Embodiments disclosed herein relate to devices and methods for accessing body cavities or other body areas.
All publications and patent applications mentioned in this specification are herein incorporated by reference to the same extent as if each such individual publication or patent application were specifically and individually indicated to be so incorporated by reference.
Certain medical procedures, including laparoscopy, endoscopy, tissue sampling, biopsy, tracheotomy, vascular access, central nervous system access, lung access, amniotic access, tumor access, natural body lumen access, etc., require fairly precise access to the body. Current trocar, cannula, needle and other types of access systems are often “blind”, or require auxiliary visualization, such as fluoroscopy, X-ray, ultrasound imaging etc.
An access device is needed which can alert the user when it is in the desired location in the body.
The conductive access devices and methods disclosed herein include conductive areas which can determine the conductivity and/or impedance of tissue as the device is moved through the tissue and placed. Certain changes in conductivity/impedance indicate when the access device is placed in its desired location. The conductive/impedance properties of the body tissues may be inherent, or may be altered by the device, or otherwise. For example, a blunt access device may blanch tissue as the tissue is spread by the device, creating changes in tissue conductivity/impedance. Another example is an access device which includes cautery or ablation capabilities. The cauterization or ablation of the tissue may change the conductivity/impedance of the tissue.
One embodiment of the access device includes an apparatus for accessing a portion of a body including a cannula configured for insertion into the body, a first electrode at or near a distal end of the cannula, where the first electrode is positioned to contact tissue adjacent to the distal end of the cannula during advancement into the body, a second electrode, a controller in communication with the first electrode via a first lead and in communication with the second electrode via a second lead, where the first lead runs through an inner lumen of the cannula and where the apparatus is configured to detect an impedance or a conductance of the tissue between the first electrode and the second electrode and where the controller is configured to receive one or more signals from the tissue adjacent to the distal end of the cannula and detect a change in property of the tissue as the cannula is advanced, and where the controller is further configured to determine a position of the distal end of the cannula during advancement into the body. Other embodiments of this aspect include corresponding computer systems, apparatus, and computer programs recorded on one or more computer storage devices, each configured to perform the actions of the methods.
Implementations may include one or more of the following features: The access device apparatus where the second electrode is positioned at or near the distal end of the cannula and the second lead runs through the inner lumen of the cannula. The apparatus where the second electrode is positioned on a skin of the body. The apparatus where the cannula includes a blunt distal tip. The apparatus where the first lead is embedded in a wall of the cannula. The apparatus where the first electrode is incorporated into a stylus that is configured to be inserted into the inner lumen of the cannula. The apparatus where the second electrode is incorporated into the stylus. The apparatus where the stylus is removable from the cannula. The apparatus where the stylus includes a stylus inner lumen. The apparatus which includes a locking mechanism to lock the stylus in place within the cannula. The apparatus where the cannula is inserted into the body manually. The apparatus where the cannula is inserted into the body automatically. The apparatus where the first lead includes an insulated portion of a shaft of the cannula and the first electrode includes an uninsulated portion of the shaft of the cannula. Implementations of the described techniques may include hardware, a method or process, or computer software on a computer-accessible medium.
One general aspect includes a method for accessing a portion of a body including advancing a cannula into the body so that the cannula contacts tissue adjacent to the cannula during advancement via a first electrode positioned at or near a distal end of the cannula. The method may also include positioning a second electrode so that it is in contact with the body. The method may also include receiving one or more signals from the tissue in contact with the first and second electrodes via the first lead and a second lead. The method may also include detecting a change in an impedance or a conductance of the tissue between the first electrode and the second electrode via a controller in communication with the first and second electrodes as the cannula is advanced. The method may also include determining, via the controller, a position of the cannula within the body based upon the change in the impedance or the conductance of the tissue between the first electrode and the second electrode as the cannula is advanced. The method may also include where the first lead runs through an inner lumen of the cannula. Other embodiments of this aspect include corresponding computer systems, apparatus, and computer programs recorded on one or more computer storage devices, each configured to perform the actions of the methods.
Implementations may include one or more of the following features: The method where the second electrode is positioned at or near the distal end of the cannula. The method where the second lead runs through the inner lumen of the cannula. The method where the cannula includes a blunt distal tip. The method where the first electrode is incorporated into a stylus that is configured to be inserted into the inner lumen of the cannula. The method where the second electrode is incorporated into the stylus. The method which includes a locking mechanism to lock the stylus in place within the cannula. The method where the first lead includes an insulated portion of a shaft of the cannula and the first electrode includes an uninsulated portion of the shaft of the cannula. Implementations of the described techniques may include hardware, a method or process, or computer software on a computer-accessible medium.
