Steam ablation system and method

Abstract

A vapor delivery device is provided that can include any of a number of features. One feature of the vapor delivery device is that it can apply condensable vapor energy to tissue, such as the prostate, to cause the prostate tissue to shrink, damage, denature. The vapor delivery device can include a handle portion and a cartridge portion. The cartridge portion can be configured to be inserted into an internal cavity of the handle portion to align and position a vapor coil of the cartridge portion within an RF coil of the handle portion. Methods associated with use of the energy delivery probe are also contemplated.

Description

[0001] This application is a divisional application of the invention patent application filed on December 21, 2017, with the international filing date of December 21, 2017, Chinese national application number 201780079437.0, entitled "Steam Ablation System and Method".

[0002] Cross-references to related applications

[0003] This application claims priority to U.S. Provisional Application No. 62 / 437,617, filed December 21, 2016, and U.S. Provisional Application No. 62 / 538,517, filed July 28, 2017, both of which are incorporated herein by reference.

[0004] This application relates to U.S. Patent Application No. 14 / 773,853, filed September 9, 2015, and International Patent Application No. PCT / US2016 / 067558, filed December 19, 2016, both of which are incorporated herein by reference in their entirety.

[0005] By incorporating references

[0006] All disclosures mentioned in this specification, including patents and patent applications, are incorporated herein by reference in their entirety as if each individual disclosure were specifically and individually indicated by reference. Technical Field

[0007] This invention relates to devices and related methods for treating the prostate using minimally invasive techniques. Background Technology

[0008] In early life, the prostate is the size and shape of a walnut and weighs about 20 grams before enlargement caused by benign prostatic hyperplasia (BPH). Prostate enlargement appears to be a normal process. As the prostate ages, its size gradually increases to twice or more of its normal size. The fibromuscular tissue of the external prostatic sac restricts expansion after the gland reaches a certain size. Due to this restriction on expansion, the tissue within the sac compresses and constricts the prostatic urethra, thus creating resistance to urine flow.

[0009] The prostate gland can be divided into three regions: the peripheral zone, the transition zone, and the central zone. The peripheral zone (PZ) accounts for approximately 70% of the male prostate volume. This posterior portion of the prostate surrounds the distal urethra, and 70% to 80% of cancers originate in the peripheral zone tissue. The central zone (CZ) surrounds the ejaculatory ducts and contains approximately 20-25% of the prostate volume. The central zone is often the site of inflammatory processes. The transition zone (TZ) is where benign prostatic hyperplasia (BPH) develops and contains approximately 5-10% of the glandular elements in a normal prostate, but can account for up to 80% in the case of BPH. The transition zone includes the two lateral lobes of the prostate and the periurethral glandular region. Natural barriers surround the transition zone: the prostatic urethra, the anterior fibromuscular stroma (FS), and the fibrous plane (FP) between the transition zone and the peripheral zone. The anterior fibromuscular stroma (FS), or fibromuscular region, is primarily composed of fibromuscular tissue.

[0010] Approximately 70% to 80% of prostate cancers originate in the peripheral area of ​​the prostate and may remain confined to this area. In recent years, local treatment of prostate cancer has received increasing attention, focusing solely on the area of ​​tissue where cancer has been found after a biopsy. Existing local therapies, such as radiofrequency ablation energy, can address this issue beyond the confines of the peripheral tissue.

[0011] Patients with advanced prostate cancer may undergo prostatectomy, but alternative surgical options are needed. A device is required that can ablate the entire prostate or an entire lobe of the prostate transurethral. In this minimally invasive approach, both the transitional and peripheral areas can be treated. Summary of the Invention

[0012] A system and method for ablating peripheral tissue without ablating non-peripheral tissue are disclosed. The transurethral method uses a steam delivery device to access peripheral tissue adjacent to the prostatic urethra.

[0013] Treatment of the entire peripheral area can be performed using a steam delivery needle that extends up to 2.5 cm from the delivery device axis located in the urethra. Guided by ultrasound and a needle position sensor, steam can be delivered at multiple locations along the needle's path.

[0014] A steam delivery needle is capable of controlled movement along its path, including stopping steam delivery. Systems and methods for moving the needle to any position within its reach using digital stepping control are disclosed.

[0015] A blunt needle is disclosed that is able to penetrate the urethral wall during initial shallow deployment, but does not penetrate the prostatic sac when the needle is advanced using an electrical pulse delivered to a needle delivery solenoid.

[0016] Most prostate cancers occur in the peripheral area. Steam delivered to the peripheral area via needle will not cross the tissue barrier to reach other areas of the prostate where cancer may not be present.

[0017] All areas of the prostate can be treated with a single transurethral steam delivery device. Partial or total prostatectomy can be performed during a single treatment in which steam is applied to some or all areas of the prostate.

[0018] A semi-disposable steam delivery device is also disclosed, wherein the handle and cable are reusable, and the syringe with needle delivery shaft and attached water and flushing lines include a disposable cartridge.

[0019] Inductive coupling is used to transfer RF power from the RF coil in the reusable handle to the vapor delivery coil in the disposable cartridge.

