Patent Publication Number: US-2023158225-A1

Title: Fluid drug spread-promoting pump

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims the benefit of and priority to U.S. Provisional Patent Application No. 63/283,126 filed Nov. 24, 2021, the entire disclosure of which is incorporated by reference herein. 
    
    
     TECHNICAL FIELD 
     The present technology is generally related to implantable medical devices, and more particularly to a fluid drug spread promoting device enabling enhanced mixing of an infused drug via a manually activated flushing pump. 
     BACKGROUND 
     Implantable medical devices, such as implantable medical pumps and ports, are useful in managing the delivery and dispensation of prescribed therapeutic agents, nutrients, drugs, infusates such as antibiotics, blood clotting agents, analgesics and other fluid or fluid like substances (collectively “infusate” or “infusates”) to patients in volume- and time-controlled doses as well as through boluses. Such implantable pumps and ports are particularly useful for treating diseases and disorders that require regular or chronic (i.e., long-term) pharmacological intervention, including tremor, spasticity, multiple sclerosis, Alzheimer&#39;s disease, Parkinson&#39;s disease, amyotrophic lateral sclerosis (ALS), Huntington&#39;s disease, cancer, epilepsy, chronic pain, urinary or fecal incontinence, sexual dysfunction, obesity, and gastroparesis, to name just a few. Depending upon their specific designs and intended uses, implantable pumps and ports are well adapted to administer infusates to specific areas within the vasculatures and central nervous system, including the subarachnoid, epidural, intrathecal, and intracranial spaces or provide access to those spaces for aspiration. 
     Providing access to the cerebrospinal fluid for the administration of infusates or aspiration of fluid has a number of important advantages over other forms of infusate administration. For example, oral administration is often not workable because the systematic dose of the substance needed to achieve the therapeutic dose at the target site may be too large for the patient to tolerate without adverse side effects. Also, some substances simply cannot be absorbed in the gut adequately for a therapeutic dose to reach the target site. Moreover, substances that are not lipid soluble may not cross the blood-brain barrier adequately if needed in the brain. In addition, infusion of substances from outside the body requires a transcutaneous catheter or access with a hypodermic needle, which results in other risks such as infection or catheter dislodgment. Further, implantable pumps avoid the problem of patient noncompliance, namely the patient failing to take the prescribed drug or therapy as instructed. 
     Despite these clear advantages, clinicians report that drug boluses delivered via a hypodermic needle during initial patient trialing can in some cases be more effective than delivery of the same dose via an implantable pump or port. Factors that may account for the more effective delivery include infusion of the bolus at a higher velocity followed by the clinician cycling the syringe plunger to affect barbotage (e.g., the repeated injection and removal of fluid), which may further enhance mixing. The present disclosure addresses this concern. 
     SUMMARY OF THE DISCLOSURE 
     The techniques of this disclosure generally relate to an implantable infusate spread promoting device configured to enable enhanced mixing of infusate delivered with an implantable pump or port via manual barbotage. In particular, embodiments of the present disclosure include a manually activated flushing pump (also referred to herein as a “button” or “modular patient compressible reservoir” that is manually depressed or actuated to the skin of the patient, thereby removing and re-injecting a quantity of fluid (e.g.,  1  mL of fluid, etc.) with each actuation. Accordingly, multiple actuations of the flushing pump can be used to establish a desired degree of mixing of the infusate with biological fluid at the targeted drug delivery site. 
     Accordingly, embodiments of the present disclosure enable enhanced mixing of infusate delivered via an implantable pump or port. In some embodiments, the manually activated flushing pump can be incorporated into an implantable pump (e.g., incorporated into a top shield of the pump). Alternatively, the manually activated flushing pump can be separate from the pump or port. For example, in some embodiments, the flushing pump can be positioned in line along the primary drug delivery catheter, such that infusate delivered by the pump or port naturally flows through the manually activated flushing pump. In other embodiments, the flushing pump can be fluidly coupled to the primary drug delivery catheter via a second lumen, such that infusate delivered by the pump or port need not flow through the flushing pump prior to delivery at the targeted drug delivery site. 
