Steam cauterization system and method

Abstract

This invention provides a steam delivery system that can deliver condensable steam energy to tissues such as the prostate gland, causing atrophy, damage, and degeneration of the prostate tissue. [Solution] The steam delivery system according to the present invention has a handle portion (102) and a cartridge portion (104). The handle portion has a lumen (103) and a solenoid (112) configured to generate a magnetic field. The cartridge portion includes a shaft (114) and a magnet (118) fixed to a steam delivery needle (116) located inside the shaft. In an assembled configuration in which the cartridge portion is inserted into the lumen of the handle portion and the steam delivery needle is in a retracted position, the magnet is aligned with the solenoid. The current flowing through the solenoid moves the magnet distally to deploy the steam delivery needle.

Description

Technical Field

[0001] [Cross - References to Related Applications] This application claims priority to U.S. Provisional Patent Application No. 62 / 437,617, filed on December 21, 2016, and U.S. Provisional Patent Application No. 62 / 538,517, filed on July 28, 2017, and the entire contents of both applications are incorporated herein by reference.

[0002] This application is related to U.S. Patent Application No. 14 / 773,853, filed on September 9, 2015, and International Patent Application No. PCT / US2016 / 067558, filed on December 19, 2016, and the entire contents of both applications are incorporated herein by reference.

[0003] All documents mentioned in this specification, including patents and patent applications, are incorporated herein by reference to the same extent as if each were specifically and individually indicated.

[0004] The present invention relates to devices and related methods for the treatment of the prostate using minimally invasive techniques.

Background Art

[0005] The prostate is walnut - sized and shaped early in life and has a weight of about 20 grams before the hypertrophy caused by BPH (benign prostatic hyperplasia). Prostatic hypertrophy appears to be a normal progression. The size of the prostate gradually increases over the years to two or more times its normal size. The fibromuscular tissue of the outer prostatic capsule limits hypertrophy after the prostate reaches a certain size. Due to such limitation during hypertrophy, the intra - capsular tissue compresses and constricts the prostatic urethra, thus creating resistance to urine flow.

[0006] The prostate gland is divided into three regions: the periphery, the transitional zone, and the central zone. The periphery (PZ) contains approximately 70% of the volume of the male prostate. This subcapsular portion of the posterior surface of the prostate surrounds the distal urethra, and 70% to 80% of cancers develop in the tissue of the periphery. The central zone (CZ) surrounds the ejaculatory ducts and contains approximately 20-25% of the volume of the prostate. The central zone is often the site of inflammatory processes. The transitional zone (TZ) is where benign prostatic hyperplasia (BPH) develops and contains approximately 5-10% of the volume of the glandular elements of a normal prostate, but in cases of BPH, it can constitute up to 80% of this volume. The transitional zone includes the two lateral prostatic lobes and the periurethral glandular zone. A natural barrier surrounds the transitional zone, namely the prostatic urethral region, the anterior fibromuscular interstitial region (FS), and the fibrous plane (FP) between the transitional and periphery. The anterior fibromuscular interstitial (FS) or fibromuscular region is primarily composed of fibromuscular tissue.

[0007] Approximately 70% to 80% of prostate cancers develop within the surrounding tissue of the prostate, and treatment may be confined to this area. In recent years, there has been growing interest in localized treatment of prostate cancer, which involves treating only the area of ​​tissue where cancer is found after biopsy. Conventional localized treatments using RF ablation energy may not be limited to the surrounding tissue. [Prior art documents] [Patent Documents]

[0008] [Patent Document 1] U.S. Patent Application No. 14 / 773,853 [Patent Document 2] International Patent Application Number PCT / US2016 / 067558 [Overview of the project] [Problems that the invention aims to solve]

[0009] In patients with advanced prostate cancer, prostatectomy may be presented, and surgical options are desired. A device capable of cauterizing the entire prostate or the entire middle lobe of the prostate via a transurethral approach is needed. This minimally invasive technique may treat both the transitional zone and surrounding areas. [Means for solving the problem]

[0010] A system and method for cauterizing surrounding tissue without cauterizing tissue outside the surrounding region are disclosed. The transurethral approach uses a vapor delivery device to access surrounding tissue located adjacent to the urethral prostatic region.

[0011] For treatment of the entire surrounding area, it is preferable to employ a vapor delivery needle extending up to 2.5 cm from a delivery device shaft placed inside the urethra. Vapor should be delivered from multiple points along the needle's path using guidance from ultrasound and a needle position sensor.

[0012] A steam delivery needle is capable of controlled movement along its path, including stopping to deliver steam. A system and method for controlling the digital step-by-step movement of the steam delivery needle to any point within its reach is disclosed.

[0013] A blunt needle is revealed, which can penetrate the urethral wall during the initial shallow deployment, but does not penetrate the prostatic capsule when the needle is advanced using an electric pulse to the needle delivery solenoid.

[0014] Most prostate cancers develop in the surrounding area. The vapor delivered through the needle to the surrounding area does not cross tissue barriers to other areas of the prostate where cancer may not be present.

[0015] It is possible to treat all areas of the prostate with a single transurethral steam delivery device. Partial or total prostatectomy may be achieved during a single treatment procedure in which steam is applied to some or all areas of the prostate.

[0016] A semi-disposable steam delivery device is also disclosed, in which the handle and cable are reusable, and the barrel, needle delivery shaft, and attachable water and wash water lines constitute a disposable cartridge.

[0017] Inductive coupling is used to transfer RF power from the RF coil in a reusable handle to the vapor delivery coil in a disposable cartridge.

