Electrosurgical device with automatic shut-off function

Abstract

To provide a device and method for creating a perforation in the atrial septum while using the curvature of a distal portion of the device to automatically stop the delivery of energy to the atrial septum upon completion of a puncture.SOLUTION: A puncturing device configured to create a puncture in a tissue comprises an elongate member comprising a proximal portion defining a longitudinal axis along the length of the elongate member. The elongate member further comprises a flexible distal portion that curves 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 the curvature of the distal portion. Thereby, 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.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure relates to a surgical perforation device configured to deliver energy to living tissue, where the delivery of energy is controlled by curvature of a distal portion of the device. More specifically, the present invention relates to a device and method for creating a perforation in the atrial septum while automatically ceasing delivery of energy to the atrial septum upon completion of puncture, utilizing the curvature of the distal portion of the device. [Background technology]

[0002] Certain medical procedures require the use of medical devices capable of creating a puncture or channel through cardiac tissue. Specifically, puncturing the septum of the heart creates a pathway to the left atrium where various cardiac procedures are performed. One device that aids in gaining access to the left atrium is a radiofrequency (RF) transseptal puncture device. In such devices, RF energy from a generator is delivered to the target tissue to create a puncture. In operation, a user positions the puncture device at a target location on the fossa ovalis, located on the septum of the heart, and turns on the generator to begin delivering energy to the target location. Delivering RF energy to the tissue causes evaporation of intracellular fluids of cells in contact with the device. Ultimately, this creates a void, hole, or channel at the target tissue site.

[0003] Currently, parameters for energy delivery include 1) duration of energy delivery, and 2) pulsed or constant delivery of energy. Typically, a user would select the parameters, e.g., constant energy delivery for a duration of 2 seconds, before performing the puncture. The user would activate the delivery by pressing a button on the generator or via a foot pedal. Once the duration of energy delivery is complete, the user would check using various means (e.g., fluoroscopy, pressure reading, ultrasound, or contrast injection) to determine whether the puncture was successful. If unsuccessful, the user would manually activate the energy delivery again. Once the duration is complete, the user would check again whether the puncture was successful. Although the user can turn off the energy delivery before the duration is complete using a button on the generator or a foot pedal, there is still no way to check whether the puncture was successful during the delivery of energy. This lack of awareness of the success of the puncture during energy delivery can lead to inadvertent damage to the surrounding tissue. For example, if the duration is set to 2 seconds, but the puncture is completed in 1 second, the puncture device delivers energy for an additional time after entering the left atrium, which may lead to an inadvertent perforation in the left atrium. Inadvertent perforation of other tissues of the heart may result in serious complications such as general tissue damage in the left atrium, auxiliary device damage (i.e., damage to the pacemaker lead located in the atrium), or cardiac tamponade or inadvertent aortic perforation. Cardiac tamponade is a life-threatening complication of transseptal puncture that occurs when a perforation is created in the left atrial wall, the left atrial roof, or the left atrial appendage. This perforation of the atrial wall may lead to the accumulation of fluid in the pericardial space surrounding the heart. This fluid accumulation compresses the heart, thereby reducing the amount of blood that can enter the heart. Inadvertent aortic perforation is a rare, life-threatening complication in which the puncture device enters and perforates the aorta, which may require surgical repair.

[0004] In view of these potential complications associated with inadvertent damage to surrounding tissue, a need exists to provide a novel radiofrequency puncture device in which the delivery of radiofrequency energy is automatically deactivated after the puncture device has completed the puncture and entered the left atrium. Summary of the Invention

[0005] In order that the invention may be readily understood, embodiments thereof are shown by way of example in the accompanying drawings, in which: FIG. [Brief description of the drawings]

[0006] [Figure 1] FIG. 1 is a diagram of a system used in creating a transseptal puncture to gain access to the left atrium of a patient. [Figure 2A] FIG. 1 is a diagram of the structure of a puncture device having a strain gauge. [Figure 2B] FIG. 1 is a diagram of a J-shaped tip guidewire with a strain gauge. [Figure 2C] FIG. 1 is a diagram of a pigtail guidewire having a strain gauge. [Figure 3A] FIG. 13 is a diagram of a J-type distal guidewire with a strain gauge attached to the core wire, underneath the insulation. [Figure 3B] FIG. 1 is a diagram of a J-type tip guidewire with a strain gauge attached to the outside of the insulator. [Figure 4A] FIG. 2 is a diagram of a puncture device constrained by a sheath and a dilator. [Figure 4B] FIG. 2 is a diagram of the puncture device unconstrained by the sheath and dilator. [Diagram 5] FIG. 13 is a diagram of an exemplary computer algorithm for controlling the cessation of energy delivery. [Figure 6A] FIG. 13 is a cross-sectional view of a puncture device including a conductive wire surrounded by a conductive coil in a distal portion. [Figure 6B] 1 is a cross-sectional view of a puncture device with a distal portion restrained to provide contact between the conductive coil and the conductive wire. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0007] Various minimally invasive procedures include creating a perforation in biological tissue. One such procedure is the performance of a transseptal puncture, which allows a surgeon to gain access to the left side of the heart by creating a puncture through the septum from the right side of the heart. Recently, medical devices have been configured to perform the puncture by delivering energy, specifically radiofrequency energy, to tissue. The delivery of radiofrequency energy to tissue causes evaporation of intracellular fluids of cells in contact with the energy delivery device. This creates a perforation at the target tissue site. One problem that can occur during a transseptal puncture is the inadvertent puncture of the left atrial wall or the aorta. These potentially life-threatening problems can result in damage to surrounding tissue or auxiliary devices, or perforation of the left atrial wall or the aorta.