     In embodiments, the manually activated flushing pump can take various forms, such as a molded rubber component, miniature metal bellows, deformable stamped metal cover, or the like. In some embodiments, an implantable pump or port in combination with the flushing pump (collectively referred to herein as a “system”) can detect actuation of the flushing pump through pressure sensors or other mechanisms to remind a patient that manual activation may be required if not performed shortly after infuse a delivery. Moreover, in some embodiments, the system can provide prospective reminders to the patient in coordination with infusate delivered. 
     One embodiment of the present disclosure provides an implantable infusate spread promoting system configured to enable improved dispersion of delivered infusate, including an implantable device configured to enable infusate delivery within a body of a patient, and an implantable manually actuatable flushing pump configured to remove and re-inject a quantity of fluid with each actuation to promote improved dispersion of the delivered infusate. 
     In one embodiment, the implantable manually actuatable flushing pump is at least one of a molded rubber pushbutton, mechanical bellows, or deformable plate. In one embodiment, the implantable manually actuatable flushing pump comprises a chamber having a volume of between about 0.25 mL and about 2 mL. 
     In one embodiment, the implantable manually actuatable flushing pump is integrally mounted within a housing of the implantable device. In one embodiment, the implantable manually actuatable flushing pump is fluidly coupled to a catheter extending from the implantable device. In one embodiment, the implantable manually actuatable flushing pump is fluidly coupled in-line with the catheter. In one embodiment, the implantable manually actuatable flushing pump is fluidly coupled to the catheter with a branched coupling. In one embodiment, the implantable manually actuatable flushing pump is configured to draw bodily fluid from an area of a patient spaced apart from a targeted drug delivery site. In one embodiment, the implantable manually actuatable flushing pump is actuatable through skin of a patient. In one embodiment, the implantable manually actuatable flushing pump is passively actuatable through regular patient motion. 
     In one embodiment, the system further includes a pressure sensor configured to detect manual actuation of the implantable manually actuatable flushing pump. In one embodiment, the pressure sensor is further configured to aid in detection and diagnosis of catheter occlusion, dislodgment, and kink issues. In one embodiment, the system further includes an external programmer in wireless communication with the implantable device. In one embodiment, the external programmer is configured to provide user notifications regarding actuation of the implantable manually actuatable flushing pump. In one embodiment, the implantable device comprises at least one of an implantable pump or implantable port. 
     Another embodiment of the present disclosure provides an implantable flushing mechanism including an implantable manually actuatable flushing pump in the form of at least one of a rubber pushbutton, mechanical bellows, or deformable plate configured to remove and re-inject a quantity of fluid with each actuation to promote improved dispersion of infusate delivered by an implantable infusion pump. In one embodiment, the implantable manually actuatable flushing pump comprises a chamber having a volume of between about 0.25 mL and about 2 mL. In one embodiment, the implantable manually actuatable flushing pump is fluidly coupled to a catheter extending from the implantable device. In one embodiment, the implantable manually actuatable flushing pump is actuatable through a skin of a patient. 
     Yet another embodiment of the present disclosure provides an implantable infusate spread promoting system including an implantable pump configured to enable infusate delivery to a catheter positioned within a body of the patient, and an implantable manually actuatable flushing pump configured to remove and re-inject a quantity of fluid of between about 0.25 mL and about 2 mL with each actuation to promote improved dispersion of the delivered infusate, the implantable manually actuatable flushing pump fluidly coupled to the catheter of the implantable pump. 
     The details of one or more aspects of the disclosure are set forth in the accompanying drawings and the description below. Other features, objects, and advantages of the techniques described in this disclosure will be apparent from the description in the drawings, and from the claims. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The disclosure can be more completely understood in consideration of the following detailed description of various embodiments of the disclosure, in connection with the accompanying drawings, in which: 
         FIG.  1    is a schematic view depicting a medical system configured to enable enhanced mixing of infusate delivered with an implantable pump or port via manual barbotage, in accordance with an embodiment of the disclosure. 
         FIGS.  2 A-B  are cross sectional views depicting an implantable device configured to incorporating a manually activated flushing pump into a housing of the implantable device, in accordance with an embodiment of the disclosure. 
         FIG.  3    is a block diagram of an implantable device and programmer configured to enable enhanced mixing of delivered infusate via manual barbotage, in accordance with an embodiment of the disclosure. 