[0018] Magnetic coupling is employed to transfer non-contact needle deployment force from a solenoid coil in a reusable handle to a needle deployment magnet in a disposable cartridge.

[0019] Inductive coupling is preferred to communicate temperature and identification data from a disposable cartridge to a reusable handle. Since the induction coil and force coil are cylindrical and symmetrical, their function is independent of the orientation of the disposable cartridge, and therefore the disposable cartridge can be rotated relative to the reusable handle, thereby enabling treatment to be performed on both sides of the prostate without rotating the delivery device handle between the patient's legs. A sliding contact between the disposable cartridge and the reusable handle for reading the vapor coil temperature is also disclosed.

[0020] A physician can treat BPH or cancer by selecting a disposable cartridge designed for the procedure, using a single reusable handle. For example, a cartridge for BPH is considered simpler and less expensive than a cartridge for prostate cancer because a variable and controllable needle depth is not required for the BPH procedure.

[0021] A handle portion having a lumen and an RF coil disposed within the lumen and connectable to a source of RF energy, and a cartridge portion configured to be inserted into the lumen of the handle portion, the cartridge portion including an elongated shaft configured to be inserted into a patient's urethra, a vapor delivery needle disposed within the elongated shaft, and a vapor coil fluidly connected to the vapor delivery needle and a fluid source, the insertion of the cartridge portion into the handle portion including aligning and positioning the vapor coil within the RF coil.

[0022] Application of RF energy to the RF coil can inductively generate vapor within the vapor coil as fluid is delivered from the fluid source to the vapor coil.

[0023] In some examples, the vapor delivery needle is configured to deliver vapor to a patient's tissue.

[0024] The cartridge portion further includes a first solenoid coil and a second solenoid coil, and a needle drive magnet attached to a proximal portion of the vapor delivery needle, the needle drive magnet being slidably disposed within the first solenoid coil when the vapor delivery needle is in a retracted position and slidably disposed within the second solenoid coil when the vapor delivery needle is in an extended position.

[0025] The device may further have a needle deployment switch in the handle portion.

[0026] In some examples, depression of the needle deployment switch can fully deploy the vapor delivery needle from a retracted position to an extended position. Each depression of the needle deployment switch can incrementally deploy the vapor delivery needle. For example, the vapor delivery needle is deployed in 1 mm increments.

[0027] The device may further include a position sensor positioned on the steam delivery needle, which is preferably configured to determine the deployed position of the steam delivery needle. A safety feature is provided which prevents the steam delivery needle from moving forward if the position sensor indicates that the steam delivery needle has not moved a desired incremental distance.

[0028] The steam coil includes, for example, Inconel® tubing material.

[0029] The device may further include a latch configured to prevent lateral movement of the cartridge portion when the cartridge portion is inserted into the lumen of the handle portion.

[0030] When the cartridge portion is inserted into the lumen of the handle portion, the cartridge portion can be rotated. This can be done to deliver vapor to multiple locations within the prostate, and to deliver vapor to both middle lobes of the prostate.

[0031] In one specific example, the delivery needle cannot extend more than 24 mm from the elongated shaft when it is in the extended position.

[0032] The vapor delivery needle includes an inflatable balloon, which is configured to prevent vapor from leaking out of the puncture site in the patient's tissue. The inflatable balloon is positioned within a recess of the vapor delivery needle. The inflatable balloon is inflated by vapor during vapor delivery.

[0033] The steam delivery device may further include an electronic controller configured to control the delivery of RF energy to the RF coil.

[0034] The steam delivery device may further include a temperature sensor located at the outlet of the steam coil, which may be electrically coupled to an electronic controller and configured to measure the temperature of the fluid or steam at the outlet of the steam coil.

[0035] As a safety measure, the electronic controller is preferably configured to initiate the cessation of RF energy transmission when the measured temperature of the steam or fluid at the outlet is outside the preferred temperature range.

[0036] A method for delivering steam to a patient's prostate is also provided, comprising: inserting the cartridge portion of a steam delivery device into the lumen of the handle portion of the steam delivery device, aligning and positioning the steam coil of the cartridge portion within the RF coil of the handle portion; inserting the elongated shaft of the cartridge portion into the patient's urethra; advancing the distal end of the elongated shaft to the prostatic portion of the patient's 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 through the steam delivery needle.

[0037] The extension may include generating a magnetic field using at least one solenoid coil to extend the vapor delivery needle into the prostate.

[0038] This method may further include rotating the cartridge portion within the handle portion.

[0039] To better understand the present invention and to see how it can actually be put into practice, some preferred embodiments are described below merely as non-limiting examples, with reference to the accompanying drawings, where similar reference letters consistently indicate corresponding features throughout similar embodiments. [Brief explanation of the drawing]

[0040] [Figure 1A] This figure shows one embodiment of a transurethral vapor delivery device. [Figure 1B] This figure shows one embodiment of a transurethral vapor delivery device. [Figure 1C]This figure shows one embodiment of a transurethral vapor delivery device. [Figure 2A] This diagram shows a disposable cartridge for a steam delivery device. [Figure 2B] This diagram shows a disposable cartridge for a steam delivery device. [Figure 3] This figure shows a reusable handle for a steam delivery device. [Figure 4] This is a diagram showing the magnets in a steam delivery device. [Figure 5] This diagram shows the direction of the current passing through the push coil and pull coil of the magnetic actuator of a steam delivery device. [Figure 6A] This figure shows the vapor needle deployment length as it moves from the BHP device to the cancer device. [Figure 6B] This figure shows the vapor needle deployment length as it moves from the BHP device to the cancer device. [Figure 7] This figure shows the changes in a solenoid as it moves from a BPH device to an oncology device. [Figure 8] This diagram shows the force generated relative to the position of the magnet. [Figure 9A] This diagram shows techniques for preventing steam leaks. [Figure 9B] This diagram shows techniques for preventing steam leaks. [Figure 10] This is a diagram of an induction steam generator. [Figure 11] This diagram shows an equivalent circuit for reading the resistance temperature sensor for the outlet tube. [Figure 12] This figure shows a delivery device inserted into the urethral prostatic region adjacent to the surrounding tissue. [Modes for carrying out the invention]

