The present invention relates generally to controlled application of medication, electrical stimulation, or both in a desired area. It finds particular application in conjunction with both microinfusion and neurostimulator systems and will be described with particular reference thereto.
Presently, infusion systems include a fully implantable pump which is capable of delivering drugs into the intrathecal space. The most common application for this device is for the delivery of intrathecal baclofen, or a variety of other intrathecal pain medications. Recently, a pump has been developed for delivery of insulin although this type of pump has not been used to deliver drugs to the central nervous system. This existing technology involves the invasive implantation of an expensive and bulky pump system.
Currently commercially available percutaneous testing electrical stimulation devices extend out of the skin and, thus, can only be used for a short duration, typically less than two weeks and most commonly about one week. A major reason for the limited duration is the increased risk of infection. Once the trial period is over, the extension through the skin is cut or otherwise removed. Nevertheless, presently used electrical stimulation devices are suspected to increase the infectious risk for the permanent implant.
Existing electrical stimulation technology generally requires an implanted pulse generator or IPG. Such devices are bulky, expensive and in many cases, nonrechargeable.
In one example embodiment of the present invention, an infusion device, e.g., a microinfusion device, is provided which includes a chamber for allowing the introduction of at least one medication into the central or peripheral nervous system (e.g., the brain) with a microcatheter.
In one example embodiment of the present invention, a microinfusion device is provided, comprising: (a) a subcutaneously implantable reservoir configured to contain a drug, the reservoir being mountable within a burr hole of a skull of a subject; (b) a dose control system configured to control flow of the drug; and (c) a microcatheter configured to deliver the drug from the reservoir to a target location.
In another example embodiment, a microinfusion device is provided, comprising: a subcutaneously implantable reservoir configured to contain a drug, the implantable reservoir having at least two outlets. The device may further include a dose control system, as described below. The device may further include respective microcatheters connected to each of the at least two outlets, wherein at least one of the respective microcatheters is connected to a reservoir infusion system, said reservoir infusion system being implantable within the body of a subject to provide a source of the drug, and the at least another of the respective microcatheters is configured to deliver the drug to a target location. In one example embodiment, the device may further include a sensor at the distal end of the at least second microcatheter to provide feedback to the dose control system. Sensors which may be used in any of the devices provided herein are described below.
In a further example embodiment of the present invention, a microinfusion device is provided, comprising: (a) a subcutaneously implantable reservoir configured to contain a drug, the reservoir being mountable within a burr hole in a skull of a patient, the reservoir being ring-shaped; and (b) a microcatheter configured to deliver the drug from the reservoir to a target location. In one preferred embodiment, the device is a burr hole ring which does not require attachment to a burr hole device, but may be directly mounted within a burr hole within a skull of a subject. The device may be configured to engage or be mounted within a burr hole ring or device, as described below. The device may further include any of a dose control system configured to control flow of the drug and a sensor, as described below. In another embodiment, the reservoir may have at least one notch for insertion of a deep brain stimulation (DBS) electrode through the at least one microcatheter.
In yet another example embodiment of the present invention, a microinfusion device is provided, comprising: (a) a subcutaneously implantable reservoir having septations configured to separate different drugs within the reservoir; and (b) at least one microcatheter configured to deliver the different drugs from the reservoir to at least one target location. The device may be directly mounted within a burr hole within a skull of a subject, i.e., it is a burr hole device/ring. The device may also be configured to engage or be mounted within a burr hole ring/device, and may further include a dose control system configured to control flow of the drug and a sensor. In another aspect, the reservoir may also have at least one notch for insertion of a deep brain stimulation electrode through the microcatheter.
In one example embodiment of the present invention, a drug or medication delivery device is provided, comprising: a reservoir configured to contain a drug, and a receiver configured to wirelessly receive signals and to control a dosing of the drug in accordance therewith. The signals may include, for example, radio frequency (RF) signals. Both the reservoir and the receiver may be subcutaneously implantable. The delivery device may include a microcatheter configured to deliver the drug to a target location, and a valve system coupled to the microcatheter and configured to control the dosing of the drug as a function of the signals. The receiver may include coils and/or antennas. The receiver may be an active or a passive device.
