Patent Description:
This disclosure relates to a tunneling tool for creating a subcutaneous pocket below a skin surface for the implantation of sensors.

Implantable sensors may be implanted within a living animal (e.g., a human) and may detect the presence or amount of an analyte (e.g., glucose or oxygen) in a medium (e.g., blood or interstitial fluid) within the living animal. Some implantable sensors are implanted in subcutaneous tissue below the skin. The subcutaneous insertion of a sensor is a relatively simple procedure and may take less than five minutes.

Known tools for inserting a sensor in subcutaneous tissue may include a tunneling tool and an insertion tool. In some embodiments, the tunneling tool may be used to create a subcutaneous pocket below a skin surface, and the insertion tool may be used to insert the sensor into the pocket.

A sensor inserted in a pocket created too deep underneath the skin or at a non-zero angle to the surface of the skin may be unable to maintain consistent communication with a reader positioned above the inserted sensor on or near the surface of the skin and configured to receive sensed information from the sensor. Furthermore, a sensor inserted in a pocket created too deep underneath the skin may be significantly more difficult to remove.

<CIT> discloses a prior art tunneling device for creating a subcutaneous pocket with a handle and a tunneling rod and a guide at the distal end of the handle.

Accordingly, there is a need for an improved tunneling device to reduce the variability (e.g., depth and angle) of a subcutaneous pocket created below a skin surface.

Aspects of the present invention relate to an improved tunneling device to reduce the variability of sensor insertion depth under the skin.

The invention is as defined in claim <NUM> with further embodiments disclosed by the dependent claims.

The invention provides a tunneling tool for creating a subcutaneous pocket below a skin surface. The tunneling tool includes a handle, a rod, and first and second prongs. The rod extends from a first end of the handle and is configured to create the subcutaneous pocket. The first and second prongs extend from the first end of the handle. The first and second prongs are configured to limit the depth at which the rod is capable of creating the subcutaneous pocket. The rod extends farther from the first end of the handle than the first and second prongs. A first gap between the rod and the first prong and a second gap between the rod and the second prong are configured to limit the angle relative to the skin surface at which rod is capable of forming the subcutaneous pocket.

The first prong comprises a first length indicator configured to indicate a length of the subcutaneous pocket formed by the rod. In some embodiments, the second prong may comprise a second length indicator configured to indicate a length of the subcutaneous pocket formed by the rod. The first prong and the second prong may have the same length. In some embodiments, the first prong and the second prong may be configured to prevent damage to the skin surface.

In some embodiments, the rod may comprise a dull tip. In some embodiments, the handle may comprise a bottom surface and the first and the second prongs may be located above the rod in a plane substantially parallel to the bottom surface of the handle. In some embodiments, the first prong may be located at a first angle to the rod and the second prong may be located at a second angle to the rod.

In some embodiments, the handle may comprise a top surface including a circular depression configured to accommodate a finger. The top surface of the handle may further include at least one or more ridges configured to accommodate another finger and a thumb. In some embodiments, the top surface of the handle may comprise a ribbed surface.

Another aspect of the disclosure may provide a method of creating a subcutaneous pocket below a skin surface. The method may include creating an incision in the skin surface. The method may include inserting a tip of a rod extending from a first end of a handle of a tunneling tool into the incision until one or more of first and second prongs extending from the first end of the handle of the tunneling tool contact the skin surface. In some embodiments, the first and second prongs may limit the depth at which the rod is capable of creating the subcutaneous pocket. The method may include reducing an angle between the tunneling tool and the skin surface by rotating the tunneling tool while the tip of the rod remains inserted in the incision. After reducing the angle between the tunneling tool and the skin surface, the method may include inserting the rod further into the incision such that the rod passes below the skin surface, the first and second prongs pass over the skin surface, the skin surface is disposed in a first gap between the rod and the first prong, and the skin surface is disposed in a second gap between the rod and the second prong. In some embodiments, the first and second gaps may be configured to limit the angle relative to the skin surface at which rod is capable of forming the subcutaneous pocket.