[0041] Generally, methods for treating BPH (benign prostatic hyperplasia) or prostate cancer involve introducing heated steam transurethrally into the internal spaces of the prostate gland, where the steam cauterizes the prostate tissue in a controllable manner. Such methods produce localized cauterization of the prostate tissue, and more specifically, localize the thermal energy imparted by the steam, cauterizing the tissue adjacent to the urethra without damaging the prostate tissue not adjacent to the urethra.

[0042] The transurethral vapor delivery device disclosed herein is used to deliver vapor transurethrally into a patient's prostate gland. The elongated shaft of the device is advanced into the patient's urethra and positioned near the prostate gland within the urethral prostatic portion, after which the vapor delivery needle is inserted into the prostate gland, penetrating the urethral wall. Vapor is then delivered into the prostate gland through the vapor delivery needle.

[0043] [Semi-disposable steam delivery device] The transurethral steam delivery device 100 is shown in its assembled form in Figure 1A, and Figure 1B is an exploded view showing the reusable handle portion 102 and disposable cartridge portion 104 of the steam delivery device. The handle portion 102 of the steam delivery device includes a lumen 103, an electrical cable 106 which plugs into an RF generator (not shown), a grip portion 107, a trigger 108 for operation of flushing, forward / retraction of the needle, and ON / OFF of RF power, an RF coil 110 (not shown) located in the lumen and configured to inductively generate steam, and a solenoid coil 112 (not shown) located in the handle portion and configured to advance or retract the steam needle.

[0044] The RF generator is configured to supply power and fluid to the transurethral steam delivery device for generating steam. For example, the RF generator is configured to supply RF energy to the RF coil in the handle portion. The RF generator is also connected to the steam delivery device to supply power and other components essential for the operation of perfusion / cooling fluid, suction, 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.

[0045] The RF generator includes an electrical connector which supplies an RF current to the steam delivery device, transmits or receives electrical signals to or from a switch on the steam delivery device, and transmits or receives measured values ​​(e.g., the temperature of the steam delivery device) and electrical signals to or from the controller of the steam delivery device (e.g., its electrical connector), where the measured values ​​and electrical signals are used to identify the steam delivery device, track the history of steam delivery, and prevent overuse of a given steam delivery system. The RF generator may also include a peristaltic pump which supplies a flow of a cooling / perfusion fluid, such as saline solution, to the steam delivery device.

[0046] The disposable cartridge 104 includes an elongated shaft 114 having a lumen for a cystoscope and a steam delivery needle 116, a needle drive magnet 118 (not shown) attached to the steam delivery needle and moving forward or backward by a magnetic field generated in a solenoid coil 112, a steam coil 120 inductively converting water into steam, and a plastic conduit 122 for irrigation with sterile water or saline solution and bladder drainage. The cartridge portion is configured to be inserted into the lumen 103 of the handle portion 102. When inserting the cartridge portion into the handle portion, the steam coil 120 of the cartridge 104 may be aligned and positioned within the RF coil 110 of the handle portion, or, as a variation (as shown in Figure 10), the RF coil 110 may be aligned and positioned around the steam coil 120. The elongated shaft 114 is sized and configured to be inserted into the patient's urethra with a length that can extend to the prostatic portion and prostate of the patient's urethra. As shown in Figure 1B, the cartridge 104 may be rotated within the handle to facilitate the delivery of vapor to the left and right middle lobes of the prostate without rotating the handle between the patient's legs.

[0047] In some procedures, steam therapy is guided at least partially by transrectal ultrasound (TRUS) imaging. In these procedures, the TRUS probe is preferably used to prevent the steam delivery device handle from being in the vertically downward position shown in Figure 1A. In some modified embodiments, the delivery device handle may extend upward from the barrel of the delivery device. In other embodiments, the barrel may be modified to include the delivery device trigger and cable, eliminating the handle portion entirely.

[0048] In several steps, the delivery device needle is advanced to deliver vapor to two or more sites after the initial puncture of the urethral wall. It is important that the vapor delivery needle remains stable against the patient's anatomical tissue to prevent vapor leakage due to enlargement of the needle entry hole. Figure 1C shows an adjustable delivery device holder 124 used to stabilize and hold the delivery device during needle delivery, advancement, and vapor delivery. This adjustable delivery device holder allows the operator to concentrate on positioning the image-guided needle and delivering the treatment. Figure 1C shows an adjustable delivery device holder having a flexible and shape-reducing shaft 126, which is adjusted by the operator to maintain the position of the delivery device needle during treatment. In other embodiments, the holding device may be electronically adjustable. The holding device may be configured to advance or retract the delivery device from the urethra. The handle in Figure 1C may be as simple as the adjustable holding device shown in Figure 1C, or as complex as a multi-axis robotic arm.