         FIG.  4    is a perspective view depicting an implantable infusate spread promoting system configured to enable enhanced mixing of infusate delivered via an implantable pump with manual barbotage via a manually activated flushing pump, in accordance with an embodiment of the disclosure. 
         FIG.  5    is a perspective view depicting an implantable infusate spread promoting system configured to enable enhanced mixing of infusate delivered via an implantable port with manual barbotage via a manually activated flushing pump, in accordance with an embodiment of the disclosure. 
         FIG.  6    is an exploded view depicting the implantable port of  FIG.  5   , in accordance with an embodiment of the disclosure. 
         FIG.  7 A  depicts dispersion of medicament within cerebrospinal fluid of a patient following an initial actuation of a manually activated flushing pump, in accordance with an embodiment of the disclosure. 
         FIG.  7 B  depicts dispersion of medicament within cerebrospinal fluid of a patient following release of the manually activated flushing pump, in accordance with an embodiment of the disclosure. 
         FIG.  7 C  depicts dispersion of medicament within cerebrospinal fluid of a patient following a subsequent actuation of a manually activated flushing pump, in accordance with an embodiment of the disclosure. 
     
    
    
     While embodiments of the disclosure are amenable to various modifications and alternative forms, specifics thereof shown by way of example in the drawings will be described in detail. It should be understood, however, that the intention is not to limit the disclosure to the particular embodiments described. On the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the subject matter as defined by the claims. 
     DETAILED DESCRIPTION 
     Referring to  FIG.  1   , a medical system  100  comprising an implantable medical device  102  configured to enable enhanced mixing of infusate delivered with an implantable pump or port via manual barbotage, is depicted in accordance with an embodiment of the disclosure. In embodiments, the medical system  100  can include an implantable catheter  104 , which can be in fluid communication with the implantable medical device  102 , which can be an implantable pump or port, configured to dispense infusate over an extended period of time. As depicted, the implantable device  102  can be implanted within the body of a patient, for example, in an interior torso cavity or in proximity to the patient&#39;s ribs or cranially for the introduction of infusate into the patient (e.g., within an intrathecal space, intracranial space, pulmonary artery, etc.) for targeted delivery of infusate. In some embodiments, the implantable device  102  can be placed subcutaneously, and can be held in position by sutures or other retaining features. 
     Various example embodiments of implantable medical devices, systems and methods are described herein providing enhanced mixing of infusate delivered by an implantable pump or port via a user activated flushing pump. Although specific examples of implantable medical pumps are provided, it is to be appreciated that the concepts disclosed herein are extendable to other types of implantable devices. It is also to be appreciated that the term “clinician” refers to any individual that can prescribe and/or program a therapeutic regimen with any of the example embodiments described herein or alternative combinations thereof. Similarly, the term “patient” or “subject,” as used herein, is to be understood to refer to an individual or object in which the infusate delivery is to occur, whether human, animal, or inanimate. Various descriptions are made herein, for the sake of convenience, with respect to the procedures being performed by a clinician on a patient or subject (the involved parties collectively referred to as a “user” or “users”) while the disclosure is not limited in this respect. 
     In some embodiments, the medical system  100  can further include an optional external programmer  106  and optional server  108  configured to communicate with the implantable device  102 . In some embodiments, the programmer  106  can be a handheld, wireless portable computing device, such as a cellular telephone, tablet, dedicated implantable device programmer, or the like. Further, in some embodiments, the medical system  100  can include one or more external physiological sensors  110 , which can be in communication with the implantable device  102 , optional external programmer  106 , and optional server  108 . In one embodiment, one or more physiological sensors  110  can be incorporated into the implantable device  102  or the external programmer  106 . In one embodiment, a physiological sensor  110  can be worn by the patient (e.g., a smart watch, wristband tracker, sensors embedded in clothing, etc.), carried by the patient (e.g., a smart phone, mobile computing device, etc.), or positioned in proximity to the patient (e.g., a stationary monitor, etc.). Examples of physiological sensors  110  include a heart rate monitor, pulse oximeter, respiratory sensor, perspiration sensor, posture orientation sensor, motion sensor, accelerometer, or the like. 
