JP2024074843A - Endoscope clearing system and method - Google Patents

Abstract

Systems and methods are provided for in situ clearing of clogs in working channels in medical devices during a procedure. An exemplary clog clearing system includes a flow sensor that senses a flow rate through the working channel and a control module that detects a channel condition indicative of the presence or absence of a clog based on the flow rate. Upon a clogged channel, the control module can control one or more of an irrigation source or aspiration source that provides irrigation fluid or aspiration pressure, respectively, to clear the clogged channel. The control module can adjust one or more of the irrigation or aspiration flow rates through the working channel to maintain a desired pressure of the anatomical environment at the anatomical site or to maintain desired flow conditions in the working channel during the procedure.Selected Figures:

Description

CLAIM OF PRIORITY 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.

This document relates generally to endoscopy systems, and more specifically to a clogging elimination system for clearing clogging in an endoscope while maintaining a controlled in situ pressure in the anatomical environment at the anatomical site during an endoscopic procedure.

Endoscopes are typically used to provide access to internal locations of a patient so that visual access is provided to the physician. Some endoscopes are used in minimally invasive surgery to remove unwanted tissue or foreign material from a patient's body. For example, an endoscopic tissue removal device is an instrument used by a clinician to remotely access necrotic, cancerous, damaged, infected or other unwanted soft tissue, bone, or other anatomical structures at an anatomical site, resect said unwanted material from adjacent anatomical structures, and transport said 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 that involves placing a nephroscope through the patient's flank into the renal pelvis. For example, stones or masses from various areas of the body can be visualized and extracted, including the urinary system, gallbladder, nasal cavity, gastrointestinal tract, stomach, or tonsils. Larger sized stones can be ablated into smaller pieces using shock waves, ultrasonic energy (via specialized devices such as ultrasonic lithotriptors), or vibrational forces such as lasers.

Some endoscopes have aspiration channels (also known as suction channels) that transport resected tissue, stones (e.g., stones or stone fragments in various stone-forming areas) and mass, among other unwanted material. During the procedure, a flow of irrigation agent (e.g., saline) can be introduced to 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. In addition, 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).

Unwanted material generated during endoscopic procedures can accumulate and clog the working channels (e.g., suction or irrigation channels) of the endoscope. Monitoring channel blockages and clearing blocked channels in a timely and efficient manner can reduce procedure times and improve the efficiency, safety, and success rate of endoscopic procedures.

This document describes systems and methods for in situ clearing of a clog in a working channel of an endoscope during an endoscopic procedure while maintaining a 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 that provides 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 rates or aspiration flow rates through the working channel 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) during the endoscopic procedure, 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.

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 includes 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 providing 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.

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 or suction sources that provide irrigation fluid or suction pressure, respectively, to clear the clog in at least one working channel so long as the detected channel condition indicates that there is a clog in at least one working channel.

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

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 application of irrigation fluid and application of suction pressure to the at least one working channel.

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 or suction sources to unclog at least one working channel by adjusting a flow rate of the irrigation fluid or a flow rate of the suction pressure, respectively.

In Example 6, the subject matter of any one or more of Examples 3-5 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 the irrigation flow rate or aspiration flow rate through at least one working channel to maintain the sensed pressure substantially at a level of the desired pressure.

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.

In Example 8, the subject matter of any one or more of Examples 6-7 optionally includes at least one working channel, which 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 or aspiration channels to provide irrigation fluid at an adjustable irrigation flow rate to one of the irrigation or aspiration channels, and to fluidly couple an suction source to the other of the irrigation or aspiration channels to provide suction pressure at an adjustable suction flow rate to the other of the irrigation or aspiration channels.

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

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 a clog in the irrigation channel; control the irrigation source to provide irrigation fluid to the suction channel to maintain the sensed pressure at substantially 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 an absence of a clog in the irrigation channel.

In Example 11, the subject matter of Example 9 optionally includes a desired pressure, which 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 an aspiration pressure to the irrigation channel at a level that substantially neutralizes the increase in the sensed pressure.

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.

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.

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.

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.

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.

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 site in 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 site; 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 in response to the detected channel condition indicating the presence of a clog in the at least one working channel and so long as the detected channel condition indicates the presence of a clog in the at least one working channel, control one or more of the irrigation or suction sources providing irrigation fluid or suction pressure, respectively, to clear the clog in the at least one working channel, and adjust one or more of the irrigation or suction flow rates through the at least one working channel to maintain the sensed pressure at substantially the level of the desired pressure.

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 includes 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 aspiration source providing an irrigation fluid or aspiration pressure, respectively, to clear the clog in the at least one working channel.

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

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 a step of detecting a clog in at least one working channel in response to a decrease in the sensed flow rate below a first threshold, and a step of detecting an absence of a clog in at least one working channel in response to an increase in the sensed flow rate above a second threshold.

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.

In Example 22, the subject matter of any one or more of Examples 18-21 optionally includes receiving, via a 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 a level of the desired pressure.

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.

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 controlling an irrigation source to provide irrigation fluid to the aspiration channel in response to a clog in the aspiration channel, controlling an irrigation source to apply an aspiration pressure to the irrigation channel to maintain the sensed pressure at substantially a desired pressure level in response to an increase in the sensed pressure of the anatomical environment at the anatomical site, and controlling an irrigation source to apply an aspiration pressure to the aspiration channel and provide irrigation fluid to the irrigation channel in response to an absence of a clog in the aspiration channel.

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 the suction source to apply an aspiration 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 to maintain the sensed pressure at substantially a desired pressure level in response to a decrease in the sensed pressure of the anatomical environment at the anatomical site, and controlling the suction source to apply an aspiration pressure to the aspiration channel and control the irrigation source to provide irrigation fluid to the irrigation channel in response to an absence of a clog in the irrigation channel.

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 hereof. 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.

Various embodiments are illustrated by way of example in the accompanying drawing figures. Such embodiments are illustrative and are not intended to be exhaustive or exclusive embodiments of the present subject matter.