[0020] Magnetic coupling is used to apply non-contact needle deployment force from a solenoid coil in the handle to a needle deployment magnet in a disposable cartridge.

[0021] Inductive coupling allows temperature and identification data to be transferred from a disposable cartridge to a reusable handle. Because the induction coil and force coil are cylindrically symmetrical, their function is independent of the orientation of the disposable cartridge, allowing the cartridge to rotate relative to the reusable handle. This enables the application of therapy to the side of the prostate without requiring the delivery device handle to be rotated between the patient's legs. A sliding contact between the disposable cartridge and the reusable handle is also disclosed for vapor coil temperature readout.

[0022] Doctors can treat BPH or cancer using a single reusable handle by choosing disposable cartridges designed for specific treatments. For example, BPH cartridges can be simpler and less expensive than prostate cancer cartridges because BPH treatment does not require variable and controllable needle depth.

[0023] A steam delivery device is provided, comprising a handle portion having an inner cavity and an RF coil disposed in the inner cavity, and a cartridge portion adapted to be inserted into the inner cavity of the handle portion, the RF coil being connected to an RF energy source, the cartridge portion comprising an elongated shaft adapted to be inserted into a patient's urethra, a steam delivery needle disposed in the elongated shaft, and a steam coil fluidly connected to the steam delivery needle and a fluid source, wherein the cartridge portion is inserted into the handle portion such that the steam coil is aligned and positioned within the RF coil.

[0024] When fluid is delivered from a fluid source to a steam coil, applying RF energy to the RF coil can inductively generate steam in the steam coil.

[0025] In some embodiments, the steam delivery needle is adapted to deliver steam to the patient's tissues.

[0026] The disclosed cartridge portion may further include a first solenoid coil and a second solenoid coil, a needle drive magnet attached to the proximal portion of the steam delivery needle, wherein the needle drive magnet is slidably disposed within the first solenoid coil when the steam delivery needle is in the retracted position, and the needle drive magnet is slidably disposed within the second solenoid coil when the steam delivery needle is in the extended position.

[0027] The device may also include a pin unfolding switch on the handle portion.

[0028] In some embodiments, by pressing the needle deployment switch, the steam delivery needle can be fully deployed from the retracted position to the extended position. The steam delivery needle can be deployed gradually with each press of the needle deployment switch. For example, the steam delivery needle can be deployed in 1 mm increments.

[0029] The device may also include a position sensor disposed on the steam delivery needle, the position sensor being configured to determine the deployed position of the steam delivery needle. A safety feature is provided in which the advance of the steam delivery needle is prevented if the sensor indicates that the steam delivery needle has not moved the required incremental distance.

[0030] Steam coils may include, for example, inconel tubing.

[0031] The device may also include a latch configured to prevent lateral movement of the cartridge portion when it is inserted into the cavity of the handle portion.

[0032] When the cartridge portion is inserted into the lumen of the handle portion, the cartridge portion can rotate. This allows steam to be delivered to multiple locations within the prostate and to both lobes of the prostate.

[0033] In one specific embodiment, when in the extended position, the delivery needle cannot extend more than 24 mm from the elongated shaft.

[0034] A steam delivery needle is provided, comprising an inflatable balloon configured to prevent steam leakage from a puncture site in patient tissue. The inflatable balloon is positioned within a notch of the steam delivery needle. During steam delivery, the inflatable balloon is inflated with steam.

[0035] The steam delivery device may also include an electronic controller configured to control the delivery of RF energy to the RF coil.

[0036] It is also believed that the steam delivery device may include a temperature sensor disposed at the outlet of the steam coil and electrically coupled to an electronic controller, the temperature sensor being configured to measure the temperature of the fluid or steam at the outlet of the steam coil.

[0037] As a safety measure, the electronic controller can be configured to trigger the shutdown of RF energy delivery if the measured temperature of the fluid or steam in the outlet is outside the preferred temperature range.

[0038] A method for delivering steam to a patient's prostate is also provided, comprising inserting a cartridge portion of a steam delivery device into the lumen of a handle portion of the steam delivery device to align and position a steam coil of the cartridge portion in an RF coil of the handle portion, inserting an elongated shaft of the cartridge portion into the patient's urethra, advancing the distal end of the elongated shaft into the patient's prostatic urethra, extending a steam delivery needle from the elongated shaft into the patient's prostate, delivering a fluid flow into the steam coil, applying RF energy to the RF coil to inductively generate steam within the steam coil, and delivering the steam to the prostate via the steam delivery needle.

[0039] The extension step may include generating a magnetic field using at least one solenoid coil to extend the steam delivery needle into the prostate.

[0040] The method may also include rotating the cartridge portion within the handle portion. Attached Figure Description

[0041] To better understand the invention and how it can be implemented in practice, some preferred embodiments will now be described with reference to the accompanying drawings by way of non-limiting examples only, wherein similar reference numerals in similar embodiments of the drawings always denote corresponding features.

[0042] Figure 1A-1C An embodiment of a transurethral steam delivery device is shown.