[0008] The problem of inadvertent puncture of the left atrium is solved by providing an electrosurgical puncture device that has a mechanism for terminating the delivery of energy after puncture of the septum is complete. In one broad aspect, an embodiment of the invention includes a puncture device configured to create a puncture in tissue. The puncture device has 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 tissue. A sensing element is disposed on the flexible distal portion of the elongate member to detect bending 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 curved, energy is not delivered to the distal tip.

[0009] In a feature of this broad aspect, the sensing element is a strain gauge. In another feature of this broad aspect, the elongated member is comprised of a conductive material. In some embodiments, the elongated member includes an insulating layer over the conductive material. In some embodiments, the sensing element is disposed over the insulating layer. In alternative embodiments, the sensing element is disposed under the insulating layer.

[0010] In a feature of this aspect, the sensing element is located on a side of the flexible distal portion that is compressed when bent. In an alternative embodiment, the sensing element is located on a side of the flexible distal portion that is under tension when bent.

[0011] In 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.

[0012] In another broad aspect, an embodiment of the invention includes a puncture device configured to create a puncture in tissue comprising an elongate member constructed from a conductive corewire. The elongate member includes 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. The flexible distal portion includes a conductive coil surrounding the conductive corewire. The flexible distal portion terminates in a distal tip configured to deliver energy to tissue, such that when the flexible distal portion of the elongate member is straightened, the conductive coil contacts the conductive corewire to enable energy delivery to the distal tip. When the flexible distal portion of the elongate member is curved, the conductive coil does not contact the conductive corewire to disable energy delivery to the distal tip.

[0013] In another broad aspect, an embodiment of the invention includes a puncture assembly for puncturing tissue. The puncture assembly includes a puncture device. The puncture device includes an elongate member having a proximal portion defining a longitudinal axis along a length of the elongate member. The puncture device further includes a flexible distal portion and a sensing element disposed on the flexible distal portion to detect curvature of the flexible distal portion. The flexible distal portion terminates at a distal tip configured to deliver energy to tissue. The puncture assembly further includes a support member including a lumen configured to receive the puncture device, whereby the flexible distal portion of the puncture device is constrained in a straight configuration when received within the lumen of the support member.

[0014] As a feature of this broad aspect, the flexible distal portion is constrained within the support member to enable energy delivery and when the flexible distal portion is unconstrained, energy delivery is disabled.

[0015] In another feature of this broad aspect, the support member includes a dilator. 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.

[0016] In another feature of this broad aspect, the sensing element is a strain gauge. In another feature of this broad aspect, the elongated member is comprised of a conductive material. In some embodiments, the elongated member includes an insulating layer over the conductive material. In some embodiments, the sensing element is disposed over the insulating layer. In alternative embodiments, the sensing element is disposed under the insulating layer.

[0017] In a feature of this aspect, the sensing element is located on a side of the flexible distal portion that is compressed when bent. In an alternative embodiment, the sensing element is located on a side of the flexible distal portion that is under tension when bent.

[0018] In another broad aspect, an embodiment of the invention includes a method for puncturing a cardiac septum using a puncture assembly including a puncture device housed within a lumen of a support member. The method includes the steps of: (i) gaining access to a patient's vasculature; (ii) advancing the puncture assembly to a target location in the septum such that a flexible, curved distal portion of the puncture device remains constrained within the support member lumen while a distal tip of the puncture device configured to deliver energy is exposed outside the distal tip of the support member, the flexible, curved distal portion of the puncture device including a sensing element for detecting bending 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 unconstrained bending of the flexible, curved distal portion of the puncture device and disables delivery of energy to the distal tip of the puncture device.

[0019] With specific reference now to the detailed drawings, it should be noted that the details shown are by way of example and are intended only for illustrative discussion of certain embodiments of the invention. Before describing 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 construction and the arrangement of components set forth in the following description or illustrated in the drawings. The invention is capable of other embodiments or of being practiced or carried out in various ways. It should also be understood that the phraseology and terminology employed herein are for the purpose of description and should not be regarded as limiting.

[0020] FIG. 1 illustrates an embodiment of an exemplary system 100 that can be used to access the left atrium via a transseptal puncture. The 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 means 150. The puncture device 110, for example a pigtail guidewire (not shown) or a J-tip guidewire, is configured to deliver energy to tissue (such as the atrial septum of the patient's heart). The 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 the sensing element is attached and transmits 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., a curved distal portion 240), the generator 140 is configured to process a signal and take a corresponding action. For example, in some embodiments, when the generator 140 receives a signal corresponding to the distal portion 240 being in an unconstrained state, the generator will automatically stop energy delivery.

