Systems and methods are disclosed herein for delivering a drug to a subject (e.g., via intrathecal delivery into the cerebrospinal fluid (CSF) or subarachnoid space of the subject’s brain or spine).
There are many instances in which it may be desirable to deliver a drug to a patient. The term “drug” as used herein refers to any functional agent that can be delivered to a human or animal subject, including hormones, stem cells, gene therapies, chemicals, compounds, small and large molecules, dyes, antibodies, viruses, therapeutic agents, etc.
Delivery of the drug can be done in a systemic manner, or can be targeted to a particular location or a particular distribution pattern. Targeted drug delivery can be challenging, however, as there are many instances in which the intended delivery target is not accessible, or not accessible in a minimally-invasive manner.
The natural physiology of the patient can also present drug delivery challenges. For example, achieving a desired or optimal drug distribution via intrathecal delivery can be difficult, at least in part due to the natural flow of CSF within the patient, which tends to be oscillatory and pulsatile with little net flow. Traditional techniques which involve delivering a large quantity of a drug to the intrathecal space and relying on natural diffusion to distribute the drug are inefficient and may be harmful to the patient.
There is a continual need for improved drug delivery systems and methods.
Drug delivery systems and methods are disclosed herein. In some embodiments, a drug delivery system can be configured to deliver a drug to a patient in coordination with a physiological parameter of the patient (e.g., the patient’s natural cerebrospinal fluid (CSF) pulsation or the patient’s heart or respiration rate). In some embodiments, a drug delivery system can be configured to use a combination of infusion and aspiration to control delivery of a drug to a patient. Catheters, controllers, and other components for use in the above systems are also disclosed, as are various methods of using such systems.
In some embodiments, a drug delivery system includes a catheter having at least one fluid lumen; a pump configured to infuse fluid through the catheter; a sensor configured to measure a physiological parameter of a patient; and a controller that controls the pump to coordinate infusion of a drug through the catheter with the physiological parameter measured by the sensor.
The controller can synchronize infusion frequency with a frequency of a patient’s natural intrathecal pulsation as measured by the sensor. The controller can synchronize infusion phase with a phase of a patient’s natural intrathecal pulsation as measured by the sensor. The controller can establish a sinusoidal approximation of the patient’s natural intrathecal pulsation as measured by the sensor. The controller can synchronize infusions with the ascending wave of the sinusoidal approximation. The controller can synchronize infusions with the descending wave of the sinusoidal approximation. The sensor can be configured to measure intrathecal pressure. The sensor can include a first sensor configured to measure intrathecal pressure and a second sensor configured to measure heart rate. The controller can be operable in a learning mode in which no infusion is performed and the controller establishes a correlation between heart rate and intrathecal pressure based on the output of the first and second sensors; and an infusion mode in which the controller coordinates infusion of the drug through the catheter with the intrathecal pulsation of the patient based on the output of the second sensor. The system can include an implantable infusion port in fluid communication with the catheter and an extracorporeal injector configured to mate with the infusion port. The catheter can include first and second fluid lumens. The controller can be configured to control the pump to alternately aspirate fluid through the first fluid lumen and infuse fluid through the second fluid lumen in coordination with the physiological parameter measured by the sensor. The sensor can be configured to measure at least one of heart rate, intrathecal pressure, intrathecal pulsation rate, respiration rate, lung capacity, chest expansion, chest contraction, intrathoracic pressure, and intraabdominal pressure.
In some embodiments, a method of delivering a drug to a patient includes inserting a catheter into an intrathecal space of the patient; measuring a physiological parameter of the patient using a sensor; and with a controller, controlling a pump to coordinate infusion of a drug through the catheter with the physiological parameter measured by the sensor.
The method can include synchronizing infusion frequency with a frequency of the patient’s natural intrathecal pulsation as measured by the sensor. The method can include synchronizing infusion phase with a phase of the patient’s natural intrathecal pulsation as measured by the sensor. The method can include establishing a sinusoidal approximation of the patient’s natural intrathecal pulsation as measured by the sensor and synchronizing infusions with an ascending wave of the sinusoidal approximation. The method can include establishing a sinusoidal approximation of the patient’s natural intrathecal pulsation as measured by the sensor and synchronizing infusions with a descending wave of the sinusoidal approximation. The sensor can be configured to measure intrathecal pressure. The sensor can include a first sensor configured to measure intrathecal pressure and a second sensor configured to measure heart rate. The method can include establishing a correlation between heart rate and intrathecal pressure based on the output of the first and second sensors when no infusion is performed; and coordinating infusion of the drug through the catheter with the intrathecal pulsation of the patient based on the output of the second sensor. The catheter can include first and second fluid lumens, and the method can include controlling the pump to alternately aspirate fluid through the first fluid lumen and infuse fluid through the second fluid lumen in coordination with the physiological parameter measured by the sensor. The sensor can be configured to measure at least one of heart rate, intrathecal pressure, intrathecal pulsation rate, respiration rate, lung capacity, chest expansion, chest contraction, intrathoracic pressure, and intraabdominal pressure. The catheter can be inserted such that it extends along the spinal cord of the patient with at least a portion of the catheter being disposed in the cervical region of the patient’s spine and at least a portion of the catheter being disposed in the lumbar region of the patient’s spine. The method can include delivering a plurality of different drugs through the catheter, each of the drugs being delivered through a respective fluid lumen of the catheter. The method can include, with the controller, controlling the pump to aspirate fluid through the catheter. The catheter can include a plurality of outlet ports spaced in a cranial-caudal direction along the length of the catheter and the method can include infusing a drug through a first port of the catheter and aspirating fluid through a second port of the catheter, the second port being cranial to the first port. The drug can be infused through a port of the catheter disposed in the cervical region of the patient’s spine to propel the infused drug into the cranial space. The method can include aspirating a volume of CSF from the patient; infusing a drug through a first, proximal port of the catheter while aspirating CSF through a second, distal port of the catheter to form a bolus of drug between the first and second ports; and infusing the previously-extracted CSF at a location proximal to the bolus to urge the bolus in a distal direction. The volume of CSF aspirated from the patient can be about 10% by volume of the patient’s total CSF. The catheter can be inserted through a percutaneous lumbar puncture in the patient. The infusion can include alternating between infusing a first volume of the drug and aspirating a second volume of the drug, the second volume being less than the first volume. The drug can be delivered to a target region, the target region being at least one of an intrathecal space of the patient, a subpial region of the patient, a cerebellum of the patient, a dentate nucleus of the patient, a dorsal root ganglion of the patient, and a motor neuron of the patient. The drug can include at least one of an antisense oligonucleotide, a stereopure nucleic acid, a virus, adeno-associated virus (AAV), non-viral gene therapy, vexosomes, and liposomes. The method can include at least one of performing gene therapy by delivering the drug, performing gene editing by delivering the drug, performing gene switching by delivering the drug, and performing non-viral gene therapy by delivering the drug. The method can include determining a total CSF volume of the patient and tailoring the infusion based on the total CSF volume.
In some embodiments, a method of delivering a drug to a patient includes inserting a catheter into an intrathecal space of the patient; with a controller, controlling a pump to infuse a drug through the catheter; with the controller, controlling the pump to aspirate fluid through the catheter; and controlling said infusion and said aspiration to target delivery of the drug to a target site within the patient.
The infusion can override the natural CSF pulsation of the patient to urge the drug towards the target site. The infusion can coordinate with the natural CSF pulsation of the patient to urge the drug towards the target site. The infusion can include delivering a bolus of the drug and then performing pulsatile delivery of a fluid behind the bolus to urge the bolus towards the target site. The fluid can include at least one of a drug, a buffer solution, and CSF aspirated from the patient through the catheter. At least a portion of the catheter can be disposed in the target region. At least one of the infusion and the aspiration can be coordinated with a physiological parameter of the patient. The physiological parameter can be at least one of heart rate, intrathecal pressure, intrathecal pulsation rate, respiration rate, lung capacity, chest expansion, chest contraction, intrathoracic pressure, and intraabdominal pressure. The catheter can include first and second fluid lumens, and the method can include controlling the pump to alternately aspirate fluid through the first fluid lumen and infuse fluid through the second fluid lumen. The catheter can be inserted such that it extends along the spinal cord of the patient with at least a portion of the catheter being disposed in the cervical region of the patient’s spine and at least a portion of the catheter being disposed in the lumbar region of the patient’s spine. The method can include aspirating a volume of CSF from the patient; infusing a drug through a first, proximal port of the catheter while aspirating CSF through a second, distal port of the catheter to form a bolus of drug between the first and second ports; and infusing the previously-extracted CSF at a location proximal to the bolus to urge the bolus in a distal direction. The method can include alternating between infusing a first volume of the drug and aspirating a second volume of the drug, the second volume being less than the first volume. The target site can be at least one of an intrathecal space of the patient, a subpial region of the patient, a cerebellum of the patient, a dentate nucleus of the patient, a dorsal root ganglion of the patient, and a motor neuron of the patient. The drug can include at least one of an antisense oligonucleotide, a stereopure nucleic acid, a virus, adeno-associated virus (AAV), non-viral gene therapy, vexosomes, and liposomes. The method can include at least one of performing gene therapy by delivering the drug, performing gene editing by delivering the drug, performing gene switching by delivering the drug, and performing non-viral gene therapy by delivering the drug. The method can include determining a total CSF volume of the patient and tailoring the infusion and/or the aspiration based on the total CSF volume.
