Abstract
The present disclosure relates to an improved implantable drug delivery device, method, and system that is powered by compression and expansion of an inert gas contained within a compressible bellows and surrounded by a biocompatible housing that forms a reservoir which is connected to restricted channel for flow rate control and further connected to a flexible reinforced catheter that delivers medicants from the reservoir to the intrathecal space or other desired bodily tissue.
Claims
1. An implantable intrathecal drug delivery device comprising: a housing; a sensor assembly comprising: a compressible bellows enclosed by the housing, the bellows comprising a gas chamber filled with an inert gas; and a bellows sensor arm coupled to the bottom of the bellows and proximally aligned with a linear positional sensor; and a reservoir formed by an inner wall of the housing and an outer wall of the bellows; wherein the reservoir contains a fluid, and wherein the reservoir is in fluid connection with a catheter for delivery of the fluid to a terminal site.
2. The device of claim 1, wherein the device is configured to deliver fluids to a terminal site at a fixed flow rate.
3. The device of claim 1, further comprising a microfabricated capillary channel in fluid connection with the reservoir for restrictive flow of the fluid to the catheter.
4. The device of claim 1, where the reservoir comprises a bladder, and wherein the bladder is made of elastomeric material.
5. The device of claim 1, wherein the sensor assembly is configured to detect the volume of fluid in the reservoir by detecting an expanded or compressed state of the bellows, wherein the reservoir is empty when the bellows are fully expanded or the reservoir is full when the bellows are fully compressed.
6. (canceled)
7. (canceled)
8. The device of claim 1, comprising a data information storage medium, where the data information can be retrieved transcutaneously from the device using an external transponder.
9. The device of claim 8, comprising an embedded RFID chip data information related to IDDS status.
10. The device of claim 8, wherein the external transponder is configured to retrieve data related to the volume of fluid contained within the reservoir from the sensor assembly.
11. The device of claim 1, further comprising a puncturable septum in fluid communication with the reservoir.
12. The device of claim 11, wherein the puncturable septum is surrounded by a raised rim capable of being palpated to locate the puncturable septum.
13. (canceled)
14. (canceled)
15. An implantable intrathecal drug delivery device comprising: a housing; a sensor assembly comprising: a compressible bellows enclosed by the housing, the bellows forming a reservoir for a fluid to be delivered by the device; and a bellows reservoir sensor arm coupled to the bottom of the bellows and proximally aligned with a linear positional sensor; and a chamber formed by an inner wall of the housing and an outer wall of the bellows filled with an inert gas; wherein the reservoir contains a fluid, and wherein the reservoir is in fluid connection with a catheter for delivery of the fluid to a terminal site.
16. The device of claim 15, wherein the device is configured to deliver fluids to a terminal site at a fixed flow rate.
17. The device of claim 15, further comprising a microfabricated capillary channel in fluid connection with the reservoir for restrictive flow of the fluid to the catheter.
18. The device of claim 15, where the chamber comprises a bladder, and wherein the bladder is made of elastomeric material.
19. The device of claim 15, wherein the sensor assembly is configured to detect the volume of fluid in the reservoir by detecting a compression state of the bellows, wherein the reservoir is full when the bellows are fully expanded, or the reservoir is empty when the bellows are fully compressed.
20. (canceled)
21. (canceled)
22. The device of claim 15, further comprising a data information storage medium, where the data information can be retrieved transcutaneously from the device using an external transponder.
23. The device of claim 22, wherein the device further comprises an RFID chip containing data information related to IDDS status.
24. (canceled)
25. The device of claim 15, further comprising a puncturable septum in fluid communication with the reservoir.
26. The device of claim 25, wherein the puncturable septum is surrounded by a raised rim capable of being palpated to locate the puncturable septum.
27. (canceled)
28. (canceled)
Description
BRIEF DESCRIPTION OF THE DRAWINGS
[0021] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate various embodiments of the present disclosure, and, together with the description, serve to explain the principles of the disclosure. In the drawings:
[0022] FIG. 1 is a cutaway sectioned view of one example of an implantable intrathecal drug delivery apparatus with housing and elastomeric reservoir in a closed static full position.
[0023] FIG. 2 is an isometric top and side view of one example of an assembled implantable intrathecal drug delivery apparatus shown with a truncated catheter.
[0024] FIG. 3 is a schematic diagram of the electronic interrogation system used to remotely retrieve pump metrics and identification information.