[0043] Figure 2A-2B A disposable cartridge of a steam delivery device is shown.

[0044] Figure 3 A reusable handle for a steam delivery device is shown.

[0045] Figure 4 The magnet of the steam delivery device is shown.

[0046] Figure 5 The direction of current in the push-pull coil of the magnetic actuator of the steam delivery device is shown.

[0047] Figures 6A-6B The steam needle extension length is shown when moving from the BHP device to the cancer device.

[0048] Figure 7 The changes in the solenoid are shown as the device moves from the BPH device to the cancer device.

[0049] Figure 8The relationship between the obtained force and the position of the magnet is shown.

[0050] Figures 9A-9B The technique used to prevent steam leakage is shown.

[0051] Figure 10 An induction steam generator is shown.

[0052] Figure 11 The equivalent circuit for reading out the output tube RTD is shown.

[0053] Figure 12 The image shows a delivery device inserted into the prostatic urethra adjacent to the surrounding tissue. Detailed Implementation

[0054] Typically, methods used to treat BPH or prostate cancer involve introducing heated steam through a gap in the urethra into the prostate, where the steam can controllably ablate prostate tissue. This method can cause localized ablation of the prostate tissue; more specifically, the heat applied by the steam can be localized to ablate tissue adjacent to the urethra without damaging prostate tissue not adjacent to the urethra.

[0055] The disclosed transurethral steam delivery device is used to deliver steam transurethral to a patient's prostate. The device's elongated shaft can be advanced into the patient's urethra, and once positioned near the prostate within the prostatic urethra, a steam delivery needle can be inserted into the prostate through the urethral wall. Steam can then be delivered into the prostate via the steam delivery needle.

[0056] Semi-disposable steam delivery device

[0057] Transurethral steam delivery device 100 Figure 1A It is shown in its assembled form, while Figure 1B An exploded view is shown to illustrate the reusable handle portion 102 and the disposable cartridge portion 104 of the steam delivery device. The handle portion 102 of the steam delivery device includes an inner cavity 103, a cable 106 for inserting an RF generator (not shown), a grip portion 107, a trigger 108 for actuating flushing, needle advance / retraction, and an RF power on / off switch, an RF coil 110 (not shown) disposed in the inner cavity and configured to inductively generate steam, and a solenoid coil 112 (not shown) disposed in the handle portion and configured to advance and retract the steam needle.

[0058] An RF generator can be configured to provide power and fluid to a transurethral steam delivery device to generate steam. For example, the RF generator is configured to provide RF energy to an RF coil in the handle portion. The RF generator can also be connected to the aforementioned steam delivery device to provide the system with power and other components essential for operation (e.g., flushing / cooling fluid, aspiration, etc.). The RF generator may include an electronic controller and a graphical user interface (GUI) to provide the user with operating parameters and control during steam therapy.

[0059] The RF generator may include electrical connectors that provide RF current to the steam delivery device, provide electrical signals to and from the switch of the steam delivery device, provide measurements such as the temperature of the steam delivery device, and provide electrical signals to / from the controller of the steam delivery device, such as in its electrical connector, to identify the steam delivery device, track its steam delivery history, and prevent overuse of a given steam delivery system. The RF generator may also include a peristaltic pump that provides a cooling / rinsing fluid flow, such as brine, to the steam delivery device.

[0060] The disposable cartridge 104 includes an elongated shaft 114 having an inner lumen for a cystoscope and a steam delivery needle 116; a needle drive magnet 118 (not shown) attached to the steam delivery needle, which is advanced or retracted by a magnetic field generated in a solenoid coil 112; a steam coil 120 in which water is inductively converted into steam; and a plastic tubing 122 for sterile water, saline irrigation, and bladder drainage. The cartridge portion is adapted to be inserted into the inner lumen of the handle portion. When the cartridge portion is inserted into the handle portion, the steam coil 120 of the cartridge is aligned and positioned within the RF coil 110 of the handle portion, or, in another manner, the RF coil 110 is aligned and positioned around the steam coil 120 (e.g., ...). Figure 10 (As shown). The slender shaft 114 is sized and constructed to be inserted into the patient's urethra, and its length can extend to the patient's prostatic urethra and prostate. Figure 1B As shown, the cartridge can be rotated inside the handle to facilitate the delivery of steam to the right and left lobes of the prostate without having to rotate the handle between the patient's legs.

[0061] In some procedures, steam therapy is at least partially guided by transrectal ultrasound (TRUS) imaging. In these procedures, the TRUS probe can prevent the steam delivery device handle from being in contact with... Figure 1A The vertically downward position is shown. In some alternative embodiments, the delivery device handle may extend upward from the syringe of the delivery device. In other embodiments, the syringe may be modified to include the delivery device trigger and cable, and the handle portion may be completely removed.

