Endoscope clog clearing system and method

Abstract

To provide a system and method for in-situ unclogging of a working channel in a medical device during a procedure.SOLUTION: An example clog clearing system includes a flow sensor to sense a flow rate through a working channel and a control module to detect a channel condition indicative of a presence or absence of a clog based on the flow rate. If there is channel clogging, the control module can control one or more of the irrigation source or the aspiration source to provide irrigation fluid or aspiration pressure, respectively, to unclog the blocked channel. The control module can adjust one or more of the irrigation flow rate or the aspiration flow rate through the working channel to maintain a desired pressure of the anatomical environment at the anatomical site or to maintain a desired flow condition in the working channel during the procedure.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] Priority claims This application claims the benefit of priority to U.S. Patent Application No. 16 / 803,612, filed February 27, 2020, the contents of which are incorporated herein by reference in their entirety.

[0002] This document relates generally to endoscopy systems, and more particularly to a declogging system for declogging an endoscope during an endoscopic procedure while maintaining a controlled in situ pressure in the anatomical environment at the anatomical site. [Background technology]

[0003] Endoscopes are typically used to provide access to internal locations in patients, providing visual access to physicians. Some endoscopes are used in minimally invasive procedures to remove unwanted tissue or foreign material from a patient's body. For example, an endoscopic tissue removal device is an instrument used by clinicians to remotely access necrotic, cancerous, damaged, infected, or otherwise unwanted soft tissue, bone, or other anatomical structures at an anatomical site, remove the unwanted material from adjacent anatomical structures, and transport the unwanted material from the anatomical site. Nephroscopes are used by clinicians to examine the renal system and perform various procedures under direct visual control. For example, percutaneous nephrolithotomy (PCNL) is a procedure involving placing a nephroscope into the renal pelvis through the patient's flank. For example, stones or masses from various areas of the body, including the urinary system, gallbladder, nasal cavity, gastrointestinal tract, stomach, or tonsils, can be visualized and extracted. Larger stones can be ablated into smaller fragments using shock waves, ultrasonic energy (via specialized devices such as ultrasonic lithotriptors), or vibrational forces such as lasers.

[0004] Some endoscopes have aspiration channels (also known as suction channels) that transport removed tissue, stones (e.g., stones or stone fragments in various stone-forming areas), and clots, among other unwanted materials. During a procedure, a flow of irrigant (e.g., saline) can be introduced into the anatomical site through an irrigation channel in the endoscope. The irrigation fluid can facilitate the removal of tissue debris, stone fragments, and other unwanted material through the suction channel. The irrigation fluid can also help maintain clear visibility of the anatomical environment for the clinician performing the procedure. Additionally, the irrigation flow can have a cooling effect on the endoscopic tissue removal device and help dissipate heat generated during the ablation of stones (e.g., kidney stones). Summary of the Invention [Problem to be solved by the invention]

[0005] Unwanted materials generated during endoscopic procedures can accumulate and clog the working channels of an endoscope (e.g., suction or irrigation channels). Monitoring channel blockages and clearing blocked channels in a timely and efficient manner can shorten procedure times and improve the efficiency, safety, and success rate of endoscopic procedures. [Means for solving the problem]

[0006] This document describes systems and methods for in situ clearing of clogs in a working channel of an endoscope during an endoscopic procedure while maintaining controlled pressure at the anatomical site during the endoscopic procedure. According to one aspect of this document, a clog clearing system includes a flow sensor configured to sense a flow rate through a working channel of the endoscope and a control module configured to use the sensed flow rate to detect a channel condition indicative of the presence or absence of a clog in the working channel. In response to the presence of a clog in the working channel, the control module can control one or more of an irrigation source or aspiration source, which provide irrigation fluid or aspiration pressure, respectively, to the working channel, to clear the clog in the working channel. The control module can automatically adjust one or more of the irrigation flow rate or aspiration flow rate through the working channel during the endoscopic procedure to maintain the pressure of the anatomical environment at the anatomical site substantially at a desired pressure level (e.g., a predetermined or user-specified pressure level) or to achieve a desired flow condition corresponding to the desired pressure. The irrigation fluid or aspiration pressure can be applied as long as a channel clog is present.

[0007] Example 1 is a system for clearing a clog in at least one working channel of a medical device during a procedure on a patient, the system including: a flow sensor configured to sense a flow rate through at least one working channel of the medical device; and a control module configured to use the sensed flow rate to detect a channel condition indicative of the presence or absence of a clog in the at least one working channel, and to control one or more irrigation or suction sources that provide irrigation fluid or suction pressure, respectively, in response to the detected channel condition indicating a clog in the at least one working channel, to clear the clog in the at least one working channel.

[0008] In Example 2, the subject matter of Example 1 optionally includes a control module that can be configured to control one or more of the irrigation sources or suction sources that provide irrigation fluid or suction pressure, respectively, to clear the clog in the at least one working channel so long as the detected channel condition indicates a clog in the at least one working channel.

[0009] In Example 3, the subject matter of any one of Examples 1-2 optionally includes a control module that can be configured to detect a clog in the at least one working channel in response to a decrease in the sensed flow rate below a first threshold, and to detect an absence of a clog in the at least one working channel in response to an increase in the sensed flow rate above a second threshold.

[0010] In Example 4, the subject matter of any one or more of Examples 1-3 optionally includes a control module that can be configured to unclog at least one working channel, including alternating between applying irrigation fluid and applying suction pressure to the at least one working channel.

[0011] In Example 5, the subject matter of any one or more of Examples 1-4 optionally includes a control module that can be configured to control one or more of the irrigation source or suction source to unclog at least one working channel by adjusting the flow rate of the irrigation fluid or the flow rate of the suction pressure, respectively.

[0012] In Example 6, the subject matter of any one or more of Examples 3 to 5 optionally includes a user input configured to receive from a user a desired pressure to be applied to an anatomical environment at an anatomical site within a patient, and a pressure sensor configured to sense the pressure of the anatomical environment at the anatomical site, and the control module is configured to adjust one or more of an irrigation flow rate or an aspiration flow rate through at least one working channel to maintain the sensed pressure substantially at the level of the desired pressure.

[0013] In Example 7, the subject matter of Example 6 optionally includes a user input configured to receive desired flow conditions in at least one working channel corresponding to a desired pressure to be applied to the anatomical environment, and a control module configured to control one or more of an irrigation flow rate or an aspiration flow rate through the at least one working channel of the medical device to maintain the desired flow conditions.

[0014] In Example 8, the subject matter of any one or more of Examples 6-7 optionally includes at least one working channel that may include an aspiration channel and an irrigation channel, and a control module that may be configured to fluidly couple an irrigation source to one of the irrigation channel or the aspiration channel to provide irrigation fluid at an adjustable irrigation flow rate to one of the irrigation channel or the aspiration channel, and to fluidly couple an suction source to the other of the irrigation channel or the aspiration channel to provide suction pressure at an adjustable suction flow rate to the other of the irrigation channel or the aspiration channel.

[0015] In Example 9, the subject matter of Example 8 optionally includes a control module that can be configured to: in response to the presence of a clog in the aspiration channel, control the irrigation source to provide irrigation fluid to the aspiration channel; in response to an increase in sensed pressure of the anatomical environment at the anatomical site, control the suction source to apply suction pressure to the irrigation channel to maintain the sensed pressure substantially at a desired pressure level; and in response to the absence of a clog in the aspiration channel, control the suction source to apply suction pressure to the aspiration channel and control the irrigation source to provide irrigation fluid to the irrigation channel.

[0016] In Example 10, the subject matter of Example 8 optionally includes a control module that can be configured to: control the suction source to apply suction pressure to the irrigation channel in response to the presence of a clog in the irrigation channel; control the irrigation source to provide irrigation fluid to the suction channel to maintain the sensed pressure substantially at a desired pressure level in response to a decrease in the sensed pressure of the anatomical environment at the anatomical site; and control the suction source to apply suction pressure to the suction channel and control the irrigation source to provide irrigation fluid to the irrigation channel in response to no clog in the irrigation channel.

[0017] In Example 11, the subject matter of Example 9 optionally includes a desired pressure that can be a substantially net zero pressure, and the control module can be configured to control the suction source, in response to an increase in the sensed pressure, to apply suction pressure to the irrigation channel at a level that substantially neutralizes the increase in the sensed pressure.

[0018] In Example 12, the subject matter of Example 10 optionally includes a desired pressure, which can be a substantially net zero pressure, and the control module can be configured to control the irrigation source, in response to a decrease in the sensed pressure, to provide irrigation fluid to the aspiration channel at an irrigation flow rate that substantially neutralizes the decrease in the sensed pressure.

[0019] In Example 13, the subject matter of Example 9 optionally includes a desired pressure, which may be a positive pressure, and the control module may be configured to control the suction source to apply suction pressure to the irrigation channel at a level that maintains the sensed pressure substantially at the level of the desired positive pressure in response to an increase in the sensed pressure.

[0020] In Example 14, the subject matter of Example 10 optionally includes a desired pressure, which may be a positive pressure, and the control module may be configured to control the irrigation source, in response to a decrease in the sensed pressure, to provide irrigation fluid to the aspiration channel at an irrigation flow rate such that the sensed pressure is maintained substantially at the level of the desired positive pressure.

[0021] In Example 15, the subject matter of Example 9 optionally includes a desired pressure, which may be a negative pressure, and the control module may be configured to control the suction source to apply suction pressure to the irrigation channel at a level that maintains the sensed pressure substantially at the level of the desired negative pressure in response to an increase in the sensed pressure.

[0022] In Example 16, the subject matter of Example 10 optionally includes a desired pressure, which may be a negative pressure, and the control module may be configured to control the irrigation source in response to a decrease in the sensed pressure to provide irrigation fluid to the aspiration channel at an irrigation flow rate such that the sensed pressure is maintained substantially at the level of the desired negative pressure.

[0023] Example 17 is an endoscopic surgery system including an endoscope including an imaging module, a surgical module, and at least one working channel configured to direct irrigation fluid or suction pressure; a user input configured to receive from a user a desired pressure to be applied to an anatomical environment at an anatomical location within a patient; a flow sensor configured to sense a flow rate through the at least one working channel of the endoscope; a pressure sensor configured to sense a pressure of the anatomical environment at the anatomical location; and a control module configured to: use the sensed flow rate to detect a channel condition indicative of the presence or absence of a blockage in the at least one working channel; and in response to the detected channel condition indicating the presence of a blockage in the at least one working channel, and for as long as the detected channel condition indicates the presence of a blockage in the at least one working channel, control one or more irrigation or suction sources providing irrigation fluid or suction pressure, respectively, to clear the blockage in the at least one working channel; and adjust one or more of the irrigation flow rate or suction flow rate through the at least one working channel to maintain the sensed pressure substantially at a level of the desired pressure.

[0024] Example 18 is a method of clearing a clog in at least one working channel of a medical device during a procedure on a patient, the method including: sensing a flow rate through at least one working channel of the medical device via a flow sensor; using the sensed flow rate to detect a channel condition indicative of the presence or absence of a clog in the at least one working channel via a control module; and, in response to the detected channel condition indicating the presence of a clog in the at least one working channel, controlling one or more of an irrigation source or a suction source providing irrigation fluid or a suction pressure, respectively, to clear the clog in the at least one working channel.

[0025] In Example 19, the subject matter of Example 18 optionally includes providing irrigation fluid or suction pressure to clear the clog in the at least one working channel, which may continue as long as the detected channel condition indicates there is a clog in the at least one working channel.