In some embodiments, a drug delivery catheter includes a tip having a first fluid lumen that extends to a first fluid port, a second fluid lumen that extends to a second fluid port, and a guidewire lumen; a hub; and a body having a first fluid tube that defines a first fluid lumen that is in fluid communication with the first fluid lumen of the tip, a second fluid tube that defines a second fluid lumen that is in fluid communication with the second fluid lumen of the tip, a guidewire having a distal end disposed within the guidewire lumen of the tip, and a sheath that defines at least one interior channel in which the guidewire and the first and second fluid tubes are disposed, wherein the sheath extends from a distal end of the hub to a proximal end of the tip.
The tip can have a tapered distal end. The first and second fluid ports can be offset from a central longitudinal axis of the tip. At least one of the first and second fluid ports can be aimed perpendicular to, or at an oblique angle with respect to, the central longitudinal axis of the tip. The first and second fluid tubes can extend uninterrupted through the hub. The first and second fluid tubes can terminate within the hub at respective connectors to which proximal extension tubes can be selectively coupled. The guidewire can extend uninterrupted through the hub. The first and second fluid tubes can have respective fluid connectors at proximal ends thereof. At least one of the first and second fluid tubes can be formed from fused silica. At least one of the first and second fluid tubes can be coated in shrink tubing. The sheath can be formed form polyurethane. The sheath can include an opening formed therein in fluid communication with a fluid port of at least one of the first and second fluid tubes. At least one of the first and second ports can have a helical interior. At least one of the first and second ports can have an interior that tapers towards the distal end of the port. The first fluid port can be proximal to the second fluid port. The catheter can include an auger rotatably mounted within the catheter. The catheter can include a piezoelectric transducer disposed within the catheter.
In some embodiments, a percutaneous needle device includes an elongate shaft that defines at least one lumen therein; a sensor disposed at a distal end of the elongate shaft; a display mounted to the elongate shaft configured to display an output of the sensor; and a connector disposed at a proximal end of the elongate shaft for making a fluid connection with the at least one lumen.
The device can include a fluid reservoir and a flush dome in fluid communication with the lumen of the needle, wherein actuation of the flush dome is effective to pump fluid from the reservoir through the lumen of the needle.
In some embodiments, a catheter includes an elongate body having one or more fluid lumens formed therein; and a fluid port formed in the catheter, the fluid port being defined by a helical slit formed in a wall of the catheter.
The catheter can include an atraumatic distal tip defined by a substantially spherical bulb. The catheter can include a second, distal-facing fluid port. The helical slit can be formed in a sidewall of a reduced-diameter portion of the catheter. The catheter can include a tapered transition between a main body of the catheter and a reduced-diameter portion of the catheter.
In some embodiments, a patient-specific infusion method includes determining a total CSF volume of a patient; aspirating a volume of CSF from the patient based on the determined total CSF volume of the patient; and infusing a drug into an intrathecal space of the patient.
The method can include, after infusing the drug, infusing the aspirated CSF of the patient to push the drug in a desired direction within the intrathecal space. The total CSF volume can be determined from a pre-operative image of the patient’s central nervous system. The aspirated volume of CSF can be in the range of about 1% to about 20% of the total CSF volume of the patient. The drug can be infused while the volume of CSF is aspirated.
Drug delivery systems and methods are disclosed herein. In some embodiments, a drug delivery system can be configured to deliver a drug to a patient in coordination with a physiological parameter of the patient (e.g., the patient’s natural cerebrospinal fluid (CSF) pulsation or the patient’s heart or respiration rate). In some embodiments, a drug delivery system can be configured to use a combination of infusion and aspiration to control delivery of a drug to a patient. Catheters, controllers, and other components for use in the above systems are also disclosed, as are various methods of using such systems.
Certain exemplary embodiments will now be described to provide an overall understanding of the principles of the structure, function, manufacture, and use of the methods, systems, and devices disclosed herein. One or more examples of these embodiments are illustrated in the accompanying drawings. Those skilled in the art will understand that the methods, systems, and devices specifically described herein and illustrated in the accompanying drawings are non-limiting exemplary embodiments. The features illustrated or described in connection with one exemplary embodiment may be combined with the features of other embodiments. Such modifications and variations are intended to be included within the scope of the present disclosure.
In some embodiments, systems and methods arc provided in which a drug is injected or otherwise delivered to the central nervous system of a patient in coordination with the natural CSF flow. For example, the drug can be injected in a plurality of stages synchronized in phase and/or frequency with the natural CSF pulse. The systems and methods herein can allow for a drug to be delivered more efficiently to a patient than in the case of traditional techniques. For example, a smaller quantity of the drug can be delivered and still reach the target destination, thereby reducing cost and/or possible side effects of delivering a large quantity of the drug.
The systems and methods disclosed herein can be used in applications where the intended delivery target is not accessible or not accessible in a minimally-invasive manner, but instead more readily-accessible and safer injection sites which are in direct fluid communication with the intended delivery site exist. For example, a drug can be delivered to the intrathecal space of a patient via an injection site in the patient’s spine (e.g., a lumbar region, a thoracic region, a cervical region, and so forth) and can be transported via the intrathecal space to a target location that is cranial to the injection site (e.g., the brain or a more-cranial region of the spine). In other embodiments, the drug can be transported to a location that is caudal to the injection site.
The systems and methods disclosed herein can include fully programmable customized injection and/or aspiration profiles which can be synchronized by real-time monitoring of physiological parameters of the patient, such as heart rate, CSF pressure, CSF pulsation rate, respiration rate, lung capacity, chest expansion and contraction, intrathoracic pressure, intraabdominal pressure, and the like. This can allow the end user to fine-tune injection/aspiration doses per cycle, time length and profile of each microinjection, relative timing (or phase) of microinjections, and other parameters. The systems and methods disclosed herein can include real-time inline pressure sensing for estimating drug delivery efficiency and ensuring patient safety.
The systems and methods disclosed herein can include custom built catheters with various lumen quantities, lumen sizes, port placement locations, and other properties. The catheters can be directionality-optimized for efficient mixing and/or such that they are adapted for a particular anatomy.
An exemplary catheter 102 which can be used with the system 100 is shown in
The tip 112 of the catheter 102 is shown in more detail in
The catheter 102 can include a steering mechanism to facilitate remote positioning of the catheter within the patient. For example, the catheter 102 can be configured to receive a guidewire 124 therethrough to allow the catheter to be inserted over the guidewire or to be steered by the guidewire. In the illustrated embodiment, the tip 112 includes a guidewire lumen 126. The guidewire lumen 126 can be a closed, blind hole as shown, or can be open to an exterior of the tip 112. Alternatively, or in addition, the catheter 102 can include one or more steering wires (not shown) that terminate at the tip 112. The wires can extend proximally from the tip 112 to a proximal end of the catheter 102, where they can be selectively tensioned to steer the tip of the catheter within the patient. For example, the catheter 102 can include first and second steering wires that extend longitudinally therethrough and which are anchored to the tip 112 at diametrically-opposed locations about the outer periphery of the tip. The steering wires can extend through respective sleeves or tubes in the body 114 of the catheter 102 to the proximal end of the catheter where tension can be selectively applied thereto to steer the tip 112 of the catheter.
The tip 112 can be formed from various materials, including biocompatible materials, stainless steel, titanium, ceramics, polymers, and the like. The tip 112 can be radiopaque or can include one or more radiopaque markers to facilitate visualization under fluoroscopy or other imaging techniques.
The tip 112 can have an outside diameter of about 3 French to about 5 French. The tip 112 can have an outside diameter of about 1 mm to about 3 mm.
The sheath 128 can have various cross-sectional profiles. For example, the sheath 128 can have a circular transverse cross-section that defines a single interior channel 130 as shown. By way of further example, the sheath 128 can have multiple interior channels. Each of the fluid tubes 132A, 132B can be disposed within its own independent channel of the sheath 128, or the sheath itself can define the fluid tubes. The guidewire 124 can be disposed in its own independent channel of the sheath 128 and the fluid tubes 132A, 132B can be disposed in a separate channel of the sheath. The guidewire channel can have a circular cross-section and the fluid tube channel can have a crescent or D-shaped cross-section.
The fluid tubes 132A, 132B can be formed from any of a variety of materials, including fused silica, polyurethane, etc. Use of fused silica can be advantageous when using the system 100 to deliver viruses, as viruses may be less prone to sticking to fused silica fluid tubes. In some embodiments, fluid tubes used for drug delivery can be formed from fused silica and fluid tubes not used for drug delivery (e.g., buffer delivery tubes or aspiration tubes) can be formed from a material other than fused silica, such as polyurethane. The fluid tubes 132A, 132B can be coated with a shrink tubing or an outer sheath to provide stress and strain relief for the fluid tubes. The sheath 128 can be formed from any of a variety of materials, including polyurethane. While use of the fluid tubes 132A, 132B to communicate fluid is generally described herein, the fluid tubes can also be used for other purposes, such as inserting a biopsy probe or other instrument, or inserting a sensor 108.
The fluid tubes 132A, 132B can have an inside diameter of about 0.005 inches to about 0.050 inches. The fluid tubes 132A, 132B can have an inside diameter of about 0.010 inches to about 0.020 inches. The body 114 can have an outside diameter of about 3 French to about 5 French. The body 114 can have an outside diameter of about 1 mm to about 3 mm.
An exemplary hub 116 is shown in
The hub 116 can be a “pass-through” type hub in which the first and second fluid tubes 132A, 132B extend completely through the hub uninterrupted as shown in
The proximal body portion 114p can include a sheath similar to that of the distal body portion 114d, or can be formed by the fluid tubes 132A, 132B extending proximally from the hub 116, or from one or more extension tubes coupled to the fluid tubes 132A, 132B at the hub 116. The proximal end of the catheter 102 can include one or more connectors 118 for making a fluid connection with the fluid tubes 132A, 132B of the catheter. For example, as shown in
The guidewire 124 can be disposed within the catheter 102 and can be used to guide, steer, or otherwise control insertion of the catheter into the patient.