The example infusion devices may include a DBS electrode to provide neurostimulation, in addition to microinfusion of drug(s) to target locations in the nervous system. Devices including such electrodes may be controlled by radio frequence (RF). In an example embodiment, as described below in greater detail, radio frequency coils or antennas configured to receive signals from an external controller, the dose control system controlling the flow of the drug in accordance with the received signals. Such devices may thus obviate the current use of implantable pulse generators (IPGs).
In accordance with another aspect of the present invention, the example microinfusion devices may include radio frequency (RF) coils or antennas disposed proximate to or externally on the reservoir, wherein the radio frequency coils or antennas are configured to receive signals from an external controller, the dose control system controlling the flow of the drug in accordance with the received signals. Microinfusion of the drug(s) may thus be controlled by radio frequency. The radio frequency coils or antennas may receive signals from the external controller to adjust and/or control dosing.
In accordance with another aspect of the present invention, the microinfusion device is attached to or is an integral part of a deep brain burr device. In example embodiments of the above-described devices, the reservoir may be mounted within a burr hole ring, which is alternatively called a burr hole device herein.
In further example embodiments of the present invention, each microinfusion device may include a dose control system. The dose control system may include a valve system between the reservoir and the microcatheter for flowing of the drug. In accordance with another aspect of the present invention, the device may include a valve system permitting predetermined dosing of the medication. The valve system may either be fixed for delivery of the drug or electronically adjustable. The drug to be delivered may a predetermined dose. An electronically adjustable valve in this system may permit control of delivery of the drug, whose dose need not be predetermined prior to being contained in the reservoir. In one embodiment, the valve system may be controlled via RF signals.
In another example of the present invention, each device may include a dose control system, wherein the dose control system includes a ball-bearing system. The ball-bearing system may be magnetically adjustable for delivery of the drug. Alternatively, the ball-bearing system may be electronically adjustable to control delivery of the drug. The drug contained in the reservoir may be in a predetermined or non-predetermined dose.
Alternate embodiments of the devices described herein may include a propulsion system in the reservoir, which system utilizes osmosis or gravity to flow the drug from the reservoir.
In another embodiment of the present invention, a subcutaneously implantable neurostimulator is provided. In one embodiment, antennas or coils are mounted subcutaneously in a burr hole ring. The coils or antennas are coupled to a neurostimulation or a brain stimulation electrode (e.g., a DBS electrode).
In another example embodiment, a drug delivery device is provided, which includes a reservoir configured to contain a drug; and a receiver configured to wirelessly receive signals and to control a dosing of the drug in accordance therewith. The signals may be radio frequency signals. The reservoir may be subcutaneously implantable. In one embodiment, the device includes a dose control system configured to control the dosing of the drug as a function of the signals. The dose control system may include, for example, a valve system. In another embodiment, the device may include a microcatheter coupled to the reservoir and configured to deliver the drug to the target location.
Further aspects and advantages of the present invention will become apparent to those of ordinary skill in the art upon reading and understanding the following Detailed Description.
The present invention may take form in various components and arrangements of components, and in various steps and arrangements of steps. The drawings are only for purposes of illustrating example embodiments and are not to be construed as limiting the present invention.
The example device further includes a base (14) having a radius larger than the base of the reservoir (12). Incorporated into the base (14) are outlets (16) at opposing sides of the reservoir (12). In alternative embodiments, many outlets may be spaced about the periphery of the base (14). Moreover, in still further embodiments, the base may include only a single outlet (16). The device also includes a dose control (20) which regulates the rate of medication to outlets (16).
In the example embodiment of the present invention illustrated in
The device illustrated in
The microcatheters coupled to the reservoir will vary in length depending upon the target location to which drugs or other therapeutic substances are to be delivered. For example epidural, subdural, and intraparenchymal/parenchymal microcatheters may be used respectively to deliver medication above the sac, or dura, that covers the brain; below the dura; or into the brain tissue. The microcatheters used for epidural infusion will be the shorter than the other two types of catheters, whereas, intraparenchymal/parenchymal microcatheters will be the longest of the three.