In some embodiments, the method may further include continuing to insert the rod into the incision until the incision is aligned with a first length indicator on the first prong. In some embodiments, the method may further include continuing to insert the rod into the incision until the incision is aligned with a second length indicator on the second prong. In some embodiments, inserting the rod further into the incision may include rocking the tunneling tool side to side thereby creating a rotating motion along a longitudinal axis of the rod to facilitate the insertion. The handle may comprise a bottom surface and the first and the second prongs may be located above the rod in a plane substantially parallel to the bottom surface of the handle. The first prong may be located at a first angle to the rod and the second prong may be located at a second angle to the rod. In some embodiments, the location of the first and second prong in relation to the rod may facilitate rocking the tunneling tool side to side.

Methods of creating a subcutaneous pocket below a skin surface or methods of using the tunneling tool are not part of the claimed invention.

Another aspect of the invention provides a tunneling tool for creating a subcutaneous pocket below a skin surface. The tunneling tool includes a handle, a rod, and first and second prongs. The rod extends from a first end of the handle and is configured to create the subcutaneous pocket. The first and second prong extend from the first end of the handle. The first prong comprises a first length indicator configured to indicate a length of the subcutaneous pocket formed by the rod and the second prong may comprise a second length indicator configured to indicate the length of the subcutaneous pocket formed by the rod. The rod extends farther from the first end of the handle than the first and second prongs. A first gap between the rod and the first prong and a second gap between the rod and the second prong are configured to limit the angle relative to the skin surface at which rod is capable of forming the subcutaneous pocket.

In some embodiments, the first prong and the second prong may have the same length. In some embodiments, the first prong and the second prong may be configured to prevent damage to the skin surface.

Another aspect of the disclosure may provide a method of creating a subcutaneous pocket below a skin surface. The method may include creating an incision in the skin surface. The method may include inserting a tip of a rod extending from a first end of a handle of a tunneling tool into the incision until one or more of first and second prongs extending from the first end of the handle of the tunneling tool contact the skin surface. The method may include reducing an angle between the tunneling tool and the skin surface by rotating the tunneling tool while the tip of the rod remains inserted in the incision. After reducing the angle between the tunneling tool and the skin surface, the method may include inserting the rod further into the incision such that the rod passes below the skin surface, the first and second prongs pass over the skin surface, the skin surface is disposed in a first gap between the rod and the first prong, and the skin surface is disposed in a second gap between the rod and the second prong. In some embodiments, the first and second gaps may be configured to limit the angle relative to the skin surface at which rod is capable of forming the subcutaneous pocket. The method may include continuing to insert the rod into the incision until the incision is aligned with at least one of a first length indicator on the first prong and a second length indicator on the second prong. In some embodiments, the first length indicator may indicate a length of the subcutaneous pocket formed by the rod and the second length indicator may indicate the length of the subcutaneous pocket formed by the rod.

In some examples, the method may further include continuing to insert the rod into the incision until the incision is aligned with a second length indicator on the second prong. In some embodiments, inserting the rod further into the incision may include rocking the tunneling tool side to side thereby creating a rotating motion along a longitudinal axis of the rod to facilitate the insertion. The handle may comprise a bottom surface and the first and the second prongs may be located above the rod in a plane substantially parallel to the bottom surface of the handle. The first prong may be located at a first angle to the rod and the second prong may be located at a second angle to the rod. In some embodiments, the location of the first and second prong in relation to the rod may facilitate rocking the tunneling tool side to side.

Other features and characteristics of the subject matter of this disclosure, as well as the methods of operation, functions of related elements of structure and the combination of parts, and economies of manufacture, will become more apparent upon consideration of the following description and the appended claims with reference to the accompanying drawings, all of which form a part of this specification, wherein like reference numerals designate corresponding parts in the various figures. Methods of operation do not form part of the claimed invention.

The accompanying drawings, which are incorporated herein and form part of the specification, illustrate various embodiments of the subject matter of this disclosure. In the drawings, like reference numbers indicate identical or functionally similar elements.