[0021] An exemplary method of accessing the left atrium of a patient using the present invention may include the following steps. (i) Gaining access to the vascular system, for example the femoral vein through the groin.

[0022] (ii) advancing the puncture device 110 and assembly (i.e., the sheath 120 and the dilator 130) to the target location, which in one embodiment is the fossa ovalis of the patient's heart. At this stage, the distal portion 240 of the puncture device 110 is constrained and straightened by the dilator 130 and sheath 120 assembly. When unconstrained, the distal portion 240 has a predetermined non-linear shape.

[0023] (iii) delivering energy from generator 140 via puncture device 110 to the fossa ovalis to create a puncture in the septum; (iv) advancing the puncture device 110 through the puncture and into the left atrium. Upon exiting the assembly, the distal portion 240 is no longer constrained by the sheath 120 and dilator 130 and returns to its predetermined non-linear shape. The sensing element detects this change in geometry and sends a signal to the generator 140 to stop delivering energy.

[0024] In an alternative method, access to the heart may be gained through the superior vena cava, with the puncture device 110 entering the vasculature via the subclavian vein. Those skilled in the art will appreciate that the dimensions of the assembly and puncture device may vary depending on the location of access to the vasculature (e.g., the subclavian vein) and the anatomy (e.g., the right atrium of the heart).

[0025] Various embodiments of the invention for use in the above-described system 100 and method can be seen in Figures 2A-2C. Referring to Figure 2A, the puncture device 110 is comprised of an elongated member 250, such as a wire, coated with an electrically insulating material 210 that substantially covers the conductive elongated member and exposes a portion of the distal tip to form the electrode 220. The elongated member 250 may further include a taper 270 at the distal portion 240 to provide flexibility. In addition to the taper 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 comprised of an electrically conductive material, such as Nitinol or stainless steel, to allow energy to be delivered from a generator along the elongated member 250 to the electrode 220. The coating 210 is constructed from an electrically insulating material, such as a PTFE (polytetrafluoroethylene) coating, to ensure that delivery of radio frequency energy travels along the length of the puncture device 110 to the exposed electrode tip 220. Alternatively, the elongate member 250 may not have an insulating coating applied. Rather, the sheath or dilator may be constructed from a non-conductive material to ensure that energy is delivered through the distal tip of the puncture device 110. In an alternative embodiment, the elongate member 250 may be constructed from a non-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 by exposure to heat while the distal region 240 is set in the desired shape, such that there is a bent curvature away from the central axis. The electrode 220 may be coupled to a conductive wire that carries energy from a generator to the electrode 220 at the distal tip of the lancing device 110 .The sensing element 230 is attached to the distal portion 240 of the puncture device 110 and is exposed to a change in geometry as the puncture device 110 transitions from a constrained state (i.e., straightened within a sheath and / or dilator as shown in FIG. 2A) to an unconstrained state (e.g., curved as shown in FIG. 2B or 2C). The sensing element 230 may include a strain gauge. One skilled in the art will appreciate that other sensing means may be used to detect the change in geometry of the distal portion 240.

[0026] 2B, the puncture device 110 has a distal portion 240 that is shaped into a J-tip configuration when unconstrained. The sensing element 230 is mounted such that when the distal portion 240 is in its unconstrained configuration (e.g., the J-tip configuration), the sensing element 230 flexes or distorts with curvature.

[0027] The puncture device 110 may comprise a distal portion 240 having a pigtail configuration when unconstrained, as illustrated in FIG. 2C. The sensing element 230 is preferably positioned at the most distal curved portion along the distal portion 240 such that the sensing element 230 bends immediately when the puncture device 110 begins to bend. A change in shape of the sensing element 230 is detected when the distal portion 240 becomes unconstrained. In response to detecting the change in shape, the generator can operate in an “auto-off” mode and automatically stop delivering RF energy. This configuration allows energy delivery to stop as soon as the puncture device 110 enters the left atrium, reducing the possibility of the puncture device 110 damaging surrounding tissue by unintentionally delivering RF.

[0028] In some embodiments, the sensing element 230 may be attached directly to the elongated member 250, as shown in FIG. 3A. For example, the sensing element 230 may be welded or glued to the elongated member 250. One skilled in the art will appreciate that other means may be used to attach the sensing element 230 to the elongated member 250. The insulating coating 210 may cover both the sensing element 230 as well as the insulated internal wire 610. In another embodiment, the sensing element 230 may be attached directly to the insulating coating 210, as shown in FIG. 3B. For example, the sensing element 230 may be attached to the insulating coating 210 by welding or gluing. The insulated internal wire 610 may extend along the length of the lancing device 110. In an alternative embodiment, the insulated internal wire 610 may be attached to the outside of the insulating coating 210 (not shown) and extend along the outside of the insulating coating 210. The insulated internal wire 610 exits the lancing device 110 at its proximal end and 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 lancing device 110. In some embodiments, the sensing element 230 is positioned in the distal portion 240 on the inside or outside portion of the curve, such that the sensing element 230 bends or distorts with the curve of the distal portion 240. In one embodiment, insulated internal wiring 610 delivers the signal from the sensing element 230 to a generator.

