Subdural sonde system with receiving lumen for electrode placement

Abstract

This is a hypotube probe comprising a main body, a curved tip, a stylet, and an electrode. The main body is configured to be placed in the patient's subdural space and has a curved tip at its anterior end. This tip is configured to be inserted at an angle to the subdural space in order to advance the main body to the target site within the subdural space. The stylet is configured to enter the channel and, after being inserted into the channel, advance to the distal opening and seal the distal opening. The electrode is configured to be inserted into the channel and then advance through the distal opening for placement in contact with the dural tissue within the subdural space.

Description

Technical Field

[0001] Cross - reference to related applications This application claims the priority of U.S. Patent Application No. 63 / 452,330, filed on March 15, 2023, and incorporates its entire content by reference herein.

Background Art

[0002] Seizures are known to occur in a specific area of the cerebral cortex called the "seizure focus site". To identify the seizure focus site, it is known to place multiple electrodes at various locations on the cerebral cortex. By doing so, a large area of the cerebral cortex is covered by the electrodes, maximizing the possibility of finding the seizure focus site.

[0003] There is a fibrous membrane on the brain surface known as the "dura mater". A "subdural space" can be formed between the brain surface and this dura mater. Surgeons place electrodes in an array within this subdural space.

[0004] One way to place electrodes is to remove a large portion of the patient's skull and carefully place a grid of electrodes on the brain surface. Naturally, this highly invasive procedure involves many risks.

[0005] In another method called "stereoelectroencephalogram", removing a large portion of the skull is avoided. In this method, the surgeon makes a number of holes in the skull and places electrodes in each hole. As a result, the electrodes are placed inside the brain itself rather than on the skull surface.

[0006] However, since a fairly large number of holes need to be made, this method is also quite invasive. Furthermore, this method has a significant drawback. The electrodes are not placed on the brain surface where the seizure focus site is supposed to be.

[0007] U.S. Patent Publication 2023 / 0077799 (incorporated herein by reference) discloses a method for inserting electrodes into the brain surface without requiring the removal of a large portion of the skull. Instead, this method uses a subdural probe assembly to facilitate the placement of a movable subdural electrode through a small opening in the skull. The electrode has multiple electrical contacts on a long, flat strip. The strip extends into the subdural space along the tangential direction of the brain surface. First, the probe is inserted so that its tip is positioned near the site where the subdural electrode is to be placed. Next, the electrode is guided through a receiving channel in the probe, and then the probe is withdrawn, leaving the electrode in the correct location. [Overview of the project]

[0008] The present invention features a subdural probe system having a hypotube probe. Such a probe has a curved tip and a flexibility that changes along the length of the probe, i.e., a "flexibility gradient". The flexibility gradient is set so that the part of the hypotube probe body closer to the front end is more flexible than the part closer to the rear end.

[0009] Hypotube sondes have a lumen, also called a "receiving channel." This lumen extends from a proximal opening, also called a "posterior opening," to a distal opening, that is, to an "anterior opening" located at the edge of the curved tip.

[0010] The sonde has an elongated body that defines the receiving channel. Before deploying the sonde, the receiving channel accepts the stylet.

[0011] The stylet enters the receiving channel so that it can advance toward the distal opening of the sonde. In some embodiments, the stylet has a structure that substantially seals the distal opening of the sonde. This reduces the risk of damaging brain tissue as the sonde advances through the subdural space. Such damage can occur when tissue is accidentally taken up by the distal opening.

[0012] The stylet also performs additional functions. In some embodiments, the stylet is configured to serve as an alternative maneuvering mechanism to assist the surgeon in guiding the probe to the correct position. In other embodiments, the stylet has a perfusion channel for delivering perfusion fluid from a fluid reservoir. In such embodiments, the fluid reservoir is connected to the perfusion channel via an adapter. An example of a suitable adapter is one that utilizes a Luer lock.