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. FIG. 2 shows a powered tissue removal device 200 that can be used in a system such as that described with reference to FIG. FIG. 2 shows a powered tissue removal device 200 that can be used in a system such as that described with reference to FIG. 1A-1C show an endoscopic system for unclogging occluded channels and maintaining pressure in an anatomical environment at a substantially desired level during an endoscopic procedure. 1A-1C show an endoscopic system for unclogging occluded channels and maintaining pressure in an anatomical environment at a substantially desired level during an endoscopic procedure. 1 illustrates an exemplary technique for clearing a blocked working channel of an endoscope according to one embodiment discussed herein. FIG. 13 illustrates the change in flow in the working channel in the presence of a clog and during the clog removal process. FIG. 13 illustrates the change in flow in the working channel in the presence of a clog and during the clog removal process. FIG. 1 illustrates an exemplary feedback control pressure regulation system that regulates environmental pressure when there is no channel blockage. FIG. 13 illustrates an exemplary feedback control pressure regulation system that regulates environmental pressure when there is a clog in the aspiration channel. FIG. 13 is a timing diagram for actuating irrigation/aspiration in the aspiration channel during unclog of a blocked aspiration channel. FIG. 13 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. FIG. 13 illustrates an exemplary feedback control pressure regulation system that regulates environmental pressure when there is a clog in the irrigation channel. FIG. 13 is a timing diagram for activating irrigation/aspiration in an irrigation channel during unclog of a blocked irrigation channel. FIG. 13 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. 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. 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 substantially at a desired level.

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. Thus, 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.

As used herein, "clog" refers to tissue debris, stones (e.g., kidney stones or stone fragments) and other material that accumulates and partially or completely blocks the lumen of a channel, and "clogging" refers to a state of partial or complete blockage of the lumen of a channel. Clogging can occur in any working channel of an endoscope. Clogging in the aspiration channel can greatly 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 expose the patient to high risk. On the other hand, clogging in an 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 the anatomical site and increase the likelihood of irrigation 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 possibility of heat buildup at the anatomical site. Also, clogging of any working channel can block the lens of the endoscope, 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.

Aspiration 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 the working channel (e.g., the aspiration or irrigation channel) can disrupt the pressure balance between the positive pressure associated with fluid flow and the negative pressure associated with aspiration, thereby exposing the internal organs to harmful excessive positive or negative pressure at the anatomical site.

Various approaches have been attempted to prevent or resolve channel blockages in endoscopes. For example, the likelihood of clogging the channel can be reduced by breaking down the unwanted material (e.g., tissue debris or stone fragments) into smaller pieces. However, this consumes more energy, can result in longer procedure times, and can increase risk to the patient due to added procedure complexity and time. Visibility is reduced due to fine particles or stone dust in the surgical field. Traditionally, clearing the blockage is typically performed externally, which requires the clinician to retract the endoscope from the body, flush the blocked endoscope to clear the blockage, and insert the endoscope back into the anatomical site. This approach increases procedure time, adds inconvenience to the clinician, and can increase surgical risk to the patient. Clearing the working channel in situ while the endoscope remains inserted and held in place typically requires high-pressure irrigation, which can create excessive positive pressure on internal organs.

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

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 keeping pressure changes on the anatomical environment under control during the procedure, while increasing the efficiency, safety, and success rate of endoscopic procedures.

Disclosed herein are systems and methods for in situ clearing of blockages in working channels in an endoscope, such as irrigation or aspiration channels, during an endoscopic procedure. According to one aspect herein, a clog clearing system can detect channel conditions indicative of the presence or absence of a blockage in the working channel using flow information sensed by a flow sensor, and clear the blocked channel by, for example, alternating application of irrigation fluid or aspiration pressure. The clog 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 pressure or a desired negative pressure as specified by a user, during the procedure.

The clog removal system and method according to various embodiments discussed herein provide an improved solution to in situ clogging of an endoscope during an endoscopic procedure. According to various aspects as described herein, the system and method provide a user with endoscopic examination without repeatedly inserting and removing endoscopic attachments and accessories for external cleaning and clogging. Compared to clogging via high pressure irrigation, which may expose the internal organs to the risk of high positive pressure, controlled irrigation and suction applied to the same clogged channel, for example, in alternation, as discussed herein, provides environmental stabilization of the internal organs. Various embodiments of this clogging removal system can avoid or minimize dangerous positive or negative pressure changes to the internal organs while clearing the channel by effectively separating different sized clogging particles that accumulate and block the channel. As a result, less invasive procedures can safely and more efficiently remove unwanted material from the anatomical site, shortening procedure times and improving patient safety and patient recovery times.

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 in a patient. The system 100 can include a medical instrument 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 instrument 110, the suction source 120, or the irrigation source 130. The aspiration/irrigation control unit can be adapted to different types of medical instruments and different types of irrigation and aspiration sources. An exemplary aspiration/irrigation control unit is discussed below with reference to FIGS. 3A-3B. The aspiration/irrigation control unit can selectively activate or deactivate irrigation and/or aspiration 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 suction and/or irrigation according to 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 the procedure.

The medical instrument 110 may 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 instrument 110 may be used in various ENT procedures, including, but not limited to, joint surgery, plastic surgery, sinus surgery, and tonsillectomy, or combinations thereof. The medical instrument 110 may 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 instrument 110 may include a handpiece or indirect control, for example, via a robotic surgery console or user interface.

An example of the medical instrument 110 may include a tissue removal device including a blade assembly configured to rotate and/or reciprocate to remove unwanted tissue from a target anatomy. The blade assembly may be driven by a motor powered by an energy source internal to the handpiece or alternatively external to the handpiece. The energy source may also perform other functions such as providing powered irrigation and suction to the medical instrument 110, as discussed below. For example, a variety of blade assemblies may be used including shavers, debriders, blades, or burrs, among others. Depending on the blade assembly used, the tissue removal device may 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 anatomy. Exemplary tissue removal devices are discussed below with reference to FIGS. 2A-2B.