Access to body cavities or body tissue is often gained using a trocar, cannula, needle, catheter etc. These devices may be solid or hollow, sharp or blunt. For example,
Alternatively, the conductive access device may be made from a non-conductive material, such as a hard polymer, and the electrodes may be made of a conductive material, such as metal. The conductive access device may be disposable or reusable. If it is made primarily from a polymer, it may be disposable, while a controller component may be reusable. If the conductive access device is made primarily from a metal, it may be reusable.
Leads 206 and 208 may pass through the head of the conductive access device, or may exit the device at any point. The leads are connected, either via wires, or wirelessly, to a controller which collects and may store the conductivity/impedance data from the electrodes, analyzes the data, and displays, or otherwise reports to the user the location of the conductive access device based on the conductivity/impedance data and/or changes in the conductivity/impedance data as the access device is advanced or moved through tissue. In some embodiments, one or more electrodes are placed at or near the distal tip of the conductive access device so that the location information informs the user of the location of the distal tip of the conductive access device.
In some embodiments, the controller may control the automatic application of force to the access device in either or both the advancing (into the body) direction and a rotational direction.
In some embodiments, the controller may have the capability to receive and analyze information from other sensors on the device or in the system. For example, the access device may incorporate pressure or force sensors, to avoid excessive force or to sense when force necessary for advancement is diminished, possibly indicating a body cavity has likely been accessed.
In use, some embodiments of the conductive access device are used as follows. As the device is advanced through body tissue toward the desired location, conductivity and/or impedance (hereafter referred to as “conductivity”) data between 2 or more electrodes is measured, effectively measuring the conductivity of the body tissue at or near the distal tip of the conductive access device. Because the conductivity of tissue is different for different tissue in different locations in the body, information relating to the location of the distal tip of the conductive access device can be obtained, and used to monitor access progress.
For example, the table below lists the electrical conductivity of various tissues up to 1 MHz. Other frequencies may be used by various embodiments of the conductive access device disclosed herein. The difference in conductivity can be used to identify the location of the conductive access device as it advances through tissue, and into different types of tissue.
In some embodiments, the conductive access device may be rotated/advanced automatically via a motor connected to the controller. The motor may automatically start, stop, slow or reverse based on signals from the controller based on data received from the device. For example, the motor may stop when the conductivity across the electrodes of the device indicate that the distal tip of the device is in the abdominal cavity, if this is the desired final location of the device. Alternatively, the motor may slow or stop if the amount of force required to advance the device is too high.
To maintain distance 904 during use of the device, locking mechanism 906 may be incorporated into the cannula component to lock the position of the stylet with respect to the cannula component. Locking mechanism 906 may be loosened and relocked in the same or different positions as appropriate. Stylet 902 may be removable from the cannula by unlocking locking mechanism 906.
In embodiments where a solid stylet is used, fluid (gas or liquid, for example CO2) may be infused or removed via port 908 in the cannula component. In these embodiments, the stylet may be removed before the inner lumen of the cannula component is used for fluid/instruments, or, fluid may be infused/removed via the annular space between the inner lumen of the cannula component and the outer surface of the stylet. Alternatively, another lumen may be incorporated into the cannula component.
Some examples of procedures where the conductive access device may be useful include, laparoscopy, endoscopy, tissue sampling, biopsy, tracheotomy, vascular access, natural body lumen access (i.e. bowel, bladder, stomach, lung access), central nervous system access, lung access, amniotic access, tumor access, etc.
Some embodiments of the conductive access device may include a force sensor, pressure sensor, or other type of sensor at or near the distal tip of the device, or elsewhere. Some embodiments of the conductive access device controller may include a force detection component which monitors the amount of force necessary to automatically advance the access device, in either or both the rotational direction and the direction toward the inside of the patient's body.
Some embodiments of the access device may use automatic insertion of the device, controlled by the controller. Some embodiments of the access device may be manual, where the device is inserted manually into the patient's body.
Some embodiments may use only one electrode. Some embodiments may use 2 electrodes, 3 electrodes, 4 electrodes or more electrodes. Embodiments which use 1 electrode, may include a reference electrode patch or other type of electrode configured to be placed on the outside of the patient's body, or elsewhere on or in the patient's body.
Some embodiments may incorporate ablation and/or cauterizing ability into the access device. For example, the same electrodes used for measuring conductance/impedance may be used to cauterize or ablate tissue. The sensing and treatment functions may alternate. For example, conductance/impedance measurements may be used to determine the extent of cauterization and/or ablation of tissue. As tissue is cauterized and/or ablated, the hydration of the tissue decreases which in turn reduces the conductivity of the tissue. This conductivity can be monitored to determine the extent of cauterization/ablation. Alternatively, separate electrodes may be used for cauterization/ablation functions and location functions.