[0029] In one embodiment, the sensing element 230 may include a strain gauge attached to the inner portion of the curve, as illustrated in FIGS. 3A and 3B. In an alternative embodiment, the strain gauge may be located on the outer portion of the curve. One skilled in the art will appreciate that the placement of the strain gauge may be anywhere along the curve that results in a difference in the strain gauge reading between the straight and curved states. The strain gauge will bend with the curvature of the distal portion 240. The strain of the strain gauge will cause the electrical resistance of the strain gauge to change. For example, when the strain gauge is compressed, the resistance will decrease, while when it is under tension, the resistance will increase. 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 dilator) or its unconstrained configuration (i.e., its predetermined shape). The detection signal from the strain gauge may be used to enable or disable the delivery of energy to the puncture device 110. For example, the measurement results can be implemented into an algorithm that compares a reference strain to the measured strain. The reference strain can be a measurement of the strain in an unconstrained state, such as the amount of strain on a strain gauge when the distal portion 240 of the puncture device 110 is curved or shaped. This measurement can be done during manufacturing. The algorithm can then compare the measured strain to this reference to determine whether the distal portion 240 is straight (i.e., constrained) or curved (i.e., unconstrained) to enable or disable the delivery of energy. For example, if the detected strain is more positive than the reference strain (i.e., the change in resistance is positive, meaning the strain gauge is under tension), then the distal portion 240 of the puncture device 110 is straight or constrained, and therefore the delivery of energy is enabled. If the detected strain is the same as the reference strain, it will indicate that the distal portion 240 of the puncture device 110 is curved or unconstrained. The generator may be configured to disable delivery of energy to the lancing device upon detecting that the current strain on the device is equal to the reference strain.

[0030] The constrained and unconstrained states of the puncture device 110 are illustrated in FIG. 4A and FIG. 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 curved distal portion 240 to straighten. This causes the sensing element 230 to straighten as well. In some embodiments, this configuration of the puncture device 110 (seen in FIG. 4A) is in a state prepared 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 strain detected will be greater than the baseline strain (i.e., the strain detected is for the puncture device in the unconstrained configuration). The generator will receive this information and enable the delivery of energy. In some embodiments, the energy delivery may be initiated by the user. For example, the generator may alert the user to begin energy delivery via a sound, a user interface prompt, an optical alert (i.e., a light), or any other alerting means. In an alternative embodiment, energy delivery may be automatic, whereby energy is delivered when the sensing element is in the constrained configuration. Once puncture is complete, the puncture device 110 is pushed through a hole in the septum and enters the left atrium. The distal portion 240 of the puncture device 110 is pushed out of the dilator 130 and enters the left atrium. Once the puncture device 110 enters the left atrium, the distal portion 240 is no longer constrained and returns to its original shape (FIG. 4B). This bending of the distal portion 240 bends the sensing element 230. The sensing element 230 detects the change in configuration of the distal portion. In one embodiment, the detected signal is determined to be that the puncture device 110 has completed puncture and the delivery of energy should be stopped. For example, if the sensing element 230 is a strain gauge, the detected strain will be approximately equal to a reference strain (obtained when the device is in an unconstrained state). In response to detecting this condition, the generator may be configured to disable delivery of energy.Additionally, the generator may alert the user to inform them that energy delivery has been disabled. This alert may be in the form of a sound, a user interface prompt, an optical alert (i.e., a light goes off), or any other means of alerting.

[0031] In some embodiments, the sensing element 230 may be positioned along the elongate member 250 proximal to the distal portion 240. As an example, the sensing element 230 may be positioned along the elongate member 250 such that the sensing element 230 is located within the curved portion of the dilator 130 when the puncture device 110 is in an optimal puncture position. In this configuration, the sensing element 230 detects a change from a straight configuration (i.e., when the sensing element 230 is proximal to the curved portion of the dilator) to a curved configuration (i.e., when the sensing element 230 is included within the curved portion of the dilator). In this embodiment, when the sensing element 230 is in a straight configuration, no energy is delivered to the electrode 220. When the sensing element 230 is in a curved configuration, energy may be delivered. In other words, when the sensing element 230 is located within the curved portion of the dilator 130 (when the puncture device 110 is in an optimal position to puncture tissue), energy is delivered to the electrode 220, enabling the device 110 to perform the puncture. Once puncturing is complete, the puncturing device 110 may be advanced and the sensing element 230 transitions from a curved configuration (e.g., located within the curved portion of the dilator 130) to a straight configuration (e.g., located within the straight portion of the dilator 130 distal to the curved portion), thereby disabling the delivery of energy. In an alternative embodiment, the sensing element 230 may be configured to enable the delivery of energy while in the straight configuration. As an example of this embodiment, the sensing element 230 may be positioned on the elongate member 250 such that when the puncturing device 110 is in an optimal position to puncture tissue, the sensing element 230 is proximal to the curved portion of the auxiliary device (e.g., the dilator 130) and in a straight shape primed to deliver energy to the tissue. Once puncturing is complete, the puncturing device 110 is advanced through the dilator 130 and enters the curved portion of the dilator 130. The sensing element 230 is configured to disable the delivery of energy in the curved configuration. In other words, energy delivery is disabled when the sensing element 230 reaches the curved portion of the dilator 130. In some embodiments, the sensing element 230 may be disposed on the insulating layer 210 of the puncture device 110.In another embodiment, the sensing element 230 may be disposed under the insulating layer 210 of the lancing device 110. In some embodiments, the sensing element 230 may be disposed on an inner portion of the lancing device. In other words, the sensing element 230 will be compressed when constrained by the curved portion of the dilator 130. In an alternative embodiment, the sensing element 230 may be disposed on an outer portion of the lancing device such that it is under tension when constrained by the curved portion of the dilator 130.