[0049] A disposable cartridge 104 is shown in cross-sectional views in Figures 2A and 2B. The steam delivery needle 116 is rigidly attached to a needle drive magnet 118, which is moved laterally by a magnetic field generated by a coil in the handle portion 102 (shown in Figure 3). The steam coil 120 is also shown in Figure 2B. The disposable cartridge includes a resistance thermometer (RTD) 119, which is wired in series with a conductive metal ring 121 via leads 123. The resistance thermometer (RTD) 119 can measure the temperature of the steam coming out of the steam coil 120. In one embodiment, the resistance thermometer (RTD) is preferably wrapped around the outlet of the steam coil.

[0050] It is preferable to place the inductive reading coil inside the reusable handle. It is preferable to place the thermocouple above the RF coil in the reusable handle portion. Experience has shown that the first component to show signs of overheating (usually smoke) is the RF coil, even when the RF coil is at a somewhat lower temperature than the adjacent inner coil. Therefore, the RF coil is a preferred location for a thermometer, preferably a thermocouple.

[0051] When a disposable cartridge 104 is inserted into the reusable handle portion 102, the cartridge 104 engages with an oblique coil within the handle. The insertion and withdrawal forces of the cartridge should be specified within a strict range so that all cartridges remain within a repeatable mechanical force range. The oblique coil functions as a sliding electrical contact, which allows the cartridge to rotate within the handle while maintaining electrical contact of the RTD outlet thermometer lead from the cartridge to the handle. When the cartridge is rotated, there is some change in the contact resistance between the ring and the coil. However, precise temperature measurement is not required during rotation, and thus, any contact resistance or any change in contact resistance during rotation should be zeroed out by software. Although the outlet thermometer is shown as a resistance thermometer (RTD), other small sensors such as thermistors or thermocouples may be employed.

[0052] The steam coil shown in Figure 2B is connected to a sterile water supply section that runs through a plastic tube extending from the cartridge, as shown in Figure 1A, and is also connected to an RF generator. The multiple windings of the steam coil are made of metal tubing, which is, for example, 18-gauge regular thickness (RW) 304 stainless steel tubing or 18-gauge thin thickness (TW) plug-drawn Inconel® 625 tubing. The individual coil windings are preferably in physical contact and preferably soldered or welded to each other to ensure good electrical contact, but the RF current passes through a sufficiently thin oxide layer separating the windings.

[0053] The water in the steam coil 120 is converted into steam by ohmic heat generated by the current flowing around the steam coil. These currents are induced by RF currents flowing through concentric RF coils located within the delivery device handle. The alternating magnetic field generated by the currents in the RF coils is preferably enhanced by manufacturing the steam coil from a permeable material. Since the permeability of 300 series stainless steel changes with cold working, it is difficult to obtain a lot of tubing material with the same permeability. Because consistency of calorie output from device to device is very important, non-magnetic tubing material is preferred for this application. Stainless steel such as 304 may be annealed to eliminate its magnetic properties, or non-magnetic steels such as Inconel® 625, MP35N, or Elgiloy may be selected for the steam coil. Inconel® 625 is preferred because its electrical resistance is almost temperature-independent over the temperature range (20°C to 350°C) that may be experienced at the distal (steam) end of the steam coil, enabling consistent steam delivery from shot to shot and from device to device.

[0054] One or more electrical leads extend from the disposable cartridge along with a sterile water line. The wire or electrical lead is connected to an RF generator and transmits or receives signals from the EPROM in the cartridge that supply cartridge identification and usage data. Other wires in this cable may supply signals from the cartridge to a thermocouple located on the vapor coil in the cartridge, supplying other diagnostic data. In another embodiment, the EPROM wire and thermocouple wire may include a small cable that extends from the disposable cartridge and plug, connects to a non-disposable handle, and passes through the non-disposable handle to a main delivery device handle cable. In a modified example, data may be inductively coupled from the cartridge without the need for physical leads, as disclosed below.

[0055] The reusable handle portion 102 of the delivery device is shown in detail in Figure 3. The solenoid coil 112 is configured in a push / pull configuration relative to the needle drive magnet as shown in Figure 2B. In the fully retracted needle position, the proximal end of the needle drive magnet aligns with the proximal / pull solenoid coil 112. In the fully extended needle position, the distal end of the needle drive magnet aligns with the distal / pull solenoid coil 112. Current flows in opposite directions within the push and pull coils, as shown in Figure 5. The push coil generates a magnetic field that repels the opposite-polarity needle drive magnet, pushing it out of the coil. Due to the repulsive force, the magnet is not in a stable equilibrium state along the axis of the push coil and tends to move laterally, which can increase the frictional resistance between the needle drive magnet and its surroundings and to axial advancement. The pull coil generates a magnetic field that attracts the needle drive magnet to the pull coil. The pull coil attracts the needle-driven magnet to the coil's axis, thereby eliminating the instability of the push coil. The combination of the push and pull coils provides approximately twice the force of a single coil. As can be seen in Figure 5, the push / pull pair of coils also forms the same backward force as the forward force by simply reversing the direction of the current to the coil pair.

[0056] Figure 3 shows the potential position of the linear magnetic position sensor 113 adjacent to the solenoid coil. The linear magnetic position sensor 113 is configured to detect the magnetic field formed by the needle-driven magnet. A relatively small magnetic field is generated by the solenoid coil. The magnetic fields formed by the two solenoid coils cancel each other out on average and in the central plane between the coils. The voltage output of the linear magnetic position sensor is a linear function of the position of the magnet (and the needle attached to the magnet). By performing a single calibration, the sensor voltage can be converted to the magnet position relative to the nearest position of the sensor.