Another example of the medical device 110 may include an endoscope. Examples of endoscopes may 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 may include a light source for illuminating the anatomical environment at the anatomical site and an imaging module for generating images or videos of the anatomical environment during the endoscopic procedure. Some endoscopes, such as endoscopic tissue removal devices, may include a tissue resection member configured to scrape, cut, scrape, or otherwise remove portions of unwanted tissue from the target anatomical structure. The resected tissue residue may then be extracted from the anatomical site. Some endoscopes may include a resection member configured to destroy or remove foreign bodies, such as crystalline mineral structures, from the anatomical environment. For example, a nephroscope may be inserted at least partially into the kidney. Among other energy modalities, ultrasonic energy, electromagnetic shock waves, or lasers can be delivered to the kidney stone to break it into fragments or "stone dust" that can then be extracted from the anatomical site. An exemplary endoscope is discussed below with reference to Figures 3A-3B.

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).

The suction source 120 can function to pull, aspirate, 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 instrument 110, inside the handpiece, or into a receptacle located remote from the medical instrument 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 instrument 110. In one example, the suction source 120 can be separate from the medical instrument 110 and connected to the medical instrument 110 via one or more tubes, wires, or hoses. In another example, the suction source 120 can be included or attached to the medical instrument 110. For example, the suction source 120 can be included in a handpiece of a tissue removal device or endoscope. The suction source can be powered by an energy source that also powers the medical device, or it can be powered by its own energy source.

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) 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 cutting 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 a pressurized irrigation flow. The irrigation fluid can be provided from the irrigation source 130 or wherever the irrigation fluid is contained to and through the external fluid supply tube and drawn into the working channel 111. Under the 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 removed from the anatomical site.

In one example, a single working channel 111 can be used for both irrigation and aspiration. The control module 160 can controllably activate irrigation and aspiration 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 an aspiration 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 and can direct unwanted material being aspirated through the suction channel 112. The irrigation channel 114 can be controllably connected to a irrigation source 130 and can direct irrigation fluid through the irrigation channel 114. 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.

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 hand piece 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, hereafter referred to as the "irrigation gap." 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 allows the clinician to advantageously regulate how much irrigation fluid to use 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.

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 aspiration, 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 to activate, deactivate, or modify 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.

The control module 160 may be at least partially implemented in a unit separate from the medical device 110, such as that shown in Figures 3A-3B. Alternatively, portions of the control module 160 may be integrated into or otherwise attached to the medical device 110. In some examples, the control module 160 may 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 may include invariably connected components (e.g., hardwired) designed to perform a particular operation. In one example, the hardware of the circuit set may include variably connected physical components (e.g., execution units, transistors, simple circuits, etc.) that include computer-readable media (e.g., magnetic, electrically movable arrangements of invariable mass particles, etc.) that are physically modified to encode instructions for a particular operation. In connecting the physical components, the underlying electrical properties of the hardware components are changed, for example, from an insulator to a conductor, or vice versa. The instructions allow the embedded hardware (e.g., execution units or loading mechanisms) to create members of the circuit set in the hardware via the variable connections to perform some of the particular operations when in operation. Thus, the computer-readable medium is communicatively coupled to other components of the circuit set members when the device 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 the second circuit set at a different time.

As shown in FIG. 1, the control module 160 is coupled to a user interface 140 and can receive user commands from the user interface 140 to activate, deactivate, or adjust one or more functionality 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 the fluid system (e.g., pump, irrigation). In one example, the user interface 140 can include one or more user controls that allow a user (e.g., 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, the control module 160 can activate or stop the aspiration flow from the aspiration source 120, or increase or decrease the aspiration pressure applied to the working channel 111 to achieve a desired aspiration flow rate. Similarly, the 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, the control module 160 can activate or stop the irrigation flow from the irrigation source 130, or increase or decrease the irrigation flow rate through the working channel 111.

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, a positionable lever, or a positionable dial that may specify a irrigation and/or suction level. In some examples, the user interface 140 allows a user to select from one of multiple specified separate irrigation or suction levels, or alternatively specify a irrigation or suction level in a continuous (e.g., non-separate) manner.

In addition to or instead of independent control of aspiration and irrigation, the control module 160 can automatically control either irrigation or aspiration based on the state of the other of irrigation or aspiration. In one example, the control module 160 can automatically turn on suction when the medical device is powered 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 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 aspiration 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 provide irrigation fluid through only the irrigation channel 114 or the irrigation gap, but not both.

The control module 160 can 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 can monitor channel conditions and detect channel clogs based on flow information in the working channel 111. The sensor circuit 150 can 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 in the working channel 111. The flow sensor, such as a microelectromechanical system (MEMS) sensor, can employ a variety of flow measurement technologies. By way of example and not limitation, the flow sensor can include, among others, a thermal anemometer that measures the rate of transfer of heat generated from a heat source, a differential pressure sensor that measures the pressure drop over a range of locations, an ultrasonic flow sensor that measures the frequency shift or Doppler effect of travel/time of flight, an electromagnetic sensor that measures a change in fluid conductance indicative of flow rate.

The clog controller 161 can detect a channel clog using flow information sensed by the 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 the channel, such as when the variability of the 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 (exceeding a specified tolerance) than the inflow rate, indicates the presence of a channel clog.

When there is a channel clog, the clog controller 161 can automatically switch from a standard mode of irrigation/aspiration operation (e.g., the suction source 120 provides aspiration 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 the clogged channel, the clog controller 161 can alternate between applying irrigation fluid and applying suction pressure to the clogged 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 occluded by a clog 412 during a standard mode of irrigation operated by the irrigation source 140. The clog 412 includes tissue debris or stone fragments of different sizes. As shown in FIG. 410, smaller particles, such as particle 412A, are located proximally, and larger particles, such as particle 412B, are located distally. Diagram 420 illustrates switching from standard mode to clog clearing mode, where clog controller 161 fluidly couples suction source 120 to the proximal portion of channel 411 and activates suction source 120 to apply 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 greater 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.

