Patent Description:
Implantable access ports, or simply "ports," such as central venous access ports provide a convenient method to repeatedly deliver a substance to remote areas of the body by way of an attached catheter without utilizing a surgical procedure each time. Ports are implantable within the body and permit the infusion of medicine, parenteral solutions, blood products, or other fluids. Additionally, ports are also used for blood sampling. In common practice, a port is subcutaneously implanted within the body, and a catheter is connected to the port in fluid communication therewith. The catheter is routed to a remote area where a fluid is desired to be delivered or removed. To deliver the fluid, a caregiver locates a septum of the port by palpation of a patient's skin. Port access is accomplished by percutaneously inserting a needle, typically a non-coring needle, through the septum of the port and into a chamber of the port. A fluid containing a drug or some other beneficial substance can then be administered by bolus injection or continuous infusion into the chamber of the port. The fluid then flows through the chamber into the catheter and finally to the remote site where the fluid is desired.

Ports, particularly port septa, can be difficult to find once the ports are implanted under the skin. Further correctly identifying the type of port, make, model and other pertinent data about the device is also important. Accordingly, there is a need to facilitate finding and identifying medical devices such as ports and their septa once such medical devices are implanted. Disclosed herein are at least implantable ports, implantable port-detecting devices, and methods thereof. <CIT> discloses an implanted fluid access port locator system for adjustable gastric bands, wherein the system may include an access port having an RFID tag with its antenna adjacent to the receiving portion of the port.

The invention is defined in appended claim <NUM>.

Disclosed herein is an implantable medical device, such as a port, including, in some embodiments, a housing and a septum over the housing. The housing includes a chamber having a major opening to the chamber. The septum is over the major opening of the housing. One or more portions of the implantable port incorporate an RFID tag for locating the septum of the implantable port in vivo by signal reflection and detection of the RFID tag.

These and other features of the concepts provided herein will become more apparent to those of skill in the art in view of the accompanying drawings and following description, which disclose particular embodiments of such concepts in greater detail.

Reference will now be made to figures wherein like structures will be provided with like reference designations. It is understood that the drawings are diagrammatic and schematic representations of exemplary embodiments of the present invention, and are neither limiting nor necessarily drawn to scale.

Labels such as "left," "right," "front," "back," "top," "bottom," "forward," "reverse," "clockwise," "counter clockwise," "up," "down," or other similar terms such as "upper," "lower," "aft," "fore," "vertical," "horizontal," "proximal," "distal," and the like are used for convenience and are not intended to imply, for example, any particular fixed location, orientation, or direction. Also, the words "including," "has," and "having," as used herein, including the claims, shall have the same meaning as the word "comprising.

With respect to "proximal," a "proximal portion" or a "proximal end portion" of, for example, a catheter disclosed herein includes a portion of the catheter intended to be near a clinician when the catheter is used on a patient. Likewise, a "proximal length" of, for example, the catheter includes a length of the catheter intended to be near the clinician when the catheter is used on the patient. A "proximal end" of, for example, the catheter includes an end of the catheter intended to be near the clinician when the catheter is used on the patient. The proximal portion, the proximal end portion, or the proximal length of the catheter can include the proximal end of the catheter; however, the proximal portion, the proximal end portion, or the proximal length of the catheter need not include the proximal end of the catheter. That is, unless context suggests otherwise, the proximal portion, the proximal end portion, or the proximal length of the catheter is not a terminal portion or terminal length of the catheter.

With respect to "distal," a "distal portion" or a "distal end portion" of, for example, a catheter disclosed herein includes a portion of the catheter intended to be near or in a patient when the catheter is used on the patient. Likewise, a "distal length" of, for example, the catheter includes a length of the catheter intended to be near or in the patient when the catheter is used on the patient. A "distal end" of, for example, the catheter includes an end of the catheter intended to be near or in the patient when the catheter is used on the patient. The distal portion, the distal end portion, or the distal length of the catheter can include the distal end of the catheter; however, the distal portion, the distal end portion, or the distal length of the catheter need not include the distal end of the catheter. That is, unless context suggests otherwise, the distal portion, the distal end portion, or the distal length of the catheter is not a terminal portion or terminal length of the catheter.

Embodiments of the present invention are generally directed to a system configured to locate and identify an implanted medical device disposed within the body of a patient. An example of such a medical device includes an implantable vascular access port, though a variety of other implantable devices can benefit from use of the present system. Ports, particularly port septa, can be difficult to find once the ports are implanted under the skin. Accordingly, there is a need to facilitate finding medical devices such as ports and their septa once such medical devices are implanted. As such, set forth below are various implantable port-detection systems, catheter assemblies including implantable ports, the implantable ports, and implantable port-detecting devices. Methods associated with the foregoing are also set forth below.