The guidewire 124 can be cylindrical and can have a substantially-straight profile. The guidewire 124 can extend completely through the catheter 102, or can terminate in a blind bore126 formed in the tip 112 of the catheter. In use, the guidewire 124 can be inserted into the patient first and guided to a target site, and the catheter 102 can then be inserted over the guidewire to position a portion of the catheter at the target site. In other embodiments, the catheter 102 can be inserted before or simultaneously with the guidewire 124, and the guidewire can be used to steer or guide the catheter.
For example, as shown in
In use, the guidewire 124 can be used to navigate the catheter 102 through the patient by twisting the proximal end of the guidewire to turn the bent distal portion and thereby steer or aim the catheter. While a single guidewire 124 is shown, it will be appreciated that the catheter 102 can include any number of guidewires and/or guidewire lumens. The guidewire 124 can be formed from any of a variety of materials, including shape-memory metals such as Nitinol.
Any of the catheters disclosed herein can be steerable. For example, a steering mechanism can be provided to allow the distal end of the catheter 102 to be guided during insertion or at another desired time. In some embodiments, the catheter 102 can include one or more steering wires having a first end coupled to the distal tip 112 of the catheter and having a second end at the proximal end of the catheter through which tension can be selectively applied to the steering wires to direct or steer the tip of the catheter in a desired direction. The steering wires can be embedded in the sidewalls of the catheter 102 or can extend through a lumen of the catheter.
In some embodiments, the catheter 102 can include a coaxial steering catheter (not shown) extending therethrough. A distal end of the steering catheter can be curved or biased towards a curved shape such that, when the steering catheter is deployed distally from the tip of the primary catheter 102, the primary catheter can be steered or guided along the curve of the steering catheter. The steering catheter can then be retracted back into the primary catheter 102 to discontinue the curved guidance. The steering catheter can be formed from or can include shape memory or resilient materials such that the steering catheter is deformable between a substantially straight line configuration when retracted into the primary catheter 102 and a flexed or curved configuration when deployed from the primary catheter. The steering catheter can be longitudinally translatable relative to the primary catheter 102 to allow for deployment and retraction.
Any of the catheters disclosed herein can include a camera or imaging device, which can be integral with the catheter or can be inserted through a working channel of the catheter. Any of the catheters disclosed herein can include markings visible under fluoroscopy, CT, MRI, or other imaging techniques to allow the catheter to be visualized in images captured using such techniques.
The catheter 102 can be configured to withstand high internal pressures. The catheter 102 can be configured to withstand a pressure of at least about 100 psi, at least about 200 psi, and/or at least about 500 psi.
It will be appreciated that a number of variations on the above-described catheter 102 are possible. For example, one or more of the fluid ports can be aimed to the side such that they exit a lateral sidewall of the catheter.
The catheter 102 can include one or more fluid ports formed proximal to the tip portion 112 of the catheter, e.g., formed in the body 114 of the catheter.
The fluid lumens of the catheter can have various internal geometries to control or direct the delivery pattern of fluid delivered therethrough.
As noted above, the catheter 102 can include any number of lumens extending therethrough. In some embodiments, a dual-lumen catheter can be used. The dual lumen catheter can include an infusion lumen and a pressure sensor lumen, an infusion lumen and an aspiration lumen, two infusion lumens, etc. In other embodiments, a tri-lumen catheter can be used. The tri-lumen catheter can include an infusion lumen, an aspiration lumen, and a pressure sensor lumen, two infusion lumens and an aspiration lumen, three infusion lumens, etc.
The catheter can include a valve system to control the direction of fluid flow therethrough. For example, a valve system can include one-way valves on each lumen to prevent infusion into an aspiration lumen and vice versa. The valve system can facilitate use of a single syringe or other pump to infuse and withdraw fluid, or can facilitate infusion and aspiration through a single lumen.
As discussed further below, the sensor 108 can be mounted to the catheter 102, formed integrally with the catheter, threaded through a lumen of the catheter, etc. For example, the catheter 102 can include a sensor 108 embedded in the tip portion 112 of the catheter, or can include a sensor threaded through a dedicated sensor lumen of the catheter.
One or more of the fluid lumens through the catheter can have fluid ports that are longitudinally offset from fluid ports of other lumens of the catheter. For example, as shown in
The catheter 102 can include features for controlling delivery of fluid through the catheter. For example, as shown in
By way of further example, as shown in
As another example, as shown in
The system 100 can include one or more transducers for delivering focused ultrasound to the patient. As shown in
The illustrated controller 104 includes a processor 156 which controls the operation of the controller 104, for example by executing embedded software, operating systems, device drivers, application programs, and so forth. The processor 156 can include any type of microprocessor or central processing unit (CPU), including programmable general-purpose or special-purpose processors and/or any of a variety of proprietary or commercially-available single or multi-processor systems. As used herein, the term processor can refer to microprocessors, microcontrollers, ASICs, FPGAs, PICs, processors that read and interpret program instructions from internal or external memory or registers, and so forth. The controller 104 also includes a memory 158, which provides temporary or permanent storage for code to be executed by the processor 156 or for data that is processed by the processor. The memory 158 can include read-only memory (ROM), flash memory, one or more varieties of random access memory (RAM), and/or a combination of memory technologies. The various components of the controller 104 can be interconnected via any one or more separate traces, physical busses, communication lines, etc.
The controller 104 can also include an interface 160, such as a communication interface or an 1/0 interface. A communication interface can enable the controller 104 to communicate with remote devices (e.g., other controllers or computer systems) over a network or communications bus (e.g., a universal serial bus). An I/O interface can facilitate communication between one or more input devices, one or more output devices, and the various other components of the controller 104. Exemplary input devices include touch screens, mechanical buttons, keyboards, and pointing devices. The controller 104 can also include a storage device 162, which can include any conventional medium for storing data in a nonvolatile and/or non-transient manner. The storage device 162 can thus hold data and/or instructions in a persistent state (i.e., the value is retained despite interruption of power to the controller 104). The storage device 162 can include one or more hard disk drives, flash drives, USB drives, optical drives, various media disks or cards, and/or any combination thereof and can be directly connected to the other components of the controller 104 or remotely connected thereto, such as through the communication interface. The controller 104 can also include a display 164, and can generate images to be displayed thereon. In some embodiments, the display 164 can be a vacuum fluorescent display (VFD), an organic light-emitting diode (OLED) display, or a liquid crystal display (LCD). The controller 104 can also include a power supply 166 and appropriate regulating and conditioning circuitry. Exemplary power supplies include batteries, such as polymer lithium ion batteries, or adapters for coupling the controller 104 to a DC or AC power source (e.g., a USB adapter or a wall adapter).
The various functions performed by the controller 104 can be logically described as being performed by one or more modules. It will be appreciated that such modules can be implemented in hardware, software, or a combination thereof. It will further be appreciated that, when implemented in software, modules can be part of a single program or one or more separate programs, and can be implemented in a variety of contexts (e.g., as part of an embedded software package, an operating system, a device driver, a standalone application, and/or combinations thereof). In addition, software embodying one or more modules can be stored as an executable program on one or more non-transitory computer-readable storage mediums. Functions disclosed herein as being performed by a particular module can also be performed by any other module or combination of modules, and the controller can include fewer or more modules than what is shown and described herein.
As shown in
The controller 104 can also include a delivery control module 170 configured to control the pump or actuator 106 to infuse or aspirate fluid from the patient and/or to control the catheter 102 (e.g., an auger, piston, transducer, ultrasound system, etc.). For example, when an “infuse” instruction is issued, the delivery control module 170 can cause power to be supplied to the pump 106 to begin pumping infusate through the catheter 102, or cause an electronically-actuated valve to open such that infusate stored under pressure is placed in fluid communication with the catheter and flows therethrough. In some embodiments, the delivery control module 170 can be configured to cut off power to the pump 106 or to close a valve when a pressure sensor indicates that the pressure in the system has reached a predetermined threshold amount. When an “aspirate” instruction is issued, the delivery control module 170 can cause power to be supplied to the pump 106 to begin pumping fluid out of the catheter 102.
The controller 104 can include a user input module 172 configured to receive one or more user inputs, e.g., as supplied by a user via the interface 160. Exemplary user inputs can include infusion parameters, patient information, treatment protocols, and so forth, as discussed further below.
The controller 104 can also include a display module 174 configured to display various information to the user on the display 164, such as a graphical or textual user interface, menus, buttons, instructions, and other interface elements. The display module 174 can also be configured to display instructions, warnings, errors, measurements, and calculations.
The user interface 176 can include a motor communication panel 178 for displaying various information associated with the motors. This information can include the connection status of the motors, an IP or other software address of the motors, and a motor communication frequency or update time. The user can interact with the motor communication panel 178 to select or change the motor addresses and the update time.
The user interface 176 can include a motor setting panel 180 for adjusting various motor settings and for displaying the current setting to the user. The motor setting panel 180 can include controls for the motor velocity, motor acceleration, distance of syringe movement as a function of motor steps, current motor positions, infusion frequency, infusion amplitude, infusion rate, infusion phase, and so forth.
The controller 104 can be configured to control various infusion and/or aspiration parameters to achieve customized delivery. This can allow the delivery to be tailored based on the therapeutic application. Exemplary parameters that can be controlled by the controller 104 include infusion type, infusion rate, infusion volume, time between infusions, oscillatory rate, infusion and withdraw ratio, infusion phase timing, aspiration type, aspiration rate, time between aspirations, aspiration volume, and so forth.