Diagram 430 shows a fluid-filled channel 411 blocked by a clog 413 during a standard mode of aspiration actuated by the suction source 120. The particles of the clog 413 accumulate differently than the clog 412, with smaller particles, such as particle 413A, located distally and larger particles, such as particle 413B, located proximally. Diagram 440 shows switching from the standard mode to the clog unclog mode, where 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 irrigate the channel 411 for a specified irrigation duration. The user can adjust the irrigation flow rate, or the pressure at which the irrigation fluid is pumped, and the irrigation duration. Clog particles of different sizes (and therefore different masses) can respond differently to the irrigation fluid for rinsing. For example, the smaller particles 413A can move toward the distal end of the channel at a faster rate and travel a greater distance during (and after) application of the irrigation than the larger particles 413B. As a result, some particles can be removed from the clog 413 and separated from larger particles.

The separated particles can be extracted down the working channel 411 using additional irrigation and/or aspiration. In one example, one or more of the suction pressure, the suction flow rate, the irrigation flow rate, or the pump pressure for pressurizing the irrigation 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.

4B-4C are diagrams illustrating the change in flow in the working channel in the presence of a clog and during the clog removal process. FIG. 4B illustrates the change in flow in a clogged irrigation channel, as shown in FIG. 4A, 410 and 420. A flow sensor placed in the irrigation channel can be used to measure flow parameters such as flow rate. The flow measurements (on the y-axis) have values between -1 and 1. Positive flow values represent a flow direction toward the distal end of the aspiration channel (or toward the anatomical environment 101, see FIG. 4A, 410). 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. 4A, 420). The values of the flow measurements are relative to the 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.

During a standard mode of irrigation of an unclogging irrigation channel, a positive flow F0 of approximately a value of "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 is reduced to F1 (less than F0). A clog is detected if the reduction 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 irrigation continues. Particles continue to accumulate until the flow rate is reduced to F2 at T2, where F2 is approximately zero, indicating substantial channel blockage (as shown in diagram 410 of FIG. 4A). An unclogging mode can be activated at T2 or at a time corresponding to a particular (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 aspiration 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 greater distance toward the proximal end of the channel. While the channel is being unclogged, suction can be continued, allowing the negative flow F3 to reach 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 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.

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

During a standard mode of aspiration applied to an unclogging aspiration channel, a positive flow F0 of approximately a value of "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 is reduced to F1 (less than F0). A clog is detected if the reduction 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 is reduced to F2 at T2, where F2 is approximately zero, indicating substantial channel blockage (as shown in diagram 430 of FIG. 4A). At T2, or at a time corresponding to a particular (e.g., user-specified) flow condition, a clog clearing mode can be activated. Irrigation fluid can be injected into the occluded 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 greater distance toward the distal end of the channel. While the channel is being unclogged, the wash continues, allowing the negative flow F3 to reach near maximum ("-1", indicating substantially unobstructed flow) at T3. After application of the wash for a specified period of wash time, the wash can be stopped at T4. As the separated particles settle in the channel, the negative flow rate can then decrease to a substantially zero flow F4. At T5, the standard suction mode is resumed by applying additional suction to extract the dislodged particles from the channel. Once the channel has been successfully unclogged and the particles have been removed from the channel, a positive flow F5 with a value of approximately "1" can be sensed by the flow sensor.

In some examples, suction pressure and cleaning fluid can be applied to the channel 411 in an alternating manner. 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 cleaning can also help reduce the occurrence of clog formation. While suction and cleaning are applied in an alternating manner, the sensor circuit 150 can monitor the flow rate. The clog unclog operation, including application of cleaning fluid or suction pressure to the blocked channel, can continue as long as the channel clog is present. If the monitored flow rate increases and exceeds a threshold, the clogged channel is deemed to have been successfully unclogged. The clog controller 161 can switch from the clog unclog mode of operation back to a standard mode of cleaning/aspiration operation.

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., to 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., as one non-limiting example, ±5% to 10%. 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, aspiration 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 have adverse effects on 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 the desired pressure level, desired flow conditions can be received, e.g., from the user interface 140. The desired flow conditions include information about the inflow (e.g., the flow rate of irrigation fluid applied to the anatomical environment) versus the 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 rate higher than outflow rate corresponds to a positive environmental pressure, and a desired flow condition of inflow rate lower than outflow rate corresponds to a negative environmental pressure. The 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.

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 environmental pressure, or a signal indicative of the environmental pressure, or otherwise correlated to the environmental 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 instrument 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 located at a more proximal location inside the tubular portion of the endoscope, away from the anatomical environment 101. The control module 160 can receive from the user interface 140 a desired environmental pressure to be maintained during the procedure. 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.

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

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 of the blockage, and environmental pressure, as sensed by the sensor circuit 150.

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 hand piece 210 and a tubular assembly 222 extending from the hand piece 210. The tubular assembly 222 includes a proximal portion 226 disposed in the hand piece 210 and an opposing distal portion 228. Although the distal portion 228 is shown as a "straight shaft" aligned with the remainder of the tubular assembly 222, in some instances the distal portion 228 can be bent or angled relative to the remainder of the tubular assembly 222, including the proximal portion 226.

An exemplary configuration of the distal portion 228 is shown in FIG. 2B. The tubular assembly 222 includes an outer tubular member 252 and an inner tubular member 254 disposed inside the outer tubular member 252. The outer member 252 includes an outer member window 262. The inner member 254 includes a cutting portion 264 and an aspiration channel 274 defined inside the inner member 254. The inner member 254 or the cutting portion 264 includes an inner member window 266 in communication with the aspiration channel 274.

The powered tissue removal device 200 includes an irrigation channel 272 disposed on the exterior or outside 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 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.