[0026] In Example 20, the subject matter of any one or more of Examples 18-19 optionally includes a step of detecting a channel condition, which may include detecting a clog in at least one working channel in response to a decrease in the sensed flow rate below a first threshold, and detecting no clog in at least one working channel in response to an increase in the sensed flow rate above a second threshold.

[0027] In Example 21, the subject matter of any one or more of Examples 18-20 optionally includes a step of clearing the blockage of at least one working channel, which may include alternating application of irrigation fluid and application of suction pressure to the at least one working channel.

[0028] In Example 22, the subject matter of any one or more of Examples 18 to 21 optionally includes receiving, via user input, a desired pressure to be applied to an anatomical environment at an anatomical site within a patient; sensing the pressure of the anatomical environment at the anatomical site via a pressure sensor; and adjusting one or more of an irrigation flow rate or an aspiration flow rate through at least one working channel such that the sensed pressure is maintained substantially at the level of the desired pressure.

[0029] In Example 23, the subject matter of Example 22 optionally includes receiving desired flow conditions in at least one working channel corresponding to a desired pressure to be applied to the anatomical environment, and adjusting one or more of an irrigation flow rate or an aspiration flow rate through the at least one working channel to maintain the desired flow conditions.

[0030] In Example 24, the subject matter of Example 22 optionally includes at least one working channel, which may include an aspiration channel and an irrigation channel. The method includes the steps of: in response to a clog in the aspiration channel, controlling an irrigation source to provide irrigation fluid to the aspiration channel; in response to an increase in sensed pressure of an anatomical environment at the anatomical site, controlling the suction source to apply aspiration pressure to the irrigation channel to maintain the sensed pressure substantially at a desired pressure level; and in response to no clog in the aspiration channel, controlling the suction source to apply aspiration pressure to the aspiration channel and controlling the irrigation source to provide irrigation fluid to the irrigation channel.

[0031] In Example 25, the subject matter of Example 22 optionally includes at least one working channel, which may include an aspiration channel and an irrigation channel. The method includes controlling a suction source to apply a suction pressure to the irrigation channel in response to a clog in the irrigation channel, controlling the irrigation source to provide irrigation fluid to the aspiration channel in response to a decrease in sensed pressure of an anatomical environment at the anatomical site to maintain the sensed pressure substantially at a desired pressure level, and controlling the suction source to apply a suction pressure to the aspiration channel and to provide irrigation fluid to the irrigation channel in response to an absence of a clog in the irrigation channel.

[0032] This Summary is an overview of some of the teachings of the present application and is not intended to be an exclusive or exhaustive treatment of the present subject matter. Further details about the present subject matter are found in the detailed description and appended claims. Other aspects of the present disclosure will become apparent to those skilled in the art upon reading and understanding the following detailed description and viewing the drawings that form a part thereof. Each of the drawings is not to be construed in a limiting sense. The scope of the present disclosure is defined by the appended claims and their legal equivalents.

[0033] Various embodiments are illustrated by way of example in the figures of the accompanying drawings, such embodiments are illustrative and are not intended to be exhaustive or exclusive embodiments of the present subject matter. [Brief explanation of the drawings]

[0034] [Figure 1] FIG. 1 is a block diagram illustrating an example of a system for in situ clearing of blockages in a working channel of an endoscope and maintaining the pressure of the anatomical environment at a substantially desired level at an anatomical site during a minimally invasive procedure. [Figure 2A] FIG. 2 shows a powered tissue removal device 200 that can be used in a system such as that described with reference to FIG. [Figure 2B] FIG. 2 shows a powered tissue removal device 200 that can be used in a system such as that described with reference to FIG. [Figure 3A] 1A-1C illustrate an endoscopic system for clearing blocked channels and maintaining the pressure of an anatomical environment at a substantially desired level during an endoscopic procedure. [Figure 3B] 1A-1C illustrate an endoscopic system for clearing blocked channels and maintaining the pressure of an anatomical environment at a substantially desired level during an endoscopic procedure. [Figure 4A] 1 illustrates an exemplary technique for clearing a blocked working channel of an endoscope according to one embodiment discussed herein. [Figure 4B] 10A-10C illustrate the change in flow in the working channel in the presence of a clog and during the clog removal process. [Figure 4C] 10A-10C illustrate the change in flow in the working channel in the presence of a clog and during the clog removal process. [Figure 5] FIG. 10 illustrates an exemplary feedback control pressure regulation system that regulates environmental pressure when there is no channel blockage. [Figure 6A] FIG. 10 illustrates an exemplary feedback control pressure regulation system that regulates environmental pressure when there is a blockage in the aspiration channel. [Figure 6B] FIG. 10 is a timing diagram for activating irrigation / aspiration in an aspiration channel during unclog of a blocked aspiration channel. [Figure 6C] FIG. 10 is a timing diagram for activating irrigation / aspiration in an irrigation channel to maintain a desired pressure at an anatomical site during unclog of an occluded aspiration channel. [Figure 7A] FIG. 10 illustrates an exemplary feedback control pressure regulation system that regulates environmental pressure when there is a blockage in the irrigation channel. [Figure 7B] FIG. 10 is a timing diagram for activating irrigation / aspiration in an irrigation channel during unclog of a blocked irrigation channel. [Figure 7C] FIG. 10 is a timing diagram for activating irrigation / aspiration in an aspiration channel to maintain a desired pressure at an anatomical site while unclogging an occluded irrigation channel. [Figure 8]1 is a flow chart illustrating a method for in situ clearing of a working channel in a medical device during a minimally invasive procedure. [Figure 9] 1 is a flow chart illustrating a method for in situ unclogging a working channel of a medical device and maintaining the pressure of the anatomical environment at an anatomical site at a substantially desired level. DETAILED DESCRIPTION OF THE INVENTION

[0035] An endoscope includes a tubular portion that can be inserted into an organ or body cavity to aid in diagnosis or treatment. One or more working channels (e.g., suction and / or irrigation channels) can be located inside the tubular portion and extend along its length. To reduce the risk of unintended tissue damage, the insertable tubular portion can have a small diameter. Accordingly, the working channel also has a small lumen diameter. Because tissue debris and foreign bodies (e.g., stones and their fragments) typically have dimensions that are one to two lumen diameters in length, some tissue or stone particles can accumulate and clog the working channel.

[0036] As used herein, "clog" refers to tissue debris, stones (e.g., kidney stones or stone fragments), and other materials that accumulate and partially or completely block the lumen of a channel, and "clogging" refers to the state of partial or complete blockage of the channel lumen. Clogging can occur in any of the working channels of an endoscope. Clogging in the aspiration channel can significantly reduce the efficiency of removing tissue debris and stone fragments through the aspiration channel. Slow or inefficient removal of unwanted material from an anatomical site can inhibit or hinder further treatment (e.g., debridement or stone removal), contaminate the anatomical site, and place the patient at increased risk. On the other hand, clogging in the irrigation channel can reduce the volume and / or flow rate of irrigation fluid flowing through the irrigation channel and delivered to the anatomical environment. Slow irrigation flow can reduce the efficiency of flushing unwanted material from an anatomical site and increase the likelihood of aspiration channel clogging. A reduction in irrigation volume and flow rate can also affect the cooling effect on the surgical components and the anatomical environment, increasing the likelihood of heat buildup at the anatomical site. Also, a clogged working channel can block the endoscope lens, impairing visibility of the object under inspection and reducing the quality of images taken of the anatomical environment, thereby increasing the difficulty and duration of the procedure.

[0037] Suction and irrigation can result in negative and positive pressure changes, respectively, in the anatomical environment at the anatomical site. If not properly controlled, negative and positive pressure changes can be harmful to internal organs exposed at the anatomical site. For example, while the body can accommodate some positive pressure changes, many organs are relatively defenseless against negative pressure changes. A blockage in a working channel (e.g., aspiration channel or irrigation channel) can disrupt the pressure balance between the positive pressure associated with fluid flow and the negative pressure associated with suction, thereby exposing the internal organs to harmful excessive positive or negative pressure at the anatomical site.

[0038] Various approaches have been attempted to prevent or resolve channel blockages in endoscopes. For example, breaking down unwanted material (e.g., tissue debris or stone fragments) into smaller pieces can reduce the likelihood of clogging. However, this consumes more energy, potentially increasing procedure times and potentially increasing patient risk due to added procedural complexity and time. Particulate matter or stone dust can reduce visibility of the surgical field. Traditionally, clearing a blockage is typically performed externally, requiring the clinician to retract the endoscope from the body, flush the blocked endoscope to clear the blockage, and then insert the endoscope back into the anatomical site. This approach increases procedure time, adds inconvenience to the clinician, and potentially increases surgical risk for the patient. Clearing a working channel in situ while the endoscope is inserted and held in place typically requires high-pressure irrigation, which can exert excessive positive pressure on internal organs.

[0039] The inventors have recognized an unmet need for an endoscopic system that allows for automatic monitoring and stabilization of a desired internal pressure while allowing user-input flow rates (e.g., aspiration flow rate and / or irrigation flow rate) to protect internal organs from pressure-related harm.

[0040] For at least the above reasons, the inventors have recognized an unmet need for a system and method that can detect a clog condition within a working channel and unclog an occluded channel while simultaneously maintaining controlled pressure changes on the anatomical environment during the procedure, increasing the efficiency, safety, and success of endoscopic procedures.

[0041] Disclosed herein are systems and methods for in situ clearing of clogs in working channels in endoscopes, such as irrigation or aspiration channels, during an endoscopic procedure. According to one aspect herein, a clearing system can use flow information sensed by a flow sensor to detect channel conditions indicative of the presence or absence of a clog in the working channel and clear the occluded channel by, for example, alternating application of irrigation fluid or aspiration pressure. The clearing system can adjust one or more of the irrigation or aspiration flow rates through one or more channels inside the endoscope to keep the pressure of the anatomical environment under control, for example, to maintain substantially net zero pressure or a desired positive or negative pressure as specified by a user during the procedure.

[0042] The various embodiments of the clog removal system and method discussed herein provide an improved solution for in-situ endoscope clearing during endoscopic procedures. According to various aspects as described herein, the system and method provide users with endoscopic examinations without repeatedly inserting and removing endoscopic attachments and accessories for external irrigation and clearing. Compared to clearing via high-pressure irrigation, which can expose internal organs to high positive pressure, controlled irrigation and suction, applied, for example, alternately to the same clogged channel, as discussed herein, provide environmental stabilization for the internal organs. Various embodiments of the clog removal system can clear channels by effectively separating different-sized clog particles that accumulate and block the channel, while avoiding or minimizing dangerous positive or negative pressure changes to the internal organs. As a result, less invasive procedures can safely and more efficiently remove unwanted material from anatomical sites, shortening procedure times and improving patient safety and recovery time.

[0043] FIG. 1 is a block diagram illustrating an example of a system 100 for maintaining a pressure in an anatomical environment 101 at a substantially desired level at an anatomical site while unclogging a working channel of an endoscope in situ during a minimally invasive procedure on a patient. The system 100 can include a medical device 110 and optional components. The optional components can include any of a suction source 120, an irrigation source 130, a user interface 140, a sensor circuit 150, or a control module 160. In various examples, the system 100 can have a modular design that enhances flexibility and facilitates configuration and replacement of individual components. In one example, the user interface 140, the sensor circuit 150, and the control module 160 can be included in an aspiration / irrigation control unit. The aspiration / irrigation control unit can be fluidly coupled to one or more of the device 110, the aspiration source 120, or the irrigation source 130. The aspiration / irrigation control unit can be compatible with different types of medical devices and different types of irrigation and aspiration sources. An exemplary aspiration / irrigation control unit is discussed below with reference to Figures 3A-3B. The aspiration / irrigation control unit can selectively activate or deactivate irrigation and / or suction through the working channel 111 and adjust one or more of the irrigation flow rate, irrigation fluid pressure, aspiration flow rate, or aspiration pressure. By controlling the aspiration and / or irrigation in accordance with various embodiments discussed herein, blocked channels can be unclogged and the pressure in the anatomical environment 101 can be maintained at a desired level during a procedure.