[0057] The RF coil 110 shown in Figure 3 is designed to be positioned as close as possible to the steam coil (steam coil 120 in Figure 2B) when the disposable cartridge is inserted into the handle portion 102, thereby achieving maximum current induction in the steam coil. The relationship between the RF coil and the steam coil in the assembled device is shown in Figure 10. In one embodiment, the steam coil includes 6 turns of #18 TW Inconel® 625 tubing, and the RF coil includes 11 turns of #22 copper litz wire composed of individual strands of #44 copper magnet wire. These dimensions are selected to optimize the electromagnetic coupling between the RF coil and the steam coil at operating frequencies in the range of 425 kHz to 475 kHz. The insulation on the litz wire of the RF coil can be 0.002'' thick extruded PFA with a temperature rating of approximately 250°C.

[0058] In the specific embodiment shown in Figure 4, the needle drive magnet 118 is manufactured from grade N52 neodymium-iron-boron and has an outer diameter of 15 mm and a length of 18 mm. The inner notch is shaped to fit into the needle mounting portion. The residual magnetic induction (residual magnetic flux density) Br of the magnet material for this particular orientation is preferably about 1.5 Tesla.

[0059] Other features of the reusable dispensing device handle include a locking latch to prevent lateral movement of the cartridge within the handle, and a return stopper that defines the rotation of the cartridge within the handle in 30-degree increments.

[0060] [Increased needle length and pulse delivery] Since the vapor for cancer treatment needs to reach the perimedial lobe of the prostate from within the urethra, the vapor needle needs to extend further from the vapor delivery needle than in the BPH procedure. The position of the vapor needle after deployment, penetrating the urethral wall, and the position of the needle when fully extended are shown in Figures 6A and 6B.

[0061] The increase in the travel of the vapor delivery needle for BPH (Figure 6A) from up to 12 mm to the travel of the vapor delivery needle for cancer (up to 24 mm) is achieved by increasing the needle length and increasing the gap width between the two coils of the solenoid, as shown in Figure 7. For example, each solenoid coil in the BPH device contains #30 magnet wire with 408 turns, resulting in a needle travel of up to 12 mm, while each solenoid coil in the cancer device contains #28 magnet wire with 605 turns, resulting in a needle travel of up to 24 mm. In some embodiments, the needle cannot extend beyond 24 mm to avoid penetrating the prostatic capsule. However, the force required to deploy the needle with enough force to overcome friction and perforate the urethral wall cannot be achieved with the #30 gauge coil in the BPH system. In one embodiment, this force is increased by winding the bobbin with a lower gauge wire with a greater number of turns. The resistance remains the same for both the cancer coil and the BPH coil, and is selected to optimize the current delivered from the generator's 24-volt power supply.

[0062] Since the diameter of #28 gauge wire is slightly larger than that of #30 gauge wire, the outer diameter of the bobbin needs to be increased and the thickness of the inner wall of the bobbin needs to be reduced to accommodate more turns of #28 gauge wire. The calculated force relative to the magnet position is shown in Figure 8, and the initial force of deployment and retraction exceeds 2 pounds (approximately 0.9 kg), which is sufficient to overcome friction. The peak force is 7.1 pounds (approximately 3.2 kg), which is greater than the peak BPH needle force. Greater forces can be achieved by using a power supply that can deliver more current and by optimizing the wire gauge of the solenoid coil to increase the force. The power (voltage × current) delivered to the solenoid should be in the range of 100 watts to 250 watts, and the current should be ON for a time range of 10 msec to 250 msec, preferably 50 msec to 150 msec.

[0063] In one embodiment, separate disposable cartridge portions may be provided for BPH and prostate cancer vapor delivery procedures, using the same reusable handle portion. Each disposable cartridge portion includes a vapor delivery needle length that varies depending on the procedure. In a modified embodiment, the distance between the solenoid coils in Figure 7 may be adjustable by the operator to select an appropriate needle delivery length for both BPH and cancer procedures while using the same disposable cartridge portion.

[0064] As described above, the vapor delivery device is inserted transurethrally into the patient to gain access to the prostate. The vapor delivery needle is guided by real-time ultrasound imaging of the vapor delivery needle within the prostate, deploying to cross or penetrate the urethral wall and advancing to its distal position within the prostate. Vapor is delivered to perform treatment during the advancement or subsequent retraction of the needle. The user will likely prefer to advance the vapor delivery needle in small increments rather than very rapid deployment over large distances, as is done in the initial deployment. To achieve this goal, pulses of current are delivered from an RF generator to a solenoid coil in response to the user pressing a trigger on the handle portion of the device. A magnetic position sensor can be used to measure the movement of the magnet and the vapor delivery needle and control the size of the increments. In a preferred embodiment, each pulse of current deploys the needle by 1 mm, and the rate at which pulses are delivered when the trigger is pressed is 1 to 5 pulses per second. It is desirable that both of these parameters be adjustable by the user.

[0065] As can be seen in Figures 6A and 6B, the tip of the vapor delivery needle is preferably blunt, which is achieved by the needle design or by removing the material of the sharp tip. The needle may be designed to be sharp enough and forceful enough to penetrate the urethral wall during initial deployment, but blunt enough not to penetrate the prostatic capsule during pulsed needle advance steps. The impact of the needle tip on the prostatic capsule is preferably observed by the user as "tenting" on the ultrasound image. If the needle position sensor records an abnormally small needle advance after the application of a pulse, a second instruction is preferably issued by the needle position sensor. The system may then stop further advance steps and / or provide the user with a warning message.