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, which is 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 vacuum from the powered tissue removal device 200 via the suction channel 274. The irrigation source 230, which is an embodiment of the irrigation source 130, can be in fluid communication with an irrigation channel 272 disposed on or outside 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.

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 an embodiment of the user interface 140, may be located on the handpiece 210 to allow for easy access and manipulation by a user during a procedure. In one example, the user controls 224 allow a user to manually control the debridement and to activate, stop, or adjust one or more of the irrigation flow rate or the aspiration flow rate, among other irrigation or aspiration parameters.

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 an 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 a separate irrigation channel or a separate aspiration channel) based on a sensed flow rate from the working channel, and clear the clog in the clogged channel, e.g., by alternating application of irrigation fluid and application of 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 a substantially user-specified desired pressure during the procedure, as discussed above with reference to FIG. 1.

3A-3B show, respectively, example endoscopic systems 300A and 300B for use in an endoscopic procedure. Endoscopic systems 300A and 300B are embodiments of system 100. Referring to FIG. 3A, system 300A includes endoscope 310A, suction source 320, irrigation source 330, and suction/irrigation control unit 340. Endoscope 310A, an example of medical device 110, can extend into a sheath including tube 311 that extends from a distal end to hub 312. Hub 312 terminates at a proximal end. Endoscope 310 can include light port 314 and visual port 315. Light port 314 can function to provide light into and out of endoscope tube 311 such that features of interest in an anatomical environment (e.g., resected tissue or stones and matter) are illuminated. For example, light port is advantageous for enhancing visibility when features of interest are located in low light conditions. The visual port 315 can function to provide a viewing window that allows the user to view features of the subject. 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 to a camera that captures images or videos of the features and anatomical environment of the subject. The images or videos can be output and displayed on a monitor.

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 transport 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 the aspiration channel are located separately within the tube 311.

In one example, the endoscope 310 can be a nephroscope. In use, a flexible distal portion of the tube 311 can be surgically inserted into the patient's kidney. A proximal portion of the tube 311 can remain outside the patient's body. The inside 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 that corresponds to the spectral peak of absorption of human blood and saline, such as 2100 nm, 1942 nm, etc. In general, 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 tissue nearby. A laser controller can be located on the graspable proximal portion of the endoscope 310. Similar to the user controls 224 that allow manual control of wound debridement as shown in FIG. 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.

The suction/irrigation control unit 340 can keep 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 the endoscope 310 during an endoscopic procedure. The suction/irrigation control unit 340 can include a pressure monitor (which is an embodiment of the sensor circuit 150), a control module (which is an embodiment of the control module 160), a pump, and a power source. The control module can communicate with a user interface 341 (which is an embodiment of the user interface 140), which is located external to the suction/irrigation control unit 340, for controlling the control module.

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 the 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 with 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.

A control module in the aspiration/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 a sensed flow rate 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 of the 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 pressure level, as discussed above with reference to FIG. 1.

System 300B as shown in FIG. 3B is similar to system 300A and includes endoscope 310B, suction source 320, irrigation source 330, and control suction/irrigation control unit 340. Similar to endoscope 310A, endoscope 310B can include tube 311, hub 312, light port 314, and visual port 315. However, instead of a single irrigation/suction port 313, endoscope 310B includes separate suction port 313A and irrigation port 313B adapted to be in fluid communication with suction source 320 and irrigation source 330, respectively. Suction source 320 is fluidly coupled to suction port 313A via external suction line 326. Irrigation source 330 is fluidly coupled to irrigation port 313B via 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 channel and suction channel are separately disposed within tube 311. The suction port 313A can be selectively opened to either the suction channel or the irrigation channel. Similarly, the irrigation port 313B can be selectively opened to either the suction channel or the irrigation channel inside the tube 311.

FIG. 5 illustrates an exemplary feedback-controlled pressure regulation system 500, which is one embodiment of the environmental pressure control portion of the system 100. The system 500 can be configured to regulate environmental pressure at an anatomical site when no channel clogging is indicated and when the system 500 operates in a standard mode of irrigation/aspiration (e.g., controlling the suction source 120 to provide aspiration pressure to the aspiration channel 112 and the irrigation source 130 to provide a flow of irrigation fluid to the irrigation channel 114). The system 500 can regulate environmental pressure via automatic adjustment of the aspiration and/or irrigation flow rates in the aspiration channel 112 and the irrigation channel 114, respectively. In one example, the longitudinal axis of the aspiration channel 112 and the longitudinal axis of the irrigation channel 114 can be parallel to one another. In one example, the aspiration channel 112 and the irrigation channel 114 can be coaxially arranged on 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 the 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.

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 the 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 positive or negative (corresponding to the desired flow condition of an imbalance between inflow and outflow). When operating in a stable pressure mode, the irrigation or aspiration flow rates 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 suction pressure to the suction channel 112. A negative pressure can be generated by suction 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 driven and maintained at substantially zero.

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

In some situations, it is desirable to maintain a positive or negative environmental pressure at an anatomical site. A controlled positive pressure within a safe range can help distend an anatomical structure (e.g., ureter, kidney, uterus, or other organ) during an endoscopic procedure, allowing better visibility 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 removing the 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 also facilitate extraction of debris from the anatomical structure without exposing internal organs to the risk of excessive negative pressure.

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

Similarly, when a desired negative environmental pressure is provided by a user, for example via the user interface 140, the system 500 can operate in a pressure control mode. The control module 160 can automatically increase the aspiration flow rate through the aspiration channel 112 to increase the negative environmental pressure at the anatomical site. Additionally or alternatively, the control module 160 can automatically decrease the irrigation flow rate through the 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.