[0025] FIG. 4. is a schematic diagram of an RFID system.
[0026] FIG. 5 is a front and side anatomical view of an implanted intrathecal drug delivery apparatus, a reinforced catheter, and a catheter attached to a port reservoir.
[0027] FIG. 6 is an illustration of a flow control capillary channel system and methods of manufacturing said flow control capillary channel system.
[0028] FIGS. 7A-D are illustrations of designs for the implantable drug delivery system.
[0029] FIG. 8 is a top and isometric view of one example of an implantable drug delivery system.
[0030] FIG. 9A is a crossection view of one example of implantable drug delivery system. FIG. 9B is a close up cross-section of one example of a refill mechanism.
[0031] FIGS. 10A-10D are illustrations of various embodiments of the refill mechanisms.
[0032] FIG. 11 illustrates examples of valving mechanisms that can be employed in implantable drug delivery systems.
[0033] FIG. 12 illustrates an example of a design that incorporates a textured bottom to enhance securement of the device.
[0034] FIG. 13 illustrates the operation of one example of a refill mechanism and refill needle design.
[0035] FIG. 14A illustrates valving mechanism that can be employed with an implantable drug delivery system to control the flow rate of the device.
[0036] FIG. 14B illustrates the changes in flow rate by rotation of the valving mechanism from low to no flow.
[0037] FIG. 15 illustrates an example of a catheter coupling design.
DETAILED DESCRIPTION OF THE INVENTION
[0038] Referring now to FIGS. 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, and/or 15 there is shown a variety perspective, schematic, illustrations, and section views of embodiments of the present invention.
[0039] Referring now to FIG. 1, shown is a section view of the implantable drug delivery system (IDDS) assembly 100 where housing 101 is a biocompatible apparatus which stores a fluid 117, which can be a medicant and/or an infusate, for example, inside a reservoir 104. The gas chamber 110 is an expandable bellows 111 that is located inside the reservoir 104 and contains an inert gas which is charged into the bellows 111 via the gas port 112 and permanently sealed by gas port plug 113. The fluid 117 is placed into the reservoir through the self-sealing, puncturable septum 103 by a non-coring injection needle 115 and upon injecting flows through the reservoir inflow channel 108 into the reservoir 104.
[0040] Surrounding the septum 103 is a raised rim 102 comprising a palpation ring which may be palpated using a touch sense to allow for locating and targeting the needle into the puncturable septum 103. The palpation ring can also include location sensors 116 and/or embedded materials that react to external extracorporeal readers for machine location of the septum.
[0041] The flow of the fluid 117 follows a path through the reservoir outflow channel 109, into a filter 114, to the microfabricated etched capillary channel system 105, and to external exit port tube 106 that is coupled to the proximal end of an exit catheter 107. The catheter may be a flexible reinforced catheter.
[0042] The IDDS assembly 100 may also include a separate in-line infusion port 119 for bolus injection into tissue via catheter conduit 107 that is tunneled to the intrathecal space or tissue to be infused.
[0043] Also included in some embodiments is an RFID chip 118 located inside the housing 101 for relaying embedded information and data on the IDDS status.
[0044] FIG. 2 provides isometric top and side views of the IDDS assembly 200. Key external components of the assembled IDDS including the housing 101, the puncturable septum 103, and adjacent palpation ring 102 are shown. The palpation ring may have location sensors 116 to guide location of the puncturable septum to deliver fluid into the IDDS. The fluid may be subsequently delivered to bodily tissues, such as the intrathecal space, via the exit catheter 107. Suture holes 201 at several locations on the housing 101 may provide attachment points for securement of the IDDS to tissues at a surgical site. Also shown in FIG. 2 is bolus port 119.
[0045] FIG. 3 provides a detailed cutaway view of an embodiment of a sensor assembly 300 which can be used to indirectly measure the volume status of fluid in the reservoir. Shown are two states 301 and 302 of the sensor, the sensor comprising a sealed expandable and collapsible bellows 111 comprising a gas chamber 110 containing inert gas. In 301, depicted is a full reservoir state in which the bellows 111 are in an expanded state and the gas chamber 110 is filled with gas. In 302, depicted is an empty reservoir state in which the bellows 111 are in a collapsed state with inert gas of the gas chamber 110 compressed. A bellows reservoir sensor arm 303 may be attached to the bottom of the bellows 111 and may be proximally aligned with linear positional sensor 304 that senses the location of the sensor arm 303 as it travels through a range of motion related to the state of the bellows 111. The state of the bellows 111 can be transmitted by the linear reader strip 304 to an external reader (not shown) to indicate changes in fluid volume, e.g., from a full reservoir state (expanded bellows 301 with gas chamber 110 filled with inert gas) to an empty reservoir state (collapsed bellows 302 with compressed inert gas in gas chamber 110).