[0032] As previously described, a software algorithm may be implemented to control the delivery of energy from the generator to the puncture device. The algorithm may use signals from the sensing elements to determine the geometry of the distal portion, which in turn is used to control the delivery of energy. For example, if the sensing elements were strain gauges positioned on the curved portion of the distal portion, the sensing elements could use the strain measurements, as previously described, to send a signal to the generator to enable or disable the delivery of energy.

[0033] In an alternative embodiment, the generator may apply a known voltage to the strain gauge. As the strain gauge bends, the resistance of the strain gauge will change, ultimately changing the current flowing back to the generator. A baseline value for the current may be determined during manufacturing and set as the value when the puncture device is unconstrained. This baseline value will be used to stop the delivery of energy as it is the value that will indicate that the puncture device has entered the left atrium after the puncture is complete. For example, referring now to FIG. 5, the generator will apply a known voltage to the strain gauge throughout the procedure (510). Using the known voltage and resistance of the strain gauge, the current of the electrical signal can be calculated (520). An algorithm can compare the current of the electrical signal to see if it matches the baseline current value (i.e., unconstrained curved distal portion) (530). When the strain gauge is placed under tension, the resistance increases. Thus, when the distal portion of the puncture device is constrained, the current will decrease compared to when it is unconstrained. Thus, if the measured current is less than the reference current value, energy delivery is enabled 540 and the measured current continues to be compared 530. If the measured current matches the current reference value, energy delivery is disabled 550, signaling that the puncture is complete and the puncture device has entered the left atrium. Those skilled in the art will appreciate that other electrical signal characteristics may be used and implemented into the algorithm to control the delivery of energy.

[0034] Alternatively, the delivery of energy may be implemented by hardware means. In one embodiment, the sensing element may control a switch in the generator that controls the delivery of energy to the lancing device. In some embodiments, the sensing element may include a strain gauge, which may have a current gate switch to control the delivery of energy. The current gate switch may be switched on or off depending on the bending of the strain gauge. For example, when the strain gauge bends (i.e. the lancing device is unconstrained), the current gate switch may be switched and the delivery of energy may be stopped.

[0035] As previously mentioned, the puncture device 110 includes an electrode 220 at a distal tip that can be used to deliver energy to puncture tissue. The puncture device 110 further includes an elongated member 250 that has a taper 270 at a distal portion 240 (as shown in FIGS. 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 elongated member 250 may be constructed of a conductive material, with an insulating layer 210 applied to the device. In an unconstrained state, the coil 260 and the elongated member 250 are not in contact with each other, as shown in FIG. 6A. However, in a constrained state, the elongated member 250 has a tendency to twist, which may result in contact between the coil 260 and the elongated member 250, as illustrated in FIG. 6B. In some embodiments, the coil 260 may be connected to a generator such that when the puncture device 110 is constrained (i.e., the elongated member 250 is twisted), energy is delivered by contact between the coil 260 and the elongated member 250. Thus, energy will be delivered from the generator to the coil 260, which in turn will be delivered to the elongated member 250 and ultimately to the electrode 220 at the distal tip. Once puncture is complete, the puncture device 110 is pushed out to an unconstrained state (FIG. 6A), where the elongated member 250 and the coil 260 are no longer in contact, thereby ceasing energy delivery to the electrode 220.

[0036] In an alternative embodiment of the present invention, the puncture device 110 comprises an electrode 220 at a distal tip configured to deliver energy to puncture tissue. In some embodiments, the 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 be comprised 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., the dilator 130), the two separate portions of the insulated wire 610 contact each other to enable the delivery of energy. In other words, when the puncture device 110 is in a prepared or optimal position for puncturing, the curved distal portion 240 of the puncture device straightens. By straightening the curved distal portion 240, the distal and proximal portions of the insulated wire 610 are compressed together, thereby enabling energy delivery. Once puncturing is complete, the puncture device 110 is advanced out of the dilator 130, which causes the curved distal portion 240 to become unconstrained and return to its curved configuration. As a result, the distal and proximal portions of the insulated wire 610 are pulled away from each other due to the distal portion of the circumference of the curved distal portion 240 being stretched. Thus, the circuit is broken and energy delivery is disabled.

[0037] Further Examples Example 1 1. A puncture device configured to create a puncture in tissue, the puncture device comprising: an elongate member including a proximal portion defining a longitudinal axis along a length of the elongate member; a flexible distal portion of the elongate member that is curved away from the longitudinal axis; a distal tip configured to deliver energy to tissue; a sensing element disposed on the flexible distal portion of the elongate member to detect bending of the distal portion; A puncture device, wherein 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.