[0062] In some procedures, after initial puncture of the urethral wall, the delivery device needle can be advanced to deliver steam at two or more sites. It is important that the steam delivery needle remain stable relative to the patient's anatomy to prevent steam leakage from the enlarged needle inlet. Figure 1C An adjustable delivery device holder 124 is shown, which can be used to stabilize and hold the delivery device during needle delivery, propulsion, and steam delivery. This adjustable delivery device holder allows the operator to focus their attention on image-guided needle placement and treatment delivery. Figure 1C An adjustable delivery device retainer is shown, having a flexible, shapeable shaft 126 adjustable by the operator to maintain the position of the delivery device needle during treatment. In other embodiments, the retainer can be adjusted electronically. It can be configured to advance or withdraw the delivery device into the urethra. Figure 1C The handle in the middle can be like Figure 1C The adjustable holding device shown can be as simple as a multi-axis robotic arm.

[0063] Disposable cartridge 104 Figure 2A-2B The image is shown in a cross-sectional view. A steam delivery needle is rigidly connected to a needle drive magnet 118, which moves laterally by a magnetic field generated by a coil in the handle portion 102 (e.g., ...). Figure 3 (As shown). Steam coil 120 is also... Figure 2B As shown in the figure, the disposable cartridge may include a resistance thermometer (RTD) 119, which is connected in series with a conductive metal ring 121 via a lead 123. The RTD 119 measures the temperature of the steam exiting the steam coil 120. In one embodiment, the RTD may be wrapped around the outlet of the steam coil.

[0064] The inductive readout coil can also be implemented in the reusable handle. The thermocouple can be placed on the RF coil within the reusable handle section. Experience shows that the first component to exhibit signs of overheating (typically smoke) is the RF coil, even if it may be slightly cooler than the adjacent internal coil. Therefore, the RF coil is the preferred location for the thermocouple, which is also the preferred location for the thermometer.

[0065] When the disposable cartridge 104 is inserted into the reusable handle portion 102, the cartridge engages with the canted coil in the handle. The insertion and withdrawal forces of the cartridge can be specified within a small range, ensuring that all cartridges fall within a repeatable range of mechanical forces. The canted coil acts as a sliding electrical contact, allowing the cartridge to rotate within the handle while maintaining electrical contact between the RTD outlet thermometer lead and the handle. Some change in contact resistance exists between the ring and the coil as the cartridge rotates. However, precise temperature measurement is not required during rotation, so any change in contact resistance during rotation can be zeroed in the software. The outlet thermometer is displayed as an RTD, but other miniature sensors, such as thermistors or thermocouples, can also be used.

[0066] Figure 2B The steam coil shown is connected to a sterile water source via a plastic tube extending from the cartridge, such as... Figure 1A As shown, it is connected to the RF generator. The steam coil windings can be made of metal tubing, such as 18-gauge regular wall (RW) 304 stainless steel tubing, or 18-gauge thin wall (TW) plug-drawn 625 nickel-chromium-iron alloy tubing. Individual coil windings can be in physical contact and can be soldered or welded together to ensure good electrical contact, although RF current can pass through a sufficiently thin oxide layer on the separate windings.

[0067] Water in steam coil 120 is converted into steam by ohmic heating generated by an electric current flowing around the circumference of the steam coil. These currents are induced by an RF current flowing in a concentric RF coil located in the delivery device handle. The alternating magnetic field generated by the current in the RF coil can be reinforced by making the steam coil from a magnetically permeable material. Because the permeability of 300 series stainless steel changes through cold working, it is difficult to obtain batches of tubing with the same permeability. Since consistency of calorie output between devices is crucial, non-magnetic tubing is preferred for this application. Stainless steel like 304 can be annealed to eliminate magnetism, or non-magnetic steels such as NiCrFe625, MP35N, or Elgiloy can be selected for the steam coil. NiCrFe625 is ideal because its resistance is almost independent of the temperature range (20°C–350°C) that may be experienced at the far (steam) end of the steam coil, thus achieving constant steam delivery between shots and between devices.

[0068] One or more electrical leads can extend from a disposable cartridge along a sterile water pipe. The wires can be inserted into an RF generator and can provide signals to / from the EPROM within the cartridge to provide cartridge identification and usage data. Other wires in the cable can provide signals from a thermocouple located on a vapor coil within the cartridge and / or other diagnostic data from the cartridge. In another embodiment, the EPROM and thermocouple wires can include a small cable extending from the disposable cartridge and inserted into a non-disposable handle, and through it to a cable for the main delivery device handle. Alternatively, as described below, data can be inductively coupled from the cartridge without the need for physical leads.

[0069] exist Figure 3 The reusable handle portion 102 of the delivery device is shown in more detail below. The solenoid coil is configured relative to... Figure 2B The push / pull configuration of the needle-driven magnet is shown. In the fully retracted needle position, the proximal end of the needle-driven magnet is aligned with the proximal / push solenoid coil 112. In the fully extended needle position, the distal end of the needle-driven magnet is aligned with the distal / pull solenoid coil 112. Figure 5 As shown, current can flow in opposite directions through the push and pull coils. The push coil establishes a magnetic field that repels the needle-driving magnet of opposite polarity from the coil. Due to this repulsive force, the magnet is not in a stable equilibrium along the axis of the push coil and is prone to lateral movement, which may increase the contact between the needle-driving magnet and its surroundings and increase the frictional resistance to axial propulsion. The pull coil establishes a magnetic field that attracts the needle-driving magnet into the pull coil. The pull coil attracts the needle-driving magnet to the axis of the coil, thus eliminating the instability of the push coil. The combination of the push and pull coils roughly doubles the force exerted by a single coil. Figure 5 As shown, the push / pull coil also simply reverses the direction of the current to the coil pair so that the retraction force is equivalent to the propulsion force.