     Referring to  FIGS.  2 A-B , cross sectional views of an implantable pump  102  incorporating a manually activated flushing pump  112  into a housing  114  of the implantable pump  102 , are depicted in accordance with an embodiment of the disclosure. The implantable device  102  can generally include a housing  114  (e.g., into a top shield, etc.), power source  116 , fluid reservoir  118 , pump  120 , manually activated flushing pump  112 , and computing device  122 . The housing  114  can be constructed of a material that is biocompatible and hermetically sealed, such as titanium, tantalum, stainless steel, plastic, ceramic, or the like. 
     The fluid reservoir  118  can be carried by the housing  114  and can be configured to contain infusate. In one embodiment, infusate within the reservoir  118  can be accessed via an access port  124 . Accordingly, the access port  124  can be utilized to refill, aspirate, or exchange fluid within the reservoir  118 . In some embodiments, the access port  124  can include one or more positional markers  126 , for example in the form of a tactile protrusion, one or more lights or LEDs to illuminate through tissue of the patient, an acoustic device to confirm location of the access port  124 , and/or one or more wireless location/orientation sensors to aid in positioning of a refilling device relative to the implantable pump  102 . 
     In some embodiments, the access port  124  can include a septum  128  configured to seal a port chamber  130  relative to an exterior of the housing  112 . The septum  128  can be constructed of a silicone rubber or other material having desirable self-sealing and longevity characteristics. The port chamber  130  can be in fluid communication with the reservoir  118 . In one embodiment, the access port  124  can further include an optional needle detection sensor  132 , for example in the form of a mechanical switch, resonant circuit, ultrasonic transducer, voltmeter, ammeter, ohmmeter, pressure sensor, flow sensor, capacitive probe, acoustic sensor, and/or optical sensor configured to detect and confirm the presence of an injection needle of a refilling apparatus. 
     The reservoir  118  can include a flexible diaphragm  134 . The flexible diaphragm  134 , alternatively referred to as a bellows, can be substantially cylindrical in shape and can include one or more convolutions configured to enable the flexible diaphragm  134  to expand and contract between an extended or full position and an empty position. In one embodiment, the flexible diaphragm  134  can divide the reservoir  118  into an infusate chamber containing liquid infusate (within the flexible diaphragm  134 ), and a vapor chamber  136  (surrounding the flexible diaphragm  134 ). As the infusate chamber is filled with infusate, the flexible diaphragm  134  extends downwardly (with reference to  FIG.  2 B ) toward a bottom portion of the housing  114  until it has reached a maximum volume or some other desired degree of fullness. Alternatively, as the infusate chamber is aspirated, the flexible diaphragm  134  contracts upwardly toward a top portion of the housing  114  until the infusate chamber reaches a minimum volume. In one embodiment, the flexible diaphragm  134  can have a compression spring rate which tends to naturally bias the flexible diaphragm  134  towards an expanded position. 
     The pump  120  and manually activated flushing pump  112  can be carried by the housing  114 . The pump  120  can be in fluid communication with the reservoir  118  and can be in electrical communication with the computing device  122 . The pump  120  can be any pump sufficient for pulling infusate from the reservoir  118  for downstream delivery, such as a peristaltic pump, piston pump, a pump powered by a stepper motor or rotary motor, a pump powered by an AC motor, a pump powered by a DC motor, electrostatic diaphragm, piezioelectric motor, solenoid, shape memory alloy, or the like. Infusate from the pump  120  can flow through the manually activated flushing pump  112 , which can be configured for manual activation for repeated cycling of fluid (e.g., expelling fluid from the flushing pump and drawing fluid into the flushing pump or vice versa) downstream of the pump  120 . In embodiments, the manually activated flushing pump  112  can be any mechanism configured to enable repeated cycling of fluid, such as a molded rubber component, miniature bellows, deformable cover, or the like. 
