The present invention relates generally to implantable infusion devices for the delivery of medication or other fluids to a patient.
Various implantable devices exist for delivering infusate, such as medication, to a patient. One such device is an implantable valve accumulator pump system. This system includes an electronically controlled metering assembly located between a drug reservoir and an outlet catheter. Doctors may refill the drug reservoir on a periodic basis (e.g., once a month) for the patient.
The systems, methods, and devices of the various embodiments provide an indication to a medical professional when an inserted needle has penetrated a septum of the drug reservoir of an implantable drug delivery device. The various embodiments may enable a medical professional to determine whether to inject drugs into the implantable drug delivery device based on an indication that the inserted needle is in the proper position. In an additional embodiment, the needle penetration detector and its associated devices may give assurances to medical professionals that drugs were delivered to the drug reservoir in the patient properly based on proper needle positioning
The accompanying drawings, which are incorporated herein and constitute part of this specification, illustrate example embodiments of the invention, and together with the general description given above and the detailed description given below, serve to explain the features of the invention.
The various embodiments will be described in detail with reference to the accompanying drawings. Wherever possible, the same reference numbers will be used throughout the drawings to refer to the same or like parts. References made to particular examples and implementations are for illustrative purposes, and are not intended to limit the scope of the invention or the claims.
The words “exemplary” or “for example” are used herein to mean “serving as an example, instance, or illustration.” Any implementation described herein as “exemplary” or “for example” is not necessarily to be construed as preferred or advantageous over other implementations.
The systems, methods, and devices of the various embodiments enable delivering metered doses of a drug or other infusate. An embodiment drug delivery system may include a needle penetration detector, an electronics module, and an external programmer to indicate to a medical professional refilling a drug reservoir of the drug delivery system a status of needle insertion into the drug reservoir. In an embodiment, the medical professional may activate the needle penetration detector with the external programmer. The electronics module connected to the needle penetration detector may measure the inductance in a coil surrounding the septum of the drug reservoir prior to insertion of a needle and after insertion of the needle into or near the septum. In an embodiment, a needle penetrating the septum may result in a change in the inductance of the coil compared to the inductance in the coil in normal conditions (i.e., when a needle is not present). In an embodiment, the electronics module may monitor the state of the inductance of the coil and the connected external programmer may indicate the proper or improper position based on the measured inductance of the coil.
Various embodiments may provide a needle penetration detector that indicates to a medical professional that he has successfully penetrated a needle into the drug reservoir to refill it. Alternatively, the needle penetration detector may indicate to the medical professional that he has not penetrated the needle into the drug reservoir and the medical professional may halt injecting the drug outside of the drug reservoir and re-attempt to penetrate the drug reservoir with the needle. In this way, patient safety is improved and the medical professional may have an instant verification that the needle is in proper position to inject drugs into the reservoir.
The two-phase fluid helps maintain the chamber 18 under a constant pressure. When the chamber is refilled, the two-phase fluid is pressurized thereby condensing a portion of the vapor and converting it to liquid. As the chamber 18 is emptied, this liquid vaporizes, thus maintaining the pressure on the bellows 16. Since the infusate in chamber 18 is under positive pressure, it is urged out of the chamber, through a bacterial filter 24 and toward the metering assembly.
The second major assembly is an electronically controlled metering assembly comprising two normally closed solenoid valves 26, 28, which are positioned on the inlet and outlet sides of a fixed volume accumulator 30. The valves are controlled electronically via an electronics module 32, which may be programmed utilizing the external programmer 34. The metering assembly is designed such that the inlet valve 26 and the outlet valve 28 are never simultaneously open.
The third major assembly is an outlet catheter 36 for medication infusion in a localized area. The delivery of fluid occurs at an infusion site that is below the accumulator pressure, thereby forcing discharge through the catheter 36.