[0046] FIG. 4 is a schematic diagram 400 of a remote transponder and reader that can retrieve information from sensors within the implanted IDDS 100. The remote transponder/reader may be battery powered. Information to be retrieved may include information embedded on a passive RFID chip and/or the reservoir fluid level. The remote transponder/reader may also control a flow restrictor of the IDDS to provide for a variable flow rate from the reservoir into tissue.
[0047] FIG. 5 is a series of illustrations 500 showing a reinforced catheter 502 which may be attached to the drug delivery device 200. The drug delivery device may be coupled via a catheter proximal section to a full-length catheter 501, the full-length catheter having a distal tip 503 located at the tissue site. As illustrated the IDDS can be attached to the abdominal wall, and the tunneled catheter 501 may be placed such that the distal tip 503 is located in the spine intrathecal space.
[0048] FIG. 6 illustrates a process by which a microfabricated etched capillary channel system may be manufactured 601 using, for example, MEMS or PDMS replication molding. In some embodiments, manufactured is a capillary bed configuration made of a membrane substrate 602 upon which a channel 603 is etched or formed, a capillary inlet port 604 coupled to the capillary channel system proximally, and a capillary outlet port 605 coupled to the capillary channel system distally.
[0049] FIGS. 7A to 7D provide illustrations of designs for the implantable drug delivery system. The designs comprising a transcutaneous supply port 102/103, a drug reservoir 104, and a delivery conduit 107 that can be fluidly connected to a target site. The body of the device can be in various shapes and geometries and can have a concave portion for guiding a needle or other device for filling or refilling the reservoir.
[0050] FIG. 8 is a top and isometric view of one example of an implantable drug delivery system. In this particular embodiment the housing (or body) 101 is configured easy handling and comprises a concave portion leading to the supply port 103, which can be punctured by needle 115. In certain aspects, any of the embodiments described herein can have the housing of the device configured to have an ergonomic design 801 to be easily graspable before and after implantation, the design including indentions or grips externally on one or more sides of the device housing to accommodate the fingers and/or thumb of persons handling the device. The device is configured with a catheter 107 providing an intrathecal delivery route. The implantable drug delivery system can have inner loops 802 for sutures.
[0051] FIG. 9A is a cross-section view of one example of implantable drug delivery system. The concave portion of the body is shown providing access to refill port 901 and its valve mechanism 902 (see FIG. 9B for additional details). The valve mechanism 902 is fluidly connected to reservoir/bellows 903 through drug refill channel 903 and fluidly connects the reservoir 904 to the delivery component 905. In a first configuration solution to be delivered is contained in the volume of the body while a gas fills the bellows. In a second configuration the solution to be delivered is contained in the bellows and a gas fills the volume of the device body. Refill port 901 can include a puncturable septum. The body forms a cavity or body volume 906 that can be filled with a noble gas or similar gas. In certain aspects, the cavity 906 can contain a RFID sensor 907 and/or other electronics to monitor, modulate, or control operation of the device. The body cavity will also contain a bellows 904 that is the reservoir for a medicament to be delivered by the device.
[0052] FIG. 9B illustrates one example of valve mechanism that can be employed. In this aspect a two headed plunger 908 having a top portion and a bottom portion connected by a stem. When in use the top portion blocks fluid path 909 from the refill port 901 to the reservoir 904 and the bottom portion is positioned to allow flow from the reservoir 904 to the delivery component 905. The stem can be configured with a spring mechanism 910 that can be depressed during filling and restore the operational positioning of the plunger once filling is completed or ceased. In certain embodiments, the medicament to be delivered is stored in the reservoir of the housing, in other embodiments, the medicament can be stored in the cavity formed inside the bellows. Also, in the event the medicament is stored in the reservoir of the housing a gas can be introduced into the bellows, and alternatively, if a medicament is stored in the bellows a gas can be introduced into the reservoir of the housing.