[0038] Example 2 2. The lancing device of example 1, wherein the sensing element is a strain gauge. Example 3 The puncture device of example 1, wherein the elongated member is constructed from a conductive material.

[0039] Example 4 The puncture device of example 3, wherein the elongate member comprises an insulating layer over the conductive material. Example 5 The lancing device of Example 4, wherein the sensing element is disposed on the insulating layer.

[0040] Example 6 The lancing device of Example 4, wherein the sensing element is disposed under an insulating layer. Example 7 The puncture device of example 1, wherein the sensing element is disposed on an inner portion of the flexible distal portion that is compressed when bent.

[0041] Example 8 The puncture device of Example 1, wherein the sensing element is disposed on an outer portion of the flexible distal portion that is subjected to tension when bent.

[0042] Example 9 The puncture device of Example 1, wherein the puncture device is a guidewire. Example 10 The puncture device of Example 9, wherein the guidewire is a J-tip guidewire.

[0043] Example 11 The puncture device of Example 9, wherein the guidewire is a pigtail guidewire. Example 12 1. A puncture device configured to create a puncture in tissue, the puncture device comprising: an elongate member constructed from a conductive core wire, the elongate member including a proximal portion defining a longitudinal axis along a length of the elongate member; a flexible distal portion of the elongate member that is curved away from the longitudinal axis, a flexible distal portion including a conductive coil surrounding a conductive core wire; a distal tip configured to deliver energy to tissue; A puncture device in which when the flexible distal portion of the elongate 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 elongate member is curved, the conductive coil does not contact the conductive core wire, disabling energy delivery to the distal tip.

[0044] Example 13 1. A piercing assembly for piercing tissue, the piercing assembly comprising: 1. A puncture device comprising an elongate member having a proximal portion defining a longitudinal axis along a length of the elongate member; a flexible distal portion of the elongate member curving away from the longitudinal axis; and a sensing element disposed on the flexible distal portion of the elongate member to detect curvature of the flexible distal portion; a puncture device having a flexible distal portion terminating in a distal tip configured to deliver energy to tissue; a support member comprising a lumen configured to receive a puncture device; A puncture assembly, the flexible distal portion being constrained in a straight configuration when received within the lumen of the support member.

[0045] Example 14 The puncture assembly of 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 not constrained.

[0046] Example 15 The puncture assembly of Example 13, wherein the support member comprises a dilator. Example 16 The puncture assembly of Example 13, wherein the puncture device comprises a puncture guidewire.

[0047] Example 17 The puncture assembly of Example 16, wherein the puncture guidewire comprises a J-tip guidewire.

[0048] Example 18 The puncture assembly of Example 16, wherein the puncture guidewire comprises a pigtail guidewire.

[0049] Example 19 The puncture assembly of Example 13, wherein the sensing element is a strain gauge. Example 20 The puncture device of Example 13, wherein the elongated member is made of a conductive material.

[0050] Example 21 21. The puncture device of Example 20, wherein the elongate member comprises an insulating layer over the conductive material.

[0051] Example 22 22. The lancing device of Example 21, wherein the sensing element is disposed on an insulating layer. Example 23 22. The lancing device of Example 21, wherein the sensing element is disposed under an insulating layer.

[0052] Example 24 14. The puncture device of Example 13, wherein the sensing element is disposed on an inner portion of the flexible distal portion that is compressed when bent.

[0053] Example 25 14. The puncture device of Example 13, wherein the sensing element is disposed on an outer portion of the flexible distal portion that is subjected to tension when bent.

[0054] Example 26 1. A method for puncturing a cardiac septum using a puncture assembly comprising a puncture device housed within a lumen of a support member, the method comprising: (i) obtaining access to a patient's vascular system; (ii) advancing the puncture assembly to a target location in the septum such that a distal tip of a puncture device configured to deliver energy is exposed outside of 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; a flexible curved distal portion of the puncture device comprising a sensing element for detecting curvature of the distal portion; (iii) delivering energy to a distal tip of the puncture device to create a puncture at the target location; (iv) advancing the puncture device such that a flexible curved distal portion of the puncture device is free from restraint within the lumen of the support member; whereby the sensing element detects unconstrained bending of the flexibly curved distal portion of the puncture device and disables delivery of energy to the distal tip of the puncture device.

[0055] Example 27 1. An assembly for piercing a target tissue, the assembly comprising: 1. A puncture device comprising: A thin member; a distal tip configured to deliver energy to a target tissue; a sensing element disposed on the elongated member; A puncture device comprising: A support member, a support member proximal portion and a support member distal portion having a lumen extending therebetween configured to receive a puncture device; a support member proximal portion and a support member distal portion, the support member distal portion including a curved portion and a straight portion distal to the curved distal portion; an open distal end at the straight portion; and a support member including: When the puncture device is inserted into the support member, the sensing element detects changes in curvature of the puncture device as the puncture device advances through the support member distal portion. assembly.

[0056] Example 28 An assembly as described in Example 27, wherein the sensing element is disposed on the elongate member such that when the distal tip of the puncture device protrudes from the open distal end of the support member, the sensing element is located within the curved portion of the support member.