In other embodiments, the valve system may be configured for fixed delivery of the drug for predetermined dosing. Alternatively, the valve system may include a ball bearing system which is magnetically or electronically adjustable for delivery of the drug (e.g., for either fixed or adjustable dosing).
A fiber optic or other sensor (32) may also be included for sensing the medication or other information at the point of interest. Sensed information may be provided to the dose control system (20) via a feedback loop (34). The feedback loop (34) may permit the dose control system (20) to adjust the rate of medication delivery depending on the sensed data. The feedback loop (34) may be a wired or wireless connection.
The sensor (32) may be provided at the distal end of the catheter (30), although other locations are possible and may be desirable. The sensor (32) may detect various physiological parameters, including e.g., intracranial pressure. The device may be configured such that if an intracranial pressure over 15-20 cm water is detected, the dose control system prevents the delivery of the drug for example, by closing valve(s) of the valve system. Another physiological parameter which may be detected by a sensor is intracranial pH. The device may be configured such if an intracranial pH of between 7.3 and 7.5 is detected, the dose control system prevents delivery of the drug. The sensor (32) may also detect physiological parameters selected from the group consisting of pO2, pCO2, glucose concentration, lactic acid concentration, or concentration of the delivered drug. In an example configuration, detection by the sensor (32) of excessive or insufficient partial pressure of oxygen or carbon dioxide or both, excessive or insufficient concentration of glucose, lactic acid, or the delivered drug, or any combination thereof, provides a signal to the dose control system to prevent delivery of the drug.
The catheter (30) of
In another embodiment, the microinfusion device shown in
Referring now to
The microinfusion devices described herein may, in some embodiments, be attached to a burr hole device, such as a burr hole ring. Reference is made herein to U.S. Pat. No. 6,044,304 and U.S. Patent Publication No. 2002/0052610 published on May 2, 2002, each of which is expressly incorporated herein by reference in its entirety.
In an alternate embodiment, the microinfusion device comprises the actual burr hole ring, thereby obviating the need to use burr hole devices, as shown in
The microinfusion device provided herein in its simplest form may be a disposable system for fixed dosing a single medication or drug which could be implanted in a patient as a tool for trial chemical modulation. Prior to the present invention, this was accomplished through the implantation of a large and bulky drug delivery system having a diameter of about 7.5 cm.
In other forms, the device is semi-permanent and reusable but still more compact than present drug delivery systems. For example, if a trial of a drug delivered with the disposable device achieves the desired effect(s) on the target location(s), a semi-permanent and reusable device may be implanted in the skull of the subject for an extended time period, e.g., to continue delivery of the drug in doses that achieve the successful effect on the target location.
In example embodiments, the compact size of either the disposable or semi-permanent devices may be advantageous when delivering a drug or chemical within the substrate of the central or peripheral nervous system. Such systems permit dosing concentrations for direct nervous system injection that are an order of magnitude smaller than either oral, intravenous, or intrathecal dosages.
In example embodiments of the above-described devices, the target location is in the nervous system of the subject, for example the central nervous system (e.g., the brain), the peripheral nervous system, systemic nervous tissue or the spinal cord. In other example embodiments, the device allows the delivery of multiple types of drugs, chemicals, medication and the like, at a controlled rate of delivery. As described above, the device may be subcutaneously implantable. The device can be utilized for delivery of drugs, chemicals, gene therapy vectors, viral vectors into the central or peripheral nervous system. Additionally, the device may be used for dosed delivery of chemotherapy or antibiotic(s) over the course of many days to weeks.
The applications of the example microinfusion devices of the present invention include (but are not limited to) drug delivery for Parkinson's Disease Essential tremor, MS, Dystonia, cerebral palsy, psychiatric disorders, obsessive compulsive disorder, depression, ALS and gene therapy vectors to allow delivery of a substance retrograde through the peripheral nerves. The example devices may also be used for controlled antibiotic therapy for meningitis, bacterial or chemical. A further use of the microinfusion device includes delivery of chemotherapy for carcinomatous meningitis, central nervous system lymphoma or other metastatic disease. The microinfusion devices may also be used to deliver other agents or therapeutic substances, for example hot or cold saline may be infused for the treatment of epilepsy.