[0053] FIGS. 10A-10D are illustrations of various embodiments of the refill mechanisms. Various designs have been envisioned for valve designs for refill compatibility. The valve mechanisms allow for the drug delivery line to be temporarily blocked while the bellows or medicament volume is being refilled. This can be achieved by twisting a valve (FIG. 10C, 10D), compressing a delivery line (see FIG. 13), and/or incorporating a spring loaded valve (FIG. 10A, 10B). Refill compatibility can be improved with valve designs that do not produce a bolus of drug during refill. Certain aspects of the refill mechanism can include features to capture/trap the tip of refill needle during refill. FIG. 13 illustrates a refill mechanism and refill needle design that provides a pinch mechanism to modulate flow.
[0054] FIG. 11 illustrates examples of twisting valve mechanisms that can be employed in implantable drug delivery systems during use and during refill. In certain aspects, the refill channel is open to a needle or like instrument supplying a medicament while the delivery pathway is closed. When filling complete and the needle of like instrument is removed the refill channel can be closed and the delivery channel can then be opened. In certain aspects, the refill mechanism is spring loaded and returns to a delivery position after refilling is complete. In certain aspects, the channels can be opened and/or closed by turning or twisting a valve member, or vertical movement of a valve member, or constriction/relaxation of a catheter channel.
[0055] FIG. 12 illustrates an example of a design that incorporates a textured bottom 1201 to enhance securement of the device. The devices described herein can include a feature/lip 1202 to allow spooling of catheter line around device, this is illustrated in FIG. 12, and can be implement in the design of any device described herein. In addition the body can be configured with 1, 2, 3, 4, or more suture loops to aid in securing the device when deployed. The suture loop(s) can be position at various positions on the device, including, but not limited to the corners of the body. Another feature that can be included is the inclusion of one or more textured surface(s) on device to reduce movement of device (two variations (grid or rib variations) are shown in FIG. 13).
[0056] FIGS. 14A-14B illustrate a valving mechanism that can be employed with an implantable drug delivery system to control the flow rate of the device. Valve designs for various flow rates include an on/off (binary) valve, a valve with different diameter flow through holes, and/or a valve with scoring/rifling to induce twisting motion of the valve as it is depressed.
[0057] FIG. 15 illustrates an example of a catheter coupling design. In certain aspects, the IDDS can include a tunable flow control valve at end of catheter line, such as that illustrated in FIG. 15, where the diameter of a connection with the conduit to the target can be decreased to limit flow rate.
[0058] While the present disclosure has been set forth in terms of a specific embodiment or embodiments, it will be understood that the present apparatus and the method of using the same herein disclosed may be modified or altered by those skilled in the art to other configurations. Accordingly, the disclosure is to be broadly construed and limited only by the scope and spirit of the claims appended hereto.
[0059] The following table lists the reference characters of names or features used herein:
TABLE-US-00001 REFERENCE CHARACTER TABLE Number Feature or Element 100 Intrathecal Drug Delivery System Section 101 Housing 102 Palpation Ring 103 Puncturable Septum 104 Reservoir 105 Microfabricated Etched Capillary Channel system 106 External Exit Port Tube 107 Exit Catheter 108 Reservoir Inflow Channel 109 Reservoir Outflow Channel 110 Gas Chamber 111 Bellows 112 Gas Injection Port 113 Gas Injection Port Seal 114 Reservoir Outlet Filter 115 Non-Coring Injection Needle 116 Location Sensors 117 Fluid 118 RFID Chip 119 Bolus Port 200 Exterior View of IDDS 201 Suture Holes 300 Sensor Assembly 301 Empty Reservoir State 302 Full Reservoir State 303 Bellows Reservoir Sensor Arm 304 Linear Positional Sensor 400 Diagram of Electronic Sensors & Reader 500 Catheter Placement & Reinforcement 501 Catheter 502 Reinforced Catheter Membrane 503 Anatomical Location of IDDS 600 Microfabricated Capillary Channels 601 Fabrication Methods 602 Membrane Substrate 603 Capillary Channel 604 Capillary Inlet Port 605 Capillary Outlet Port 801 Ergonomic inset 802 Suture loops 901 Self Sealing Refill Port 902 Valve mechanism 903 Refill channel 904 Bellows 905 Delivery route 906 Device volume 907 Valve piston 909 Drug delivery from reservoir 910 Piston spring 1201 Textured bottom 1202 Lip for catheter wrap