<FIG> illustrates an example of the conventional tunneling tool <NUM> for creating a subcutaneous pocket below a skin surface. As illustrated in <FIG>, the conventional tunneling tool <NUM> may have a rod/shaft <NUM> extending from a handle <NUM>. The conventional tunneling tool <NUM> requires the experienced handling of a trained physician or other clinician to create a subcutaneous pocket at the appropriate depth below and parallel to the skin surface. However, even a trained clinician may make mistakes, and the conventional tunneling tool <NUM> does not effectively restrict the clinician from creating inadvertently the subcutaneous pocket at a non-zero angle to the surface of the skin and/or creating a pocket too deep below the surface of the skin.

The embodiments described in the present disclosure may obviate one or more of the above noted problems with the conventional tunneling tool <NUM>. Specifically, the embodiments described in the present disclosure may provide the advantages of creating a subcutaneous pocket that is parallel to a surface of the skin and not created too deep underneath the surface of the skin.

<FIG> is top view of a tunneling tool <NUM> embodying aspects of the present disclosure. The tunneling tool <NUM> includes a handle <NUM>, a rod/shaft <NUM> (referred to as "rod" hereinafter) extending from an end of the handle <NUM>, and first and second prongs 206a and 206b extending from the end of the handle <NUM>. In some embodiments, the first and second prongs 206a-b may be integrally formed in the handle <NUM>. In some non-limiting embodiments, the first and second prongs 206a-b may be integrally formed in the handle <NUM>, for example and without limitation, with the handle <NUM> comprising a single plastic overmold. In some embodiments, the rod <NUM> may include a trocar. In some non-limiting embodiments, the trocar may be, for example and without limitation, a steel trocar (e.g., a stainless steel trocar) or made of another material suitable for surgical tools.

As illustrated in <FIG>, the rod <NUM> extends farther from the end of the handle <NUM> than the first and second prongs 206a-b. In some embodiments, in operation, a tip <NUM> of the rod <NUM> may be inserted into an incision made in a skin surface. In some embodiments, the incision may be, for example and without limitation, <NUM>-<NUM> wide and <NUM>-<NUM> deep. The first prong 206a and the second prong 206b function as depth guards configured to limit the depth at which the rod <NUM> is inserted into the skin surface. Accordingly, the length of the first prong 206a and the second prong 206b may be configured to physically prevent the rod <NUM> from being inserted too deep beneath the surface of the skin, thereby preventing the creation of a subcutaneous pocket too far below the surface of the skin. In some embodiments, the length of the first prong 206a and length of the second prong 206b may be the same. In some non-limiting embodiments, the length of the first prong 206a and the second prong 206b may be, for example and without limitation, <NUM>. In some non-limiting embodiments, the rod <NUM> may extend beyond the ends of the first and second prongs 206a-b by, for example and without limitation, <NUM>. However, these specific lengths and dimensions are not required, and some alternative embodiments may use different lengths and/or dimensions.

The first prong comprises a first length indicator 208a. In some embodiments, one or more of the first and second prongs 206a-206b may include a length indicator. In some non-limiting embodiments, as shown in <FIG>, the first and second prongs 206a and 206b may include first and second length indicators 208a and 208b, respectively. In some embodiments, in operation, the tunneling tool <NUM> may be rotated with the tip <NUM> of the rod <NUM> inserted in the incision made in the skin surface to reduce an angle between the tunneling tool <NUM> and the skin surface, i.e., to reduce an entry angle for the tunneling tool <NUM>. That is, the tunneling tool <NUM> may be rotated with the tip <NUM> of the rod <NUM> inserted in the incision to reduce the entry angle of the tunneling tool <NUM>. In some embodiments, the tunneling tool <NUM> may be rotated until a bottom surface of the tunneling tool <NUM> contacts the skin surface. In some embodiments, rotating the tunneling tool <NUM> until the bottom surface of the tunneling tool <NUM> contacts the skin surface may minimize the entry angle between the bottom surface of the tunneling tool <NUM> and the skin surface.

