0096] The flexible, curved, and distal portion of the puncture device includes a sensing element to detect the curvature of the distal portion.

[0097] (iii) Delivering energy to the distal tip of the puncture device to create a puncture at the target location; and

[0098] (iv) Advance the puncture device so that the flexible, curved, distal portion of the puncture device is no longer constrained within the lumen of the support member;

[0099] The sensing element thus detects the flexibility, bending, and unconstrained curvature of the distal portion of the puncture device, and prevents energy delivery to the distal tip of the puncture device.

[0100] 27) A component for puncturing target tissue, the component comprising:

[0101] The puncture device includes:

[0102] Elongation member;

[0103] The distal tip is configured to deliver energy to the target tissue;

[0104] The sensing element is positioned on the elongated member;

[0105] Supporting member, the supporting member comprising:

[0106] The support member has a proximal portion and a distal portion having a lumen, the lumen being configured to be accommodated therein and extending therebetween the puncture device;

[0107] The distal portion of the support member includes a curved portion and a straight portion at the distal end of the curved distal portion, wherein the straight portion;

[0108] The distal end of the opening;

[0109] Furthermore, when the puncture device is inserted into the support member, the sensing element detects the change in the curvature of the puncture device as it is advanced through the distal portion of the support member.

[0110] 28) The component according to Example 27, wherein the sensing element is positioned on the elongated member such that when the distal tip of the puncture device protrudes from the distal end of the opening of the support member, the sensing element is located within the curved portion of the support member.

[0111] 29) The component according to Example 28, wherein the sensing element is configured to enable energy delivery when constrained within the curved portion of the support member, and to disable energy delivery when not constrained by the curved portion.

[0112] 30) The component according to Example 27, wherein the sensing element is positioned on the elongated member such that when the distal tip of the puncture device protrudes from the distal end of the opening of the support member, the sensing element is located at the proximal end of the curved portion of the support member.

[0113] 31) The component according to Example 30, wherein the sensing element is configured to enable energy delivery when not constrained by the curved portion and to disable energy delivery when constrained by the curved portion.

[0114] 32) The component according to any one of Examples 27 to 31, wherein the support member is an expander.

[0115] 33) The component according to any one of Examples 27 to 32, wherein the sensing element is positioned below the insulating layer of the puncture device.

[0116] 34) The component according to any one of Examples 27 to 32, wherein the sensing element is positioned on the insulating layer of the puncture device.

[0117] 35) The component according to any one of Examples 27 to 34, wherein the sensing element is positioned on an external portion of the puncture device such that it is subjected to tension when bent by the bending portion.

[0118] 36) The component according to any one of Examples 27 to 34, wherein the sensing element is positioned on an internal portion of the puncture device such that it is compressed when bent by the bending portion.

[0119] 37) The component according to any one of Examples 27 to 36, wherein the puncture device is a flexible J-shaped tip guidewire.

[0120] 38) The component according to any one of Examples 27 to 36, wherein the puncture device is a flexible pigtail guidewire.

[0121] 39) A puncture device for puncturing target tissue, the puncture device comprising:

[0122] An elongating member, including a proximal portion that defines a longitudinal axis along the length of the elongating member;

[0123] The flexible distal portion of the elongated member that bends away from the longitudinal axis;

[0124] The distal tip is configured to deliver energy to the tissue;

[0125] A first conductive wire extending along the proximal portion of the elongated member, wherein the first conductive wire terminates at a distance along the flexible distal portion;

[0126] A second conductive wire coupled to the distal tip, wherein the second conductive wire terminates at the distal end of the first conductive wire;

[0127] The first conductive wire and the second conductive wire are positioned along the outer edge of the flexible distal portion;

[0128] Therefore, when the flexible distal portion is straightened, the first conductive wire contacts the second conductive wire, thereby enabling energy delivery; and

[0129] Therefore, when the flexible distal portion bends, the first conductive wire does not contact the second conductive wire, thereby disabling energy delivery.

[0130] The embodiments of the present invention described above are intended to be exemplary. The scope of the invention is therefore intended to be limited only by the scope of the appended claims.

[0131] It should be understood that certain features of the invention described in the context of individual embodiments for clarity may also be provided in combination in a single embodiment. Conversely, various features of the invention described in the context of individual embodiments for brevity may also be provided individually or in any suitable sub-combination.

[0132] Although the invention has been described in conjunction with its specific embodiments, it will be apparent to those skilled in the art that many alternatives, modifications, and variations will be readily apparent. Therefore, it is intended to include all such alternatives, modifications, and variations that fall within the broad scope of the appended claims. All publications, patents, and patent applications mentioned in this specification are incorporated herein by reference in their entirety, to the extent that each individual publication, patent, or patent application is specifically and individually indicated to be incorporated herein by reference. Furthermore, any reference or identification in this application should not be construed as an admission that such reference is prior art to the invention.

Claims

1. A puncture device configured to create a puncture in tissue, comprising: An elongating member, including a proximal portion that defines a longitudinal axis along the length of the elongating member; The flexible distal portion of the elongated member bends away from the longitudinal axis; The distal tip is configured to deliver energy to the tissue; as well as A sensing element is placed on the flexible distal portion of the elongated member, such that the sensing element detects the curvature of the distal portion. The sensing element is positioned on the inner portion of the flexible distal portion that is subjected to compression when bent, or the sensing element is positioned on the outer portion of the flexible distal portion that is subjected to tension when bent. Specifically, when the flexible distal portion of the elongated member is straightened, energy is delivered to the distal tip, and when the flexible distal portion of the elongated member is bent, energy is not delivered to the distal tip.

2. The puncture device according to claim 1, wherein, The sensing element is a strain gauge.

3. The puncture device according to claim 1 or 2, wherein, The elongation member is made of a conductive material.

4. The puncture device according to claim 3, wherein, The elongating member includes an insulating layer on top of the conductive material.

5. The puncture device according to claim 4, wherein, The sensing element is positioned on the insulating layer.

6. The puncture device according to claim 4, wherein, The sensing element is positioned beneath the insulating layer.

7. The puncture device according to claim 1 or 2, wherein, The puncture device is a guidewire, a J-shaped tip guidewire, or a pigtail guidewire.

8. The puncture device according to claim 1 or 2, further comprising: The support member includes a cavity configured to receive the elongated member; The flexible distal portion is constrained into a straightened structure when housed within the cavity of the support member.

9. The puncture device according to claim 8, wherein, When the flexible distal portion is constrained within the support member, energy delivery to the distal tip is enabled, and when the flexible distal portion is unconstrained, energy delivery to the distal tip is disabled.

10. The puncture device according to claim 8 or 9, wherein, The support member includes an expander.

11. The puncture device according to claim 8 or 9, wherein, The support member includes a distal portion containing a curved portion and a straight portion at the distal end of the curved portion.

12. The puncture device according to claim 1 or 2, wherein, The elongating member includes a coil.

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