[0070] Figure 3 The possible location of a linear magnet position sensor 113 adjacent to a solenoid coil is shown. The linear magnet position sensor is configured to detect the magnetic field generated by a needle-driven magnet. The solenoid coil generates a smaller magnetic field. The magnetic fields generated by the two solenoid coils are average and cancel each other out in the central plane between the coils. The linear magnet position sensor voltage output is a linear function of the position of the magnet (and the needle connected to the magnet). A calibration can be performed to convert the sensor voltage to the magnet position (relative to its nearest end).

[0071] Figure 3 The RF coil 110 shown is designed to be as close as possible to the vapor coil when the disposable cartridge is inserted into the handle portion 102. Figure 2BThe steam coil 120 provides maximum current induction in the steam coil. The relationship between the RF coil and the steam coil in the assembled device is... Figure 10 As shown in the diagram. In one embodiment, the vapor coil comprises a six-turn #18TW 625 nickel-chromium-iron alloy tube, and the RF coil comprises 11 turns of #22 copper stranded wire consisting of single strands of #44 copper magnetic wire. These dimensions are chosen to optimize the electromagnetic coupling between the RF coil and the vapor coil at operating frequencies ranging from 425 kHz to 475 kHz. The electrical insulation on the RF coil stranded wire may be 0.002″ thick extruded PFA with a temperature rating of approximately 250°C.

[0072] In a specific implementation plan, such as Figure 4 As shown, the needle-driven magnet 118 is made of N52 grade neodymium-iron-boron and has an outer diameter of 15 mm and a length of 18 mm. The shape of the internal cutout is suitable for mounting on a needle attachment fixture. The residual induction of this particular oriented magnet material can be Br ≈ 1.5 Tesla.

[0073] Other features of the reusable delivery device handle include a locking latch that prevents the cartridge from moving laterally within the handle, and a brake that limits the cartridge's rotation within the handle by 30 degrees.

[0074] Increased needle length and pulse delivery

[0075] Because the steam used for cancer treatment needs to reach the peripheral lobes of the prostate from inside the urethra, the steam needle must extend further from the steam delivery needle compared to that used for BPH surgery. Figures 6A-6B The image shows the position of the steam needle after it has spread through the urethral wall, and its position when the needle is fully extended.

[0076] like Figure 7 As shown, the delivery of steam from the BPH needle is achieved by increasing the needle length and the gap width between the two coils of the solenoid. Figure 6A The stroke is increased from ~12 mm to ~24 mm for the needle used in cancer vapor delivery. For example, each solenoid coil in a BPH device may include 408 turns of #30 magnet wire (resulting in a ~12 mm needle stroke), while each solenoid coil in a cancer device may include 605 turns of #28 magnet wire (resulting in a ~24 mm needle stroke). In some embodiments, the needle cannot extend more than 24 mm to avoid puncturing the prostatic sac. However, the force required to overcome friction and to deploy the needle with sufficient force to pierce the urethral wall is not achievable with the #30 gauge coil of the BPH system. In one embodiment, the force is increased by winding more turns of lower gauge wire onto the spool. For both the cancer coil and the BPH coil, the resistance remains the same, and this resistance is selected to optimize the current delivered from the 24-volt generator power supply.

[0077] Because the diameter of #28 wire is slightly larger than that of #30 wire, placing more turns of #28 wire requires increasing the outer diameter of the spool and decreasing the inner wall thickness. The calculated relationship between force and magnet position is as follows: Figure 8 As shown, the initial force required for deployment and retraction exceeds 2 pounds, sufficient to overcome friction. The peak force is 7.1 pounds, greater than the peak force of the BPH needle. Greater force can be achieved by using a power source that can provide more current, and by optimizing the specifications of the wire used in the solenoid coil to increase the force. The power delivered to the solenoid (voltage multiplied by current) can range from 100 watts to 250 watts, and the current-on time ranges from 10 milliseconds to 250 milliseconds, preferably from 50 milliseconds to 150 milliseconds.

[0078] In one implementation, separate disposable cartridge portions can be provided for both BPH and prostate cancer steam delivery procedures, using the same reusable handle portion. Each disposable cartridge portion may include a steam delivery needle length that varies depending on the procedure. In an alternative implementation, Figure 7 The distance between the solenoid coils can be adjusted by the operator to select a needle delivery length suitable for BPH and cancer surgery, while using the same disposable cartridge portion.