The pump or actuator system 106 can be configured to supply a drug or a drug-containing fluid to the catheter 102 and/or to aspirate fluid from the catheter. The system 106 can include one or more pumps. For example, the system 106 can include a plurality of pumps, each being associated with and in fluid communication with a corresponding lumen of the catheter 102. The pumps can also be associated with and in fluid communication with respective reservoirs for holding a volume of fluid. In some embodiments, the system 106 can include first and second syringe pumps coupled to electronic linear actuators configured to advance or retract the plungers of the syringe pumps in response to control signals received from the controller 104. In some embodiments, the system 106 can include a peristaltic pump, an auger pump, a gear pump, a piston pump, a bladder pump, etc. One or more portions of the system 106 can be implanted in the patient. The system 106 can include any of a variety of implantable or extracorporeal pumps. In some embodiments, the system 106 can include a fully-implanted, programmable pump and a fully-implanted fluid reservoir containing fluid to be delivered using the system. In some embodiments, the entire system 106 can be implantable, e.g., to facilitate chronic treatment methods.
The sensor 108 can be a single sensor or a plurality of sensors. Exemplary sensors include pressure sensors, electrocardiogram sensors, heart rate sensors, temperature sensors, PH sensors, respiration rate sensors, respiration volume sensors, lung capacity sensors, chest expansion and contraction sensors, intrathoracic pressure sensors, intraabdominal pressure sensors, and the like. One or more of the sensors 108 can be implanted in the patient. One or more of the sensors 108 can be mounted on, inserted through, or formed in or on the catheter 102. The sensors 108 can also be remote from the catheter 102. In some embodiments, the sensors 108 can include a pressure sensor disposed in or on the catheter 102 for measuring CSF pressure adjacent to the catheter and an ECG sensor for measuring the patient’s heart rate. The sensors 108 can be connected (via wires or via a wireless connection) to the sensor input module 168 of the controller 104.
As noted above, one or more components of the delivery system 100 and, in some embodiments, all components of the delivery system, can be implanted in the patient. Implanting some or all of the delivery system 100 can facilitate chronic or long-term drug delivery (e.g., over a period of days, weeks, months, or years) via non-invasive or outpatient procedures.
As shown in
The system 100 illustrated in
For example, the catheter 102 can be used to deliver three different drugs (e.g., one drug through each different lumen of the catheter).
By way of further example, the catheter 102 can be used for localized delivery of different drugs to different areas of the spine.
As yet another example, the catheter 102 can be used to deliver the same drug with substantially instantaneous distribution along the entire spinal column.
In another example, one port of the catheter 102 can be used to aspirate while another is used to infuse in order to draw the infused fluid through the spinal canal. In some embodiments, fluid can be infused through a lower-lumbar port 122P and fluid can be aspirated through a cervical port 122D to “pull” the infused fluid up the spinal column.
In another example, fluid can be infused through a port 122D disposed in the cervical region of the patient’s spine to propel infused drug into the cranial space.
By way of further example, the catheter 102 can be used to substantially contain an infused drug to a given area of the spine. In some embodiments, fluid can be infused through a lower-lumbar port 122P and fluid can be withdrawn from a mid-lumbar port 122M to keep the infused drug between the two ports 122P, 122M in the lumbar region of the patient’s spine.
In an exemplary method, infusions and aspirations via multiple lumens and ports can be staged or combined in a sequence to create and advance a significant bolus at improved, controlled, and convenient rates. The method can include simultaneous aspiration / infusion between deliberately spaced ports. The delivery can be enhanced by a preparation step of removing a safe amount of CSF to be replaced in later procedure steps when advancing the bolus. The method can include a final stage of synchronized pulsatile infusion. The method can allow a large bolus to be formed more quickly, can allow controlled dosing, and/or can allow the bolus to be delivered closer to the brain or other target site. The method can be performed using a catheter that tapers from the proximal end towards the distal end. A tapered catheter profile in which the catheter diameter reduces distal of each port can enable the catheter to be longer, be easier to introduce / navigate, and have device reach significantly closer to the target site. Port designs and locations can be optimized based on dose and other factors. The catheter can be placed such that fluid exiting the ports flows against patient anatomy (e.g., a blind lumen end, lumen sidewall, or lumen constriction) to promote turbulent flow of the infusate upon exiting the catheter. In an initial step, a volume of patient CSF can be aspirated through one or more ports of the catheter. In an exemplary embodiment, about 10% by volume of the patient’s CSF can be aspirated through the catheter and stored in a reservoir. The amount of CSF that is aspirated can be based on a clinically-determined safe level. In a subsequent delivery step, CSF can be aspirated from the patient through a distal fluid port 122D of the catheter 102 while a drug is simultaneously infused into the patient through a middle port 122M of the catheter. This can cause a bolus of drug to form between the middle and distal ports 122M, 122D. The ports can be located along the length of the catheter to define the bolus size or dose. In an advancement step, the bolus of drug can be advanced within the patient. This can be achieved by infusing previously-aspirated CSF from the reservoir into the patient through a proximal port 122P of the catheter 102. This infusion can urge the bolus distally towards the target site and can continue until normal or safe CSF pressure is reached within the patient. While previously-aspirated CSF is used to advance the bolus in the above example, other fluid can be used instead or in addition, such as drug-containing fluid. Before, during, or after advancement of the bolus, infusion of CSF and/or drug-containing fluid can be performed in a pulsatile manner in coordination with one or more physiological parameters of the patient. The above method can also be performed using only a proximal port 122P and a distal port 122D. The proximal, middle, and distal ports 122P, 122M, 122D can be spaced along the length of the spinal column as shown in
The systems disclosed herein can be used in any of a variety of drug delivery methods.
In an exemplary method, the infusion pump 106 can be configured to pump a drug or a drug-containing fluid through the catheter 102 and into a patient (e.g., into an intrathecal space of the patient). The catheter 102 can be inserted into the patient at any of a variety of locations. For example, a percutaneous puncture can be formed in the patient using a needle. The puncture can be formed in the lumbar region of the spine, or in any other region of the spine, e.g., the cervical region between Cl and C2. The needle can have a bent distal tip that helps steer the catheter 102 to be parallel to the spinal cord. The catheter 102 can be inserted through the needle and guided through the intrathecal space along the spinal cord. The infusion can be performed in proximity to the percutaneous puncture, or the catheter 102 can be advanced some distance within the patient. In some embodiments, the catheter 102 can be inserted in the lumbar spine and advanced to the cervical spine or to the cisterna magna. Infusion can be performed at any point along the length of the catheter 102. Fluid can be infused from a distal end of the catheter 102 (e.g., in a cervical region of the spine), the catheter can be withdrawn proximally, and further infusion can be performed at a more caudal location (e.g., in a lumbar region of the spine).
The pump 106 can be controlled by the controller 104 to synchronize or otherwise coordinate delivery of the drug with the patient’s natural CSF flow or pulsation, or with other physiological parameters of the patient (e.g., heart rate, respiration rate, lung capacity, chest expansion and contraction, intrathoracic pressure, intraabdominal pressure, etc.). The infusion profile can be tailored to override the natural CSF pulsation to drive the infusate to a target site. Alternatively, or in addition, the infusion profile can be tailored to coordinate with and leverage the natural CSF pulsation to move the infusate towards the target site.
Readings from a pressure sensor 108 can be received by the controller 104, which can perform signal processing on the sensor output to determine various characteristics of the patient’s CSF flow (e.g., phase, rate, magnitude, etc.). The controller 104 can then control the pump 106 based on these measured characteristics to deliver a drug in coordination with the natural CSF flow, optionally synchronizing the delivery in real time. For example, as shown in the upper portion of
In some instances, the pressure sensed by the pressure sensor 108 can be influenced by the infusion through the catheter 102. Accordingly, it can be desirable to have another way of detecting or estimating CSF flow. Thus, in some embodiments, the system 100 can be operated initially in a “learning” mode in which no infusion takes place and the controller 104 establishes a correlation between CSF pulsation and heart rate (e.g., as detected by an ECG sensor 108 in communications coupling with the controller). In general, CSF pulsation tracks heart rate with a slight delay. Once a con-elation is established, the system 100 can be operated in an “infusion” mode in which infusate is delivered through the catheter 102 and the CSF pulsation is detected or estimated based on measured heart rate (instead of or in addition to detecting or estimating the CSF pulsation based on the pressure sensor 108 output). In other words, the system 100 can interpolate or estimate the CSF flow based on the ECG output, without necessarily having to rely on the pressure sensor output. This can allow the pressure sensor to be used for other purposes, such as monitoring the infusion pressure to allow the controller 104 to automatically regulate delivery to a target pressure or pressure range.
In one example use of the systems described herein, a drug can be delivered to the intrathecal space via a simple bolus injection (a fast infusion of a volume of fluid) which then just diffuses slowly along the spinal column.
In another example, a bolus injection can be performed to deliver the drug and then the system can be used to create a pulsation behind the bolus by changing oscillation rate/pulsation rate to override the natural CSF pulse and make the bolus move more quickly towards a target location (e.g., the brain). The pulsation can be created by repeatedly withdrawing or aspirating a volume of CSF and then pumping that same volume back into the patient to create a pulse.
In another example, infusion of the drug itself can be used to create a pulsation effect to urge the drug along the intrathecal space. In this example, a first volume of the drug can be infused (e.g., 0.1 ml) and then a second, smaller volume can be withdrawn (e.g., 0.05 ml). This can be repeated to create a pulse with a net infusion on each cycle. The process can be repeated until the desired dose is delivered. While an infusion-to-withdrawal ratio of 2:1 is discussed above, it will be appreciated that any ratio can be used. In addition, the rate of infusion and withdrawal can be controlled (e.g., by infusing quickly and withdrawing slowly) to create a burst of fluid towards a target location (e.g., the top of the spinal column).