     For example, in one embodiment, the flushing pump  112  can include a deformable wall  113  defining a chamber  115 . In embodiments, actuation of the flushing pump  112  can cause the deformable wall  113  to temporarily deform under an external pressure thereby decreasing the volume of the chamber  115 . Subsequent release of the external pressure can cause a natural bias or resiliency of the deformable wall  113  to return to its original shape, thereby restoring the initial volume of the chamber  115 . In embodiments, the manually activated flushing pump  112  can be configured to displace a quantity of fluid sufficient to enable mixing of the infusate with bodily fluids of the patient (e.g., 0.25 mL, 0.5 mL, 0.75 mL, 1.0 mL, 1.25 mL, 1.5 mL, 1.75 mL, 2.0 mL, etc.). Other fluid quantity displacement volumes are also contemplated. 
     Referring to  FIG.  3   , a block diagram of an implantable pump  102  and programmer  106  configured to enable enhanced mixing of delivered infusate via manual barbotage, is depicted in accordance with an embodiment of the disclosure. The implantable pump  102  can include a computing device  122 , which can be carried in the housing  114  (as depicted in  FIG.  2 A ) and can be in electrical communication with the pump  120  and power source  116 . The power source  116  can be a battery, such as a rechargeable lithium-ion battery, nickel cadmium battery, or the like. The power source  116 , which can be monitored via the battery monitor  158 , can be carried in the housing  114  to power the pump  120  and computing device  122 . Control of the pump  120  can be directed by a drive/monitor element  160 . 
     The computing device  122  can include a processor  142 , memory  144 ,  146  and  147 , and transceiver circuitry  148 . In one embodiment, the processor  142  can be a microprocessor, logic circuit, Application-Specific Integrated Circuit (ASIC) state machine, gate array, controller, or the like. The computing device  122  can generally be configured to control delivery of infusate according to programmed parameters or a specified treatment protocol. The programmed parameters or specified treatment protocol can be stored in the memory  144 ,  146  and  147  for specific implementation by a control register  156 . A clock/calendar element  154  can maintain system timing for the computing device  122 . In one embodiment, an alarm drive  152  can be configured to activate one or more notification, alert or alarm features, such as an illuminated, auditory or vibratory alarm  152 . In some embodiments, the processor  142  can be configured to selectively activate the needle detection sensor  132  and access port marker  126 , prior to a physical attempt to insert a needle of the refill device into the access port  124  of the implantable pump  102 . Further, in some embodiments, the processor  142  can be configured to receive input from the drive/monitor element  160  and optional pressure sensor  140 , which can be configured to monitor for user activation following infusion delivery. Accordingly, in some embodiments, the implantable pump  102  can detect manual actuation of the flushing pump  112  through the pressure sensor  140  to remind the patient then manual activation may be required if not performed shortly after infusion delivery. 
     Additionally, in some embodiments, the optional pressure sensor  140  can serve as an aid in detecting occlusions and generally monitoring pressure decay within the catheter  104  downstream of the pump  120  to assist in the detection and diagnosis of catheter occlusion, dislodgment, kink in other system  100  issues. Further, in some embodiments, the downstream pressure and pressure decay can be inferred from a sensed electromotive force (EMF) voltage of the pump  120  by noting movement in the rotor of the pump after power has been removed. In operation of the pump  120 , drive currents to a stator are selectively applied and removed by the drive/monitor element  160 . Through computing device  122 , a resulting EMF voltage can be sensed in each of a series of stator coils after the drive currents are removed, from which a position of the rotor can be determined. 
     In particular, the rotor naturally comes to rest at an equilibrium position determined by the magnetic forces between the stator and rotor, as well as external forces (e.g., pressurized fluid within the catheter  104 ). In a normal, un-occluded state, the EMF voltage will fluctuate as the rotor rocks back and forth slightly to settle in an equilibrium position. By contrast, when the pump is occluded (and the downstream pressure is elevated), oscillations in the EMF voltage will be diminished, as movement of the rotor is significantly dampened by pressurized medicament trapped downstream. Accordingly, dampened oscillations in sensed EMF voltage can be indicative of slow pressure decay (e.g., occlusion, kinked tubing, system issues, etc.). 