[0044] The medical device 110 can be used in diagnostic, analytical, or therapeutic applications, including, for example, minimally invasive surgery such as endoscopic procedures. By way of example and not limitation, the medical device 110 can be used in various ENT procedures, including, but not limited to, joint surgery, plastic surgery, sinus surgery, and tonsillectomy, or combinations thereof. The medical device 110 can be controlled by a user to perform a procedure on an organ within the anatomical environment 101 or to remove organ tissue. Control of the medical device 110 can include a handpiece or indirect control, for example, via a robotic surgical console or user interface.

[0045] An example of a medical instrument 110 can include a tissue removal device including a blade assembly configured to rotate and / or reciprocate to remove unwanted tissue from a target anatomical structure. The blade assembly can be driven by a motor powered by an internal or alternatively external energy source within the handpiece. The energy source can also perform other functions, such as providing powered irrigation and suction to the medical instrument 110, as discussed below. For example, various blade assemblies can be used, including shavers, debriders, blades, or burrs, among others. Depending on the blade assembly used, the tissue removal device can function to scrape, cut, scrape, or otherwise remove necrotic, cancerous, damaged, infected, or otherwise unwanted soft tissue, bone, or other anatomical features or objects at or from the target anatomical structure. Exemplary tissue removal devices are discussed below with reference to FIGS. 2A-2B.

[0046] Another example of the medical device 110 can include an endoscope. Examples of endoscopes can include, among others, a cystoscope for examining the bladder, a nephroscope for examining the kidneys, a bronchoscope for examining the bronchi, an arthroscope for examining the joints, a colonoscope for examining the colon, a cholangioscope for examining the biliary region (e.g., the bile duct), a duodenoscope for examining the gastrointestinal region, or a laparoscope for examining the abdomen or pelvis. The endoscope can include a light source that illuminates the anatomical environment at the anatomical site and an imaging module that generates images or videos of the anatomical environment during the endoscopic procedure. Some endoscopes, such as endoscopic tissue removal devices, can include a tissue resectioning element configured to scrape, cut, scrape, or otherwise remove portions of unwanted tissue from the target anatomical structure. The resected tissue residue can then be extracted from the anatomical site. Some endoscopes can include a resectioning element configured to destroy or remove foreign material, such as crystalline mineral structures, from the anatomical environment. For example, a nephroscope can be inserted at least partially into the kidney. Among other energy modalities, ultrasound energy, electromagnetic shock waves, or lasers can be delivered to the kidney stone to break it into fragments or "stone dust," which can then be extracted from the anatomical site. An exemplary endoscope is discussed below with reference to Figures 3A-3B.

[0047] The medical device 110 may include one or more working channels 111 that transport cut, cut, resected, scraped, or removed tissue, bone, or other anatomical features or objects, stones and debris, bodily fluids at the anatomical site, and irrigation fluids, collectively referred to herein as "unwanted material." The working channels 111 may be selectively coupled to one or more of a suction source 120 (e.g., via a suction port on the medical device 110) or an irrigation source 130 (e.g., via an irrigation port on the medical device 110).

[0048] The suction source 120 can function to pull, suck, draw, aspirate, or otherwise move or remove unwanted material from the anatomical site. The unwanted material can be moved to the proximal end of the medical device 110, inside a handpiece, or into a receptacle remote from the medical device 110. In one example, the handpiece can include a container or reservoir for at least temporarily collecting the unwanted material before the handpiece is cleaned and the collected material is removed. The suction source 120 can perform the aforementioned functions by generating and applying a vacuum, suction, or negative pressure to the working channel 111 of the medical device 110. In one example, the suction source 120 can be separate from the medical device 110 and connected to the medical device 110 via one or more tubes, wires, or hoses. In another example, the suction source 120 can be included in or attached to the medical device 110. For example, the suction source 120 can be included in the handpiece of a tissue removal device or endoscope. The suction source may be powered by the energy source that also powers the medical device, or may be powered by its own energy source.

[0049] The irrigation source 130 can function to provide irrigation fluid to the working channel 111 to aid in the removal of unwanted material (e.g., tissue debris or stone fragments) passing through the working channel 111. The irrigation fluid can also help cool the tissue removal device or cutting element during rotational or reciprocating debridement or ablation and dissipate heat generated during stone fragmentation. The irrigation fluid can be gravity-fed or pressurized. In one example, the irrigation source can include a bag that produces irrigation fluid that is elevated and gravity-fed relative to the medical device 110 and the anatomical site. In another example, a pump can generate the pressurized irrigation flow. The irrigation fluid can be provided from the irrigation source 130 or a location where the irrigation fluid is contained to and through an external fluid supply tube and drawn into the working channel 111. Under suction pressure provided by the suction source 120, the irrigation fluid, along with the unwanted material, can flow proximally down the working channel 111 and be removed from the anatomical site.

[0050] In one example, a single working channel 111 can be used for both irrigation and suction. The control module 160 can controllably activate irrigation and suction through the working channel 111 at separate times. In another example, the medical device 110 can include two or more separate working channels, such as a suction channel 112 and an irrigation channel 114, as shown in FIG. 1 . The suction channel 112 can be controllably connected to a suction source 120 to direct unwanted material being suctioned through the suction channel 112. The irrigation channel 114 can be controllably connected to an irrigation source 130 to direct irrigation fluid therethrough. In one example, the suction channel 112 can be controllably connected to the irrigation source 130. In one example, the irrigation channel 114 can be controllably connected to the suction source 120. Irrigation and aspiration according to the various examples discussed herein can be used to, among other things, assist in removing unwanted material, clearing blockages in one or more working channels, transferring heat generated during treatment at a tissue site, maintaining pressure in the anatomical environment at a desired level, and maintaining desired flow conditions in the working channel corresponding to the desired pressure.

[0051] In one example, the suction channel 112 and the irrigation channel 114 can be arranged in a parallel orientation along the length of the tubular portion of the handpiece of the medical instrument 110. In one example, the suction channel 112 and the irrigation channel 114 can be arranged coaxially on a common axis, such as in a nested configuration. In one example, the medical instrument 110 includes an outer member and an inner member disposed within the outer member. The suction channel 112 can be disposed inside the inner member. The irrigation channel 114 can be disposed outside the outer member. In some configurations, in addition to or instead of supplying irrigation fluid through the irrigation channel 114, the irrigation fluid can be supplied through a gap defined between the inner and outer members of the medical instrument 110, hereinafter referred to as an "irrigation gap." Either the irrigation channel 114 or one of the irrigation gaps can be selectively activated to supply irrigation fluid to the medical instrument 110. In some examples, both the irrigation channel 114 and the irrigation gap can be activated to supply irrigation fluid simultaneously. This advantageously allows a clinician to adjust how much irrigation fluid is used during a procedure. For example, when more tissue debris or stone fragments are being generated, or if a blockage is detected within the channel, both the irrigation channel 114 and the irrigation gap can be activated to provide a larger amount of fluid to the medical device 110.

[0052] The control module 160 can be configured to control the operation of the medical device 110, including one or more of tissue or stone removal, illumination, imaging, irrigation, and suction, among other functionality during an endoscopic procedure. In one example, the control module 160 can be implemented as part of a microprocessor circuit, such as a dedicated processor, an application specific integrated circuit (ASIC), a microprocessor, or other type of processor for processing information and generating control signals that activate, deactivate, or alter the operation of components of the system 100. Alternatively, the microprocessor circuit can be a processor capable of receiving and executing instructions to perform the functions, methods, or techniques described herein.

[0053] The control module 160 can be at least partially implemented in a unit separate from the medical device 110, such as that shown in FIGS. 3A-3B. Alternatively, portions of the control module 160 can be integrated into or otherwise attached to the medical device 110. In some examples, the control module 160 can include a circuit set that, alone or in combination, performs the functions, methods, or techniques described herein. In one example, the hardware of the circuit set can include invariably connected components (e.g., hardwired) designed to perform specific operations. In one example, the hardware of the circuit set can include variably connected physical components (e.g., execution units, transistors, simple circuits, etc.) that include computer-readable media (e.g., magnetically or electrically movable arrangements of invariable mass particles, etc.) physically modified to encode instructions for specific operations. When connecting the physical components, the underlying electrical properties of the hardware components are changed, for example, from insulator to conductor, or vice versa. The instructions enable embedded hardware (e.g., an execution unit or loading mechanism) to create elements of the circuit set in the hardware through the variable connections to perform some of the specific operations when activated. Thus, the computer-readable medium is communicatively coupled to other components of the circuit set members when the apparatus is operating. In one example, any of the physical components may be used in more than one member of more than one circuit set. For example, during operation, an execution unit may be used in a first circuit of a first circuit set at one time and reused by a second circuit in the first circuit set or by a third circuit in a second circuit set at a different time.

[0054] As shown in FIG. 1 , the control module 160 is coupled to the user interface 140 and can receive user commands from the user interface 140 to activate, deactivate, or adjust one or more functionalities of the medical device 110. The user interface 140 can be at least partially integrated into or otherwise attached to the medical device 110. Alternatively, the user interface 140 can be separate from the medical device 110, such as in the exemplary system shown in FIGS. 3A-3B . The user interface 140 can be mobile and attached to the medical device 110 and fluid systems (e.g., pumps, irrigation). In one example, the user interface 140 can include one or more user controls that allow a user (e.g., a clinician) to turn suction on or off or adjust suction flow rate or pressure. The user controls can be located on a mobile user interface that is separate from the medical device 110. Alternatively, the user controls can be located on the medical device 110, such as the handpiece of an endoscope or tissue removal device, such as the device shown in FIG. 2A . In response to user commands, control module 160 can activate or deactivate aspiration flow from suction source 120 or increase or decrease the aspiration pressure applied to working channel 111 to achieve a desired aspiration flow rate. Similarly, user interface 140 can include one or more user controls that allow a user to turn irrigation on or off or adjust the irrigation flow rate or irrigation fluid pressure (e.g., via a pump). In response to user commands, control module 160 can activate or deactivate irrigation flow from irrigation source 130 or increase or decrease the irrigation flow rate through working channel 111.

[0055] In some examples, the user controls on the user interface 140 may include a depressible flush control button that, when pressed repeatedly, cycles through one or more irrigation and / or suction levels before turning off irrigation and suction. In some examples, a single control may control irrigation and suction together. Other suitable control elements may also be used, such as a positionable slide, positionable lever, or positionable dial that may specify a irrigation and / or suction level. In some examples, the user interface 140 may allow a user to select from one of multiple specified, separate irrigation or suction levels, or alternatively, to specify a irrigation or suction level in a continuous (e.g., non-separate) manner.

[0056] In addition to, or instead of, independent control of suction and irrigation, the control module 160 can automatically control either irrigation or suction based on the status of the other. In one example, the control module 160 can automatically turn on suction when the medical device is powered on or when the irrigation source 130 supplies irrigation fluid to the medical device 110, and automatically turn off suction when the medical device is not powered on or when the irrigation source 130 stops supplying irrigation fluid to the medical device 110. In one example, the control module 160 can automatically adjust the irrigation flow rate or fluid volume in response to the suction flow rate (e.g., by activating or deactivating flow in the irrigation gap defined between the inner and outer members). For example, when suction increases (e.g., due to a large amount of unwanted material to be removed), the control module 160 can automatically increase the irrigation flow rate or supply irrigation fluid through both the irrigation channel 114 and the irrigation gap. Conversely, if suction decreases (e.g., due to a small amount of unwanted material to be removed), the control module 160 can automatically decrease the irrigation flow rate or supply irrigation fluid through only one of the irrigation channel 114 or the irrigation gap, but not both.