[0079] As described above, the steam delivery device can be inserted transurethral into the patient to reach the prostate. The steam delivery needle can be guided by real-time ultrasound imaging of the prostate, unfolding across the urethral wall and advancing to the most distal position within the prostate. Steam therapy can be delivered during advancement or during subsequent needle withdrawal. Users prefer to advance the steam delivery needle in small incremental steps rather than unfolding a large distance very rapidly, as occurs during the initial unfolding. To achieve this, current pulses can be delivered from an RF generator to a solenoid coil in response to the user pressing a trigger on the device handle. A magnetic position sensor can be used to measure the movement of the magnet and the steam delivery needle and control the size of the incremental steps. In a preferred embodiment, each current pulse unfolds the needle by one millimeter, and the pulse delivery rate is between one and five pulses per second when the trigger is pressed. These parameters are all adjustable by the user.

[0080] like Figures 6A-6BAs shown, the tip of the steam delivery needle can be blunt, which can be achieved through needle design or by removing material from a sharp tip. The needle can be designed to be sharp enough and forceful enough to penetrate the urethral wall during initial deployment, but blunt enough that the advance steps of the pulsed needle do not force the needle through the prostatic sac. The impingement of the needle tip on the prostatic sac can be observed by the user as a “bulge” on an ultrasound image. If an abnormally small needle advance is recorded after pulse application, a needle position sensor can provide a secondary indication. The system can then lock further advance steps and / or provide a warning message to the user.

[0081] In some procedures, it can be difficult to prevent steam leakage from the needle puncture site in the urethral wall. Post-puncture movement of the delivery device and needle can widen the entry hole and facilitate steam leakage. Techniques for preventing steam leakage are available in… Figures 9A-9B As shown in the diagram. In this embodiment, an expandable balloon material 130 is placed in a notch in a steam delivery needle 116 at a distance of 4 to 24 mm proximal to the steam delivery port. During steam delivery through the steam port 117, steam can also enter the balloon 130 through a hole 132 in the needle wall, and the balloon expands to contact the tissue near the needle and prevent steam leakage from the puncture site. The balloon material can be non-compliant and expandable to the diameter set in production. Non-compliant balloon materials can be selected from PET (polyethylene terephthalate), nylon, or other materials used for non-compliant medical balloons. The balloon material and thickness can be selected to provide thermal insulation between the steam and surrounding tissue.

[0082] The number and diameter of the steam delivery holes can be selected for specific applications. Figures 9A-9B A needle with three rows of two steam delivery orifices is shown. The shorter orifice length provides more precise targeted steam delivery, which is especially important when treating small peripheral areas or narrow regions.

[0083] Improvement in the consistency of therapy delivery

[0084] The calorie output of the steam delivery device of the present invention is related to the power input of the RF generator during therapeutic delivery via an efficiency coefficient. If the delivered power is constant, the calorie output will remain consistent between injections, regardless of variations in component values ​​caused by thermal cycling of the device. If the input power remains constant for a given therapy, and if the efficiency coefficients are consistent between devices, the calorie output will remain consistent between devices. Consistency between devices is achieved through the consistency of device manufacturing. Furthermore, consistency improves as the power coupling efficiency approaches 100%, provided the input power remains constant. In other words, as the percentage of constant delivered input power to output approaches 100%, variations in device parameters have a diminishing effect on the output.

[0085] Figure 10 The RF coil 110 and vapor coil 120 have the advantage of efficient and consistent therapeutic delivery. Firstly, the relatively fewer turns on the vapor coil ( Figure 10 The 6 turns shown mean that excess heat generated at the far end of the steam coil can be conducted back through the thermally conductive metal of the six windings to preheat the room-temperature water entering the coil. It has been observed that, possibly due to thermal feedback, for a given calorie output from the device, the exit temperature of the cancer steam coil is lower than that of the BPH steam coil. Furthermore, for larger diameter coils, the change in the transformer coupling coefficient between the RF and steam coils caused by variations in the spacing between the coils is smaller.

[0086] Steam delivery system sensors

[0087] The steam temperature at the steam coil outlet and the temperature of the steam coil itself can be continuously measured and monitored by the system controller. Temperatures outside the set range may indicate damage to the steam coil or insufficient delivery of steam therapy, and may trigger automatic shutdown and guide the user to make corrective actions. For example, excessively high temperatures may indicate kinks or blockages in the water pipes. Excessively low temperatures may indicate RF power loss to the RF coil. The semi-disposable design of the described device is adapted to wireless sensors, where the temperature inside the disposable cartridge is measured and transmitted via a wireless readout mechanism in the delivery device handle. The wireless method allows for free rotation of the disposable item within the handle, an important clinical function that requires no additional cost.

[0088] Figure 11An equivalent circuit for reading the temperature RTD of departing vapor is shown. By correctly selecting the circuit parameters, it can be seen that the detected voltage is a monotonic function of Rsense, where Rsense is the resistance RTD of the copper wire, which is a linear function of the temperature through the temperature coefficient of the copper wire. Inverting the expression for Vsense gives the temperature formula of the internal coil as a function of the detected voltage Vsense. Typically, a single frequency of the oscillator is chosen to distinguish it from any other frequency that might exist in the operating room, including the generator frequency. On the other hand, in one embodiment, Figure 11 The single-frequency oscillator in this system can be considered as a fraction of the RF power supply voltage to reduce cost and minimize the number of components. In this case, care must be taken to manage any inductive pick-up from the RF coil during treatment.