     The transceiver circuitry  148  can be configured to receive information from and transmit information to the one or more physiological sensors  110 , external programmer  106 , and server  108 . The implantable pump  102  can be configured to receive programmed parameters and other updates from the external programmer  106 , which can communicate with the implantable device  102  through well-known techniques such as wireless telemetry, Bluetooth, or one or more proprietary communication schemes (e.g., Tel-M, Tel-C, etc.). In some embodiments, the external programmer  106  can be configured for exclusive communication with one or more implantable devices  102 . In other embodiments, the external programmer  106  can be any computing platform, such as a mobile phone, tablet or personal computer. In some embodiments, the implantable device  102  and external programmer  106  can further be in communication with a cloud-based server  108 . The server  108  can be configured to receive, store and transmit information, such as program parameters, treatment protocols, drug libraries, and patient information, as well as to receive and store data recorded by the implantable device  102 . 
     In embodiments, various notifications, alerts and alarms regarding timing and instructions for manual barbotage can be presented by the programmer  106 . For example, in some embodiments, the programmer  106  can notify a patient that an infusion has occurred or will soon occur, and potentially in combination with pressure sensor  140  can direct the patient to manually actuate the flushing pump  112 . In other embodiments, notification can be in the form of vibration or an audible sound from alarm  152 . Accordingly, in some embodiments, the system  100  (e.g., via programmer  106  or alarm  152 ) can provide perspective reminders to the patient in coordination with infusate delivery. 
     In one embodiment, the programmer  106  or components thereof can comprise or include various modules or engines, each of which is constructed, programmed, configured, or otherwise adapted to autonomously carry out a function or set of functions. The term “engine” as used herein is defined as a real-world device, component, or arrangement of components implemented using hardware, such as by an application specific integrated circuit (ASIC) or field programmable gate array (FPGA), for example, or as a combination of hardware and software, such as by a microprocessor system and a set of program instructions that adapt the engine to implement the particular functionality, which (while being executed) transform the microprocessor system into a special-purpose device. An engine can also be implemented as a combination of the two, with certain functions facilitated by hardware alone, and other functions facilitated by a combination of hardware and software. In certain implementations, at least a portion, and in some cases, all, of an engine can be executed on the processor(s) of one or more computing platforms that are made up of hardware (e.g., one or more processors, data storage devices such as memory or drive storage, input/output facilities such as network interface devices, video devices, keyboard, mouse or touchscreen devices, etc.) that execute an operating system, system programs, and application programs, while also implementing the engine using multitasking, multithreading, distributed (e.g., cluster, peer-peer, cloud, etc.) processing where appropriate, or other such techniques. Accordingly, each engine can be realized in a variety of physically realizable configurations and should generally not be limited to any particular implementation exemplified herein, unless such limitations are expressly called out. In addition, an engine can itself be composed of more than one sub-engine, each of which can be regarded as an engine in its own right. Moreover, in the embodiments described herein, each of the various engines corresponds to a defined autonomous functionality; however, it should be understood that in other contemplated embodiments, each functionality can be distributed to more than one engine. Likewise, in other contemplated embodiments, multiple defined functionalities may be implemented by a single engine that performs those multiple functions, possibly alongside other functions, or distributed differently among a set of engines than specifically illustrated in the examples herein. 
     In some embodiments, the programmer  106  can include a processor  164 , memory  166 , a control engine  168 , a communications engine  170 , and a power source  172 . Processor  164  can include fixed function circuitry and/or programmable processing circuitry. Processor  164  can include any one or more of a microprocessor, a controller, a DSP, an ASIC, an FPGA, or equivalent discrete or analog logic circuitry. In some examples, the processor  162  can include multiple components, such as any combination of one or more microprocessors, one or more controllers, one or more DSPs, one or more ASICs, or one or more FPGAs, as well as other discrete or integrated logic circuitry. The functions attributed to processor  164  herein may be embodied as software, firmware, hardware or any combination thereof. 
     The memory  166  can include computer-readable instructions that, when executed by processor  164  can direct the control engine  168  to perform various functions. Memory  166  can include volatile, non-volatile, magnetic, optical, or electrical media, such as a random access memory (RAM), read-only memory (ROM), non-volatile RAM (NVRAM), electrically-erasable programmable ROM (EEPROM), flash memory, or any other digital media. Control engine  168  can include instructions to control the components of the programmer  106  and instructions to selectively control the implantable medical device  102 . 