In some embodiments, in operation, after reducing the angle between the tunneling tool <NUM> and the skin surface (e.g., by rotating the tunneling tool <NUM>), the rod <NUM> may be inserted further into the incision such that the rod <NUM> passes below the skin surface, and the skin surface is disposed between the rod <NUM> and the first and second prongs 206a-b. In such embodiments, the first length indicator 208a and the second indicator 208b may indicate a length of the subcutaneous pocket formed by the rod <NUM>. In some embodiments, the first and second length indicators 208a-b may include a contrasting color, ridge shape, indentation or a combination to be distinguishable from the handle <NUM>. In some embodiments, the first and second length indicators 208a-b may be located on a top surface of the first and second prongs 206a-b, respectively. In such embodiments, the first and second length indicator 208a-b may be visible to a user during use of the tunneling tool <NUM>, e.g., while inserting the rod <NUM> into an incision in the skin surface such that the rod <NUM> passes below the skin surface and the skin surface is disposed between the rod <NUM> and the first and second prongs 206a-b. In some non-limiting embodiments, the first and second length indicator 208a-b may be printed onto the top surface of the first and second prongs 206a-b, respectively.

In some embodiments, the rod <NUM> may include a tip <NUM> at the end of the rod <NUM>. In some embodiments, the tip <NUM> may be a dull tip. In some embodiments, the dull tip <NUM> of the rod <NUM> may enable the rod <NUM> to create space between layers of tissue underneath the skin surface. In some embodiments, the dull tip <NUM> may prevent the rod <NUM> from being able to pierce through vital tissue in the portion of the living animal (e.g., wrist, arm, leg, or abdomen) in which the subcutaneous pocket is being created.

<FIG> is a front view of the tunneling tool <NUM> embodying aspects of the present disclosure. In some embodiments, as illustrated in <FIG>, the first and second prongs 206a-b may be located above the rod <NUM> in a plane substantially parallel to a bottom surface of the handle <NUM>. In some embodiments, the tunneling tool <NUM> may include a first gap 302a between the first prong 206a and the rod <NUM> and a second gap 302b between the second prong 206b and the rod <NUM>. In some embodiments, the first prong 206a and the second prong 206b may each be located at an angle from the rod <NUM> with respect to the x-axis, as shown in <FIG>. For example and without limitation, the first prong 206a and the second prong 206b may each be located at a <NUM> degree angle from the rod <NUM> with respect to the x-axis. However, it is not required that the first prong 206a and the second prong 206b be located at <NUM> degree angles, and one or more of the first and second prong 206a-b may be located at a different angle with respect to the x-axis in some alternative embodiments. As described above, in some embodiments, the rod <NUM> may be inserted into the incision such that the rod <NUM> passes below the skin surface. In such embodiments, the skin surface may be disposed in the first gap 302a between the rod <NUM> and the first prong 206a and between the rod <NUM> and in the second gap 302b between the second prong 206b. The location of the first and second prongs 206a-b with respect to the rod <NUM> (e.g., the angle formed between each of the prongs 206a-b and the rod <NUM>) may enable a user to rock the tunneling tool <NUM> side to side while inserting the rod <NUM> further into the incision. Rocking the tunneling tool <NUM> side to side may create a rotating motion along a longitudinal axis of the rod <NUM>. Rocking the tunneling tool <NUM> may thereby provide a controlled insertion of the rod into the incision and prevent the rod <NUM> from piercing through vital tissue during the insertion. In some embodiments, the first and second gaps 302a-b may be uniform throughout the length of the first and second prongs 206a-b. The first and second gaps 302a-b limit the angle (relative to the skin surface) of the subcutaneous pocket created by the insertion of the rod <NUM> into the incision. In some embodiments, the first and second gap 302a-b may enable the rod <NUM> to create a subcutaneous pocket substantially parallel to the surface of the skin. In some embodiments, the first and second prongs 206a-b may be configured to prevent damage to the skin, such as a puncture, due to misuse of the tunneling tool <NUM>. In some non-limiting embodiments, the first prong 206a and the second prong 206b may comprise a smooth rounded surface, which may prevent damage to the skin.