[0013] Once the subdural probe is guided to the target site, the stylet is withdrawn from the proximal opening of the probe. The electrode is then advanced using the now-empty receiving channel. The probe thus acts as a sheath, preventing the electrode from accidentally puncturing brain tissue or causing harmful interactions with it. Examples of suitable electrodes include thin tubular electrodes with multiple ring-shaped electrical contacts, deep electrodes, and planar electrodes with multiple electrical contacts arranged on a plane.

[0014] The above process can be repeated by inserting this probe (or another probe) into the same opening and guiding it towards a different target site in the subdural space, while advancing another electrode toward the distal opening of the probe.

[0015] As mentioned earlier, the subdural probe of the hypotube has a structure that exhibits flexibility that changes along its length. This means that when a certain force is applied, the displacement will differ at different points along its length. Furthermore, this flexibility is directional. Therefore, the deflection of the probe in response to a given force depends on the direction of that force.

[0016] In some embodiments, the hypotube probe is made of a lubricating material.

[0017] In other embodiments, the slender body of the probe has a flexibility-changing property. The change in rigidity along the curved tip extending from the distal end of the probe allows the initial sharp-angle entry necessary to position the curved tip in an open position within the subdural space simply by pushing the probe in.

[0018] Another embodiment involves attaching an optical sensor, electrical sensor, or chemical sensor to the probe to confirm its position within the subdural space when it is inserted into the subdural space.

[0019] An additional feature is the use of the placed electrodes for purposes other than epilepsy, such as cerebral cortex stimulators and cyber prostheses (e.g., for the formation of brain-machine interfaces).

[0020] In some embodiments, the electrodes are components of a permanent prosthesis. In other embodiments, the electrodes are intended solely for temporary monitoring.

[0021] The structural features of the subdural probe described herein allow the probe to be advanced within the subdural space with minimal resistance, reducing the risk of damaging brain tissue, such as by accidentally perforating or scraping it. Therefore, surgeons can guide the probe to the desired location with gentle pushing or poking motions, without the need for complex navigation or imaging equipment.

[0022] Of course, the availability of such equipment and devices is also useful for enabling more accurate guidance. For example, image data can be acquired via the optical fiber attached to the subdural sonde and used to assist in guidance. Alternatively, the position of the sonde can be determined by extracorporeal imaging using X-ray or magnetic resonance imaging. For this purpose, it is useful to attach a radiopaque indicator to the sonde.

[0023] In some embodiments, the subdural probe includes a distance sensing device, and in such embodiments, markings are included. This distance sensing device is useful for quickly checking how far the probe has already advanced into the patient's body.

[0024] A further advantage of the implementations described herein is that removal after electrode insertion is much easier than removal of conventional flat subdural electrodes. Removal of flat subdural electrodes typically requires taking the patient to an operating room and performing complex electrode removal procedures.

[0025] In one aspect, the present invention is characterized by a subdural probe system including a hypodermic tube probe, the hypodermic tube probe comprising an elongated body having a rear end with a proximal opening, a front end with a distal opening, and a channel that is a receiving channel extending from the proximal end to the front end, the elongated body configured to be disposed within the subdural space of a patient, a curved tip disposed at the front end, the curved tip configured to be inserted at an inclination with respect to the subdural space so as to advance the body to a target site within the subdural space, a stylet configured to enter the channel, the stylet configured to advance to the distal opening and seal the distal opening after being inserted into the channel, and an electrode configured to advance through the distal opening for placement in contact with the dura tissue within the subdural space after being inserted into the channel.

[0026] In some embodiments, the body has a flexible circular lumen defining the channel.

[0027] In other embodiments, the body has a first region and a second region adjacent to the first region. In such embodiments, the first region has a first rigidity and the second region has a second rigidity different from the first rigidity.

[0028] In some embodiments, the body has a first region and a second region adjacent to the first region, the second region has a front end, and the second region is more flexible than the first region.