In the devices and methods disclosed herein, infusion and/or aspiration can be coordinated with one or more physiological parameters of a patient (e.g., natural CSF flow, heart rate, respiration rate, etc.).
The direction of drug distribution at an intrathecal target site can be controlled at least to some degree based on the timing at which the drug is delivered relative to the timing of the CSF flow. For example, infusion that is synchronized with the ascending wave of CSF flow, as shown in
In some embodiments, a dual- or multi-lumen catheter can be used for alternating, repetitive infusion and aspiration, which can further enhance drug distribution.
The systems and methods disclosed herein can provide an improved means for delivering a drug to the intrathecal space, as compared with traditional lumbar bolus injections which do not reach the remote portions of the spinal canal or brain efficiently (if at all).
While intrathecal delivery is generally described in the examples given above, it will be appreciated that the systems and methods herein can be used in other applications, with appropriate modification of size or other parameters as will be appreciated by those having ordinary skill in the art. For example, the systems and methods disclosed herein can be used for intrarterial or intravenous delivery. Such systems and methods can include infusion and/or aspiration that is coordinated with one or more physiological parameters of a patient (e.g., natural CSF flow, heart rate, respiration rate, etc.).
In some embodiments, the drug can be delivered in a non-pulsatile manner and/or without necessarily coordinating the delivery with a physiological parameter of the patient. For example, alternating or otherwise-coordinated aspiration and infusion can be used to deliver the drug to a target site. By way of further example, the drug can be infused and then a buffer can be infused behind the drug to enhance distribution or to move the drug towards a target site.
An exemplary method can include inserting at least a portion of a catheter into a patient and delivering a drug to a target region of the patient. At least a portion of the catheter can be disposed in the target region. The drug can be delivered in a pulsatile manner. The drug can be delivered in coordination with a physiological parameter of the patient (e.g., the patient’s natural CSF flow and/or the patient’s heart rate).
The target region can be an intrathecal space of the patient. The target region can be a subpial region of the patient (e.g., a subpial region of the spinal cord and/or a subpial region of the brain). The target region can be a cerebellum of the patient. The target region can be a dentate nucleus of the patient. The target region can be a dorsal root ganglion of the patient. The target region can be a motor neuron of the patient. The drug can include an antisense oligonucleotide. The drug can include a stereopure nucleic acid. The drug can include a virus. The drug can include adeno-associated virus (AAV). The drug can include a non-viral gene therapy. The drug can include vexosomes. The drug can include liposomes. The method can include performing gene therapy by delivering the drug (e.g., by delivering a virus such as AAV). The method can include performing gene editing by delivering the drug (e.g., by delivering a virus such as AAV). The method can include performing gene switching by delivering the drug (e.g., by delivering a virus such as AAV). The method can include performing non-viral gene therapy by delivering the drug (e.g., by delivering vexosomes and/or liposomes).
In some embodiments, the method can include determining a total CSF volume of the patient and tailoring the delivery based on the total CSF volume. For example, MRI or other imaging techniques, with or without contrast, can be used to assess the overall CSF volume of the patient. The delivery of the drug can then be tailored based on the measured volume. For example, a larger volume of buffer can be used with patients having a greater total CSF volume and a smaller volume of buffer can be used with patients having a lesser total CSF volume. By way of further example, infusion amplitude, infusion velocity, aspiration volume, aspiration amplitude, and other parameters can be varied in accordance with the measured total CSF volume.
The infusion volume can range from about 0.05 mL and about 50 mL. The infusion rate can range from about 0.5 mL/min to about 50 mL/min.
The following are exemplary drug delivery methods that can be performed using the systems disclosed herein:
Example A:
Infusion description: At lumbar section Pump 1 infuses 0.11 mL at 15 mL/min, a 100 ms pause, Pump 2 infuses 0.22 mL at 15 mL/min, a 100 ms pause (cycle 1). This is repeated for a total of 10 cycles at the lumbar. Catheter is threaded up to the cisterna magna. Pump 1 infuses 0.11 mL at 15 mL/min, a 100 ms pause, Pump 2 infuses 0.22 mL at 15 mL/min, a 100 ms pause (cycle 1). This is repeated for a total of 10 cycles at the cisterna magna.
Example B:
Infusion description: At lumbar section Pump 1 infuses 0.231 mL at 4 mL/min, a 1000 ms pause, Pump 2 infuses 2.0 mL at 4 mL/min, a 5000 ms pause (cycle 1). This is repeated for a total of 13 cycles at the thoracic region.
Example C:
Infusion description: At lumbar section Pump 1 infuses 1 mL at 37 mL/min, a 10 ms pause, Pump 2 infuses 1.6 mL at 30 mL/min, a 100 ms pause (cycle 1). This is repeated for a total of 5 cycles at the thoracic region.
As shown in
In some embodiments, the pump system 310 can include first and second pumps configured to infuse and/or aspirate fluid through respective lumens of the catheter 304. Any of a variety of pumps can be used, including a linear-actuator syringe pump of the type shown in
The needle 302 can be defined by a hollow tubular body configured to receive a catheter and/or fluid therethrough. The needle 302 can be a lumbar puncture needle sized and configured for insertion into the intrathecal space through a lumbar insertion point. The needle 302 can have a curved distal tip configured to naturally steer the needle into the intrathecal space as the needle is inserted into the patient in the lumbar region of the spine. An opening can be formed in the distal end of the needle 302 through which an inserted catheter 304 can extend.
The proximal end of the needle can be coupled to a fluid hub 312. As shown in
As shown in
In some embodiments, the hub can be omitted and fluid can be delivered to or aspirated from the needle 302 directly. For example, the needle 302 can be directly attached to the pump system 310 via one or more fluid lines, or a catheter 304 can be directly attached to the pump system via one or more fluid lines and inserted through the needle without a proximal hub.
The system 300 can include one or more valves to control or limit fluid flow through the system. For example, the system 300 can include check valves 314 disposed in-line with respective fluid paths from the pump system 310 to the patient to isolate the paths from one another in a single direction or in both directions. In an exemplary arrangement, the system 300 can include first and second independent fluid sections or channels. The first fluid section or channel can include a first pump configured to deliver a first fluid through a first fluid tube and through a first fluid lumen of the catheter 304. The second fluid section or channel can include a second pump configured to deliver a second fluid through a second fluid tube and through a second fluid lumen of the catheter 304. A first valve, e.g., a check valve, can be disposed in the catheter, in the first fluid tube, or in the first pump to prevent fluid being infused or aspirated by the second pump from entering the first fluid section of the system. Similarly, a second valve, e.g., a check valve, can be disposed in the in the catheter, in the second fluid tube, or in the second pump to prevent fluid being infused or aspirated by the first pump from entering the second fluid section of the system. In some embodiments, only one of the first and second fluid channels includes a valve. The first fluid section can be used to infuse a drug and the second fluid section can be used to infuse a fluid, e.g., drug, buffer, chaser, CSF, artificial CSF, saline, etc. The first fluid section can be used to infuse a fluid and the second fluid section can be used to aspirate a fluid.
The needle 302 or the catheter 304 can include a sensor 314 (e.g., a pressure sensor) mounted adjacent a distal tip of thereof. Accordingly, upon insertion of the needle 302 or catheter 304 into the patient, the sensor 314 can measure the pressure or other properties of the patient’s CSF. The needle 302 or catheter 304 can also include an integrated or remote display for displaying the output of the sensor 314 to a user. In some embodiments, the display can be mounted along the length of the needle or catheter, distal to a proximal hub or other connector. The needle body can be a tubular shaft with a sharpened or angled tip. A distal end of the needle can be curved in one or more planes.
As shown in
The needle 302 can have a length in the range of about 2 inches to about 5 inches, e.g., a length of about 3.5 inches. The hub 312 can have a length in the range of about 1 inch to about 3 inches, e.g., about 2 inches. The needle 302 can have an outside diameter in the range of about 26 gauge to about 10 gauge, e.g., about 17 gauge. The catheter 304 can have an outside diameter in the range of about 0.020 inches to about 0.125 inches. The needle 302 can have an inside diameter in the range of about 0.020 inches to about 0.2 inches. The catheter 304 can be inserted through the needle 302 such that the catheter protrudes from the distal end of the needle by a protrusion distance. The protrusion distance can be in the range of about 1 mm to about 5 cm, e.g., about 1 cm. The protrusion distance can be zero such that the catheter 304 does not protrude from the needle 302. Limiting the degree to which the catheter 304 protrudes from the needle 302 can advantageously obviate the need to thread the catheter through the intrathecal space. This can be make the delivery procedure safer and/or less invasive and reduce the level of skill required to use the system 300.
The catheter 304 can have any of the features of the catheters described above.
While a helical-shaped slit is shown, the catheter 304 can alternatively or additionally have ports with other shapes. Exemplary port shapes include circular holes, a plurality of discrete holes arranged in a helical pattern about the catheter, cage or mesh type openings, and so forth. As shown in
The distal end of the catheter 304 can have an atraumatic geometry. For example, the catheter can include a substantially spherical or bulb-shaped portion 322 at a distal end thereof as shown. In embodiments in which the catheter 304 includes a stepped-down or reduced-diameter portion, the catheter can include a fillet or flange 324 to transition between the different diameters. For example, as shown in
The distal portion of the catheter 304 can be formed from, coated with, or impregnated with a radiopaque, magnetic, or other image-able material. For example, a separate inner tube in which the fluid port is formed can be formed from such a material and attached to the outer catheter body. The image-able material can facilitate visualization and guidance of the tip of the catheter under fluoroscopy or other imaging techniques such as MRI, CT, PET, and the like.