[0057] The control module 160 may include a clog controller 161 configured to detect channel conditions indicative of the presence or absence of a clog in the working channel 111 and control one or more of the suction source 120 or irrigation source 130 to provide aspiration pressure or irrigation fluid, respectively, to unclog the occluded working channel. In one example, the clog controller 161 may monitor channel conditions and detect a channel clog based on flow information in the working channel 111. The sensor circuit 150 may include circuitry disposed inside the working channel 111 and coupled to a flow sensor configured to sense the flow rate or volume of moving liquid therein. The flow sensor, such as a microelectromechanical system (MEMS) sensor, may employ a variety of flow measurement technologies. By way of example and not limitation, the flow sensor may include a thermal anemometer that measures the rate of transfer of heat generated from a heat source, a differential pressure sensor that measures pressure drop over a range of locations, an ultrasonic flow sensor that measures frequency shift or the Doppler effect of travel / time of flight, an electromagnetic sensor that measures changes in fluid conductance indicative of flow rate, among others.

[0058] The clog controller 161 can detect a channel clog using flow rate information sensed by a flow sensor. In one example, the clog controller 161 can detect a channel clog in response to a decrease in the sensed flow rate, such as below a first flow rate threshold, and can detect the absence of a clog or successful unclog of an occluded working channel if the sensed flow rate increases and exceeds a second flow rate threshold. In another example, the stability of the flow rate inside a channel, such as when the variability of flow rate measurements exceeds a threshold, can be used to detect a channel clog. In some examples, the clog controller 161 can detect a channel clog by comparing the inflow rate of fluid entering the channel with the outflow rate of fluid exiting the channel. A discrepancy between the inflow and outflow rates, such as the outflow rate being substantially lower than the inflow rate (exceeding a specified tolerance), indicates the presence of a channel clog.

[0059] When a channel clog is present, the clog controller 161 can automatically switch from a standard mode of irrigation / aspiration operation (e.g., in which the suction source 120 provides suction pressure to the suction channel 112 and the irrigation source 130 provides a flow of irrigation fluid to the irrigation channel 114) to an unclog mode of irrigation / aspiration operation, as discussed above. To unclog a blocked channel, the clog controller 161 can alternate between applying irrigation fluid and suction pressure to the blocked channel. Referring now to FIG. 4A , the diagram therein illustrates a channel unclog technique according to one embodiment discussed herein. FIG. 410 illustrates a fluid-filled channel 411 blocked by a clog 412 during a standard mode of irrigation activated by the irrigation source 140. The clog 412 contains tissue debris or stone fragments of different sizes. As shown in FIG. 410, smaller particles, such as particle 412A, are located proximally, while larger particles, such as particle 412B, are located distally. Diagram 420 illustrates switching from standard mode to clog clearing mode, in which clog controller 161 fluidly couples suction source 120 to the proximal portion of channel 411 and activates suction source 120, applying suction pressure to channel 411 for a specified suction duration. A user can adjust the suction pressure and suction duration via user interface 140. Clog particles of different sizes (and therefore different masses) can respond differently to the applied suction pressure. For example, smaller particles 412A can move toward the proximal end of the channel at a faster rate and travel a longer distance during (and after) application of suction than larger particles 412B. As a result, some particles can be removed from clog 412 and separated from the larger particles.

[0060] FIG. 430 shows a fluid-filled channel 411 blocked by a clog 413 during a standard mode of suction activated by the suction source 120. Particles in the clog 413 accumulate differently than clog 412, with smaller particles, such as particle 413A, located distally and larger particles, such as particle 413B, located proximally. FIG. 440 shows switching from standard mode to clog unclog mode, in which the clog controller 161 fluidly couples the irrigation source 140 to the proximal portion of the channel 411 and activates the irrigation source 140 to apply irrigation fluid to clean the channel 411 for a specified cleaning duration. The user can adjust the irrigation flow rate, or the pressure at which the irrigation fluid is pumped, and the cleaning duration. Clog particles of different sizes (and therefore different masses) can respond differently to the irrigation fluid. For example, smaller particles 413A can move toward the distal end of the channel at a faster rate and travel a longer distance during (and after) application of the irrigation fluid than larger particles 413B. As a result, some particles can be removed from the clog 413 and separated from larger particles.

[0061] The separated particles can be extracted down the working channel 411 using additional washing and / or suction. In one example, one or more of the aspiration pressure, aspiration flow rate, washing flow rate, or pump pressure for pressurizing the washing fluid can be varied (e.g., via the user interface 140) to separate particles by size. For example, a higher flow rate can be applied through the channel 411 to remove larger particles, and a lower flow rate can be applied to remove smaller particles.

[0062] 4B-4C illustrate the flow changes in the working channel in the presence of a clog and during the clog removal process. FIG. 4B shows the flow changes in a clogged irrigation channel, as shown in FIGS. 410 and 420 of FIG. 4A. A flow sensor located in the irrigation channel can be used to measure flow parameters such as flow rate. Flow measurements (on the y-axis) have values ​​between -1 and 1. Positive flow values ​​represent the flow direction toward the distal end of the aspiration channel (or toward the anatomical environment 101, see FIG. 410 of FIG. 4A). Negative flow values ​​represent flow in the opposite direction, i.e., toward the proximal end of the aspiration channel (or away from the anatomical environment 101, see FIG. 420 of FIG. 4A). The values ​​of the flow measurements are relative to unoccluded flow through the irrigation channel. That is, a flow value of "1" represents the flow rate during irrigation of an unoccluded channel, and a flow value of "-1" represents the flow rate during aspiration of an unoccluded channel.

[0063] During the standard mode of irrigation of an unclogging irrigation channel, a positive flow F0 with a value of approximately "1" can be detected by the flow sensor. As shown, the flow F0 includes fluctuations superimposed on a constant flow, indicating that small debris is being aspirated. At T1, the flow rate decreases to F1 (less than F0). A clog is detected when the decrease in F0-F1 exceeds the clog detection threshold. In this example, F1 is at a level greater than zero, indicating that the channel is not completely blocked and irrigation continues. Particles continue to accumulate until the flow rate decreases to F2 at T2. F2 is approximately zero, indicating substantial channel blockage (as shown in diagram 410 of FIG. 4A). An unclog mode can be activated at T2 or at a time corresponding to a specific (e.g., user-specified) flow condition. Suction can be applied to the blocked channel, drawing fluid and clots in the blocked channel toward the proximal end of the suction channel (as shown in diagram 420 of FIG. 4A). A negative flow F3 can be sensed by the flow sensor. As discussed above with reference to diagram 420 of FIG. 4A, suction can break up the clog, allowing smaller-sized particles to dissociate from the rest of the clog and travel a longer distance toward the proximal end of the channel. While the channel is unclogged, suction can continue, allowing the negative flow F3 to reach a near maximum ("-1", indicating substantially unclogged flow) at T3. After suction is applied for a specified period of suction time and the dislodged particles are extracted from the channel, suction can be stopped at T4. The negative flow rate can then be reduced to a substantially zero flow F4. At T5, the standard wash mode is resumed by applying wash fluid to the unclogged channel. Once the channel is successfully unclogged and the particles are removed from the channel, a positive flow F5 with a value of approximately "1" can be sensed by the flow sensor.

[0064] FIG. 4C illustrates the change in flow in a clogged aspiration channel, as shown in diagrams 430 and 440 of FIG. 4A. A flow sensor located in the aspiration channel can be used to measure flow parameters such as flow rate. Flow measurements (on the y-axis) have values ​​between −1 and 1. Positive flow values ​​represent a flow direction toward the proximal end of the aspiration channel (or away from the anatomical environment 101, see diagram 430 of FIG. 4A). Negative flow values ​​represent flow in the opposite direction, i.e., toward the distal end of the aspiration channel (or toward the anatomical environment 101, see diagram 440 of FIG. 4A). The values ​​of the flow measurements are relative to unoccluded flow through the aspiration channel. That is, a flow value of “1” represents the flow rate during aspiration of an unoccluded channel, and a flow value of “−1” represents the flow rate during irrigation of an unoccluded channel.

[0065] During a standard mode of aspiration applied to an unclogging aspiration channel, a positive flow F0 with a value of approximately "1" can be detected by the flow sensor. As shown, the flow F0 includes fluctuations superimposed on a constant flow, indicating that small debris is being aspirated. At T1, the flow rate decreases to F1 (less than F0). A clog is detected if the decrease in F0-F1 exceeds a clog detection threshold. In this example, F1 is at a level greater than zero, indicating that the channel is not completely blocked and aspiration continues. Particles continue to accumulate until the flow rate decreases to F2 at T2. F2 is approximately zero, indicating substantial channel blockage (as shown in diagram 430 of FIG. 4A). A clog elimination mode can be activated at T2 or at a time corresponding to a specific (e.g., user-specified) flow condition. Irrigation fluid can be injected into the blocked channel toward the distal end of the aspiration channel and toward the anatomical environment (as shown in diagram 440 of FIG. 4A). A negative flow F3 can be sensed by the flow sensor. As discussed above with reference to diagram 440 of FIG. 4A, the wash fluid can break up the clog, allowing smaller-sized particles to dissociate from the rest of the clog and travel a longer distance toward the distal end of the channel. While the channel is being unclogged, wash continues, allowing the negative flow F3 to reach a near maximum ("-1", indicating substantially unclogged flow) at T3. After application of the wash for a specified period of time, wash can be stopped at T4. As the separated particles settle within the channel, the negative flow rate can then decrease to a substantially zero flow F4. At T5, standard suction mode is resumed by applying additional suction to extract the dislodged particles from the channel. Once the channel is successfully unclogged and the particles are removed from the channel, a positive flow F5 with a value of approximately "1" can be sensed by the flow sensor.

[0066] In some examples, suction pressure and irrigation fluid can be applied alternately and repeatedly to the channel 411. This allows for more efficient separation of clog particles without the need to know or determine the structure of the clog 412 in advance. Continuous application of suction followed by occasional irrigation can also help reduce the occurrence of clog formation. While suction and irrigation are applied alternately and repeatedly, the sensor circuit 150 can monitor the flow rate. The unclog operation, which includes application of irrigation fluid or suction pressure to the blocked channel, can continue as long as the channel clog exists. If the monitored flow rate increases and exceeds a threshold, the blocked channel is deemed to have been successfully unclogged. The clog controller 161 can switch from the unclog mode of operation back to the standard mode of irrigation / aspiration operation.