[0029] In still other embodiments, the curved distal end has a first side, a second side, a third side, and a fourth side. In these embodiments, the first side has a curved contour shape with respect to the first axis of the body, the second side has a flat contour shape with respect to the first axis, and the third and fourth sides define a tapered contour shape with respect to the second axis of the body.

[0030] Some embodiments include a stylet having a lumen configured to deliver a perfusion fluid through a channel, and a perfusion adapter connected to the proximal end of the stylet, the perfusion adapter being configured to direct the perfusion fluid through the channel.

[0031] A variety of electrodes can be used. Examples of electrodes include a cylindrical electrode, a multi-ring electrode having a plurality of ring-shaped contacts extending along a cylindrical body, and an elongated structure having a plurality of electrical contacts disposed on a flat side.

[0032] [[ID=******]]In another aspect, the present invention is a method characterized by the following: making a hole in a patient's skull to access a target tissue in the subdural space of the patient's brain region; inserting a stylet into a channel defined in the body of the sonde, the channel being a receiving channel extending from a proximal opening at the rear end of the sonde to a distal opening at the front end of the sonde, the sonde being a hypodermic tube sonde and the body being an elongated body having a curved distal end at the front end; sealing the distal opening with the stylet; guiding the sonde to a target site in the subdural space; removing the stylet from the receiving channel after reaching the target site; inserting an electrode into the receiving channel after removing the stylet; and advancing the electrode through the channel toward the distal end for placement in contact with the target tissue in the subdural space.

[0033] These and other features of the present invention will become apparent from the following detailed description and accompanying drawings. [Brief explanation of the drawing]

[0034] [Figure 1] This diagram shows the components of a subdural probe system. [Figure 2] Figure 1 is a magnified view of the hypotube sonde in the sonde system. [Figure 3] Figure 1 is a magnified view of the hypotube sonde in the sonde system. [Figure 4] Figure 1 is a magnified view of the hypotube sonde in the sonde system. [Figure 5] Figure 1 is a magnified view of the stylet of the sonde system. [Figure 6] Figure 1 is a magnified view of the hypotube sonde in the sonde system. [Figure 7] Figure 1 is a magnified view of the hypotube sonde in the sonde system. [Figure 8] Figure 1 shows the tube electrode of the sonde system after it has been placed through the receiving channel of the hypotube sonde shown in Figures 2-4 and 6-7. [Figure 9] Figure 1 shows the tube electrode of the sonde system after it has been placed through the receiving channel of the hypotube sonde shown in Figures 2-4 and 6-7. [Figure 10] Figure 1 shows the tube electrode of the sonde system after it has been placed through the receiving channel of the hypotube sonde shown in Figures 2-4 and 6-7. [Modes for carrying out the invention]

[0035] Figure 1 below shows the components of a disassembled subdural probe system 10. The components include a hypotube probe 12, a stylet 14 (or "guide"), and an electrode 16 (the rightmost component in Figure 1), the electrode in this case being a tubular electrode such as a deep electrode.

[0036] Figures 2-4 and 6-7 are enlarged views of the hypotube sonde 12.

[0037] Figure 5 is a magnified view of the stylet 14, and Figures 8 to 10 show the cylindrical electrode 16 inserted into the receiving channel of the hypotube sonde 12.

[0038] Referring to Figure 1, the hypotube sonde 12 has an elongated body 18 configured to be placed in the subdural space of the patient's brain region. This elongated body 18 defines a receiving channel 20 and a curved tip 22. The receiving channel 20 extends from the proximal opening at the posterior end 24 of the hypotube sonde 12 to the distal opening at the anterior end 26 of the hypotube sonde 12. The curved tip 22 is located at the anterior end 26 of the elongated body 18 and is configured to be inserted at an angle to the patient's subdural space in order to advance the elongated body 18 to the target site in the subdural space.

[0039] The system 10 further includes a stylet 14 and an electrode 16, both of which are configured to be inserted into the receiving channel 20.