[0057] Example 29 29. The assembly of 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.

[0058] Example 30 An assembly as described in Example 27, wherein the sensing element is positioned on the elongate member such that when the distal tip of the puncture device protrudes from the open distal end of the support member, the sensing element is located proximal to the curved portion of the support member.

[0059] Example 31 The assembly of 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.

[0060] Example 32 The assembly of any one of Examples 27 to 31, wherein the support member is a dilator.

[0061] Example 33 An assembly according to any one of Examples 27 to 32, wherein the sensing element is disposed under an insulating layer of the lancing device.

[0062] Example 34 An assembly according to any one of Examples 27 to 32, wherein the sensing element is disposed on an insulating layer of the lancing device.

[0063] Example 35 An assembly described in any one of Examples 27 to 34, wherein the sensing element is positioned on an outer portion of the puncture device so as to be subjected to tension when bent by the bent portion.

[0064] Example 36 An assembly described in any one of Examples 27 to 34, wherein the sensing element is disposed in an inner portion of the puncture device such that it is compressed when bent by the bent portion.

[0065] Example 37 The assembly of any one of Examples 27 to 36, wherein the puncture device is a flexible J-tip guidewire.

[0066] Example 38 The assembly of any one of Examples 27 to 36, wherein the puncture device is a flexible pigtail guidewire.

[0067] Example 39 A puncture device for puncturing a target tissue, the puncture device comprising: an elongate member including a proximal portion defining a longitudinal axis along a length of the elongate member; a flexible distal portion of the elongate member that is curved away from the longitudinal axis; a distal tip configured to deliver energy to tissue; a first conductive wire extending along a proximal portion of the elongate member and terminating a distance along the flexible distal portion; a second conductive wire coupled to the distal tip, the second conductive wire terminating distally from the first conductive wire; a first conductive wire and a second conductive wire are disposed along an outer edge of the flexible distal portion; When the flexible distal portion straightens, the first conductive wire contacts the second conductive wire, thereby enabling energy delivery; and A puncture device whereby when the flexible distal portion is bent, the first conductive wire does not contact the second conductive wire, thereby disabling energy delivery.

[0068] The above-described embodiments of the invention are intended to be illustrative only, and the scope of the invention is therefore intended to be limited only by the appended claims. It will be appreciated that certain features of the invention, which are, for clarity, described in the context of separate embodiments, can also be provided in combination in a single embodiment. Conversely, various features of the invention, which are, for brevity, described in the context of a single embodiment, can also be provided separately or in any suitable subcombination.

[0069] Although the present invention has been described in relation to specific embodiments thereof, it is apparent that many alternatives, modifications, and variations will become apparent to those skilled in the art. Accordingly, it is intended to embrace 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 same extent as if each individual publication, patent, or patent application was specifically and individually indicated to be incorporated herein by reference. Furthermore, citation or identification of any reference in this application should not be construed as an admission that such reference is available as prior art to the present invention.

Claims

1. 1. A puncture device configured to create a puncture in tissue, the puncture device comprising: an elongate member including a proximal portion defining a longitudinal axis along a length of the elongate member; a flexible distal portion of the elongate member that is curved away from the longitudinal axis; and a distal tip configured to deliver energy to the tissue; a sensing element disposed on the flexible distal portion of the elongate member to detect bending of the distal portion; 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. Puncture device.

2. The lancing device of claim 1 , wherein the sensing element is a strain gauge.

3. The puncture device of claim 1 , wherein the elongate member is constructed from an electrically conductive material.

4. The puncture device of claim 3 , wherein the elongate member includes an insulating layer over the conductive material.

5. The lancing device of claim 4 , wherein the sensing element is disposed on the insulating layer.

6. The lancing device of claim 4 , wherein the sensing element is disposed beneath the insulating layer.

7. The puncture device of claim 1 , wherein the sensing element is disposed on an inner portion of the flexible distal portion that is compressed when bent.

8. The puncture device of claim 1 , wherein the sensing element is disposed on an outer portion of the flexible distal portion that is under tension when bent.

9. The puncture device of claim 1 , wherein the puncture device is a guidewire.

10. The puncture device of claim 9 , wherein the guidewire is a J-tip guidewire.

11. The puncture device of claim 9 , wherein the guidewire is a pigtail guidewire.

12. 1. A puncture device configured to create a puncture in tissue, the puncture device comprising: an elongate member constructed from a conductive core wire, the elongate member including a proximal portion defining a longitudinal axis along a length of the elongate member; a flexible distal portion of the elongate member that is curved away from the longitudinal axis, a flexible distal portion including a conductive coil surrounding the conductive core wire; a distal tip configured to deliver energy to the tissue; when the flexible distal portion of the elongate 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 elongate member is curved, the conductive coil does not contact the conductive core wire, disabling energy delivery to the distal tip. Puncture device.

13. 1. A piercing assembly for piercing tissue, the piercing assembly comprising:

1. A puncture device comprising an elongate member having a proximal portion defining a longitudinal axis along a length of the elongate member; a flexible distal portion of the elongate member curving away from the longitudinal axis; and a sensing element disposed on the flexible distal portion of the elongate member to detect curvature of the flexible distal portion; a puncture device, the flexible distal portion terminating in a distal tip configured to deliver energy to the tissue; a support member comprising a lumen configured to receive the puncture device; the flexible distal portion is constrained in a straight configuration when received within the lumen of the support member. Puncture assembly.