[0089] Figure 11 The 1k ohm resistor in the circuit converts the single-frequency oscillator voltage into a single-frequency current source. Figure 11 In this configuration, the oscillator and 1k ohm resistor can be replaced by a single-frequency current source. A single-frequency current in the 10mA to 100mA range will provide excellent signal-to-noise ratio in Vsense measurements and in the outlet temperature readout calculated by Vsense. The temperature is averaged over a 0.5″ length sensor winding. This spatial average smooths out temperature fluctuations that can occur intermittently due to the unstable behavior of the steam at the outlet.

[0090] Wireless read / write RFID tags are commercially available. Some of these are also capable of temperature measurement. If added to disposable cartridges, such devices must be priced economically. In another embodiment, the ID of the disposable cartridge is read by an RF generator, but written to an electronic cloud via an internet connection linked to the RF generator. All generators in the service can connect to the cloud before each treatment to retrieve usage information of the disposable device inserted into the delivery device handle. At the end of the treatment, the number of therapeutic sprays delivered by the device is transmitted to and stored in the cloud.

[0091] Method using the transurethral system

[0092] Figure 12 The image shows a delivery device inserted into the prostatic urethra adjacent to the peripheral tissue. Catheter placement can be guided by ultrasound imaging and a cystoscopic camera, and can be further guided from the location of the peripheral inlet just behind the verumontanum, a clearly visible landmark. As measured by the needle position sensor, the needle is initially advanced approximately 11 mm. The initial advance distance can be in the range of 6-12 mm, and the needle must be spread to penetrate the urethral lining and enter the peripheral tissue.

[0093] Further pressing the release trigger switch activates a current pulse in the solenoid. The rate can be fixed or user-selectable, and this rate can be in the range of one to five pulses per second. In one embodiment, the current pulse has a maximum amplitude that can be provided by the system generator and an initial pulse width that is fixed or user-selectable. In one embodiment, the initial pulse width is T = 1.5 milliseconds. As the pulse is delivered to the solenoid, the needle position sensor measures the distance the needle has traveled. If the needle has traveled less than a target distance (e.g., 1 mm), the width of the next pulse is increased, and if the needle has traveled more than the target distance, the width of the next pulse is decreased. On average, the needle travels the target distance with each pulse. The target distance can be fixed or user-selectable, and in a preferred embodiment is 1 mm. At any time, the user can enable pulse withdrawal or complete withdrawal. At any time, the user can release the trigger to stop the pulse advance / withdrawal of the needle, for example, in the delivery of steam therapy. The output of the needle position sensor can be displayed so that the user knows the distance along the needle between the needle tip and the axis of the delivery device.

[0094] Safety features can be achieved by limiting the pulse width, and thus restricting the force applied to the needle to a value that prevents penetration of the prostatic cyst. If the needle travels less than 1 mm of the target distance over N consecutive pulses, needle blockage can be indicated, and the user can be warned. Alternatively, if needle blockage is indicated, further advancement of the steam delivery needle can be prevented. Blockage may occur due to the needle contacting the outer cyst of the prostate, and the value of N is chosen to limit the pulse width to the maximum safe value determined in tissue studies, ensuring the needle cannot penetrate either healthy or cancerous cysts. N can range from 4 to 10 pulses, and the corresponding maximum pulse width can range from 2 to 5 milliseconds. The user can confirm that the needle has contacted the cyst by observing a bulge in the tissue on an ultrasound image.

[0095] In an alternative implementation, the user can directly control the pulse width and the number of pulses per second. This manual needle movement mode retains the safety features of the aforementioned automatic mode.

[0096] Transurethral steam therapy can be used in conjunction with a thermocouple inserted through the perineum to the outside of the prostatic sac to warn of temperatures high enough to damage nerves on the outer surface of the sac. Saline solution can be delivered to the outside of the prostatic sac to cool and protect the nerves. Alternatively, transurethral prostatic ablation can be delivered in multiple jets, each jet short enough that sufficient time between jets is allowed to prevent significant heat conduction through the sac to the nerves. For example, a single jet treatment lasting 10 seconds or less, with at least 30 seconds between jets, can result in complete ablation of the prostatic tissue without the need for external thermocouples or saline injection needles.

[0097] In some implementations, the peripheral zone and transition zone can be treated separately. In other implementations, the vapor delivery needle is long enough to reach the cancerous peripheral zone tissue after penetrating the transition zone. Therapy can be delivered to both the peripheral and transition zone tissues during pulse deployment or withdrawal. In other implementations, central zone tissue touching the urethra can be ablated during cancer therapy treatment. The central zone can be treated alone, or in some cases, after passing through the transition zone. Both the central and transition zone tissues can be treated during a single needle deployment or withdrawal.