The catheter 304 can be formed form any of a variety of materials. Exemplary materials include polyimide, PEEK, polyurethane, silicone, and combinations thereof.
The drug delivery system 300 can be used in a manner similar or identical to the drug delivery systems described above.
A controller 104, e.g., a programmable computer processor, or a user can control the pump system 310 to infuse and/or aspirate fluid from the patient via the catheter and/or needle.
In an exemplary embodiment, a drug can be infused through a first fluid channel of the system 300 and, thereafter, a chaser can be infused through the same or a different fluid channel of the system to push the drug through the intrathecal space of the patient. Exemplary chasers include drug-containing fluid, buffer fluid, artificial CSF, natural CSF previously aspirated from the patient, saline, etc. In some embodiments, the chaser can be CSF previously aspirated from the patient and the CSF can be aspirated and infused using the same syringe without removing the CSF from the syringe, thereby maintaining a closed sterile system.
The needle can have any of a variety of fluid ports formed therein. For example, as shown in
In some embodiments, volume displacement of CSF can be used to move an infused drug through the intrathecal space of the patient. For example, fluid can be aspirated from the intrathecal space before, during, or after drug infusion to urge the drug in a desired direction within the intrathecal space. The fluid used for such volume displacement can be in the range of about 1% to about 20% of the patient’s total CSF volume. The fluid can be aspirated from the patient and then subsequently re-infused.
The systems disclosed herein can be used for patient-specific infusion. In an exemplary patient-specific infusion method, a specific patient’s CSF volume can be determined, for example by calculating or estimating. For example, a preoperative or intraoperative image of the patient can be captured. The image can be one or more MRI images of the patient’s head and spine and/or entire central nervous system. Image processing routines or manual estimation techniques can be used, e.g., with correlation to a 3D anatomical model, to calculate or estimate the total CSF volume of the patient. The calculated or estimated CSF volume can be used to tailor an infusion and/or aspiration profile to that particular patient. For example, about 1% to about 20% of the calculated or estimated total CSF volume can be aspirated from the patient and re-infused behind an infused drug to urge the drug in a desired direction, e.g., cranially or caudally within the patient’s intrathecal space.
In some embodiments, a method can include measuring the CSF head to body volume of a human using magnetic resonance imaging or other means. The method can include therapy or drug infusion performed by removal and/or infusion of 0.5 to 20% of the patient’s total CSF volume. The method can include therapy or drug infusion performed by removal and/or infusion of artificial CSF, buffer solutions, or saline in conjunction with delivery of drug or therapy. The method can include delivering the drug or therapy at volume flow rates in the range of about 0.1 ml/min to about 30 ml/min. The drug and additional volume (e.g., aspirated CSF, artificial CSF, buffer, etc.) can be infused using pulsatile delivery as disclosed herein and/or using pulsatile delivery based on a physiological parameter as disclosed herein. The drug and additional volume can be infused serially or in parallel. Volume displacement and/or patient-specific drug or therapy infusion can advantageously provide better biodistribution of the infused drug.
The infusion flow rate of the systems disclosed herein can be in the range of about 0.001 ml / min to about 50 ml/min.
In some embodiments, the delivery device can be or can include a needle, e.g., a spinal needle. An exemplary spinal needle can be referred to herein as a “Pulsar Spinal Needle (SN).”
In some embodiments, the delivery device can be or can include a catheter 600, e.g., a threadable and/or steerable catheter. An exemplary catheter 600 can be referred to herein as a “Pulsar Threadable / Steerable Catheter (TC/SC)” or “Pulsar Catheter.”
The catheters 600 herein can include features that allow the catheter 600 to “grow” or expand over time, e.g., in conjunction with the growth of a patient in which the catheter is implanted.
The catheter 600 can include a tubing set 682, e.g., for making fluid connections to a proximal end 642 of the catheter 600.
The port 722 can be rotated using an external actuator 724. The actuator 724 can be magnetic. The actuator 724 can be formed as an interlocking mechanism to allow the port 722 to be rotated precisely to the desired catheter length. The port 722 and actuator 724 can have predetermined positions or markings corresponding to desired units of length to expand the catheter. The catheter 600 can be a Pulsar Catheter. The catheter 600 can include any of the features of other catheters or delivery devices disclosed herein.
Catheters 600 disclosed herein can include anchoring features 726, e.g., to prevent the catheter 600 from dislodging once implanted.
Multi-port intrathecal catheter designs have been described in the literature and continue to be developed for their design advantages for infusion coverage and reach. Some uses for catheter designs having ports located along the catheter in addition to the catheter tip rely on flow outside the catheter in the intrathecal space. The catheter shown in
In this case, a smooth round crescent lumen multi-lumen extruded tube catheter having 0.042″ OD was used in a sheep to infuse an omnipaque solution in the intrathecal space and follow the contrast with normal saline “chaser.” With one fluoroscopic view there was a thin, high contrast line on one side of the device (due to additive effect of superimposed lines of contrast media flow), whereas the fluoroscopic angle 90 degrees from that view produced a wider, lower contrast flow image.
The catheter 600 can be splined or channeled along some or all of the catheter length. The illustrated arrangement shows splines 764 on the exposed “stagger” length of the catheter shaft, e.g., the length of the catheter along which multiple ports 620, 634 are longitudinally spaced. The actual dimensions and proportions can be changed to balance various design requirements including flow channel capacity and tissue spanning of channels 760. Narrow, relatively deep channels 760 can be advantageous, as they can remain open and the number of channels 760 can be relatively high. The spline extrusion ID can be the lumen 614 for the tip port 634, which can also serve as an over-the-wire guidewire lumen. This spline tube can be exposed within the stagger length (tip port 634 - to - side port 620). The spline tube can nest within a proximal outer tube 766. The spline channels 760 can be used as stagger port lumens as well. The second, outer tube 766, having a smooth inner and/or outer surface, can attach to or cover the spline tube. As shown in
Any of a variety of additional features can be included or incorporated in the delivery devices disclosed herein, including the various catheters and needles. The device can include sensors, which can be connected to a pump or external devices. A pressure sensor can be used to measure CSF pressure, e.g., to calibrate the pump for CSF pulsatility, and/or to measure max CSF pressure during infusion for safety. Other sensors can be used to measure drug concentration, biomarkers, and the like. The device can include a micro-camera and light source.
The devices disclosed herein can be used in any of a variety of methods. In some embodiments, a convection-dispersion method can be used in which the drug is followed by saline, or the patient’s own aspirated CSF, or artificial CSF, or drug buffer, or another biocompatible fluid, to convectively displace and disperse the drug and enhance biodistribution in the CSF space including the cranium.
In some embodiments, alternate small pulsatile infusions of drug and another fluid can be used. This can include aspiration of CSF, followed by pulsatile/constant infusion of drug and another fluid.
In some embodiments, a small amount of another fluid can be infused first, followed by drug.
In some embodiments, a small amount of another fluid can be infused, then drug, then again followed by another fluid.
In some embodiments, a small amount of another fluid can be infused, then drug and another fluid in alternate pulses.
After infusion, the CSF space can be pulsed (by withdrawing and infusing CSF, e.g., 0.1-1 mL of CSF, net 0 mL) to generate micro-pulsatility in the CSF space to enhance interstitial space and other small-space drug uptake.
A number of methods can be particularly useful for threadable catheters including any one or more of: (i) simultaneous aspiration and infusion-aspiration of CSF from distal tip and infusion of the drug from staggered outlet to enhance drug distribution in intrathecal space; (ii) infuse drug and another fluid from distal tip to push into the cisterna and cranial space; (iii) infuse drug from distal tip, and another fluid from staggered outlet; (iv) aspirate CSF from tip prior to any infusion; (v) aspirate CSF from the tip port synchronous with infusion from one or a sequence of staggered outlet(s) to convey drug towards tip, ceasing aspiration at a specific volume of infusion to prevent aspiration of drug, continuing infusion from staggered port and/or a distal port at or near the tip; (vi) infuse a CSF compatible fluid, within safe limits, prior to infusion of any of these methods in order to create space for accelerated infusion flow; (vii) aspiration from Touhy needle after infusion to normalize ICP/CSF pressure; (viii) infuse drug from one outlet and aspirate CSF from another staggered outlet to convect drug towards staggered outlet; (ix) recirculate drug between staggered ports to keep drug distribution localized between the ports; and (x) infuse, aspirate between the Tuohy outlet and catheter outlets, including the synchronous tip aspiration/(needle) infusion.
The systems herein can connect to a sensor or a vest worn by a patient, where the vest can compress/decompress timed with the pulsatile infusions to enhance spread of drug in CSF space.
The systems herein can connect to a light-guide that switches colors to instruct the patient to breathe with the light, and the infusion pulses can be timed to the light for controlled and enhanced spread.
Priming methods for the systems herein can include pre-washing the lumen with saline, buffer, CSF, artificial CSF, HAS, or other fluid to prevent drug particle sticking.
Priming methods for the systems herein can include pre-fill and soaking lumen with drug to coat the lumen to prevent additional drug particle sticking.
The systems herein can allow introduction and infusion of in-line-air in a controlled manner at the end of the infusion to minimize drug dead volume.