The control module 160 may include a safety mechanism that keeps the pressure of the anatomical environment within a safety range defined by a lower limit of negative pressure and an upper limit of positive pressure. If the sensed environmental pressure reaches the upper limit of positive pressure, the control module 160 may automatically stop, reduce, or maintain the irrigation flow at the current amount to prevent further increases in environmental pressure. Similarly, if the sensed environmental pressure reaches the lower limit of negative pressure, the control module 160 may automatically stop, reduce, or maintain the aspiration flow at the current amount to prevent further decreases in environmental pressure. When the system operates in pressure control mode, the desired positive pressure and the desired negative pressure received from the user are checked to ensure that the desired positive pressure and the desired negative pressure are within the safety 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 (e.g., from the user interface 140) can be issued 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 a safety mechanism, the control module 160 can maintain the environmental pressure at a user-specified level while simultaneously preventing or minimizing excessive positive or negative pressure on the anatomical environment during a procedure.

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

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 the environmental pressure via 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 the aspiration pressure, to drive the environmental pressure toward a desired level of pressure.

In one example, the desired pressure is substantially a net zero pressure. The pressure controller 162 can adjust the aspiration flow rate or aspiration pressure in the irrigation channel 114 to substantially counteract the increase 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.

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 actuating irrigation/aspiration in the aspiration channel when a clog occurs in the aspiration channel 112 (as shown in Figure 6A). To clear the clog in the aspiration channel, irrigation is applied to the aspiration channel for duration t1 ("irrigation duration"). After a transition period _td , suction pressure is applied to the aspiration channel for duration t2 ("suction duration"). The transition period _td allows clogged particles of different sizes and masses to travel different distances along the aspiration channel, which facilitates particle separation and clearing of the channel. Irrigation can induce a positive anatomical pressure (+PA) 661 and suction can induce a negative pressure (-PA) 662 at the anatomical site.

FIG. 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 irrigation to the irrigation channel 114, which can generate a negative anatomical pressure (−PA) 671 to counteract 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 counteract the negative anatomical pressure (−PA) 662 at the anatomical site. In this manner, the pressure of the anatomical environment can be maintained at a desired level while the blocked aspiration channel is being unclogged.

When the flow monitor 650 senses an increase in flow 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 suction source to apply aspiration pressure to the aspiration channel and controlling 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.

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

Application of suction pressure to the irrigation channel 114 may result in a pressure decrease at the anatomical site of the anatomical environment 101. The pressure controller 162 of the control module 160 may regulate the environmental pressure via 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 may be sensed by the pressure monitor 550), the pressure controller 162 may automatically activate irrigation fluid flow into the aspiration channel 112. If the aspiration channel 112 is not clogged, the irrigation fluid applied to the aspiration channel 112 may generate a positive pressure to offset the pressure decrease in the anatomical environment 101 generated by the aspiration through the irrigation channel 114. In one example, the pressure monitor 550 may continuously or periodically monitor the environmental pressure, and the pressure controller 162 may adjust the irrigation flow rate to direct the environmental pressure toward a desired level of pressure.

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 directed 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 directs the sensed environmental pressure toward the desired level of positive pressure. 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 directs the sensed environmental pressure toward the desired level of negative pressure.

FIG. 7B is a timing diagram for actuating irrigation/aspiration in the irrigation channel when a clog occurs in the irrigation channel 114 (as shown in FIG. 7A). To unclog the irrigation channel, suction is applied to the irrigation channel for duration t3 ("aspiration duration"). After a transition period _td , irrigation pressure is applied to the irrigation channel for duration t4 ("irrigation duration"). The transition period _td allows clog particles of different sizes and masses to travel different distances along the irrigation channel, which facilitates particle separation and channel unclog. At the anatomical site, suction can induce a negative anatomical pressure (-PA) 761 and irrigation can induce a positive anatomical pressure (+PA) 762.

FIG. 7C is a timing diagram of actuating 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 actuate 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 actuate 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 of the anatomical environment can be maintained at a desired level while the blocked irrigation channel is being unclogged.

When the flow monitor 650 senses an increase in flow 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 suction source to apply aspiration pressure to the aspiration channel and controlling 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.

FIG. 8 is a flow chart illustrating a method 800 for in situ clearing of a blockage in a 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 can include tissue removal devices, such as those shown in FIGS. 2A-2B, or endoscopes, such as those shown in FIGS. 3A-3B, among others. The medical device can include one or more working channels configured to provide irrigation fluid to an anatomical site and transport tissue debris, stones or masses, bodily fluids, and irrigation fluid away from the anatomical site, collectively referred to herein as unwanted material. The working channels can be disposed at least partially inside the tubular portion of the medical device. In one example, the working channel is a unified irrigation/aspiration channel that is controllably used (e.g., at different times) for irrigation and aspiration. In another example, the working channel can include separate irrigation and aspiration channels disposed within the tubular portion of the medical device. The irrigation and aspiration channels can each receive irrigation fluid or aspiration pressure, for example under automated control by a controller unit, and can perform different tasks or serve different functions during an endoscopic procedure, according to various embodiments discussed herein.

Method 800 includes one or more processes for operating a clog clearing 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 depicted herein.

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 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 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, for example using a clog controller 161. In one example, a channel clog can be detected in response to a decrease in flow rate, for example 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.

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

Clog particles of different sizes (and therefore different masses) can respond differently to suction or to a washing fluid. As shown in FIG. 4A, smaller particles can move faster and travel longer distances along the direction of the suction flow or fluid flow than larger particles, so suction, washing, or alternating suction and washing can help remove smaller particles from the clog mass and separate them from the rest of the clog. Additional suction or washing flows can be applied to the working channel to more easily and efficiently extract separated particles down the working channel. In one example, one or more of the suction pressure, suction flow rate, washing 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.

During the unclogging process, the flow rate can be continuously or periodically monitored (810). If the monitored flow rate increases and exceeds a threshold at 830, the blocked channel is deemed to be successfully unclogging. The unclogging mode of operation can then be returned to the standard mode of irrigation/aspiration operation.