[0040] The stylet 14 enters the receiving channel 20. As a result, the stylet 14 is inserted into the receiving channel 20 and advances to the distal opening, effectively sealing the distal opening.

[0041] When the receiving channel 20 is no longer occupied by the stylet 14, the electrode 16 can be inserted into the receiving channel 20 and advanced through the distal opening to contact and position it with the dural tissue in the subdural space.

[0042] Examples of the electrode 16 include a cylindrical electrode, a multi-ring electrode having a plurality of ring-shaped contacts on a cylindrical body, and a planar electrode including an elongated structure in which a plurality of electrical contacts are arranged on a substantially flat first surface.

[0043] In some embodiments, the elongated body 18 has a flexible circular lumen that defines the receiving channel 20. In some embodiments, the elongated body 18 of the hypotube sonde 12 has multiple regions (adjacent regions) that are connected along the length of the subdural sonde. These connected regions each have different rigidity. In a preferred embodiment, the most flexible and least rigid part of the elongated body 18 is the distal end.

[0044] In some examples, the curved tip 22 has a first side having a curved contour shape defined with respect to the first axis (axis when viewed from the third and fourth sides) of the elongated body 18, a second side having a substantially flat contour shape with respect to the first axis, and third and fourth sides having tapered contour shapes with respect to the second axis (axis when viewed from the first and second sides) of the elongated body 18.

[0045] In some embodiments, the stylet 14 has an internal channel configured to deliver perfusion fluid that can pass through the receiving channel 20 of the hypotube sonde 12. The subdural sonde system 10 may further include a perfusion adapter (connectable to a perfusion mechanism) coupled to the proximal end of the stylet 14, which is configured to guide the perfusion fluid through the receiving channel 20 defined in the elongated body 18 of the hypotube sonde 12, thereby facilitating the movement of the subdural sonde in the subdural space.

[0046] In the procedure, positioning the electrode 16 in the patient's subdural space involves drilling a hole in the patient's skull to access target tissue in the subdural space of the patient's brain region and inserting a stylet 14 into a receiving channel 20 defined in the elongated body 18 of the hypotube sonde 12, the receiving channel 20 extending from the proximal opening at the posterior end of the hypotube sonde 12 to the distal opening at the anterior end of the hypotube sonde 12, the hypotube sonde 12 further having a curved tip 22 at the distal end of the elongated body 18. The inserted stylet 14 substantially seals the distal opening of the elongated body 18 of the hypotube sonde 12. The procedure for positioning the electrode 16 further includes inserting the stylet 14 into the receiving channel 20 of the hypotube sonde 12, passing the hypotube sonde 12 through the opening to guide it to the target site in the subdural space, removing the stylet 14 from the receiving channel 20 of the elongated body 18 of the hypotube sonde 12, inserting the electrode 16 (a cylindrical electrode or an electrode with a flat surface) into the receiving channel 20 of the elongated body 18 of the hypotube sonde 12 in which the stylet 14 was inserted, and advancing the electrode 16 through the receiving channel 20 defined in the elongated body 18 of the hypotube sonde 12 toward the distal end of the hypotube sonde 12 at the target site, thereby positioning the electrode 16 in contact with the target tissue in the patient's subdural space.

[0047] Unless otherwise stated, all technical and scientific terms used herein have the same meaning as they are commonly or conventionally understood. As used herein, the articles “a” and “an” refer to one or more (i.e., at least one) of the grammatical objects of the article. For example, “an element” means one or more elements. Where used herein to refer to measurable values ​​such as quantities and temporal durations, “about” and / or “approximately” include variations of ±20%, ±10%, ±5%, or +0.1% from the specified value, and such variations are appropriate in the context of the systems, devices, circuits, methods, and other implementations described herein. In this specification, the term "substantially" used when referring to measurable values ​​such as quantity, temporal duration, and physical attributes (such as frequency) also includes variations of ±20%, ±10%, ±5%, or +0.1% from the specified value, and such variations are appropriate in the context of the systems, devices, circuits, methods, and other implementations described herein.