[0067] Returning to FIG. 1 , the control module 160 can include a pressure controller 162 configured to keep the pressure of the anatomical environment (also referred to as “ambient pressure”) under control, e.g., maintain the ambient pressure substantially at a desired pressure level (e.g., a predetermined level or as specified by a user via the user interface 140). In one example, the ambient pressure is considered to be maintained at the desired pressure level if the difference between the ambient pressure measurement (e.g., by a pressure sensor) and the desired pressure is within an acceptable range, e.g., ±5% to ±10%, as a non-limiting example. The desired pressure level to be maintained at the anatomical site of the anatomical environment 101 can be received from the user interface 140. As previously mentioned, suction can result in negative pressure changes at the anatomical site, while irrigation can result in positive pressure changes at the anatomical site. Negative and positive pressure changes can adversely affect internal organs exposed to the anatomical site. Maintaining the ambient pressure at a controlled pressure level can increase patient safety and effectively reduce procedure time. In some examples, in addition to or instead of receiving a desired pressure level, desired flow conditions can be received, for example, from user interface 140. The desired flow conditions include information about inflow (e.g., the flow rate of irrigation fluid applied to the anatomical environment) relative to outflow (e.g., the flow rate of aspiration applied to the anatomical environment). The desired flow conditions correspond to the desired pressure to be applied to the anatomical environment. For example, a desired flow condition of substantially equal inflow and outflow rates corresponds to a substantially net-zero environmental pressure, a desired flow condition of inflow higher than outflow corresponds to a positive environmental pressure, and a desired flow condition of inflow lower than outflow corresponds to a negative environmental pressure. Pressure controller 162 can control one or more of the irrigation or aspiration flow rates through one or more working channels to maintain the desired flow conditions during a procedure.

[0068] The pressure controller 162 can achieve the controlled pressure by automatically activating, deactivating, or adjusting one or more of the suction or irrigation. The sensor circuit 150 can monitor the pressure of the anatomical environment (“ambient pressure”) during the endoscopic procedure. In one example, the sensor circuit 150 can be coupled to a pressure sensor to sense the ambient pressure or a signal indicative of, or otherwise correlated to, the ambient pressure. Examples of pressure sensors can include resistive, capacitive, piezoelectric, optical, or microelectromechanical systems (MEMS) pressure sensors. In one example, the pressure sensor can be attached to or integrated into a distal portion of the medical device 110, such as the distal tip of the insertable tubular portion of the endoscope, such that the pressure sensor contacts the anatomical environment 101. In one example, the pressure sensor can be positioned at a more proximal location inside the tubular portion of the endoscope, away from the anatomical environment 101. The control module 160 can receive a desired ambient pressure to be maintained during the procedure from the user interface 140. The control module 160 can compare the sensed environmental pressure to a desired environmental pressure and adjust one or more of the irrigation flow rate or the aspiration flow rate to move the environmental pressure toward the desired environmental pressure level.

[0069] The pressure controller 162 can maintain a controlled environmental pressure when the system 100 operates in a standard irrigation / aspiration mode (when no clogs are detected in any of the working channels) and in a irrigation / aspiration unclog mode (when at least one, but not all, of the working channels is clogged). An exemplary system for regulating environmental pressure via automatic adjustment of aspiration and / or irrigation flow rates is discussed below with reference to Figure 5 (when no channel clogs are present) and Figures 6-7 (when a channel clog is present).

[0070] The user interface 140 may include an output unit, such as a display, that presents information collected during the endoscopic procedure, including, among other things, images of the surgical field (including live video), the operational status of the medical device 110, including the status of the working channel 111, information about the channel status, such as channel blockage or successful clearing, and environmental pressure as sensed by the sensor circuit 150.

[0071] 2A shows a perspective view of a powered tissue removal device 200, which is an example of a medical instrument 110. The powered tissue removal device 200 can include a handpiece 210 and a tubular assembly 222 extending from the handpiece 210. The tubular assembly 222 includes a proximal portion 226 disposed in the handpiece 210 and an opposing distal portion 228. Although the distal portion 228 is shown as a "straight shaft" aligned with the rest of the tubular assembly 222, in some instances the distal portion 228 can be bent or angled relative to the rest of the tubular assembly 222, including the proximal portion 226.

[0072] An exemplary configuration of distal portion 228 is shown in FIG. 2B. Tubular assembly 222 includes an outer tubular member 252 and an inner tubular member 254 disposed inside outer tubular member 252. Outer member 252 includes an outer member window 262. Inner member 254 includes a cutting portion 264 and a suction channel 274 defined inside inner member 254. Inner member 254 or cutting portion 264 includes an inner member window 266 in communication with suction channel 274.

[0073] The powered tissue removal device 200 includes an irrigation channel 272 disposed externally or externally of the outer member 252. The irrigation channel 272 extends along the length of the outer member 252. The proximal end of the irrigation channel 272 includes a proximal irrigation port 282 that is in fluid communication with the irrigation source 230, and the distal end of the irrigation channel 272 includes a distal irrigation port 284 that is attached to the powered tissue removal device 200 or the outer member 252.

[0074] The powered tissue removal device 200 can be coupled to an energy source 240, a suction source 220, and an irrigation source 230. The energy source 240 is configured to power the powered tissue removal device 200, the suction source 220, the irrigation source 230, or a combination thereof. The suction source 220, an embodiment of the suction source 120, can be in fluid communication with a suction channel 274 defined inside the inner member 254. The suction source 220 is configured to apply suction to or draw a vacuum from the powered tissue removal device 200 via the suction channel 274. The irrigation source 230, an embodiment of the irrigation source 130, can be in fluid communication with the irrigation channel 272 located externally or externally of the outer member 252. The irrigation source 230 can alternatively or additionally be in fluid communication with a gap between the inner member 254 and the outer member 252.

[0075] The powered tissue removal device 200 includes one or more user controls 224 for operating the powered tissue removal device 200, the energy source 240, the suction source 220, the irrigation source 230, or a combination thereof. By way of example and not limitation, the user controls 224, which are embodiments of the user interface 140, may be located on the handpiece 210 to allow for easy user access and operation during a procedure. In one example, the user controls 224 allow a user to manually control the debridement and activate, stop, or adjust one or more of the irrigation flow rate or the aspiration flow, among other irrigation or aspiration parameters.

[0076] The powered tissue removal device 200 includes a control module (not shown) disposed at least partially inside the handpiece 210. The control module, which may be one embodiment of the control module 160, may be configured to control the operation of the powered tissue removal device 200 in response to user commands from the user control 224, including one or more of tissue wiping, irrigation, and aspiration, among other functionalities. In one example, the control module may detect a clog in a working channel (e.g., a unified irrigation / aspiration channel, or separate irrigation or separate aspiration channels) based on the flow rate sensed from the working channel and clear the clogged channel, e.g., by alternating the application of irrigation fluid and aspiration pressure to the clogged channel. The control module may operate and adjust one or more irrigation flow parameters or one or more aspiration flow parameters to keep the pressure of the anatomical environment (“ambient pressure”) under control, e.g., to maintain the ambient pressure at substantially a user-specified desired pressure during the procedure, as discussed above with reference to FIG. 1 .

[0077] 3A-3B illustrate, by way of example, endoscopic systems 300A and 300B for use in endoscopic procedures. Endoscopic systems 300A and 300B are embodiments of system 100. Referring to FIG. 3A, system 300A includes an endoscope 310A, a suction source 320, an irrigation source 330, and an suction / irrigation control unit 340. Endoscope 310A, an example of medical device 110, can extend into a sheath including a tube 311 extending from a distal end to a hub 312. Hub 312 terminates at a proximal end. Endoscope 310 can include a light port 314 and a visual port 315. Light port 314 can function to provide light into and out of endoscope tube 311 to illuminate features of interest in an anatomical environment (e.g., excised tissue or stones and material). For example, the light port can be advantageous for enhancing visibility when the features of interest are located in low light conditions. The visual port 315 can function to provide a viewing window that allows a user to observe features of interest. In one example, the visual port 315 can be an optical window at the proximal end that provides visual access to a viewing lens at the distal end. In another example, the visual portion 315 can provide a connection point for a camera that captures images or video of the features and anatomical environment of interest. The images or video can be output and displayed on a monitor.

[0078] The endoscope 310A can include an irrigation / aspiration port 313 for receiving suction or irrigation fluid. The irrigation / aspiration port 313 can be located on the exterior of the hub 312 or elsewhere on the endoscope 310A, such as at the proximal end of the endoscope 310A. The irrigation / aspiration port 313 opens into a working channel (not shown) inside the tube 311. The working channel can be sized, shaped, and configured to deliver and / or aspirate irrigation fluid. In one example, the same working channel can be used for irrigation and aspiration (also referred to as a unified irrigation / aspiration channel). In another example, the irrigation channel and aspiration channel are located separately within the tube 311.

[0079] In one example, the endoscope 310 can be a nephroscope. During use, a flexible distal portion of the tube 311 can be surgically inserted into a patient's kidney. A proximal portion of the tube 311 can remain outside the patient's body. The interior of the tube 311 can include an optical fiber extending along the length of the endoscope 310. The optical fiber can be a multimode fiber or a single-mode fiber. A laser external to the nephroscope can generate a laser beam. The laser beam can be coupled to the proximal end of the optical fiber via an appropriate connector. The optical fiber can deliver the laser beam to the kidney stone to ablate it into fragments. In some examples, the laser beam can have a wavelength corresponding to the spectral peak of absorption in human blood and saline, such as 2100 nm, 1942 nm, etc. Generally, it can be beneficial to deliver a laser beam that is significantly absorbed by blood and saline because such a laser beam can be minimally invasive to surrounding tissue, thereby reducing or eliminating damage to the kidney stone or nearby tissue. A laser controller can be located on the graspable proximal portion of the endoscope 310. Similar to the user controls 224 that allow for manual control of debridement as shown in Figure 2A, the laser controller can allow the user to switch the state of the laser beam between an operational state ("on") and a non-operational state ("off"). In some examples, the user can adjust one or more settings of the laser, such as output power, on the laser housing rather than via the laser controller.

[0080] Aspiration / irrigation control unit 340 can maintain the pressure of the anatomical environment under control, for example, maintaining the pressure substantially at a user-specified pressure level (e.g., the user-specified pressure plus a tolerance such as ±5%-10%) while providing suction and irrigation to endoscope 310 during an endoscopic procedure. Aspiration / irrigation control unit 340 can include a pressure monitor (which is an embodiment of sensor circuit 150), a control module (which is an embodiment of control module 160), a pump, and a power supply. The control module can communicate with a user interface 341 (which is an embodiment of user interface 140), which is located external to aspiration / irrigation control unit 340, for controlling the control module.

[0081] The suction source 320 can be connected to the suction / irrigation control unit 340 via an external suction line 326. The suction / irrigation control unit 340 includes a control valve 342 configured to control suction between the suction source 320 and the endoscope 310 so that suction can be turned off during all or part of an irrigation fluid application cycle. The irrigation source 330 can be connected to the suction / irrigation control unit 340 via an external irrigation line 336. A pump included in the suction / irrigation control unit 340 can pressurize the irrigation fluid before it enters the endoscope 310 via the irrigation line 336. As shown in FIG. 3A , the external suction line 326 and the external irrigation line 336 can be connected together by a common fitting 350, which can be coupled to a common line 356 for supplying fluid or suction to the endoscope 310 via the irrigation / suction port 313.

[0082] A control module within the suction / irrigation control unit 340 can be configured to control the operation of the endoscope 310 in response to user commands from the user interface 341. In one example, the control module can detect a clog in a working channel (e.g., a unified irrigation / aspiration channel, a separate irrigation channel, or a separate aspiration channel) based on the flow rate sensed from the working channel and unclog the occluded channel, e.g., by alternating application of irrigation fluid and aspiration pressure. The control module can automatically activate and adjust one or more irrigation flow parameters or one or more aspiration flow parameters to keep the pressure of the anatomical environment (“ambient pressure”) under control, e.g., to maintain the ambient pressure substantially at a user-specified pressure level, as discussed above with reference to FIG. 1.