<FIG> illustrates an exemplary environment of use for the present system <NUM> for locating and identifying an implanted medical device according to one embodiment. The system <NUM> includes an infusion set <NUM>, a medical device, such as a vascular access port ("port") <NUM>, a catheter <NUM>, and a user interface <NUM>. As used herein, a port <NUM> is used as an exemplary medical device, however it will be appreciated that embodiments of the system <NUM> can also include other implantable medical devices such as catheters, stents, pumps, combinations thereof, or the like. In addition, port <NUM> is shown throughout the drawings with certain features, such as septum bumps, which are optional. In addition, the port <NUM> is shown as having a certain shape, which is also optional. It should be appreciated that the locating and identifying system described herein is possible for any type of vascular access port or other implanted medical device. The port <NUM> is subcutaneously implanted in a patient <NUM> with a catheter <NUM> fluidly connecting the port <NUM> with a vasculature <NUM> of the patient <NUM>. An infusion set <NUM> can transcutaneously access the port <NUM> to deliver medicaments or other fluids to the port <NUM> and to the vasculature <NUM> of the patient by way of catheter <NUM>. As used herein, the infusion set <NUM> can include any infusion set, extension set, or needle device that can be used to fluidly access the implanted port <NUM> for the delivery of medicaments or other fluids.

<FIG> illustrate further details of the system <NUM> for locating and identifying an implanted medical device, according to one embodiment. The port <NUM> includes a body <NUM> and a needle-penetrable septum <NUM> that cooperates with the body <NUM> to define a fluid reservoir <NUM>. Optionally, the port body <NUM> can include suture holes <NUM>. An indwelling catheter <NUM> is fluidly connected to an outlet <NUM> of the reservoir <NUM> of the port <NUM> so as to enable medicaments or other fluids transcutaneously delivered to the port reservoir <NUM> via a needle <NUM> of an infusion set <NUM> (via needle piercing of the septum <NUM>) to be delivered to the vasculature <NUM> of the patient <NUM>.

The port <NUM> further includes at least two radiofrequency identification ("RFID") tags 222A and 222B included with the body <NUM>. In an embodiment, the RFID tags 222A, 222B are disposed on an outer surface of the medical port <NUM> using an adhesive, weld, fasteners, or similar techniques known in the art. In an embodiment, the RFID tags 222A, 222B are integrated within the body <NUM> of the port <NUM>. In an embodiment, the RFID tags 222A, 222B are disposed in a co-planar arrangement with respect to a substantially horizontal plane <NUM> that is parallel with a top surface of the septum <NUM>. Further, the RFID tags 222A, 222B are positioned so as to be equidistant from a centerline <NUM> of the port body <NUM>, which centerline <NUM> also passes through a centerpoint <NUM> of the septum <NUM>, as shown in <FIG>. It will be appreciated that the port <NUM> can include more than two RFID tags orientated in other positional arrangements and are considered to fall within the scope of the present invention. For example, port <NUM> can include three or four RFID tags orientated along the plane <NUM> and are spaced about the port septum centerpoint <NUM>, equidistant from each other as well equidistant from the port septum centerpoint <NUM>.

The RFID tags 222A, 222B in the port <NUM> enables the system <NUM> to detect, identify, and locate the position of the port <NUM> after implantation within the patient. As shown in <FIG>, the system <NUM> includes a detector <NUM> configured to detect the presence of the RFID tags 222A, 222B. The detector <NUM> is positioned so as to be central to the needle <NUM>, and as such, in the present embodiment the detector <NUM> includes a central hole <NUM> through which the needle <NUM> passes. When access to the port <NUM> by the infusion set <NUM> is desired, the detector-equipped infusion set <NUM> is hovered over the patient's skin <NUM> in an approximate location at which the implanted port <NUM> is disposed, similar to that shown in <FIG>. The system <NUM> is configured such that the detector can detect the presence of the RFID tags 222A, 222B when hovered over the centerline <NUM> above the implanted port <NUM>. When this occurs, the system <NUM> determines that the needle <NUM> is disposed above the center of the septum <NUM>. Vertically lowering the needle <NUM> at this point enables the distal end 152B thereof to pierce the skin <NUM> and pass through the septum <NUM> to enter the port reservoir <NUM>, as desired. Although only one detector <NUM> is shown, it will be appreciated that the detector <NUM> can also include an array of two or more detectors associated with the infusion set <NUM>, as discussed herein. Exemplary detectors can include MIFARE® RFIO-RC522 RFID detectors.

In an embodiment, the RFID tags 222A, 222B can be passive RFID tags that do not require a power source but obtains energy from an interrogating signal, emitted by the detector <NUM>. Advantageously this extends the useful life of the implanted medical device as it is not limited by a finite power source. Exemplary RFID tags can include MIFARE® <NUM> RFID tags. The interrogating signal induces a current in the RFID tag. The induced current is sufficient to allow the tag to process the interrogating signal and provide a return signal that includes information encoded on the RFID tag. In an embodiment, the return signal can contain at least a kilobyte of information. In an embodiment, the detector <NUM> is configured to detect information encoded in the return signal of the one or more RFID tags 222A, 222B. For example, such information can include make, model, type of the port or components thereof, port body composition, capabilities of the port such as power injectability, MRI compatibility, number of catheter lumens connected, date of manufacture, serial number, lot number, combinations thereof, or the like.