[0048] In this specification, including the claims, the "or" used in lists of items beginning with "at least one of..." or "one or more of..." indicates a logical OR list, for example, the list "at least one of A, B, or C" means A or B or C or AB or AC or BC or ABC (i.e., A and B and C), or a combination of two or more features (e.g., AA, AAB, ABBC, etc.). Also in this specification, unless otherwise specified, the statement that a function or operation is "based on" an item or condition means that the function or operation is based on the specified item or condition, and may be based on one or more items and / or conditions in addition to the specified item or condition.

[0049] While this specification discloses specific embodiments in detail, these are for illustrative purposes only and do not limit the claims appended below. Features of the disclosed embodiments can be combined or rearranged within the scope of the invention to produce many more embodiments. Other aspects, advantages, and modifications are deemed to fall within the scope of the claims described below. The presented claims represent at least some of the embodiments and features disclosed herein. Other embodiments and features not claimed are also conceivable.

[0050] The present invention and its preferred embodiments have been described, but the following are claimed to be novel and protected by patent law:

Claims

1. It is an instrument that includes a subdural probe system, The aforementioned sonde is a hypotube sonde, A slender body configured to be placed in the subdural space of a patient, having a posterior end with a proximal opening, an anterior end with a distal opening, and a channel which is a receiving channel extending from the proximal end to the anterior end, The curved tip portion positioned at the front end is configured to be inserted at an angle to the subdural space in order to advance the main body to the target site in the subdural space, A stylet configured to enter the channel, and configured to advance to the distal opening and seal the distal opening, An instrument comprising: an electrode, which, after being inserted into the channel, is configured to advance through the distal opening for a position in contact with the dural tissue in the subdural space.

2. The apparatus according to claim 1, wherein the main body has a flexible circular lumen that defines the channel.

3. The apparatus according to claim 1, wherein the main body has a first region and a second region adjacent to the second region, the first region has a first rigidity, the second region has a second rigidity, and the first rigidity is higher than the second rigidity.

4. The apparatus according to claim 1, wherein the main body has a first region and a second region adjacent to the second region, the second region has the front end, and the second region is more flexible than the first region.

5. The apparatus according to claim 1, wherein the curved tip portion has a first side, a second side, a third side, and a fourth side, the first side having a curved contour shape with respect to the first axis of the main body, the second side having a flat contour shape with respect to the first axis, and the third and fourth sides defining tapered contour shapes with respect to the second axis of the main body.

6. The device according to claim 1, wherein the stylet has a lumen configured to deliver perfusion fluid through the channel.

7. The apparatus according to claim 1, further comprising a perfusion adapter connected to the proximal end of the stylet, the perfusion adapter configured to guide the perfusion fluid through the channel.

8. The apparatus according to claim 1, wherein the electrode includes a cylindrical electrode.

9. The apparatus according to claim 1, wherein the electrode includes multiple ring electrodes extending along a cylindrical body.

10. The apparatus according to claim 1, wherein the electrode includes an elongated structural portion on which a plurality of electrical contacts are arranged on the flat side.

11. This involves drilling a hole in the patient's skull to access target tissue in the subdural space of the patient's brain region, Inserting a stylet into a channel defined in the body of the sonde, wherein the channel is a receiving channel extending from the proximal opening at the rear end of the sonde to the distal opening at the front end of the sonde, the sonde is a hypotube sonde, and the body is an elongated body having a curved tip at the front end, The distal opening is sealed by the stylet, To guide the aforementioned probe to the target site within the subdural space, The stylet is removed from the receiving channel after reaching the target site, After removing the stylet, insert the electrode into the receiving channel, A method comprising advancing the electrode toward the distal end through the channel for placement in contact with target tissue in the subdural space.

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