[0066] In some procedures, it can be difficult to prevent vapor from leaking from the needle entry hole in the urethral wall. Movement of the delivery device and needle after puncture can enlarge the entry hole, facilitating vapor leakage. Techniques for preventing vapor leakage are shown in Figures 9A and 9B. In this embodiment, an inflatable balloon material 130 is provided 4 to 24 mm proximal to the vapor delivery hole and in a recess of the vapor delivery needle 116. During vapor delivery through the vapor port 117, vapor also enters the balloon 130 through the hole 132 in the needle wall, causing the balloon to inflate and strike the tissue adjacent to the needle, preventing vapor from leaking back out of the puncture site. The balloon material may be non-compliant and should inflate to a diameter set during manufacturing. The non-compliant balloon material should be selected from PET (polyethylene terephthalate), nylon, or other materials used for non-compliant medical balloons. The balloon material and thickness should be selected to provide insulation between the vapor and the surrounding tissue.

[0067] The number and diameter of the steam outlets should be selected to suit the specific application. Figures 9A and 9B show a needle with three rows of two steam outlets. Shorter hole lengths result in more precise steam delivery, which can be particularly important when treating small peripheral or narrow areas.

[0068] [Improving the consistency of delivery for treatment] 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 through the efficiency coefficient. The calorie output is consistent or constant from shot to shot if the delivered power is a constant independent of changes in component values ​​due to the thermal cycle of the device. The calorie output is consistent or constant from device to device if the input power is always the same for a given treatment and the efficiency coefficient is consistent from device to device. Device-to-device consistency or invariance is achieved by consistency in device manufacturing. Furthermore, consistency improves as the power coupling efficiency approaches 100%, provided that the input power is kept constant. In other words, variations in device parameters have less impact on the output as the proportion of constant input power delivered to the output approaches 100%.

[0069] The RF coil 110 and steam coil 120 in Figure 10 offer advantages in efficient and consistent therapeutic delivery. Firstly, the relatively small number of turns in the steam coil (6 turns as shown in Figure 10) means that excess heat generated at the distal end of the steam coil can be returned to preheat the preheating room-temperature water entering the coil and pass through the heat-conducting metal of the six turns. The outlet temperature of the steam coil for cancer has been observed to be lower than the outlet temperature of the steam coil for BPH for a given calorie output from the device, in some cases due to thermal feedback. Furthermore, the change in the transformer coupling coefficient between the RF coil and the steam coil, resulting from changes in the separation between the coils, is smaller for larger diameter coils.

[0070] [Steam delivery system sensor] The steam temperature at the steam coil outlet and the steam coil temperature should be continuously measured and monitored by the system controller. Temperatures outside the set range may indicate damage to the steam coil or insufficient steam therapy delivery, and should be used as a trigger for automatic shutdown and guidance to the user regarding corrective action. For example, excessive temperature may indicate kinking or blockage in the water line tubing. Insufficient temperature may indicate loss of RF power to the RF coil. The semi-disposable design of the device described measures the temperature in a disposable cartridge and transmits it to a wireless sensor communicated through a wireless reading mechanism in the delivery device handle. The wireless method allows for free rotation of the disposable cartridge in the handle, which is an important clinical feature without additional cost.

[0071] Figure 11 shows an equivalent circuit for temperature reading of an injection vapor RTD (resistance temperature sensor). With appropriate selection of circuit parameters, the sensed voltage can be shown to be a monotonic function of Rsense, i.e., the resistance of the copper wire RTD, and this monotonic function is a linear function of temperature through the temperature coefficient of the copper wire. The equation for Vsense is inversely transformed to show the equation for the temperature of the inner coil as a function of the sensed voltage Vsense. Typically, the single frequency of the oscillator is selected to be different from any other frequencies that may be present in the treatment room, including the generator frequency. On the other hand, in one embodiment, the single-frequency oscillator in Figure 11 can be taken as a very small RF power supply voltage to reduce costs and minimize the number of components. In this case, care must be taken to manage any inductive pickup from the RF coil during treatment.

[0072] The 1kOhm resistor in Figure 11 converts the single-frequency oscillator voltage into a single-frequency current source. The oscillator and 1kOhm resistor can be replaced by the single-frequency current source in Figure 11. A single-frequency current in the range of 10mA to 100mA provides an excellent signal-to-noise ratio (SNR) in Vsense measurements and outlet temperature readings calculated from Vsense. The temperature is the average value over a 0.5'' length of the sensor winding. This spatial average smooths out temperature fluctuations, which can occur at multiple points due to erroneous vapor behavior at the outlet.

[0073] Wireless read / write RFID tags are commercially available. Some of these can measure temperature. Such devices should be economically priced when added to disposable cartridges. In another embodiment, the ID of the disposable cartridge is read by an RF generator but written to an e-cloud via an internet connection to the RF generator. All generators in use can connect to the cloud before each treatment procedure to retrieve usage information for the disposable device inserted into the delivery device handle. At the end of the treatment, the number of treatment shots delivered by that device will be relayed to the cloud and stored therein.

[0074] [Method using a transurethral system] Figure 12 shows a delivery device inserted into the prostatic portion of the urethra adjacent to the surrounding tissue. Catheter placement is often guided by ultrasound imaging and a cystoscopy camera, and may also be guided by the location of access to the surrounding region directly behind the seminal cumulus, which is a visible landmark. Initially, the needle is advanced over a travel distance of approximately 11 mm, as measured by a needle position sensor. The initial travel distance is often in the range of 6–12 mm, and the needle must be deployed from the inner lining of the urethra into the surrounding tissue.