<FIG> is a side view of the tunneling tool <NUM> embodying aspects of the present disclosure. In some embodiments, as illustrated in <FIG>, the tunneling tool <NUM> may include a side grip <NUM> on one or both sides of the handle <NUM>. In some embodiments, the tunneling tool <NUM> may include one or more of a bump <NUM> on a top surface the handle <NUM> and a depression <NUM> formed on the top surface of the handle <NUM>. In some embodiments, in operation, the tunneling tool <NUM> may be gripped by a user so that a thumb contacts a side grip <NUM> on one side of the tunneling tool <NUM> while a middle finger contacts a side grip <NUM> on the other side of the tunneling tool <NUM>. In some embodiments, the side grip <NUM> may include one or more ridges configured to accommodate a finger and a thumb. In some embodiments, the bump <NUM> may fit into a palm of a user's hand when using the tunneling tool <NUM>. In some embodiments, a user's index finger may fit into the depression <NUM> formed on the top surface of the handle <NUM>. In some embodiments, the depression <NUM> may have a circular or oval form configured to accommodate a finger. In some embodiments, the handle <NUM> may include a ribbed top surface to enhance friction between the user's hand and the handle.

<FIG> is a cross-sectional side view of the tunneling tool <NUM> embodying aspects of the present disclosure. In some embodiments, as illustrated in <FIG>, the handle <NUM> may be molded around an end of the rod <NUM> to securely hold the rod in place. In some embodiments, the molded over portion of the handle <NUM> may determine the length of the rod <NUM> extending from an end of the handle. In some embodiments, the first and second prongs 206a-b may be integrally formed with the handle <NUM> comprising a single overmold. <FIG> is a perspective view of the tunneling tool <NUM> embodying aspects of the present disclosure. <FIG> provides an illustration of the tunneling tool <NUM> gripped by a user, according to embodiments described in <FIG>.

<FIG> illustrate a method of creating a subcutaneous pocket embodying aspects of the present disclosure. In some embodiments, the tunneling tool <NUM> described above in <FIG> may be used to create the subcutaneous pocket according to the method described in <FIG>.

In some embodiments, the method may include a first step in which an incision may be made in a skin surface <NUM> at an insertion location for the tunneling tool <NUM>. In some embodiments, the incision may be, for example and without limitation, <NUM>-<NUM> wide and <NUM>-<NUM> deep. However, these dimensions are not required, and some alternative embodiments may use different dimensions.

In some embodiments, the method may include a second step in which, as shown in <FIG>, the tip <NUM> of the rod <NUM> of the tunneling tool <NUM> may be inserted into the incision. In some embodiments, the tip <NUM> of the rod <NUM> may be inserted into the incision to form an angle between the tunneling tool <NUM> and the skin surface <NUM>, i.e. an entry angle of the tunneling tool <NUM>. In some embodiments, the tip <NUM> of the rod <NUM> may be inserted into the incision at, for example and without limitation, a <NUM> degree entry angle. In some embodiments, the tip <NUM> of the rod <NUM> may be inserted into the incision until at least one or more of the first and second prongs 206a-b contact the skin surface <NUM>. In some embodiments, the rod <NUM> may be inserted into the incision until the tip <NUM> and the beveled portion of the rod <NUM> are under the skin surface <NUM>.

In some embodiments, the method may include a third step in which, as shown in <FIG>, after one or more of the first and second prongs 206a-b contact the skin surface <NUM>, the tunneling tool <NUM> is rotated with the tip <NUM> of the rod <NUM> inserted in the incision made in the skin surface <NUM> to reduce the entry angle. In some embodiments, the tunneling tool <NUM> may be rotated to reduce the entry angle to, for example and without limitation, <NUM>-<NUM> degrees. In some embodiments, the tunneling tool <NUM> may be rotated until a bottom surface of the tunneling tool <NUM> contacts the skin surface <NUM>. In some embodiments, the user may grip the tunneling tool <NUM> on one or more of the side surface and top surface of the tunneling tool <NUM>. In some embodiments, doing so may avoid creating a steep entry angle caused by a finger under a bottom surface of handle <NUM> or the rod <NUM>. For example, in some embodiments, the user may grip the tunneling tool <NUM> using the side grip <NUM> on one or both sides of the handle <NUM>, a bump <NUM> on a top surface the handle <NUM>, and a depression <NUM> formed on the top surface of the handle <NUM>, as described above with respect to <FIG>.