[0083] System 300B, as shown in FIG. 3B, is similar to system 300A and includes an endoscope 310B, a suction source 320, an irrigation source 330, and a control suction / irrigation control unit 340. Like endoscope 310A, endoscope 310B may include a tube 311, a hub 312, an optical port 314, and a viewing port 315. However, instead of a single irrigation / suction port 313, endoscope 310B includes separate suction port 313A and irrigation port 313B adapted for fluid communication with suction source 320 and irrigation source 330, respectively. Suction source 320 is fluidly coupled to suction port 313A via an external suction line 326. Irrigation source 330 is fluidly coupled to irrigation port 313B via an external irrigation line 336. Suction port 313A and irrigation port 313B can each open into one or more working channels inside tube 311. In one example, the irrigation and suction channels are separately disposed within tube 311. The suction port 313A can selectively open to either the suction channel or the irrigation channel. Similarly, the irrigation port 313B can selectively open to either the suction channel or the irrigation channel inside the tube 311.

[0084] FIG. 5 illustrates an exemplary feedback-controlled pressure regulation system 500, which is one embodiment of the environmental pressure control portion of system 100. System 500 can be configured to regulate environmental pressure at an anatomical site when no channel blockage is present and when system 500 operates in a standard irrigation / aspiration mode (e.g., controlling suction source 120 to provide suction pressure to suction channel 112 and irrigation source 130 to provide irrigation fluid flow to irrigation channel 114). System 500 can regulate environmental pressure through automatic adjustment of aspiration and / or irrigation flow rates in suction channel 112 and irrigation channel 114, respectively. In one example, the longitudinal axes of suction channel 112 and irrigation channel 114 can be parallel to one another. In one example, suction channel 112 and irrigation channel 114 can be coaxially positioned about a common axis, e.g., in a nested configuration. In one example, irrigation and suction can be applied at different times through the same working channel, such as a unified irrigation / aspiration channel. A pressure monitor 550 can monitor the pressure of the anatomical environment 101 via pressure sensor 352. By way of example and not limitation, the control module 160 can include a proportional-integral (PI) controller or a proportional-integral-derivative (PID) controller, among other feedback controllers. The difference between the sensed pressure (at pressure monitor 550) and the desired pressure, also referred to as the "error," can be used to determine the P, I, or D terms in the feedback controller.

[0085] Depending on the desired pressure (or desired flow condition) provided by the user, the system 500 can operate in a stable pressure mode when the desired pressure is substantially net zero (corresponding to a desired flow condition of substantially equal irrigation fluid inflow and suction outflow applied to the anatomical environment), or in a pressure control mode when the desired pressure is a positive or negative pressure (corresponding to a desired flow condition of an imbalance between inflow and outflow). When operating in the stable pressure mode, the irrigation flow rate or aspiration flow rate can be manually adjusted by the user, for example, via respective user controls on the user interface 140. During an endoscopic procedure, an increase in irrigation flow rate can result in an increase in environmental pressure at the anatomical site, which can be sensed by the pressure monitor 550. The control module 160 can responsively activate suction by applying aspiration pressure to the aspiration channel 112. Aspiration can generate a negative pressure to offset the increase in pressure generated by irrigation. The control module 160 can adjust the aspiration flow rate or aspiration pressure until the pressure increase (due to the increased irrigation) is substantially neutralized by the aspiration flow. The environmental pressure can then be directed towards and maintained at substantially zero.

[0086] Similarly, an increase in aspiration flow rate can result in a decrease in environmental pressure at the anatomical site. The control module 160 can actuate irrigation proactively by providing a flow of irrigation fluid to the irrigation channel 114. The irrigation can generate a positive pressure to offset the decrease in pressure generated by the suction. The control module 160 can adjust the irrigation flow rate until the pressure drop (due to the increase in suction) is substantially neutralized by the irrigation flow. The environmental pressure can then be driven toward and maintained at substantially zero.

[0087] In some situations, it is desirable to maintain a positive or negative environmental pressure at an anatomical site. Controlled positive pressure within a safe range can help distend anatomical structures (e.g., ureters, kidneys, uterus, or other organs) during endoscopic procedures, allowing for better visualization of the anatomical structure through the endoscope without causing tissue damage from excessive positive pressure. Positive pressure can prevent tissue debris or stone fragments from becoming lodged in the anatomical structure and aid in the removal of tissue debris or stone fragments from the anatomical structure. In some cases, maintaining controlled negative pressure within a safe range during endoscopic procedures can also facilitate the extraction of debris from the anatomical structure without exposing internal organs to the risk of excessive negative pressure.

[0088] For example, when a desired positive environmental pressure is provided by a user via user interface 140, system 500 can operate in a pressure control mode. Control module 160 can automatically increase the irrigation flow rate through irrigation channel 114 to increase the positive environmental pressure at the anatomical site. Additionally or alternatively, control module 160 can automatically decrease the aspiration flow rate through suction channel 112 to reduce the negative pressure at the anatomical site. Automatic adjustment of irrigation and / or aspiration can continue until the sensed environmental pressure substantially reaches the desired positive pressure level.

[0089] Similarly, when a desired negative environmental pressure is provided by a user, for example, via user interface 140, system 500 can operate in a pressure control mode. Control module 160 can automatically increase the aspiration flow rate through aspiration channel 112 to increase the negative environmental pressure at the anatomical site. Additionally, or alternatively, control module 160 can automatically decrease the irrigation flow rate through irrigation channel 114 to reduce the positive pressure at the anatomical site. Automatic adjustment of irrigation and / or aspiration can continue until the sensed environmental pressure substantially reaches the desired level of negative pressure.

[0090] The control module 160 may include a safety mechanism that keeps the pressure of the anatomical environment within a safe range defined by a lower negative pressure limit and an upper positive pressure limit. If the sensed environmental pressure reaches the upper positive pressure limit, the control module 160 may automatically stop, reduce, or maintain the irrigation flow at its current rate to prevent further increases in environmental pressure. Similarly, if the sensed environmental pressure reaches the lower negative pressure limit, the control module 160 may automatically stop, reduce, or maintain the aspiration flow at its current rate to prevent further decreases in environmental pressure. When the system operates in pressure control mode, the desired positive pressure and desired negative pressure received from the user are checked to ensure they are within the safe range. In one non-limiting example, the desired positive pressure is 5 pounds per square inch (psi) (or approximately 34.5 kilopascals (kPa)), the desired negative pressure is −5 psi (or approximately −34.5 kPa), and the safety range is between a lower limit of −6 psi (or approximately 41.4 kPa) and an upper limit of 6 psi (or approximately 41.4 kPa). In one example, a warning can be issued (e.g., via user interface 140) if the desired positive pressure received from the user exceeds the upper positive pressure limit or if the desired negative pressure is below the negative pressure safety limit. With such safety mechanisms, control module 160 can maintain environmental pressure at a user-specified level while preventing or minimizing excessive positive or negative pressure on the anatomical environment during a procedure.

[0091] 6A is a diagram illustrating an exemplary feedback-controlled pressure regulation system 600, which is one embodiment of system 100. System 600 can be configured to regulate the pressure of anatomical environment 101 ("ambient pressure") when there is a clog in aspiration channel 112. As discussed above with reference to FIG. 4A, when a clog in aspiration channel 112 is detected, clog controller 161 of controller module 160 can switch from a standard mode (see FIG. 5) that applies aspiration pressure to aspiration channel 112 to a clog removal mode in which irrigation source 130 is fluidly coupled to aspiration channel 112 to provide an irrigation flow to aspiration channel 112.

[0092] Application of irrigation flow to the aspiration channel 112 can result in an increase in anatomical pressure at the anatomical site. The pressure controller 162 of the control module 160 can regulate environmental pressure through automatic adjustment of the aspiration and / or irrigation flow rates through the aspiration channel 112 and the irrigation channel 114. For example, in response to an increase in environmental pressure (as sensed by the pressure monitor 550), the pressure controller 162 can automatically apply aspiration pressure to the irrigation channel 114. If the irrigation channel 114 is not clogged, the suction applied to the irrigation channel 114 can create a negative pressure in the anatomical environment 101 to offset the pressure increase created by the irrigation through the aspiration channel 112. In one example, the pressure monitor 550 can continuously or periodically monitor the environmental pressure, and the pressure controller 162 can adjust the aspiration flow rate or aspiration pressure to direct the environmental pressure toward the desired pressure level.

[0093] In one example, the desired pressure is substantially net zero pressure. The pressure controller 162 can adjust the aspiration flow rate or aspiration pressure in the irrigation channel 114 to substantially counteract increases in the sensed environmental pressure. In this manner, the environmental pressure can be directed toward and maintained at substantially zero. In another example, the desired pressure is a positive pressure. The pressure controller 162 can adjust the aspiration flow rate or aspiration pressure in the irrigation channel 114 at a level that directs the sensed environmental pressure toward the desired positive pressure level. An example of the desired positive pressure is 5 pounds per square inch (psi), or approximately 34.5 kPa. In yet another example, the desired pressure is a negative pressure, and the pressure controller 162 can adjust the aspiration flow rate or aspiration pressure in the irrigation channel 114 at a level that directs the sensed environmental pressure toward the desired negative pressure level. An example of the desired negative pressure is -5 psi, or equivalently, approximately -34.5 kPa.

[0094] As discussed above with reference to Figures 3A-3B, clearing the clog can involve alternating application of suction and irrigation to the blocked channel. Figure 6B is a timing diagram for activating irrigation / suction in the aspiration channel when a clog occurs in the aspiration channel 112 (as shown in Figure 6A). To clear the aspiration channel clog, irrigation is applied to the aspiration channel for a duration t1 ("irrigation duration"). During the transition period t d After the transition period t, suction pressure is applied to the suction channel for a duration t2 ("suction duration"). d This allows clogged particles of different sizes and masses to travel different distances along the suction channel, which facilitates particle separation and channel unclog. Irrigation can create positive anatomical pressure (+PA) 661, and suction can create negative pressure (-PA) 662 at the anatomical site.

[0095] 6C is a timing diagram for activating irrigation / aspiration in the irrigation channel to achieve pressure control at the anatomical site, e.g., to maintain a desired anatomical pressure during the unclog process. During t1, the pressure controller 162 can activate suction to the irrigation channel 114, which can generate a negative anatomical pressure (−PA) 671 to offset the positive anatomical pressure (+PA) 661 at the anatomical site. During t2, the pressure controller 162 can activate irrigation to the irrigation channel 114, which can generate a positive anatomical pressure (+PA) 672 to offset the negative anatomical pressure (−PA) 662 at the anatomical site. In this manner, the pressure in the anatomical environment can be maintained at a desired level while the blocked aspiration channel is being unclogged.

[0096] When the flow monitor 650 senses an increase in flow rate through the aspiration channel 112 via the flow sensor 652, the blocked channel is determined to be successfully unclogged. The clog controller 161 can return to a standard mode of irrigation / aspiration operation (e.g., controlling the aspiration source to apply aspiration pressure to the aspiration channel and the irrigation source to provide irrigation fluid to the irrigation channel). The pressure controller 162 can operate the aspiration and irrigation to keep the environmental pressure under control, as discussed above with reference to FIG. 5.

[0097] 7A is a diagram illustrating an exemplary feedback-controlled pressure regulation system 700, which is one embodiment of system 100. System 700 can be configured to regulate the pressure exerted on anatomical environment 101 ("ambient pressure") when there is a clog in irrigation channel 114. As discussed above with reference to FIG. 4A, when a clog in irrigation channel 114 is detected, clog controller 161 of controller module 160 can switch from a standard mode that supplies irrigation fluid to irrigation channel 114 to a clog-relief mode that can fluidly couple suction source 120 to irrigation channel 114 to aspirate or suction the blocked irrigation channel 114.