The drug reservoir, electronically controlled metering assembly, and needle penetration detector may be contained within a biocompatible housing, also containing a power source (e.g., battery), that may be implanted within the body of a human or animal patient. The outlet catheter may be integral with the housing, or may be a separate component that is attached to the housing. An access port 31, in communication with the catheter 36, may be provided downstream of the metering assembly. The access port 31 may be used, for example, to manually provide a bolus dose of medication to the patient.
The fourth assembly of the system of
In an embodiment, the controller 92 may be coupled to an inductance monitoring circuit 45 of the needle penetration detector 41. The inductance monitoring circuit 45 may measure the inductance of the induction coil 42 and provide indications of the measurements of the inductance to controller 92. The AC power source 50 may be coupled to the induction coil 42 via a switch 90 coupled to the controller 92. The controller 92 may control the operation of the switch 90 to induce a magnetic field on coil 12.
In an embodiment, the inductance monitoring circuit 45 may measure the inductance of the induction coil 42 resulting from the change in inductance from an approaching needle and provide the measurement of the inductance to the controller 92. The controller 92 may compare the change in inductance from the approaching needle to an established baseline inductance. The controller 92 may determine the needle's position and communicate that determination to the external programmer 34, which may subsequently indicate the position of the needle 40. In another embodiment, the controller 92 may generate indications of the measurements of the inductance received from the inductance monitoring circuit 45 and communicate the indications of the measurements to the external programmer 34.
In an embodiment, the external programmer 34 may include a processor 47 coupled to a memory 46 and to an indicator 48. Software instructions may be stored in the memory 46 before they are accessed and loaded into the processor 47. The external programmer 34 may include an AC power source 95 coupled to a wireless communication coil 94 via a switch 96 coupled to the processor 47. The processor 47 may control the operation of switch 96 to induce a magnetic field on the wireless communication coil 94 to receive and communicate information. For example, the wireless communication coil 94 may be controlled to communicate information from the electronics module 32. The processor 47 may be coupled to the wireless communication coil 94 and may monitor the current, voltage, and/or inductance of the coil 94 to receive information from the via the wireless communication coil 94. As an example, the processor 47 may receive information via the wireless communication coil 94 from the electronics module 32 of the implantable drug delivery device 200 regarding whether a needle has been detected within the induction coil 42. The processor 47 may be connected to an indicator 48 to indicate the position of a needle based on received indication instructions from the electronics module 32. For example, the indicator may be a display, a speaker for an audio sound or message, or a vibrator to generate haptic feedback.
In an embodiment, the external programmer 34 may receive, via the wireless communication link 97 described above, information regarding the position of the needle 40 and/or indications of the measurements of the inductance of the induction coil 42 from the implantable drug delivery device 200. The information communicated from the implantable drug delivery device 200 may be a direct measure of inductance of the induction coil 42 or data that the external programmer processor 47 can used to determine changes in inductance. For example, the processor 47 may compare the change in inductance from the approaching needle 40 to a baseline inductance established before the needle 40 was inserted into the patient to detect when the needle 40 is in a proper or improper position. Alternatively, the processor 43 of the implantable drug delivery device 200 may compare measurements of the inductance of the induction coil 42 and transmit to the external programmer 34 an indication of whether the needle 40 is in a proper or improper position. If the needle 40 is in an improper position, the external programmer 34 may inform the medical professional via the indicator 48, thereby allowing the medical professional to reposition the needle into the refill septum 12 of the drug reservoir.
In block 404 the induction monitor 45 of the electronics module may collect a baseline measurement from the needle penetration detector 41. For example, the electronics module 32 may collect a baseline measurement of the inductance of the induction coil 42 before a needle is inserted into the refill septum. In block 406 the electronics module 32 may indicate the baseline measurement to the external programmer 34. For example, the electronics module 32 may transmit the baseline measurement to the external programmer 34 via the coils 93, 94.