[0098] In some embodiments, ultrasound imaging is used to guide the delivery of steam to the prostate tissue. Additionally, a needle position sensor provides sub-millimeter accuracy for needle positioning and can be used to measure the distance between therapeutic jets. It is important to space the steam delivery at a distance that would provide overlap damage, but with sufficient spacing between jets to prevent overheating and potential conduction through the prostate capsule. In some embodiments, therapeutic jets are delivered with a 1 cm interval between jets.

[0099] The treatment methods and devices disclosed in Provisional Patent Application 720 can be used in transurethral procedures. For example, a sensor adding a sensing tissue capacitance at the needle tip can distinguish between prostate and non-prostate tissue, preventing steam delivery to non-prostate tissue and accidental penetration of the prostate sac. Tissue type sensing can be used in conjunction with a needle / magnet position sensor to confirm the magnet is within the prostate tissue, and specifically, to determine when the needle is adjacent to the prostate sac. Preoperative images can be used to determine the optimal puncture site along the urethra and the number of steam therapy jets to be delivered at each puncture site. The prescribed distance between the therapy jets then allows transurethral prostate ablation to be performed without external image guidance. As in BPH procedures, the delivery device probe is advanced to a predetermined location in the urethra by identifying anatomical landmarks in the cystoscopic image. Guided by the output of the magnet / needle position sensor and / or by markings on the needle visible through the cystoscope, the needle is advanced through the urethral wall to the prescribed distance. Therapy can be delivered during needle advancement, or the needle can be advanced to the prostate sac wall, as indicated by the sensor, and delivered during withdrawal.

[0100] In another embodiment, an electromagnetic sensor or transmitter placed at or near the needle tip can help track the position of the needle tip relative to preoperative or real-time images of the prostate. In the case of ultrasound, a second sensor or transmitter can be placed near the ultrasound transducer, so the position and orientation of the needle tip relative to the transducer are known, which facilitates autofocusing and image enhancement. Tracking the needle tip enables robotic steering or navigation of the needle. Advanced steam therapy delivery systems can use a robot to advance the needle to a point on an image selected by the operator and deliver a prescribed dose of steam at that location. As used in other catheter systems, the tip of the delivery device needle can be manipulated using a drawstring. Image guidance with steering enables the delivery of therapy to a location with optimal separation in a three-dimensional pattern. More exotic steering mechanisms can be employed, such as by attaching a magnet to the needle tip and using a large external magnet to steer the needle tip.

[0101] Although specific embodiments of the invention have been described in detail above, it should be understood that this description is for illustrative purposes only, and the above description of the invention is not exhaustive. Specific features of the invention are shown in some figures but not in others, merely for convenience, and any feature can be combined with another feature according to the invention. Many variations and alternatives will be apparent to those skilled in the art. These alternatives and variations are intended to be included within the scope of the claims. Specific features presented in the dependent claims can be combined and fall within the scope of the invention. The invention also includes embodiments in which the dependent claims are rewritten to refer to other independent claims in multiple reference forms.

Claims

1. A steam delivery device, comprising: The handle portion has: An inner cavity, wherein the inner cavity has a proximal opening and a distal opening; A solenoid coil, which is configured to generate a magnetic field; as well as A radio frequency coil disposed in the cavity, wherein the radio frequency coil can be connected to a radio frequency generator; as well as A cartridge portion configured to be inserted distally into the cavity of the handle portion through the proximal opening, wherein the cartridge portion includes: A shaft configured for insertion into the urethra; A steam delivery needle is disposed in the shaft; A magnet fixedly connected to the steam delivery needle; and A steam coil connected to (a) a steam delivery needle and (b) a fluid source. In the assembled configuration, the cartridge portion is inserted into the inner cavity of the handle portion, and the vapor coil is inside the radio frequency coil; In the assembled configuration, the cartridge portion is rotatable relative to the handle portion to deliver steam to multiple portions of the prostate. The solenoid coil is configured to receive current, thereby causing the magnet to move to the distal end to deploy the steam delivery needle.

2. The steam delivery device according to claim 1, wherein the cartridge portion further includes a thermometer, and wherein, When the cartridge portion rotates, the thermometer makes electrical contact with the handle portion.

3. The steam delivery device according to claim 2, wherein the cartridge portion includes at least one conductive ring extending around the outer surface of the cartridge portion, wherein the at least one conductive ring is electrically connected to the thermometer.

4. The steam delivery device according to claim 3, wherein the handle portion includes at least one tilting coil, and wherein the thermometer is in electrical contact with the handle portion through a contact between at least one conductive ring of the cartridge portion and the at least one tilting coil.

5. The steam delivery device according to claim 3, wherein at least one conductive ring is located near the steam coil.

6. The steam delivery device according to claim 1, wherein, In the assembled configuration, the longitudinal axis of the cartridge portion extends through the central opening of the steam coil.

7. The steam delivery device according to claim 1, wherein the steam coil is wound around the outer surface of the cartridge portion.

8. The steam delivery device according to claim 1, wherein, In the assembled configuration, the handle portion completely radially surrounds at least a portion of the cartridge portion.

9. The steam delivery device according to claim 1, wherein the cartridge portion is rotatable by at least 30 degrees.

10. The steam delivery device according to claim 1, wherein the cartridge portion is disposable.

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