[0075] Further pressing of the deployment trigger switch causes the solenoid to actuate a current pulse at a fixed or user-selected speed, which is preferably in the range of 1 to 5 pulses / second. In one embodiment, the current pulse has the maximum amplitude that the system generator can supply and a fixed or user-selected initial pulse width. In one embodiment, the initial pulse width T is 1.5 msec. As a pulse is delivered to the solenoid, a needle position sensor measures the needle travel distance and increases the width of the next pulse if the needle has not traveled more than a target travel distance, e.g., 1 mm, and decreases the width of the next pulse if the needle has traveled more than the target travel distance. On average, the needle travels by the target travel distance in each pulse. The target travel distance may be fixed or user-selected, and in a preferred embodiment, it is 1 mm. At any time, the user may enable pulsed retraction or full retraction of the needle. At any time, the user may release the trigger to stop pulsed forward / retraction of the needle, for example, to deliver steam therapy. It is preferable to display the output of the needle position sensor so that the user can know the distance along the needle between the needle tip and the delivery device shaft.

[0076] It is preferable to implement safety features that limit the pulse width, and therefore limit the force applied to the needle to a value that prevents it from penetrating the prostatic capsule. If the needle has not moved more than 1 mm of target travel distance for a series of N pulses, a needle obstruction condition is indicated and the user is warned. As a variation, it is preferable to prevent further advancement of the vapor delivery needle when a needle obstruction condition is indicated. A needle obstruction condition may be caused by the needle hitting the outer capsule of the prostate, and the value of N is selected to limit the pulse width to the safe maximum value determined in the tissue examination, so that with respect to the safe maximum value, the needle cannot penetrate a healthy or cancerous capsule. N is preferably in the range of 4 to 10 pulses, and the corresponding maximum pulse width is preferably in the range of 2 to 5 msec. The user may confirm that the needle has hit the capsule by observing tissue tenting on the ultrasound image.

[0077] In the modified embodiment, the user may directly control the pulse width and the number of pulses per second. This manual needle movement mode is preferable to retain the safety features of the automatic mode described above.

[0078] Transurethral steam therapy may be used in conjunction with thermocouples inserted through the perineum outside the prostatic capsule to warn of temperatures high enough to damage nerves on the outer surface of the capsule. Saline solution can be delivered outside the prostatic capsule to cool and protect the nerves. Transurethral resection of the prostate, on the other hand, can be performed using multiple shots, each shot being sufficient with enough time between shots to prevent significant heat conduction through the capsule to the nerves. For example, complete cauterization of the prostatic tissue can be achieved with individual treatments lasting 10 seconds or less, with at least 30 seconds between shots, without the need for thermocouples or saline injection needles outside the capsule.

[0079] In some embodiments, the periphery and transitional regions can be treated separately. In other embodiments, the vapor delivery needle is long enough to reach the peri-cancer tissue after passing through the transitional region. Treatment can be performed on both the periphery and transitional region tissues during pulse deployment or withdrawal. In other embodiments, the central region tissue in contact with the urethra may be cauterized during the cancer treatment procedure. The central region can be treated individually or, in some cases, after passing through to the transitional region. Both the central and transitional region tissues can be treated during a single needle deployment or withdrawal.

[0080] In some embodiments, ultrasound imaging is used to guide the delivery of vapor into the prostate tissue. Furthermore, needle position measurement by a needle position sensor has sub-mm accuracy and can be used to measure the distance between treatment shots. To prevent excessive heating and potential conduction across the prostate capsule, it is important to space the vapor delivery by a sufficient distance between shots to avoid overlapping obstructions. In some embodiment procedures, shots are performed using a 1 cm separation between shots.

[0081] The treatment methods and means disclosed in Provisional Patent Application 720 can be used for transurethral procedures. For example, by adding a tissue capacitance sensing sensor to the needle tip, it is possible to distinguish between prostatic and non-prostatic tissue, preventing vapor delivery to non-prostatic tissue and thus preventing accidental passage through the prostatic capsule. Using tissue type sensing in conjunction with a needle / magnet position sensor, it is possible to confirm that the magnet is in prostatic tissue and, in particular, determine when the needle is adjacent to the prostatic capsule. Using preoperative images, it is possible to determine the optimal puncture site along the urethra and the number of vapor treatment shots that need to be delivered to each puncture site. Subsequently, a predetermined distance between treatment shots allows the transurethral resection of the prostate to be performed without external image guidance. The delivery device probe is advanced to a predetermined position in the urethra by identifying anatomical landmarks in the cystoscopy image, as in the BPH procedure. The needle is advanced a predetermined distance through the urethral wall, guided by the magnet / needle position sensor output and / or by markings on the needle visible through the cystoscope. Treatment can be performed while the needle is advancing, or the needle can be advanced into the prostatic capsule wall when indicated by a sensor, and treatment can be performed while the needle is retracting.

[0082] In another example, an electromagnetic sensor or transmitter placed at or near the needle tip can facilitate tracking the tip's position against pre-operative or real-time images of the prostate. In the case of ultrasound, a second sensor or transmitter can be placed adjacent to the ultrasound transducer so that the needle tip's position and orientation are detected relative to the transducer, facilitating autofocus and image enhancement. Needle tip tracking can enable robotic guidance or needle navigation. In advanced vapor therapy delivery systems, the needle can be robotically advanced to an image point selected by the operator, and a predetermined vapor dose can be delivered at that site. The tip of the delivery device needle can be steerable using a pull wire when used with other catheter systems. Image guidance with steering allows treatment to be performed using optimally separated positions in a three-dimensional pattern. More specialized steering means can be used, for example, by using a large external magnet attached to the needle tip to steer the tip.