     The communications engine  170  can include any suitable hardware, firmware, software, or any combination thereof for communicating with other components of the medical device  102  and/or external devices. Under the control of processor  164 , the communication engine  170  can receive downlink telemetry from, as well as send uplink telemetry to one or more external devices (e.g., the implantable medical device  102 , etc.) using an internal or external antenna. In addition, communication engine  170  can facilitate communication with a networked computing device and/or a computer network  108 . For example, communications engine  170  can receive updates to instructions for control engine  168  from one or more external devices. In another example, communications engine  170  can transmit data regarding the state of system  100  to one or more one or more external devices. 
     Power source  172  is configured to deliver operating power to the components of the programmer  106 . Power source  172  can include a battery and a power generation circuit to produce the operating power. In some examples, the battery is rechargeable to allow extended operation. Power source  172  can include any one or more of a plurality of different battery types. In some embodiments, the programmer  106  can further include an external power supply port. 
     With additional reference to  FIG.  4   , an implantable infusate spread promoting system  100 ′ configured to enable enhanced mixing of infusate delivered via an implantable device  102  with manual barbotage via a manually activated flushing pump  112  is depicted in accordance with an embodiment of the disclosure. Various embodiments of the present disclosure will be described in detail with reference to the drawings, wherein like reference numerals represent like parts and assemblies throughout the several views. 
     Accordingly, in some embodiments, the flushing pump  112  can be separate from the implantable device  102 , such that the manually activated flushing pump  112  is physically separated or distinct from the implantable device  102 , thereby enabling the addition of a flushing pump  112  to existing implantable devices  102  to create new systems  100  designed to promote improved mixing of delivered infusates. For example, in some embodiments, the flushing pump  112  can be fluidly coupled in-line with the main catheter  104 , such that the flushing pump  112  is positioned between a first catheter portion  104 A originating at the implantable device  102 , and a second catheter portion  104 B terminating at a targeted drug delivery site within the patient (such as that depicted in  FIG.  5   ). In such embodiments, separation of the manually actuated flushing pump  112  from the implantable device  102  enables the flushing pump  112  to be positioned just beneath the patient&#39;s skin in an area easily accessible by the user, whereas the implantable device  102  may be positioned deeper within an anterior torso cavity of the patient. Alternatively, separation of the manually actuated flushing pump  112  from the implantable device  102  may enable the flushing pump  112  to be positioned in an area of the patient&#39;s body for passive actuation (e.g., via breathing or other natural movement or motion). 
     In other embodiments (such as that depicted in  FIG.  4   ), the flushing pump  112  can be operably coupled to the main catheter  104  via a secondary lumen  105 A, for example via a Y-connector  107  or other branching mechanism. Such embodiments enable the use of a shorter or more direct main catheter  104 , for example where the implantable device  102  is positioned relatively close to the target drug delivery site and the flushing pump  112  is positioned some distance away. Moreover, such embodiments may be beneficial in reducing the quantity of medicament potentially retained within the flushing pump  112  between actuations. To further reduce the quantity of medicament pulled into the flushing pump  112 , in some embodiments, a tertiary lumen  105 B can be fluidly coupled to the flushing pump  112  can be configured to enable fluid to be drawn from one area of the patient (e.g., via tertiary lumen  105 B) and expelled through the secondary lumen  105 A into the main catheter  104 . Other embodiments are also contemplated. 
       FIG.  5    depicts a medical system  100 ″ comprising an implantable device  102 ′ in the form of an implantable port along with a manually actuated flushing pump  112  configured to enable enhanced mixing of infusate via manual barbotage, in accordance with an embodiment of the disclosure.  FIG.  6    depicts an exploded view of the implantable port  102 ′ of  FIG.  5   . In one embodiment, the implantable port  102 ′ can include a housing  174 , for example including a first portion  174 A and a second portion  174 B, which can be constructed of a material that is biocompatible and hermetically sealed, such as titanium, tantalum, stainless steel, plastic, ceramic, or the like. 