In some embodiments, the method may include a fourth step in which, as shown in <FIG>, the rod <NUM> may be inserted further into the incision such that the rod <NUM> passes below the skin surface <NUM> and the skin surface <NUM> is disposed between the rod <NUM> and the first and second prongs 206a-b. In such embodiments, the first length indicator 208a and the second indicator 208b may indicate a length of the subcutaneous pocket formed by the rod <NUM>. In some embodiments in which the incision is made on the skin surface <NUM> of an arm, the rod <NUM> may be inserted further into the incision in a direction towards the shoulder, while maintaining the reduced entry angle for the rod <NUM>. In some embodiments, the rod <NUM> may be inserted into the incision with the skin surface <NUM> disposed between the rod <NUM> and the first and second prongs 206a-b until the incision reaches the first length indicator 208a and the second length indicator 208b. In some embodiments, after the incision reaches the first length indicator 208a and the second length indicator 208b, the rod <NUM> may be removed from the incision.

<FIG> illustrates a flowchart of a method <NUM> for creating a subcutaneous pocket below a skin surface embodying aspects of the present disclosure. In some embodiments, the method <NUM> may include a step <NUM>, in which an incision may be created in the skin surface.

In some embodiments, the method <NUM> may include step <NUM>, in which a tip of a rod extending from a first end of a handle of a tunneling tool may be inserted into the incision until one or more of first and second prongs extending from the first end of the handle of the tunneling tool contact the skin surface. In some embodiments, the first and second prongs may limit the depth at which the rod is capable of creating the subcutaneous pocket.

In some embodiments, the method <NUM> may include step <NUM>, in which an angle between the tunneling tool and the skin surface may be reduced by rotating the tunneling tool while the tip of the rod remains inserted in the incision.

In some embodiments, the method <NUM> may include step <NUM>, in which after reducing the angle between the tunneling tool and the skin surface, the rod may be inserted further into the incision. In some embodiments, the rod may be inserted further into the incision such that the rod passes below the skin surface, the first and second prongs pass over the skin surface, the skin surface is disposed in a first gap between the rod and the first prong, and the skin surface is disposed in a second gap between the rod and the second prong, wherein the first and second gaps are configured to limit the angle relative to the skin surface at which rod is capable of forming the subcutaneous pocket.

In some embodiments, the method <NUM> may further include a step, in which the rod may be continuously inserted into the incision until the incision is aligned with a first length indicator on the first prong. In some embodiments, the method <NUM> may further include a step, in which the rod may be continuously inserted into the incision until the incision is aligned with a second length indicator on the first prong. The method and method of using the tunneling tool are not part of the claimed invention.

Claim 1:
A tunneling tool (<NUM>) for creating a subcutaneous pocket below a skin surface, the tunneling tool comprising:
a handle (<NUM>); and
a rod (<NUM>) extending from a first end of the handle and configured to create the subcutaneous pocket;
characterized in that the tunneling tool further comprises:
first and second prongs (206a and 206b) extending from the first end of the handle, wherein the first and second prongs are configured to limit the depth at which the rod is capable of creating the subcutaneous pocket, the rod extends farther from the first end of the handle than the first and second prongs, and the first prong comprises a first length indicator (208a) configured to indicate a length of the subcutaneous pocket formed by the rod,
wherein a first gap (302a) between the rod and the first prong and a second gap (302b) between the rod and the second prong are configured to limit the angle relative to the skin surface at which rod is capable of forming the subcutaneous pocket.