The systems herein can include an implantable catheter and/or a pump. The catheter can be a valved catheter of the type described herein. The pump can be a constant flow or micro-dosing programmable implantable, programmable and refillable (optional) pump. The catheter can include a flow and/or pressure sensor at the distal end of the catheter to detect catheter displacement and/or blockage. The pump can be an implantable chambered pump with double or single reservoir (one reservoir containing drug and one containing another fluid such as artificial CSF or drug buffer) attached to the catheter. Infusion through the catheter can include (i) slowly continuously through one lumen/outlet, multiple lumens/outlet, or same lumen/multiple staggered sized outlets; (ii) pulsatile infusions; (iii) consecutive infusion of drug and drug buffer; and/or (iv) infuse/aspirate to create pulsation, with net positive infusion.
The systems herein can be used to pulse the CSF space (by withdrawing and infusing small volumes) to generate micro-pulsatility in the CSF space to enhance interstitial space and other small-space drug uptake.
The systems herein can include an implanted pump connected to a computer (via wireless-architecture or otherwise) to monitor real-time drug infusion/pressure data. A drop in the infusion rate, increase in pressure, or other detected parameter can trigger an alert to be sent to a care-giver or user.
The systems and methods herein can be used to treat any of a variety of conditions or diseases, including Parkinson’s, Friedreich’s Ataxia, Canavan’s disease, ALS, Congenital Seizures, Drevets Syndrome, pain, SMA, Tauopathies, Huntington’s, Brain/Spine/CNS tumors, inflammation, Hunters, Alzheimer’s, hydrocephalus (therapeutic cure for hydrocephalus), Sanfillippa A, B, Epilepsy, Epilepsy pre-visualase, PCNSL, PPMS, Acute disseminated encephalomyelitis, Rx of motor fluctuations in advanced Parkinson’s patients, Acute repetitive seizures, Status epilepticus, ERT, and/or Neoplastic meningitis.
The systems and methods herein can be used to deliver any of a variety of drugs, including antisense oligonulceotides, Adeno Viruses, Gene therapy (AAVs and non-AAV) including gene editing and gene switching, Oncolytic immunotherapies, monoclonal and polyclonal antibodies, stereopure nucleic acids, small molecules, methotrexate, Edavaronc-conjugate, Conotoxin, abomorphinc, Prednisolone hemisuccinate sodium, Carbidopa/Levodopa, tetrabenazine, BZD (Diazepam and Midazolam), Alphaxalone or other derivative, Cyclophosphamide, Idursulfase (Elaprase), Iduronidase (Aldurazyme), Topotecan, and/or Buslfan.
The systems herein can provide a customized drug delivery platform to address the unmet need of delivering drugs intrathecally and beyond. This can be particularly useful for CNS as the presence of the blood brain barrier (BBB) is a major impediment for drug delivery to the Central Nervous System (CNS). The most practical way of delivering drug to CNS by circumventing the BBB is through the intrathecal space. However, current manual intrathecal delivery techniques are sub-optimal, and not suited for the delivery of therapeutics. The systems herein can provide improved controlled and repeatable bio-distribution and spread of the therapeutic in the CNS space. An exemplary system can include a programmable multi-syringe pump with custom algorithm, which can provide controlled intrathecal delivery of therapeutics.
An exemplary system can include any one or more of the following features:
The drives of the pump system can have any one or more of the following specifications:
The systems herein can include a pump system. The pump system can be configured to hold 1-10 injectable drug vials or injection syringes, each operated independently on a separate drive or via synchronous drives. The pump system can use independent syringes or a same syringe for CSF aspiration and infusion. An infusion profile can be customized manually or remotely based on clinical infusion protocols. Remote control (cabled hand module or local wireless) capability can range from start/stop, monitoring, or program/parameter settings. Infusion/aspiration program/profiles can be pre-planned, stored on media for reference, or use. The pump can incorporate patient or environmental monitored parameters to integrate for display, feedback, and/or as data for algorithm input for infusion / aspiration control.
The system can include customizable software with programmable manual or via secure cloud algorithm for infusions/aspirations per drug protocol. The system can be programmable based on need to increase concentration of the drug to the Targets of Interest (TOIs). The software can be configured to concurrently infuse and aspirate at the same time with same or varying flow rates. The software can allow selectable, concurrent or sequencing of syringes to infuse/aspirate from various device port locations. The software can allow selection of volumes, flowrates, aspirate and infuse, different modes of infusion/aspiration profile such as constant rate infusion, pulsatile infusion, step-ramp infusion, timing of aspiration and infusion delays, etc.
Drug infusion protocol data can be input into the pump system. The data can be input manually or remotely (e.g., via secure cloud), can be USB pre-programmed, can be input from some other type of hard-drive/hardwire, can be downloaded from the cloud, etc.
The system can store infusion and patient data in a cloud. The system can be compact to be bedside. The system can be MR compatible. The system can include respiration per minute (RPM) inputs, respiratory diaphragm movement inputs, electrical inputs for patient ECG, respiration, CSF pressure, arterial/venous pressure or other physiological parameters. The system can time infusions in small pulses (e.g., 0.1 - 1.0 mL each) with these patient variables to spread the drug in desired profile.
The system can connect to one or more wearable sensors placed or worn by the patient, e.g., in an article of clothing such as a vest, where the sensor or vest can compress/decompress timed with the pulsatile infusions to enhance spread of drug in CSF space.
The system can connect to a light-guide that switches colors to instruct the patient to breathe with the light, and the infusion pulses can be timed to the light for controlled maximum spread.
The system can connect to in-line pressure measurement system during prescribed infusions over time and analyze the pressure data to dictate the pump for emergency stop.
The system can include wireless connection capability to computers and sensors to monitor different conditions of the patient. The system can be configured to provide automated delivery of secondary infusion when necessary or desirable. The system can be configured for remote calibration capacity for dose accuracy. Dose data can be sent to a secondary computing software to monitor the infusion profile vs. the delivered dose in real-time to ensure dose accuracy. The system can be configured such that pump infusion data can be accessed anytime from any computer to get access to patient infusion information and pump data management. The system can include an automated priming feature that detects and eliminates in-line air. Priming vials can be selected separately and the pump can use the fluid from that vial to prime the connected lines until no air is present in the system. The system can be configured to introduce and infuse in-line-air in a controlled manner at the end of the infusion to minimize drug dead volume.
A drug delivery system is disclosed that includes a catheter having at least one fluid lumen; a pump configured to infuse fluid through the catheter; a sensor configured to measure a physiological parameter of a patient; and a controller that controls the pump to coordinate infusion of a drug through the catheter with the physiological parameter measured by the sensor.
The system can include one or more of: the controller synchronizes infusion frequency with a frequency of a patient’s natural intrathecal pulsation as measured by the sensor; the controller synchronizes infusion phase with a phase of a patient’s natural intrathecal pulsation as measured by the sensor; the controller establishes a sinusoidal approximation of the patient’s natural intrathecal pulsation as measured by the sensor and synchronizes infusions with the ascending wave of the sinusoidal approximation; the controller establishes a sinusoidal approximation of the patient’s natural intrathecal pulsation as measured by the sensor and synchronizes infusions with the descending wave of the sinusoidal approximation; the sensor is configured to measure intrathecal pressure; the sensor comprises a first sensor configured to measure intrathecal pressure and a second sensor configured to measure heart rate, and the controller can be operable in: a learning mode in which no infusion is performed and the controller establishes a correlation between heart rate and intrathecal pressure based on the output of the first and second sensors and an infusion mode in which the controller coordinates infusion of the drug through the catheter with the intrathecal pulsation of the patient based on the output of the second sensor; further including an implantable infusion port in fluid communication with the catheter and an extracorporeal injector configured to mate with the infusion port; the catheter comprises first and second fluid lumens, and wherein the controller is configured to control the pump to alternately aspirate fluid through the first fluid lumen and infuse fluid through the second fluid lumen in coordination with the physiological parameter measured by the sensor; or the sensor is configured to measure at least one of heart rate. intrathecal pressure, intrathecal pulsation rate, respiration rate, lung capacity, chest expansion, chest contraction, intrathoracic pressure, and intraandominal pressure.
A method of delivering a drug to a patient is disclosed that includes inserting a catheter into an intrathecal space of the patient; measuring a physiological parameter of the patient using a sensor; and with a controller, controlling a pump to coordinate infusion of a drug through the catheter with the physiological parameter measured by the sensor.