     In some embodiments, a first portion of the housing  174 A can define an access port  176 , configured to enable an introduction of an infusate into the implantable medical device  102 ′. The access port  176  can include a septum  178  with self-sealing properties, thereby enabling a needle or other fluid introduction mechanism to pierce the septum while maintaining a fluid impermeable seal upon removal of the needle. Fluid introduced into the access port  176  can enter an access port chamber  180 . Infusate introduced into the access port chamber  180  can flow through a filter  182  and into a catheter connector  184 . In some embodiments, the implantable port  102 ′ can include electrical circuitry (such as that described in  FIG.  3   ), configured to enable enhanced functionality and sensing. In such an embodiment, said electrical circuitry can be positioned in a compartment  186  of the implantable port  102 ′ at least partially surrounding the access port chamber  180 . 
     In operation, manual actuation of the flushing pump  112  enables enhanced mixing of delivered infusate. For example, with reference to  FIGS.  7 A-C , dispersion of medicament  200  within cerebrospinal fluid of the patient upon manual actuation of the flushing pump  112  is depicted in accordance with an embodiment of the disclosure. Following drug disbursement (e.g., via an implantable pump or port) infusate exits the catheter  104  at the targeted drug delivery site. In some cases, a combination of low circulation of the cerebrospinal fluid and relative low velocity of infusate exiting the catheter  104  can result in slow mixing of the infusate into the cerebrospinal fluid, which can adversely affect the therapeutic effect of the infusate. Accordingly, as depicted in  FIG.  7 A , manually depressing or actuating the flushing pump  112  can cause a rush of fluid (e.g., a combination of infusate and cerebrospinal fluid) to be expelled from the catheter  104 . As depicted in  FIG.  7 B , subsequent release of the flushing pump  112  can cause the flushing pump to return to its original shape under a natural bias, thereby withdrawing fluid from the end of the catheter  104  into a chamber of the flushing pump  112 . Thereafter, as depicted in  FIG.  7 C , subsequent actuation of the flushing pump  112  can cause a rush of fluid to be expelled from the catheter  104 . 
     Accordingly, when the flushing pump  112  is pressed (e.g., through the skin of the patient) the pump  112  displaces the volume of liquid into the cerebrospinal fluid via the catheter  104 . When released, the flushing pump  112  draws cerebrospinal fluid into the flushing pump  112 . By repeatedly pressing the flushing pump  112 , a significant mixing can be created, thereby dispersing infusate along the spinal canal. Thus, through the repeated injection and removal of fluid, the flushing pump  112  is configured to enable enhanced mixing of infusate delivered with an implantable pump or port via manual barbotage. With some medicaments, increased dispersion may significantly improve patient outcomes, particularly where the beneficial effects of the medicament are directly tied to a rapid delivery or disbursement of the medicament. 
     Embodiments of the present disclosure enable greater user control over spread of the medicament and dilution of the drug following infusion. The desired degree of mixing can be prescribed by a clinician based on clinical studies or perceived patient observations or effects of the medicament distribution. Moreover, embodiments of the present disclosure provide a mechanism for patient involvement, while still limiting the potential quantity of medicament delivery over longer periods of time. 
     It should be understood that various aspects disclosed herein may be combined in different combinations than the combinations specifically presented in the description and accompanying drawings. It should also be understood that, depending on the example, certain acts or events of any of the processes or methods described herein may be performed in a different sequence, may be added, merged, or left out altogether (e.g., all described acts or events may not be necessary to carry out the techniques). In addition, while certain aspects of this disclosure are described as being performed by a single module or unit for purposes of clarity, it should be understood that the techniques of this disclosure may be performed by a combination of units or modules associated with, for example, a medical device. 
     In one or more examples, the described techniques may be implemented in hardware, software, firmware, or any combination thereof. If implemented in software, the functions may be stored as one or more instructions or code on a computer-readable medium and executed by a hardware-based processing unit. Computer-readable media may include non-transitory computer-readable media, which corresponds to a tangible medium such as data storage media (e.g., RAM, ROM, EEPROM, flash memory, or any other medium that can be used to store desired program code in the form of instructions or data structures and that can be accessed by a computer). 
     Instructions may be executed by one or more processors, such as one or more digital signal processors (DSPs), general purpose microprocessors, application specific integrated circuits (ASICs), field programmable logic arrays (FPGAs), or other equivalent integrated or discrete logic circuitry. Accordingly, the term “processor” as used herein may refer to any of the foregoing structure or any other physical structure suitable for implementation of the described techniques. Also, the techniques could be fully implemented in one or more circuits or logic elements.