The inner diameter of the cannula portion of the access device may be around 1.6 mm. Alternatively, the inner diameter of the cannula portion of the access device may be around 1.2-2 mm. Alternatively, the inner diameter of the cannula portion of the access device may be around 2-5 mm. Alternatively, the inner diameter of the cannula portion of the access device may be around 5-10 mm.
The outer diameter of the stylet may be around 1.6 mm. Alternatively, the outer diameter of the stylet may be around 1.2-2 mm. Alternatively, the outer diameter of the stylet may be around 2-5 mm. Alternatively, the outer diameter of the stylet may be around 5-10 mm.
The outer diameter of the cannula portion of the access device may be around 2 mm. Alternatively, the outer diameter of the cannula portion of the access device may be around 1.5-2.5 mm. Alternatively, the outer diameter of the cannula portion of the access device may be around 2.5-5 mm. Alternatively, the outer diameter of the cannula portion of the access device may be around 5-10 mm.
Some embodiments may incorporate imaging capabilities, such as fiber optics through, or in conjunction with, the access device. The controller may process the images, or images may be viewed directly by the user or both. The controller may collect image processing data, such as the presence of adhesions, tumors, abnormalities etc., and this data may be used to correlate the presence or absence of certain features with conductance/impedance of tissue, force necessary for advancement through tissue, etc. This correlation may then be used to help guide the access device.
Example of Data Processing System
As shown in
Typically, the input/output devices 2510 are coupled to the system through input/output controllers 2509. The volatile RAM 2505 is typically implemented as dynamic RAM
(DRAM) which requires power continuously in order to refresh or maintain the data in the memory. The non-volatile memory 2506 is typically a magnetic hard drive, a magnetic optical drive, an optical drive, or a DVD RAM or other type of memory system which maintains data even after power is removed from the system. Typically, the non-volatile memory will also be a random access memory, although this is not required.
While
Some portions of the preceding detailed descriptions have been presented in terms of algorithms and symbolic representations of operations on data bits within a computer memory. These algorithmic descriptions and representations are the ways used by those skilled in the data processing arts to most effectively convey the substance of their work to others skilled in the art. An algorithm is here, and generally, conceived to be a self-consistent sequence of operations leading to a desired result. The operations are those requiring physical manipulations of physical quantities.
It should be borne in mind, however, that all of these and similar terms are to be associated with the appropriate physical quantities and are merely convenient labels applied to these quantities. Unless specifically stated otherwise as apparent from the above discussion, it is appreciated that throughout the description, discussions utilizing terms such as those set forth in the claims below, refer to the action and processes of a computer system, or similar electronic computing device, that manipulates and transforms data represented as physical (electronic) quantities within the computer system's registers and memories into other data similarly represented as physical quantities within the computer system memories or registers or other such information storage, transmission or display devices.
The techniques shown in the Figures can be implemented using code and data stored and executed on one or more electronic devices. Such electronic devices store and communicate (internally and/or with other electronic devices over a network) code and data using computer-readable media, such as non-transitory computer-readable storage media (e.g., magnetic disks; optical disks; random access memory; read only memory; flash memory devices; phase-change memory) and transitory computer-readable transmission media (e.g., electrical, optical, acoustical or other form of propagated signals—such as carrier waves, infrared signals, digital signals).
The processes or methods depicted in the preceding Figs may be performed by processing logic that comprises hardware (e.g. circuitry, dedicated logic, etc.), firmware, software (e.g., embodied on a non-transitory computer readable medium), or a combination of both. Although the processes or methods are described above in terms of some sequential operations, it should be appreciated that some of the operations described may be performed in a different order. Moreover, some operations may be performed in parallel rather than sequentially.
From the foregoing, it will be appreciated that specific embodiments of the invention have been described herein for purposes of illustration, but that various modifications may be made without deviating from the spirit and scope of the various embodiments of the invention. For example, several embodiments may include various suitable combinations of components, devices and/or systems from any of the embodiments described herein. Further, while various advantages associated with certain embodiments of the invention have been described above in the context of those embodiments, other embodiments may also exhibit such advantages, and not all embodiments need necessarily exhibit such advantages to fall within the scope of the invention.
This application claims the benefit of priority to U.S. Provisional Application No. 62/528,388 filed Jul. 3, 2017 and U.S. Provisional Application No. 62/652,448 filed Apr. 4, 2018, each of which is incorporated herein by reference in its entirety.
Number | Date | Country | |
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62528388 | Jul 2017 | US | |
62652448 | Apr 2018 | US |