[0098] Applying suction pressure to the irrigation channel 114 can result in a decrease in pressure at the anatomical site in the anatomical environment 101. The pressure controller 162 of the control module 160 can regulate the environmental pressure through automatic adjustment of the aspiration and / or irrigation flow rates through the aspiration channel 112 and the irrigation channel 114. For example, in response to a decrease in environmental pressure (which can be sensed by the pressure monitor 550), the pressure controller 162 can automatically activate the flow of irrigation fluid into the aspiration channel 112. If the aspiration channel 112 is not clogged, the irrigation fluid applied to the aspiration channel 112 can create a positive pressure to offset the decrease in pressure in the anatomical environment 101 created by the suction through the irrigation channel 114. In one example, the pressure monitor 550 can continuously or periodically monitor the environmental pressure, and the pressure controller 162 can adjust the irrigation flow rate to direct the environmental pressure toward the desired pressure level.

[0099] In one example, the desired pressure is substantially net zero pressure. The pressure controller 162 can adjust the irrigation flow rate through the aspiration channel 112 to a level that substantially counteracts the decrease in the sensed environmental pressure. The environmental pressure as sensed by the pressure monitor 550 can then be driven toward or maintained at substantially zero. In another example, the desired pressure is a positive pressure. The pressure controller 162 can adjust the irrigation flow rate through the aspiration channel 112 at a level that drives the sensed environmental pressure toward the desired positive pressure level. In yet another example, the desired pressure is a negative pressure, and the pressure controller 162 can adjust the irrigation flow rate through the aspiration channel 112 at a level that drives the sensed environmental pressure toward the desired negative pressure level.

[0100] 7B is a timing diagram for activating irrigation / aspiration in the irrigation channel 114 when a clog occurs in the irrigation channel (as shown in FIG. 7A). To clear the clog in the irrigation channel, suction is applied to the irrigation channel for a duration t3 ("aspiration duration"). During the transition period t dAfter the transition period t, a flushing pressure is applied to the flushing channel for a duration t4 ("flushing duration"). d This allows clogged particles of different sizes and masses to travel different distances along the irrigation channel, which facilitates particle separation and channel unclog. At an anatomical site, suction can induce a negative anatomical pressure (-PA) 761 and irrigation can induce a positive anatomical pressure (+PA) 762.

[0101] 7C is a timing diagram for activating irrigation / aspiration in the aspiration channel to achieve pressure control at the anatomical site, e.g., to maintain a desired anatomical pressure during the unclog process. During t3, the pressure controller 162 can activate irrigation to the aspiration channel 112, which generates a positive anatomical pressure (+PA) 771 to counteract the negative anatomical pressure (-PA) 761 at the anatomical site. During t4, the pressure controller 162 can activate suction to the aspiration channel 112, which generates a negative anatomical pressure (-PA) 772 to counteract the positive anatomical pressure (+PA) 762 at the anatomical site. In this manner, the pressure in the anatomical environment can be maintained at a desired level while the blocked irrigation channel is being unclogged.

[0102] When the flow monitor 650 senses an increase in flow rate through the aspiration channel 112 via the flow sensor 652, the blocked channel is determined to be successfully unclogged. The clog controller 161 can return to a standard mode of irrigation / aspiration operation (e.g., controlling the aspiration source to apply aspiration pressure to the aspiration channel and the irrigation source to provide irrigation fluid to the irrigation channel). The pressure controller 162 can operate the aspiration and irrigation to keep the environmental pressure under control, as discussed above with reference to FIG. 5.

[0103] FIG. 8 is a flowchart illustrating a method 800 for in situ clearing of a clogged working channel in a medical device during a minimally invasive procedure, such as an endoscopic procedure. The medical device includes a tubular portion insertable into a hollow organ or cavity of the body to aid in medical diagnosis or surgical treatment. Examples of medical devices may include, among others, a tissue removal device, such as that shown in FIGS. 2A-2B, or an endoscope, such as that shown in FIGS. 3A-3B. The medical device may include one or more working channels configured to provide irrigation fluid to an anatomical site and transport tissue debris, stones or clots, bodily fluids, and irrigation fluid away from the anatomical site, collectively referred to herein as unwanted material. The working channel may be at least partially disposed inside the tubular portion of the medical device. In one example, the working channel is a unified irrigation / aspiration channel controllably used for irrigation and aspiration (e.g., at different times). In another example, the working channel may include separate irrigation and aspiration channels disposed within the tubular portion of the medical device. The irrigation channel and the suction channel can each receive irrigation fluid or suction pressure, for example under automatic control by a controller unit, and can perform different tasks or serve different functions during an endoscopic procedure according to various embodiments discussed herein.

[0104] Method 800 includes one or more processes for operating a clog clearance system, such as system 100, or a variation thereof, such as one of systems 200, 300A, or 300B. Although the processes of method 800 are depicted in a flowchart, the processes are not required to be performed in a particular order. In various examples, some of the processes may be performed in a different order than shown herein.

[0105] At 810, the flow rate through the working channel can be sensed using a flow sensor, which can be disposed inside the working channel of the medical device. Examples of flow sensors can include, among others, a thermoanemometer that measures the rate of heat transfer generated from a heat source; a differential pressure sensor that measures pressure drop over a range of locations; an ultrasonic flow sensor that measures frequency shift or the Doppler effect of travel / time of flight; and an electromagnetic sensor that measures changes in fluid conductance, indicative of flow rate. At 820, a channel condition indicative of the presence or absence of a clog in the working channel can be detected based on the sensed flow rate, using, for example, a clog controller 161. In one example, a channel clog can be detected in response to, for example, a decrease in flow rate below a first flow rate threshold. An increase in the sensed flow rate above a second flow rate threshold can detect the absence of a clog or successful unclog of the occluded working channel. In one example, the first flow rate threshold or the second flow rate threshold can each be relative to (e.g., a specific percentage of) a baseline flow rate, such as that measured in an unclogged channel.

[0106] If the sensed flow rate at 830 indicates a clog in the working channel, an unclog mode of irrigation / aspiration operation is activated at 840 to unclog the blocked working channel. When separate irrigation and aspiration channels are used in the medical device, the unclog mode includes applying a flow of irrigation fluid to the aspiration channel and / or applying aspiration pressure to the irrigation channel. This unclog mode differs from the standard mode of irrigation / aspiration operation, in which a suction source provides aspiration pressure to the aspiration channel and an irrigation source provides a flow of irrigation fluid to the irrigation channel. In one example, the unclog mode at 840 can include alternating irrigation and aspiration into the blocked channel. As discussed above with reference to FIG. 4A , the clog controller 161 can controllably activate a suction source (e.g., suction source 120) to provide aspiration pressure to the blocked working channel (as shown in panel 420 of FIG. 4A ) for a specified aspiration duration. Alternatively, or in addition, clog controller 161 can activate an irrigation source (e.g., irrigation source 140) to apply a flow of irrigation fluid to the blocked working channel for a specified irrigation duration (as shown in panel 440 of FIG. 4A). The aspiration pressure, aspiration flow rate, irrigation flow rate, or pump pressure pressurizing the irrigation fluid can be adjusted by the user.

[0107] Clog particles of different sizes (and therefore different masses) can respond differently to suction or to irrigation fluid. As shown in FIG. 4A, smaller particles can move faster and travel longer distances in the direction of suction or fluid flow than larger particles, so suction, irrigation, or alternating suction and irrigation can help remove smaller particles from the clog mass and separate them from the rest of the clog. Applying additional suction or irrigation flow to the working channel can more easily and efficiently extract separated particles down the working channel. In one example, one or more of the suction pressure, suction flow rate, irrigation flow rate, or pump pressure can be varied to separate particles by size. For example, a higher flow rate can be applied to remove larger particles, and a lower flow rate can be applied to remove smaller particles through the channel.

[0108] During the unclog process, the flow rate can be continuously or periodically monitored 810. If the monitored flow rate increases and exceeds a threshold value at 830, the blocked channel is considered to be successfully unclogged. The unclog mode of operation can then be returned to the standard mode of irrigation / aspiration operation.

[0109] 9 is a flow chart illustrating a method 900 for in situ unclogging of a working channel of a medical device while keeping the pressure of the anatomical environment ("ambient pressure") under control, for example, maintaining the ambient pressure substantially at a user-specified pressure level. The process of controlling the ambient pressure may be implemented and performed by a pressure controller, such as pressure controller 162. The processes of method 900 are not required to be performed in a particular order. For example, some steps may be performed in a different order than shown herein.

[0110] Method 900 includes steps 910 through 940 for detecting a blockage in the working channel and clearing the blocked channel, which steps are similar to steps 810 through 840 of method 800. Method 900 further includes steps 950 through 980 for adjusting environmental pressure during a procedure (e.g., an endoscopic procedure) with or without a channel blockage. As previously discussed, aspiration can result in negative pressure changes at an anatomical site, while irrigation can result in positive pressure changes at an anatomical site. Negative and positive pressure changes can adversely affect internal organs exposed at the anatomical site. Maintaining environmental pressure at a controlled pressure level can improve patient safety and effectively reduce procedure time.

[0111] Regulation of environmental pressure can be achieved through automatic adjustment of suction and / or irrigation flow rates in one or more working channels. Specifically, at 950, a pressure sensor can be used to sense environmental pressure. The pressure sensor can be attached to or incorporated into a distal portion of the medical device such that the sensor is in contact with the anatomical environment. Examples of pressure sensors can include resistive, capacitive, piezoelectric, optical, or microelectromechanical systems (MEMS) pressure sensors.

[0112] At 960, the sensed tissue pressure can be compared to a desired pressure, as provided by the user via the user interface 140. The desired pressure represents the pressure to be maintained in the anatomical environment during the procedure. In one example, the desired pressure is substantially net zero pressure. In another example, the desired pressure is a positive pressure. In yet another example, the desired pressure is a negative pressure. Maintaining a controlled positive pressure within a safe range can help dilate anatomical structures (e.g., ureters, kidneys, or other organs) during an endoscopic procedure, allowing for better visualization of the anatomical structure through the endoscope without causing tissue damage from excessive positive pressure. Positive pressure can also prevent tissue debris or stone fragments from becoming lodged in the anatomical structure and aid in the removal of tissue debris or stone fragments from the anatomical structure. In some cases, maintaining a controlled negative pressure within a safe range during an endoscopic procedure can facilitate the extraction of debris from the anatomical structure without exposing internal organs to the risk of excessive negative pressure.

[0113] If the pressure sensed at 960 does not substantially reach the desired pressure level (i.e., within a tolerance, such as ±5%-10% of the desired pressure), then at 970, one or more of the irrigation or aspiration flow rates through one or more working channels can be adjusted, e.g., using pressure controller 162, to move the environmental pressure toward the desired pressure level. In some examples, desired flow conditions can be received, e.g., from user interface 140, in addition to or instead of the desired pressure level. The desired flow conditions include information about the inflow (e.g., the flow rate of irrigation fluid applied to the anatomical environment) relative to the outflow (e.g., the flow rate of aspiration applied to the anatomical environment) and correspond to the desired pressure to be applied to the anatomical environment. One or more of the irrigation or aspiration flow rates through one or more working channels can be altered to maintain the desired flow conditions during the procedure.