[0083] While specific embodiments of the present invention have been described in detail above, it will be understood that this description is for illustrative purposes only and that the further description of the present invention is not exhaustive. Certain features of the present invention are shown in some drawings but not in others, for convenience only, and any feature can be combined with other features according to the present invention. Several variations and substitutions will be obvious to those skilled in the art. Such substitutions and variations are intended to be included in the claims. Certain features shown in dependent claims can be combined to fall within the scope of the present invention. The present invention also includes embodiments in which dependent claims refer to other independent claims and are written in place of them in a plurality of dependent claim formats. [Explanation of Symbols]

[0084] 100 Steam delivery devices 102 Handle section 103 Lumen 104 Cartridge section 110 RF coils 112 Solenoid coil 114 Long and slender shaft 116 Steam delivery needle 118 Needle-driven magnet 120 Steam Coil 122 Plastic conduits

Claims

1. A steam delivery device, The handle part, It has a cartridge part, The handle portion comprises a lumen and an RF coil disposed within the lumen and connectable to an RF energy source. The cartridge portion is configured to be inserted into the lumen of the handle portion. The cartridge portion includes an elongated shaft configured to be inserted into the patient's urethra, a vapor delivery needle positioned within the elongated shaft, and a vapor coil fluidly connected to the vapor delivery needle and a fluid source. A steam delivery device that aligns and positions the steam coil within the RF coil by inserting the cartridge portion into the handle portion.

2. The steam delivery device according to claim 1, wherein when a fluid is delivered from the fluid source to the steam coil, steam is generated in the steam coil by inductively supplying RF energy to the RF coil.

3. The steam delivery device according to claim 2, wherein the steam delivery needle is configured to deliver steam to the patient's tissue.

4. The cartridge portion further includes a first solenoid coil and a second solenoid coil, and a needle drive magnet attached to the proximal portion of the steam delivery needle. The steam delivery device according to claim 1, wherein the needle drive magnet is slidably disposed within the first solenoid coil when the steam delivery needle is in the retracted position, and slidably disposed within the second solenoid coil when the steam delivery needle is in the extended position.

5. Furthermore, the steam delivery device according to claim 4, wherein the handle portion is provided with a needle deployment switch.

6. The steam delivery device according to claim 5, wherein the steam delivery needle is fully extended from the retracted position to the extended position by pressing the needle deployment switch.

7. The steam delivery device according to claim 5, wherein the steam delivery needle is deployed incrementally by each press of the needle deployment switch.

8. The steam delivery device according to claim 7, wherein the steam delivery needle is extended in increments of 1 mm.

9. The steam delivery device according to claim 7, further comprising a position sensor disposed on the steam delivery needle, the position sensor configured to determine the deployment position of the steam delivery needle.

10. The steam delivery device according to claim 9, wherein if the position sensor indicates that the steam delivery needle has not moved by a desired incremental distance, the steam delivery needle is prevented from moving forward.

11. The steam delivery device according to claim 1, wherein the steam coil includes Inconel® tubing.

12. The steam delivery device according to claim 1, further comprising a latch configured to prevent lateral movement of the cartridge portion when the cartridge portion is inserted into the lumen of the handle portion.

13. The steam delivery device according to claim 1, wherein the cartridge portion can be rotated when the cartridge portion is inserted into the lumen of the handle portion.

14. The steam delivery device according to claim 5, wherein the delivery needle cannot extend more than 24 mm from the elongated shaft when it is in the extended position.

15. The vapor delivery device according to claim 1, wherein the vapor delivery needle includes an inflatable balloon, the inflatable balloon being configured to prevent vapor from leaking out of a puncture site in the patient's tissue.

16. The steam delivery device according to claim 15, wherein the inflatable balloon is positioned within the recess of the steam delivery needle.

17. The steam delivery device according to claim 15, wherein the inflatable balloon is inflated by steam during steam delivery.

18. Furthermore, the steam delivery device according to claim 1, further comprising an electronic controller configured to control the delivery of RF energy to the RF coil.

19. Furthermore, the steam delivery device according to claim 18, further comprising a temperature sensor positioned at the outlet of the steam coil, wherein the temperature sensor is electrically coupled to the electronic controller and configured to measure the temperature of the fluid or steam at the outlet of the steam coil.

20. The steam delivery device according to claim 19, wherein the electronic controller is configured to initiate the cessation of RF energy delivery when the measured temperature of the steam or fluid at the outlet is outside a preferred temperature range.

21. A method of injecting vapor into the patient's prostate, Insert the cartridge portion of the steam delivery device into the lumen of the handle portion of the steam delivery device, and align and position the steam coil of the cartridge portion within the RF coil of the handle portion. The slender shaft of the aforementioned cartridge portion is inserted into the patient's urethra, The distal end of the aforementioned elongated shaft is advanced to the prostatic portion of the patient's urethra, Extending the vapor delivery needle from the elongated shaft into the patient's prostate, Sending a fluid flow into the steam coil, The RF energy is applied to the RF coil to inductively generate steam in the steam coil, A method comprising delivering vapor to the prostate gland through the vapor delivery needle.

22. The method according to claim 21, wherein the extension includes generating a magnetic field using at least one solenoid coil to extend the vapor delivery needle into the prostate.

23. Furthermore, the method according to claim 21, further comprising rotating the cartridge portion within the handle portion.

Images