FIG. 9 is a flow chart illustrating a method 900 for in situ clearing of a blockage in a working channel of a medical device while keeping the pressure of the anatomical environment ("ambient pressure") under control, e.g., 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.

Method 900 includes steps 910-940 for detecting a blockage in the working channel and clearing the blocked channel, which are similar to steps 810-840 of method 800. Method 900 further includes steps 950-980 for adjusting the environmental pressure during a procedure (e.g., an endoscopic procedure) when there is or is not a channel blockage. As previously mentioned, 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 the environmental pressure at a controlled pressure level can effectively reduce procedure time with improved patient safety.

Regulation of environmental pressure can be accomplished 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 the 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.

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 a 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 expand an anatomical structure (e.g., a ureter, kidney, or other organ) during an endoscopic procedure to allow better visibility of the anatomical structure through the endoscope without causing tissue damage from excessive positive pressure. The positive pressure can also prevent tissue debris or stone fragments from becoming lodged in the anatomical structure and aid in removing 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 extraction of debris from the anatomical structure without exposing internal organs to the risk of excessive negative pressure.

If the pressure sensed at 960 does not substantially reach the desired level of pressure (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 drive the environmental pressure toward the desired level of pressure. In some examples, in addition to or instead of the desired pressure level, desired flow conditions can be received, e.g., from user interface 140. The desired flow conditions include information about the inflow (e.g., flow rate of irrigation fluid applied to the anatomical environment) relative to the outflow (e.g., 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.

When no blockage 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, the suction applied to the aspiration channel can generate a negative pressure in the anatomical environment, which can counteract the increase in environmental pressure generated by the increase in irrigation flow rate. The aspiration flow rate, or aspiration pressure, can be adjusted until the increase in sensed pressure (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 provided to the irrigation channel can generate a positive pressure in the anatomical environment, which can counteract the decrease in environmental pressure generated by aspiration. The irrigation flow rate can be adjusted until the decrease in sensed pressure (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.

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

In another example where the irrigation channel is clogged and the aspiration channel is not clogged, suction pressure can be applied to the irrigation channel to unclog the blocked irrigation channel. This 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 counteract a negative increase in the anatomical environment. The irrigation flow rate can be adjusted until the decrease in the 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.

At 980, check if the procedure is complete. If not, flow sensing and clearing processes 910 to 940 and pressure control processes 950 to 980 can continue.

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

Additional Notes The above detailed description includes references to the accompanying drawings, which form a part of the detailed description. The drawings show, by way of example, 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 those elements (or one or more aspects thereof) shown or described with respect to the particular example (or one or more aspects thereof) or with respect to other examples (or one or more aspects thereof) shown or described herein.

In this specification, the terms "a" or "an" are used to include one or more than one, as is common in patent documents, independent of any other instances or usages of "at least one" or "one or more." In this specification, the term "or" is used to refer to a non-exclusive or, such that "A or B" includes "A but not B," "B but not A," and "A and B," unless otherwise specified. In this specification, 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., a system, device, article, composition, formulation, or process that includes several elements in addition to those recited after such terms in a claim is still considered to be within the scope of that claim. Also, in the following claims, terms such as "first," "second," and "third" are used merely as labels and are not intended to impose numerical requirements on these objects.

The above description is intended to be illustrative, not limiting. For example, the above examples (or one or more aspects thereof) can be used in combination with each other. Other embodiments can be used by those of ordinary skill in the art who have reviewed the above description, for example. 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 features are essential to any claim. Rather, inventive subject matter may not satisfy all features of a particular disclosed embodiment. Thus, it is contemplated that the following claims are incorporated herein in the Detailed Description 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 present invention should be determined with reference to the appended claims, along with the full scope of equivalents to which such claims are entitled.

100 System 101 Anatomical environment 110 Medical device 111 Working channel 112 Aspiration channel 114 Irrigation channel 120 Suction source 130 Irrigation source 140 User interface 150 Sensor circuit 160 Control module 161 Clogging controller 162 Pressure controller 200 Powered tissue removal device 210 Hand piece 220 Suction source 222 Tubular assembly 224 User control 226 Proximal portion 228 Distal portion 230 Irrigation source 240 Energy source 252 Outer tubular member 254 Inner tubular member 262 Outer member window 264 Cutting portion 266 Inner member window 272 Irrigation channel 274 Aspiration channel 282 Proximal irrigation port 284 Distal irrigation port 300A Endoscope system 300B Endoscope system 310A Endoscope 310B Endoscope 311 Tube 312 Hub 313 Irrigation/Aspiration Port 313A Aspiration Port 313B Irrigation Port 314 Light Port 315 Vision Port 320 Suction Source 326 External Suction Line 330 Irrigation Source 336 External Irrigation Line 340 Aspiration/Irrigation Control Unit 341 User Interface 342 Control Valve 350 Connector 352 Pressure Sensor 356 Common Line 411 Fluid Fill 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 (17)