In an embodiment, the return signal from the RFID tag is directional. As such the return signal strength from the RFID tag to the detector decreases quickly when the distance between the RFID tag and the detector increases along the x, y, or z -axes, or when the RFID tag and detector are not co-planar. When the RFID tag and the detector <NUM> are parallel and co-axially aligned, the return signal is strongest. Accordingly, in a preferred embodiment, two or more RFID tags can be orientated side by side in a port device, orientated in the same plane and have the same normal direction. As such, the detector <NUM> will determine a center point of the port device when a return signal from both tags is both equal and strongest. For example, <FIG> shows four different positions of the detector, 140a-140d, with respect to RFID tags 222A, 222B. At a detector position 140a, the return signal from RFID tag 222A is weaker (lighter arrow) than that from RFID tag 222B (heavier arrow). Conversely, at detector position 140c, the return signal from RFID tag 222B is weaker than that from RFID tag 222A. At detector position 140b, the return signals from both RFID tags 222A, 222B are equal, as such the detector <NUM> is positioned over the center point. Similarly, a difference in absolute signal strength can indicate differences in distance along a vertical, or z-axis. For example, an equal but relatively weak signal would indicate a that the detector is at a greater vertical distance from the port <NUM>, e.g. detector position 140d, compared to detector position 140b.

As shown in <FIG>, in an embodiment, the system <NUM> can include a user interface <NUM> to interpret and communicate the above-described information to a user during operation. The user interface <NUM> can be integrated with the infusion set <NUM> or can be a separate device from that of the infusion set <NUM> and wired or wirelessly coupled thereto. The user interface <NUM> can include a screen and can depict written, numerical, or iconic information, or combinations thereof, regarding the position of the detector <NUM> with respect to the implanted port <NUM>. Such information can include distance, direction in three-dimensional space, orientation of the infusion set <NUM> and port <NUM> with respect to each other. Such information can be depicted as written instructions, numerical data, iconic, color-coded, or pictorial renderings, or combinations thereof, to display the information. Exemplary user interface devices <NUM> can include laptops, computer terminals, mobile device, palm top, smartphones, tablets, wearable devices, smartwatches, heads up displays (HUD), Virtual Reality (VR) devices, Augmented Reality (AR) devices, combinations thereof, or the like.

In an exemplary embodiment, as shown in <FIG>, when neither RFID tag 222A, 222B is detected, the user interface <NUM> can depict information indicating that the port is not detected. As shown in <FIG>, when the infusion set <NUM> is within a proximity of only one RFID tag, the user interface <NUM> can depict information about the port <NUM>, e.g. make, model, serial number, capabilities, etc. As shown in <FIG>, when the infusion set <NUM> is within a proximity two or more of the RFID tags, the user interface <NUM> can depict both information about the port <NUM> as well as directional information e.g. direction, distance, orientation, etc. As shown in <FIG>, when both RFID tags 222A, 222B are detected and the return signal is both equal and strongest, the user interface <NUM> can indicate that the infusion set <NUM> is positioned correctly over the port <NUM>.

While only two RFID tags are shown, it will be appreciated that more than two RFID tags can be used and fall within the scope of the present invention. The system <NUM> can use the relative position between the detector <NUM> and the two or more RFID tags 222A, 222B to triangulate an exact position of the needle tip 152B with respect to the septum center point <NUM> in three dimensional space. In an embodiment, only a single RFID tag can be used, such a system can advantageously be smaller, cheaper and simpler to produce. In an embodiment, if an unknown RFID tag is detected, a message indicating that the tag is unrecognized can be depicted. These and other messages can be employed corresponding to a variety of detection scenarios.

It will be appreciated that the strength of the return signal from the RFID tags 222A, 222B is dependent on the strength of the interrogating signal from the detector <NUM>. Accordingly, the system <NUM> can vary the strength of the interrogating signal from the detector <NUM> depending on whether the system is improving detection range or positional accuracy. For example, if one or no tags are detected the interrogation signal can be increased to improve detection range. As two or more tags are detected, the interrogation signal can be reduced to improve positional accuracy.

In an embodiment, detector <NUM> can include an array of detectors arranged normally to each other. Advantageously, this can improve the accuracy and detection range of the system <NUM>. Moreover, the different orientations of the detectors can identify the orientation of the port <NUM> relative to the infusion set <NUM> and/or the patients skin <NUM>. For example, the port may have shifted position or flipped such that the septum is not orientated towards the skin surface. The system <NUM> can alert a clinician to such problems prior to insertion of the needle even if the port cannot be detected visually or by palpation.

Claim 1:
A system for detecting a medical device implanted in a body of a patient, the system comprising:
as an implantable medical device a vascular access port (<NUM>) which includes a body (<NUM>) and a needle-penetrable septum (<NUM>) that cooperates with the body (<NUM>) to define a fluid reservoir (<NUM>), wherein the vascular access port (<NUM>) includes at least two radiofrequency identification (RFID) tags (222A, 222B) included with the body (<NUM>); and
an infusion set (<NUM>) including a needle (<NUM>) and a detector (<NUM>), the detector (<NUM>) providing an interrogation signal inducing each of the RFID tags (222A, 222B) to provide a return signal.