The method can include one or more of: synchronizing infusion frequency with a frequency of the patient’s natural intrathecal pulsation as measured by the sensor; synchronizing infusion phase with a phase of the patient’s natural intrathecal pulsation as measured by the sensor; establishing a sinusoidal approximation of the patient’s natural intrathecal pulsation as measured by the sensor and synchronizing infusions with an ascending wave of the sinusoidal approximation; establishing a sinusoidal approximation of the patient’s natural intrathecal pulsation as measured by the sensor and synchronizing infusions with a descending wave of the sinusoidal approximation; the sensor is configured to measure intrathecal pressure; the sensor comprises a first sensor configured to measure intrathecal pressure and a second sensor configured to measure heart rate; establishing a correlation between heart rate and intrathecal pressure based on the output of the first and second sensors when no infusion is performed and coordinating infusion of the drug through the catheter with the intrathecal pulsation of the patient based on the output of the second sensor; the catheter comprises first and second fluid lumens, and wherein the method includes controlling the pump to alternately aspirate fluid through the first fluid lumen and infuse fluid through the second fluid lumen in coordination with the physiological parameter measured by the sensor; the sensor is configured to measure at least one of heart rate. intrathecal pressure, intrathecal pulsation rate, respiration rate, lung capacity, chest expansion, chest contraction, intrathoracic pressure, and intraabdominal pressure; the catheter is inserted such that it extends along the spinal cord of the patient with at least a portion of the catheter being disposed in the cervical region of the patient’s spine and at least a portion of the catheter being disposed in the lumbar region of the patient’s spine; delivering a plurality of different drugs through the catheter, each of the drugs being delivered through a respective fluid lumen of the catheter; with the controller, controlling the pump to aspirate fluid through the catheter; the catheter includes a plurality of outlet ports spaced in a cranial-caudal direction along the length of the catheter and wherein the method includes infusing a drug through a first port of the catheter and aspirating fluid through a second port of the catheter, the second port being cranial to the first port; the drug is infused through a port of the catheter disposed in the cervical region of the patient’s spine to propel the infused drug into the cranial space; aspirating a volume of CSF from the patient; infusing a drug through a first, proximal port of the catheter while aspirating CSF through a second, distal port of the catheter to form a bolus of drug between the first and second ports; infusing the previously-extracted CSF at a location proximal to the bolus to urge the bolus in a distal direction; the volume of CSF aspirated from the patient comprises about 10% by volume of the patient’s total CSF; the catheter is inserted through a percutaneous lumbar puncture in the patient; the infusion comprises alternating between infusing a first volume of the drug and aspirating a second volume of the drug, the second volume being less than the first volume; the drug is delivered to a target region, the target region being at least one of an intrathecal space of the patient, a subpial region of the patient, a cerebellum of the patient, a dentate nucleus of the patient, a dorsal root ganglion of the patient, and a motor neuron of the patient; the drug includes at least one of an antisense oligonucleotide, a stereopure nucleic acid, a virus, adeno-associated virus (AAV), non-viral gene therapy, vexosomes, and liposomes; the method includes at least one of performing gene therapy by delivering the drug, performing gene editing by delivering the drug, performing gene switching by delivering the drug, and performing non-viral gene therapy by delivering the drug; determining a total CSF volume of the patient and tailoring the infusion based on the total CSF volume.
A method of delivering a drug to a patient is disclosed that includes inserting a catheter into an intrathecal space of the patient; with a controller, controlling a pump to infuse a drug through the catheter; with the controller, controlling the pump to aspirate fluid through the catheter; and controlling said infusion and said aspiration to target delivery of the drug to a target site within the patient.
The method can include one or more of: the infusion overrides the natural CSF pulsation of the patient to urge the drug towards the target site; the infusion coordinates with the natural CSF pulsation of the patient to urge the drug towards the target site; the infusion comprises delivering a bolus of the drug and then performing pulsatile delivery of a fluid behind the bolus to urge the bolus towards the target site; the fluid comprises at least one of a drug, a buffer solution, and CSF aspirated from the patient through the catheter; at least a portion of the catheter is disposed in the target region; at least one of the infusion and the aspiration is coordinated with a physiological parameter of the patient; the physiological parameter is at least one of heart rate, intrathecal pressure, intrathecal pulsation rate, respiration rate, lung capacity, chest expansion, chest contraction, intrathoracic pressure, and intraabdominal pressure; the catheter comprises first and second fluid lumens, and wherein the method includes controlling the pump to alternately aspirate fluid through the first fluid lumen and infuse fluid through the second fluid lumen; the catheter is inserted such that it extends along the spinal cord of the patient with at least a portion of the catheter being disposed in the cervical region of the patient’s spine and at least a portion of the catheter being disposed in the lumbar region of the patient’s spine; aspirating a volume of CSF from the patient, infusing a drug through a first, proximal port of the catheter while aspirating CSF through a second, distal port of the catheter to form a bolus of drug between the first and second ports, and infusing the previously-extracted CSF at a location proximal to the bolus to urge the bolus in a distal direction; alternating between infusing a first volume of the drug and aspirating a second volume of the drug, the second volume being less than the first volume; the target site is at least one of an intrathecal space of the patient, a subpial region of the patient, a cerebellum of the patient, a dentate nucleus of the patient, a dorsal root ganglion of the patient, and a motor neuron of the patient; the drug includes at least one of an antisense oligonucleotide, a stereopure nucleic acid, a virus, adeno-associated virus (AAV), non-viral gene therapy, vexosomes, and liposomes; at least one of performing gene therapy by delivering the drug, performing gene editing by delivering the drug, performing gene switching by delivering the drug, and performing non-viral gene therapy by delivering the drug; determining a total CSF volume of the patient and tailoring the infusion and/or the aspiration based on the total CSF volume.
A drug delivery catheter is disclosed that includes a tip having a first fluid lumen that extends to a first fluid port, a second fluid lumen that extends to a second fluid port, and a guidewire lumen; a hub; and a body having a first fluid tube that defines a first fluid lumen that is in fluid communication with the first fluid lumen of the tip, a second fluid tube that defines a second fluid lumen that is in fluid communication with the second fluid lumen of the tip, a guidewire having a distal end disposed within the guidewire lumen of the tip, and a sheath that defines at least one interior channel in which the guidewire and the first and second fluid tubes are disposed, wherein the sheath extends from a distal end of the huh to a proximal end of the tip.
The device can include one or more of: the tip has a tapered distal end; the first and second fluid ports are offset from a central longitudinal axis of the tip; at least one of the first and second fluid ports is aimed perpendicular to, or at an oblique angle with respect to, the central longitudinal axis of the tip; the first and second fluid tubes extend uninterrupted through the hub; the first and second fluid tubes terminate within the hub at respective connectors to which proximal extension tubes can be selectively coupled; the guidewire extends uninterrupted through the hub; the first and second fluid tubes have respective fluid connectors at proximal ends thereof; at least one of the first and second fluid tubes is formed from fused silica; at least one of the first and second fluid tubes is coated in shrink tubing; the sheath is formed form polyurethane; the sheath includes an opening formed therein in fluid communication with a fluid port of at least one of the first and second fluid tubes; at least one of the first and second ports has a helical interior; at least one of the first and second ports has an interior that tapers towards the distal end of the port; the first fluid port is proximal to the second fluid port; an auger rotatably mounted within the catheter; a piezoelectric transducer disposed within the catheter.
A percutaneous needle device is disclosed that includes an elongate shaft that defines at least one lumen therein; a sensor disposed at a distal end of the elongate shaft; a display mounted to the elongate shaft configured to display an output of the sensor; and a connector disposed at a proximal end of the elongate shaft for making a fluid connection with the at least one lumen.
The device can include a fluid reservoir and a flush dome in fluid communication with the lumen of the needle, wherein actuation of the flush dome is effective to pump fluid from the reservoir through the lumen of the needle.
A catheter is disclosed that includes an elongate body having one or more fluid lumens formed therein; a fluid port formed in the catheter, the fluid port being defined by a helical slit formed in a wall of the catheter.
The catheter can include one or more of: an atraumatic distal tip defined by a substantially spherical bulb; the catheter includes a second, distal-facing fluid port; the helical slit is formed in a sidewall of a reduced-diameter portion of the catheter; the catheter includes a tapered transition between a main body of the catheter and a reduced-diameter portion of the catheter.
A patient-specific infusion method is disclosed that includes determining a total CSF volume of a patient; aspirating a volume of CSF from the patient based on the determined total CSF volume of the patient; and infusing a drug into an intrathecal space of the patient.
The method can include one or more of: after infusing the drug, infusing the aspirated CSF of the patient to push the drug in a desired direction within the intrathecal space; the total CSF volume is determined from a pre-operative image of the patient’s central nervous system; the aspirated volume of CSF is in the range of about 1% to about 20% of the total CSF volume of the patient; the drug is infused while the volume of CSF is aspirated.
A drug delivery system is disclosed that includes an intrathecal catheter or needle having at least one fluid lumen; and a pump configured to infuse fluid through the catheter according to a programmed infusion profile. The pump can include a plurality of syringes.
A method is disclosed that includes inserting a catheter into an intrathecal space of a patient, the catheter being configured to increase in length with growth of the patient.
The method can include one or more of: excess lumen of the catheter is initially implanted with a port and, as the patient grows, the catheter can be manipulated to extend in length with patient growth; or a distal anchoring mechanism to enable axial tension for catheter to increase in length with patient growth.
A method of applying targeted infusions to lumbar, thoracic, and cervical regions of the spine as well as the brain is disclosed. The method of can include using an infusion profile that targets specific areas of the intrathecal space and mechanism to assist in targeting
A method of anchoring a catheter within a spinal column of a patient as to avoid migration of catheter while implanted is disclosed.
A method of easily implanting a catheter from the lumbar region to the cervical region of a patient is disclosed. The method can include a catheter configured for such easy implantation.
A needle configured for maximum dispersion during injection is disclosed. The needle can include multiple lumens to allow drug and buffer infusions, simultaneously or independently.
U.S. Provisional Application No. 62/159,552, filed on May 11, 2015; U.S. Provisional Application No. 62/239,875, filed on Oct. 10, 2015; U.S. Provisional Application No. 62/303,403, filed on Mar. 4, 2016; U.S. Application No. 15/151,585, filed on May 11, 2016; and U.S. Application No. 15/662,416, filed on Jul. 28, 2017; are all hereby incorporated herein by reference in their entirety.
Although the invention has been described by reference to specific embodiments, it should be understood that numerous changes may be made within the spirit and scope of the inventive concepts described. Accordingly, it is intended that the invention not be limited to the described embodiments.
This application is a continuation of U.S. Application No. 16/192,500, filed Nov. 15, 2018, which claims the benefit of the filing date of U.S. Provisional Application No. 62/586,498, filed Nov. 15, 2017, the entireties of which are hereby incorporated by reference. This application relates to U.S. Provisional Pat. Application No. 62/437,168, filed on Dec. 21, 2016, which is hereby incorporated by reference herein in its entirety.
Number | Date | Country | |
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62586498 | Nov 2017 | US |
Number | Date | Country | |
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Parent | 16192500 | Nov 2018 | US |
Child | 18095334 | US |