1. A system for clearing a blockage in at least one working channel of a medical device during a procedure on a patient, comprising:
a flow sensor configured to sense a flow rate through the at least one working channel of the medical device;
detecting a channel condition indicative of a presence or absence of a clog in the at least one working channel based on the sensed flow rate;
and in response to the detected channel condition indicating a clog in the at least one working channel, alternating application of an irrigation flow and an aspiration flow to the at least one working channel, separating the application of the irrigation flow and the application of the aspiration flow by a specified or adjustably specifiable time interval to allow separation of clog particles by motion.
A control module configured as follows:
Including,
a first period of time for applying one of the irrigation flow or the suction flow to the at least one working channel, then ceasing application of the irrigation flow and the suction flow for a predetermined transition period to allow clogged particles of different sizes and masses to travel different distances along the at least one working channel, thereby facilitating separation of the particles, and then applying the other of the irrigation flow or the suction flow to the at least one working channel for a second period of time. The system of claim 1, wherein the control module is configured to alternate between the application of the irrigation flow and the application of the aspiration flow for as long as the detected channel condition indicates a clog in the at least one working channel. The system of claim 1 or 2, wherein the control module is configured to apply the irrigation flow to the at least one working channel using a first adjustable pressure or a first adjustable flow rate, and to apply suction to the at least one working channel at a second adjustable pressure or a second adjustable flow rate. The system of any one of claims 1 to 3, wherein the control module is configured to apply the irrigation flow to the at least one working channel for a first specified or adjustably specifiable duration and to apply suction to the at least one working channel for a second specified or adjustably specifiable duration. The control module includes:
detecting a clog in the at least one working channel in response to a decrease in the sensed flow rate below a first threshold;
detecting the 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.
The system according to any one of claims 1 to 4, configured so as to The system further includes a pressure sensor configured to sense a pressure of an anatomical environment at the patient's anatomical location, and the control module further comprises:
receiving a desired pressure to be applied to an anatomical environment at an anatomical site within the patient;
adjusting one or more of the irrigation flow or the aspiration flow to maintain the sensed pressure in the anatomical environment substantially at the desired pressure level.
The system according to any one of claims 3 to 5, configured as follows: The system further includes a pressure sensor configured to sense a pressure of an anatomical environment at the patient's anatomical location, and the control module further comprises:
receiving a desired flow condition within the at least one working channel representing a relative state between the irrigation flow and the aspiration flow and corresponding to a desired pressure to be applied to the anatomical environment;
adjusting one or more of an irrigation flow or an aspiration flow to maintain the desired flow conditions in the at least one working channel;
The system according to any one of claims 3 to 5, configured as follows: The at least one working channel includes an aspiration channel and an irrigation channel, and the control module is further configured to:
fluidly coupling an irrigation source to one of the irrigation channel or the aspiration channel to provide the irrigation flow at an adjustable pressure or an adjustable flow rate to the one of the irrigation channel or the aspiration channel;
a suction source fluidly coupled to the other of the irrigation channel or the aspiration channel to provide the aspiration flow at an adjustable pressure or an adjustable flow rate to the other of the irrigation channel or the aspiration channel;
The system according to claim 6 or 7, configured as follows. The control module includes:
In response to a clog in the aspiration channel, controlling the irrigation source to provide an irrigation flow to the aspiration channel;
in response to an increase in the sensed pressure in the anatomical environment, controlling the suction source to apply aspiration flow to the irrigation channel to maintain the sensed pressure substantially at a level of the desired pressure;
in response to the absence of a clog in the aspiration channel, controlling the suction source to apply aspiration flow to the aspiration channel and controlling the irrigation source to provide an irrigation flow to the irrigation channel.
The system of claim 8 , configured as follows: The control module includes:
controlling the suction source to apply a suction flow to the irrigation channel in response to a clog in the irrigation channel;
controlling the irrigation source to provide an irrigation flow to the aspiration channel in response to a decrease in the sensed pressure of the anatomical environment at the anatomical site to maintain the sensed pressure substantially at a level of the desired pressure;
in response to the absence of a clog in the irrigation channel, controlling the suction source to apply an aspiration flow to the suction channel and controlling the irrigation source to provide an irrigation flow to the irrigation channel.
The system of claim 8 , configured as follows: The system of claim 9, wherein the desired pressure is substantially a net zero pressure, and the control module is configured to control the suction source in response to the increase in the sensed pressure to apply suction flow to the irrigation channel at an adjustable flow rate to substantially neutralize the increase in the sensed pressure. 11. The system of claim 10, wherein the desired pressure is substantially a net zero pressure, and the control module is configured to control the irrigation source in response to the decrease in the sensed pressure to provide an irrigation flow to the aspiration channel at an adjustable flow rate to substantially counteract the decrease in the sensed pressure. The system of claim 9, wherein the desired pressure is a positive pressure, and the control module is configured to control the suction source in response to the increase in the sensed pressure to apply aspiration flow to the irrigation channel at an adjustable rate to maintain the sensed pressure substantially at a level of the desired positive pressure. 11. The system of claim 10, wherein the desired pressure is a positive pressure, and the control module is configured to control the irrigation source in response to the decrease in the sensed pressure to provide irrigation flow to the aspiration channel at an adjustable flow rate to maintain the sensed pressure substantially at the level of the desired positive pressure. The system of claim 9, wherein the desired pressure is a negative pressure, and the control module is configured to control the suction source in response to the increase in the sensed pressure to apply aspiration flow to the irrigation channel at an adjustable rate to maintain the sensed pressure substantially at a level of the desired negative pressure. 11. The system of claim 10, wherein the desired pressure is a negative pressure, and the control module is configured to control the irrigation source in response to the decrease in the sensed pressure to provide an irrigation flow to the aspiration channel at an adjustable flow rate to maintain the sensed pressure substantially at a level of the desired negative pressure. an endoscope including an imaging module, a surgical module, and at least one working channel configured to pass irrigation or aspiration flow therethrough;
a user input configured to receive from a user a desired pressure to be applied to the anatomical environment at the anatomical location of the 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
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;
in response to the detected channel conditions indicating a clog in the at least one working channel, and for as long as the detected channel conditions indicate a clog in the at least one working channel, alternating application of an irrigation flow and an aspiration flow to the at least one working channel, separating the application of the irrigation flow and the application of the aspiration flow by a specified or adjustably specifyable time interval to allow separation of clog particles by motion;
adjusting one or more of irrigation or aspiration flows through the at least one working channel to maintain the sensed pressure substantially at the level of the desired pressure.
A control module configured as follows:
Including,
An endoscopic surgery system comprising: applying one of the irrigation flow or the aspiration flow to the at least one working channel for a first period of time, then ceasing application of the irrigation flow and the aspiration flow for a predetermined transition period to allow clogged particles of different sizes and masses to travel different distances along the at least one working channel, thereby facilitating separation of the particles, and then applying the other of the irrigation flow or the aspiration flow to the at least one working channel for a second period of time.