[0114] When no clog is detected in any of the working channels or the blocked channel is successfully unclogged, the pressure control process at 970 can be performed via the standard mode of irrigation / aspiration operation. As described above with reference to FIG. 5 , suction applied to the aspiration channel can create a negative pressure in the anatomical environment, which can offset the increase in environmental pressure created by an increase in irrigation flow rate. The aspiration flow rate or aspiration pressure can be adjusted until the sensed increase in pressure (such as caused by increased irrigation) is substantially counteracted by the aspiration flow, thereby resulting in a desired substantially zero net pressure, or until the sensed environmental pressure reaches a substantially desired positive or negative pressure level. Similarly, the flow of irrigation fluid supplied to the irrigation channel can create a positive pressure in the anatomical environment, which can offset the decrease in environmental pressure created by aspiration. The irrigation flow rate can be adjusted until the sensed decrease in pressure (such as caused by increased suction) is substantially counteracted by the irrigation flow, thereby resulting in a desired substantially zero net pressure, or until the sensed environmental pressure reaches a substantially desired positive or negative pressure level.

[0115] When at least one, but not all, of the working channels is clogged, a pressure control process at 970 can be performed via an irrigation / aspiration operation unclog mode. FIG. 6A shows an example in which the aspiration channel is clogged and the irrigation channel is unclogged. As discussed therein, a flow of irrigation fluid can be applied to the aspiration channel to unclog the blocked aspiration channel. This can generate an increase in environmental pressure, which can be detected by a pressure sensor. Aspiration pressure can be applied to the irrigation channel, which can generate a negative pressure to offset the pressure increase in the anatomical environment. The aspiration flow rate or aspiration pressure in the irrigation channel can be adjusted until the sensed increase in pressure (due to increased irrigation in the blocked aspiration channel) is substantially neutralized by the aspiration flow, thereby resulting in a desired substantially zero net pressure, or until the sensed environmental pressure reaches substantially the desired positive or negative pressure level.

[0116] In another example where the irrigation channel is clogged but the aspiration channel is not, suction pressure can be applied to the irrigation channel to unclog the blocked irrigation channel, which can generate a decrease in environmental pressure. As discussed above with reference to FIG. 7A, a flow of irrigation fluid can be applied to the aspiration channel, which can generate a positive pressure to offset a negative increase in the anatomical environment. The irrigation flow rate can be adjusted until the decrease in sensed pressure (due to increased suction in the blocked irrigation channel) is substantially counteracted by the irrigation flow, thereby resulting in a desired substantially net zero pressure, or until the sensed environmental pressure substantially reaches the desired positive or negative pressure level.

[0117] A check is made to see if the procedure is complete at 980. If the procedure is not complete, the flow sensing and unclogging processes 910 through 940 and the pressure control processes 950 through 980 can continue.

[0118] Controlled irrigation and aspiration, including alternating application of irrigation fluid and application of suction pressure to the same clogged channel, as described in methods 800 and 900, can effectively unclog a channel by separating different sized debris that accumulates and clogs the channel. Pressure control via application of irrigation and / or aspiration within one or more working channels, as described in method 900, can effectively avoid or minimize excessive positive or negative pressure on internal organs during an endoscopic procedure, both with and without a clogged channel. As a result, overall procedure time can be reduced and patient safety can be improved.

[0119] postscript The above detailed description includes references to the accompanying drawings, which form a part of the detailed description. The drawings show, by way of illustration, specific embodiments in which the invention may be practiced. These embodiments are also referred to herein as "examples." Such examples may include elements in addition to those shown or described. However, the inventors also contemplate examples in which only those elements shown or described are provided. The inventors also contemplate examples that use any combination or permutation of these elements (or one or more aspects thereof) shown or described with respect to a particular example (or one or more aspects thereof), or with respect to other examples (or one or more aspects thereof) shown or described herein.

[0120] As used herein, the terms "a" or "an" are used, as is common in patent documents, to include one or more than one, independently of any other instance or usage of "at least one" or "one or more." As used herein, the term "or" is used to refer to a non-exclusive or, unless otherwise stated, such that "A or B" includes "A but not B," "B but not A," and "A and B." As used herein, the terms "including" and "in which" are used as the plain-English equivalents of the respective terms "comprising" and "wherein." Also, in the following claims, the terms "including" and "comprising" are open-ended, i.e., systems, devices, articles, compositions, formulations, or processes that include elements in addition to those recited after such terms in a claim are still deemed to be within the scope of that claim. Also, in the following claims, the terms "first," "second," and "third," etc., are used merely as labels and are not intended to impose numerical requirements on these objects.

[0121] The above description is intended to be illustrative, not limiting. For example, the above-described examples (or one or more aspects thereof) can be used in combination with each other. Other embodiments may be employed by one of ordinary skill in the art upon review of the above description. The Abstract is provided to comply with 37 CFR § 1.72(b) to enable the reader to quickly ascertain the nature of the technical disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims. Also, in the above Detailed Description, various features may be grouped together to simplify the disclosure. This should not be construed as intending that unclaimed disclosed functionality is essential to any claim. Rather, inventive subject matter may not feature all features of a particular disclosed embodiment. Accordingly, it is contemplated that the following claims are incorporated into the Detailed Description herein as examples or embodiments, with each claim standing on its own as a separate embodiment, and that such embodiments can be combined with each other in various combinations or permutations. The scope of the invention should be determined with reference to the appended claims, along with the full range of equivalents to which such claims are entitled. [Explanation of symbols]

[0122] 100 systems 101 Anatomical environment 110 Medical Devices 111 Working Channel 112 suction channel 114 Washing Channel 120 Suction source 130 Cleaning Source 140 User Interface 150 Sensor Circuit 160 Control Module 161 Clogging Controller 162 Pressure Controller 200 Electric tissue removal device 210 Handpiece 220 Suction source 222 Tubular Assembly 224 User Control 226 Proximal part 228 Distal part 230 Cleaning Source 240 Energy Sources 252 Outer tubular member 254 Inner tubular member 262 External member window 264 Cutting part 266 Inner Component Window 272 Washing Channel 274 Suction Channel 282 Proximal Irrigation Port 284 Distal Irrigation Port 300A Endoscope System 300B Endoscopy System 310A Endoscope 310B Endoscope 311 Tube 312 Hub 313 Irrigation / Aspiration Port 313A Suction Port 313B Washing Port 314 optical port 315 Visual Port 320 Suction source 326 External suction line 330 Cleaning Source 336 External Cleaning Line 340 Suction / Irrigation Control Unit 341 User Interface 342 Control valve 350 Connectors 352 Pressure Sensor 356 Common Line 411 Fluid-filled Channel 412 Clogging 413 Clogging 500 Feedback Control Pressure Regulation System 550 Pressure Monitor 600 Feedback Control Pressure Regulation System 650 Flow Monitor 652 Flow Sensor 700 Feedback Control Pressure Regulation System

Claims

1. 1. A system for monitoring and maintaining flow within at least one working channel of a medical instrument during a medical procedure, comprising: an irrigation system configured to be fluidly coupled to the at least one working channel, the irrigation system including an irrigation source and a suction source; a flow sensor configured to sense a fluid flow condition within the at least one working channel; and a controller circuit configured to adjust one or more of an irrigation setting of the irrigation source or an aspiration setting of the aspiration source in a specified time pattern when there is a flow disturbance in the at least one working channel to maintain sensed fluid flow conditions substantially at target flow conditions during the medical procedure; A system comprising:

2. 2. The system of claim 1, wherein the particular time pattern for adjusting one or more of the irrigation or suction settings includes alternating irrigation via the irrigation source and suction via the suction source through the at least one working channel, the irrigation and the suction being separated by a transition period during which both the irrigation and the suction are stopped.

3. 3. The system of claim 2, wherein the controller circuit is further configured to detect a flow disturbance indicative of a clog in the at least one working channel based on a change in the sensed flow conditions, and to promote spatial separation of clog-causing particles of different sizes or masses in the at least one working channel by alternating the irrigation and the aspiration separated by the transition periods.

4. 2. The system of claim 1, wherein adjusting one or more of the irrigation settings or the suction settings includes turning one or more of the irrigation source or the suction source on or off, or adjusting one or more of an irrigation flow rate of the irrigation source or a suction pressure of the suction source.

5. The system of claim 1 , wherein the target flow condition comprises a target flow rate.

6. The system of claim 5 , further comprising a user interface configured to receive user input of the target flow rate.

7. the at least one working channel includes an aspiration channel and an irrigation channel; The system of claim 1 , wherein the controller circuit is configured to fluidly couple one of the aspiration channel or the irrigation channel to the irrigation source and fluidly couple the other of the aspiration channel or the irrigation channel to the aspiration source.

8. 8. The system of claim 7, wherein the controller circuit is configured to alternate between irrigation and aspiration of the aspiration channel by switching coupling of the aspiration channel between the irrigation source and the aspiration source when there is a flow disturbance in the aspiration channel.

9. 8. The system of claim 7, wherein the controller circuit is configured to alternate between aspirating and irrigating the irrigation channel by switching the coupling of the irrigation channel between the suction source and the irrigation source when there is a flow disturbance in the irrigation channel.

10. further comprising a pressure sensor configured to sense pressure at the anatomical site; 2. The system of claim 1, wherein the controller circuit is configured to adjust one or more of the irrigation setting or the aspiration setting to achieve the target flow conditions in the at least one working channel such that the pressure sensed at the anatomical site is maintained at a target pressure during the medical procedure.

11. The system of claim 10 , wherein the target pressure is a substantially net zero pressure.

12. The system of claim 10 , further comprising a user interface configured to receive user input of the target pressure.

13. 1. A method of monitoring and maintaining flow within at least one working channel of a medical device during a medical procedure, comprising: fluidly coupling the at least one working channel to an irrigation system including an irrigation source and a suction source; sensing fluid flow conditions within the at least one working channel using a flow sensor; detecting a flow disturbance in the at least one working channel; adjusting one or more of an irrigation setting of the irrigation source or an aspiration setting of the aspiration source in a specific time pattern in response to the flow disturbance to maintain the sensed fluid flow conditions during the medical procedure substantially at a target flow condition; A method comprising:

14. 14. The method of claim 13, wherein adjusting one or more of the irrigation or suction settings in the specified time pattern comprises alternating irrigation via the irrigation source and suction via the suction source through the at least one working channel, the irrigation and the suction being separated by a transition period during which both the irrigation and the suction are stopped.

15. detecting a flow disturbance includes detecting a blockage in the at least one working channel; 15. The method of claim 14, wherein the transition period between the irrigation and the aspiration is configured to promote spatial separation of clog-causing particles of different sizes or masses within the at least one working channel.

16. 14. The method of claim 13, wherein adjusting one or more of the irrigation settings or the suction settings comprises turning one or more of the irrigation source or the suction source on or off, or adjusting one or more of an irrigation flow rate of the irrigation source or a suction pressure of the suction source.

17. the at least one working channel includes an aspiration channel and an irrigation channel; 14. The method of claim 13, wherein fluidly coupling the at least one working channel to an irrigation system comprises fluidly coupling one of the suction channel or the irrigation channel to the irrigation source, and fluidly coupling the other of the suction channel or the irrigation channel to the suction source.

18. 18. The method of claim 17, wherein the specific time pattern of adjusting one or more of the irrigation setting or the suction setting includes switching coupling to the suction channel between the irrigation source and the suction source in response to the flow disturbance in the suction channel, thereby alternating between irrigation and suction of the suction channel.

19. 18. The method of claim 17, wherein the particular time pattern of adjusting one or more of the irrigation setting or the suction setting includes switching coupling to the irrigation channel between the suction source and the irrigation source in response to the flow disturbance in the irrigation channel, thereby alternating between suction and irrigation of the irrigation channel.

20. further comprising sensing pressure at the anatomical site with a pressure sensor; 14. The method of claim 13, wherein adjusting one or more of the irrigation or aspiration settings to achieve the target flow conditions in the at least one working channel comprises maintaining a pressure sensed at the anatomical site during the medical procedure at a target pressure.

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