In block 408 the induction monitor 45 of the electronics module 32 may collect a new measurement from the needle penetration detector 41. The new measurement may be collected after the medical professional inserts a needle into the patient. In block 410, the electronics module 32 may communicate the new inductance measurement to the external programmer 34. In block 412, a processor of the external programmer 34 may compare the baseline and new measurements to determine the difference between measurements. The comparison may result in a high state 54, an intermediate state 56, or a low state 58 as shown in
In determination block 414, a processor 47 of the external programmer 34 may determine whether the difference in measurements is below a threshold 52. In response to determining that the difference in measurements is below the threshold 52 (i.e., determination block 414=“Yes”), the processor 47 of the external programmer 34 may indicate via an indicator 48 or display that the needle did not penetrate the refill septum in block 416. For example, a medical professional may have inserted the needle 40 outside of the refill septum 12 in which case the indicator 48 of the external programmer may display an appropriate warning or message, such as “FAIL.” Based on the indication, the medical professional may re-insert or move the needle and the electronics module and the external programmer may repeat blocks 408, 410, 412. In an embodiment, the processor 47 of the external programmer 34 may provide an intermediate indication via the indicator 48 when the measured inductance indicates that the needle is close but not yet within the refill septum. This intermediate indication may aid a medical professional in aligning the needle with the refill septum before penetrating the skin of the patient.
In response to determining that the difference in measurements is equal to or greater than the threshold 52 (i.e., determination block 414=“No”), the processor 47 of the external programmer 34 may indicate the needle did penetrate the septum in block 418. For example, a medical professional may have inserted the needle 40 directly in the center of the refill septum 12, in which case the indicator 48 of the external programmer may display an appropriate message, such as “SUCCESS.”
In alternative embodiment, the processor 43 within the implantable drug delivery device may be configured with processor-executable instructions to perform the operations of blocks 412 and 414 and communicate an indication of success or failure (and optionally an intermediate indication) to the external programmer 34. In this embodiment, the processor 47 of the external programmer 34 may receive the indication from the implantable drug delivery device and use the received indication to generate a corresponding warning or message on the indicator 48 or display.
In block 420, the electronics module 32 of the implantable drug delivery device may deactivate the needle penetration detector based on a received deactivation instruction from the external programmer 34. For example, a medical professional may press a button labeled “Deactivate” on the external programmer 34, which prompts the external programmer to send a deactivate instruction via coil 94 to coil 93 of the electronics module 32 of the implantable drug delivery device. Upon receiving the deactivation instructions, the electronics module of the implantable drug delivery device may cut off electricity to the induction coil 42 of the needle penetration detector 41, thereby conserving the battery life of the electronics module 32.
The foregoing method descriptions and the process flow diagrams are provided merely as illustrative examples and are not intended to require or imply that the blocks of the various aspects must be performed in the order presented. As will be appreciated by one of skill in the art the order of blocks in the foregoing aspects may be performed in any order. Words such as “thereafter,” “then,” “next,” etc. are not intended to limit the order of the blocks; these words are simply used to guide the reader through the description of the methods. Further, any reference to claim elements in the singular, for example, using the articles “a,” “an” or “the” is not to be construed as limiting the element to the singular.
The various illustrative logical blocks, modules, circuits, and algorithm blocks described in connection with the aspects disclosed herein may be implemented as electronic hardware, computer software, or combinations of both. To clearly illustrate this interchangeability of hardware and software, various illustrative components, blocks, modules, circuits, and blocks have been described above generally in terms of their functionality. Whether such functionality is implemented as hardware or software depends upon the particular application and design constraints imposed on the overall system. Skilled artisans may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present invention.
The previous description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the invention. Thus, the present invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.
This application claims the benefit of priority to U.S. Provisional Application No. 61/763,277 entitled “Needle Penetration Detection Method and Device for Refillable and Implantable Drug Delivery Systems” filed Feb. 11, 2013, the entire contents of which are hereby incorporated by reference in their entirety for all purposes.
Number | Date | Country | |
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61763277 | Feb 2013 | US |