14. The puncture assembly of claim 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.

15. The puncture assembly of claim 13 , wherein the support member comprises a dilator.

16. The puncture assembly of claim 13 , wherein the puncture device comprises a puncture guidewire.

17. The puncture assembly of claim 16 , wherein the puncture guidewire comprises a J-tip guidewire.

18. The puncture assembly of claim 16 , wherein the puncture guidewire comprises a pigtail guidewire.

19. The puncture assembly of claim 13 , wherein the sensing element is a strain gauge.

20. The puncture device of claim 13 , wherein the elongate member is constructed from an electrically conductive material.

21. 21. The puncture device of claim 20, wherein the elongate member includes an insulating layer over the conductive material.

22. 22. The lancing device of claim 21, wherein the sensing element is disposed on the insulating layer.

23. 22. The lancing device of claim 21, wherein the sensing element is disposed beneath the insulating layer.

24. The puncture device of claim 13 , wherein the sensing element is disposed on an inner portion of the flexible distal portion that is compressed when bent.

25. The puncture device of claim 13 , wherein the sensing element is disposed on an outer portion of the flexible distal portion that is under tension when bent.

26. 1. A method for puncturing a cardiac septum using a puncture assembly comprising a puncture device housed within a lumen of a support member, the method comprising: (i) obtaining access to a patient's vascular system; (ii) advancing the puncture assembly to a target location in the septum such that a distal tip of the puncture device configured to deliver energy is exposed outside the distal tip of the support member while a flexible, curved distal portion of the puncture device remains constrained within a lumen of the support member, the flexible, curved distal portion of the puncture device comprising a sensing element for detecting bending of the distal portion; (iii) delivering energy to the distal tip of the puncture device to create a puncture at the target location; (iv) advancing the puncture device such that the flexible curved distal portion of the puncture device is unconstrained within the lumen of the support member, whereby the sensing element detects unconstrained bending of the flexible curved distal portion of the puncture device and disables delivery of energy to the distal tip of the puncture device; A method comprising:

27. 1. An assembly for piercing a target tissue, the assembly comprising:

1. A puncture device comprising: A long and thin member; a distal tip configured to deliver energy to the target tissue; a sensing element disposed on the elongated member; A puncture device comprising: A support member, a support member proximal portion and a support member distal portion having a lumen extending therebetween configured to receive the puncture device; a support member proximal portion and a support member distal portion, the support member distal portion including a curved portion and a straight portion distal to the curved distal portion; an open distal end at the straight portion; and a support member including: When the puncture device is inserted into the support member, the sensing element detects a change in curvature of the puncture device as the puncture device advances through the support member distal portion. assembly.

28. 28. The assembly of claim 27, wherein the sensing element is positioned on the elongate member such that when the distal tip of the puncture device protrudes from the open distal end of the support member, the sensing element is located within the curved portion of the support member.

29. 30. The assembly of claim 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.

30. 28. The assembly of claim 27, wherein the sensing element is positioned on the elongate member such that when the distal tip of the puncture device protrudes from the open distal end of the support member, the sensing element is located proximal to the curved portion of the support member.

31. 31. The assembly of claim 30, wherein the sensing element is configured to enable energy delivery when unconstrained by the curved portion and to disable energy delivery when constrained by the curved portion.

32. The assembly according to any one of claims 27 to 31, wherein the support member is a dilator.

33. An assembly according to any one of claims 27 to 32, wherein the sensing element is disposed beneath an insulating layer of the lancing device.

34. An assembly according to any one of claims 27 to 32, wherein the sensing element is disposed on an insulating layer of the lancing device.

35. An assembly according to any one of claims 27 to 34, wherein the sensing element is arranged on an outer portion of the lancing device such that it is under tension when bent by the bent portion.

36. An assembly according to any one of claims 27 to 34, wherein the sensing element is arranged in an inner portion of the puncture device such that it is compressed when bent by the bent portion.

37. The assembly of any one of claims 27 to 36, wherein the puncture device is a flexible J-tip guidewire.

38. The assembly of any one of claims 27 to 36, wherein the puncture device is a flexible pigtail guidewire.

39. 1. A puncture device for puncturing a target tissue, the puncture device comprising: an elongate member including a proximal portion defining a longitudinal axis along a length of the elongate member; a flexible distal portion of the elongate member that is curved away from the longitudinal axis; and a distal tip configured to deliver energy to the tissue; a first conductive wire extending along the proximal portion of the elongate member and terminating a distance along the flexible distal portion; a second conductive wire coupled to the distal tip, the second conductive wire terminating distally from the first conductive wire; the first conductive wire and the second conductive wire are disposed along an outer edge of the flexible distal portion; whereby, when the flexible distal portion straightens, the first conductive wire contacts the second conductive wire, thereby enabling energy delivery; and whereby, when the flexible distal portion is bent, the first conductive wire does not contact the second conductive wire, thereby disabling energy delivery. Puncture device.

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