In
In one example embodiment of the neurostimulation device, the RF coil(s) is sized so as to be implanted in the subgaleal space or other locations susceptible to external stimulation. In another aspect, the device may include a small temporary impulse generator coupled to a previously implanted neurostimulation electrode. The small temporary impulse generator may be implanted in a location conducive to external, that is outside the skin, stimulation. In accordance with another aspect of the present invention, the neurostimulator device may include a burr hole with a number of grooves. In another embodiment of the neurostimulation device, the burr hole ring cap includes RF coils. In a further embodiment, the RF coils are sealed in a discrete compartment which can be tunneled at a site distance to the burr hole. In accordance with another aspect of the present invention, the device includes an external transmitting assembly. The device may further include an extension system to connect to a single or, alternately, a plurality of electrodes.
Another example embodiment of the present neurostimulation device includes a set of compact RF compatible receiving coils or a smaller temporary impulse generator which is coupled to an already implanted deep brain stimulator electrodes or any other neurostimulation electrode such as that which is used for motor cortex or spinal cord stimulation. This compact receiving RF coil or smaller temporary impulse generator may be implanted in the subgaleal space and may be externally stimulated with an accessory external antenna (outside of the skin) connected to a battery powered transmitter (in the case of an RF system).
In
In
In an alternative embodiment of the devices described above, the neurostimulator device (33) may include one or more semiconductor ball implants, rather than, for example, a DBS electrode. An implantable neurostimulator with one or more semiconductor ball implants is described in U.S. Pat. No. 6,415,184, issued on Jul. 2, 2002 to Ishikawa et al., which is expressly incorporated herein by reference in its entirety.
In this example embodiments described above, its smaller size may allow for its implantation into the head or via a small incision after the insertion of a percutaneous spinal cord stimulator system. Additionally, it may be cheaper and smaller than the currently available totally implantable pulse generators (IPGs). The neurostimulation devices provided herein may be implanted to allow a patient with a deep brain stimulation electrode to trial the effects of stimulation especially in the case of pain, psychiatric disorders, dystonia, addictions, brain injury, or epilepsy, where the benefits of stimulation are not anticipated to occur for days to few months. The costliest part of a current deep brain stimulation procedure may be the cost of the IPGs. One RF device may run both coils and electrodes. This arrangement may obviate the need for externalized wires for trial testing.
This neurostimulation devices described herein may have wide application including the entire neurostimulation spectrum for pain, as well as all of the emerging applications of brain stimulation for which the efficacy has yet to be been fully determined. The devices may be used for neurostimulation in dystonia, psychiatric disorders such as OCD, depression, schizophrenia, epilepsy, traumatic brain injury, morbid obesity, etc. In these common scenarios, there could be a substantial cost incurred to the medical industry and society if each of these patients were to receive the currently used totally implantable pulse generator (IPG) costing $10,000 each. The current system provided by the present invention may obviate another surgical procedure and such an up-front cost, which in most circumstances would include two impulse generators for bilateral or system type disease.
The present invention has been described with reference to example embodiments. However, mdifications and alterations will occur to others upon reading and understanding the preceding Detailed Description. For example, various portions of the example embodiments may be combined in ways other than expressly described herein above.
This application claims the benefit under 35 U.S.C. § 119(e) of U.S. provisional application Ser. No. 60/353,706 filed Feb. 1, 2002, and U.S. provisional application Ser. No. 60/358,176, filed Feb. 20, 2002, the entire contents of which are hereby incorporated herein by reference in their entirety.
Filing Document | Filing Date | Country | Kind |
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PCT/US03/02843 | 1/31/2003 | WO |
Number | Date | Country | |
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60353706 | Feb 2002 | US | |
60358176 | Feb 2002 | US |