Additional objects and features of the present invention will become more apparent and the invention itself will be best understood from the following Detailed Description of Exemplary Embodiments, when read with reference to the accompanying drawings.
The preferred embodiments of the invention described herein relate particularly to a medical device with multiple piercing elements with hollow passageways suitable for diagnosis, energy therapy, sampling and medicinal delivery with respect to target tissue of a patient. While the description sets forth various embodiment specific details, it will be appreciated that the description is illustrative only and should not be construed in any way as limiting the invention. Furthermore, various applications of the invention, and modifications thereto, which may occur to those who are skilled in the art, are also encompassed by the general concepts described herein.
One aspect of the invention provides a probe device with an outer sheath and multiple piercing elements deployable from the sheath, each piercing element comprises a piercing tip, a shape memory delivery member having a hollow delivery channel and a proximal portion attached to a delivery body inside the outer sheath. In one embodiment, the shape memory delivery member is sized and configured to self expand radially outwardly when the piercing element is deployed out of the sheath. In another embodiment, the piercing tip and a portion of the hollow delivery channel is collapsible to prevent occlusion of the channel as the piercing element penetrates to the treatment site.
For diagnosis purposes, the piercing tip may comprise a temperature sensor, a pressure sensor, or a biochemical sensor for sensing pH values, solute concentration, electrolyte type, and the like. For therapy purposes, the piercing tip may comprise an energy delivery function, such as for delivering radiofrequency energy, ultrasonic energy, microwave energy, laser energy, cryogenic energy or combinations thereof through electric wires, transducers, or optic fibers. For sampling purposes, the piercing tip may serve to intake surrounding fluid to an external assay instrument or to analyze surrounding fluid in situ, such as in an antibody-antigen conjugate assay process. For medicinal delivery, the piercing tip serves as an injector to load or deliver desired bioactive agent(s) to the surrounding tissue site-specifically and locally in vivo. The bioactive agent may further include micro-beads or nano-beads of radioactive material for irradiation therapy. Delivery of medicinal agent may be accomplished by an extracorporeal pumping operation.
The term “piercing” is broadly defined herein as an activity used in penetrating into a tissue for intended functions, including diagnosis, therapy, sampling and medicinal delivery with respect to a target tissue locally inside the body of a patient.
The piercing tip 12 may be sized and configured to penetrate into the target tissue with ease and provide intended functions of diagnosis, therapy, sampling and medicinal delivery to a patient. The piercing tip of the present invention may be selected from various configurations or configured similar to a dispenser as illustrated in U.S. Pat. No. 6,695,830, entire contents of which are incorporated herein by reference. The dispenser may include a base and a penetrating section. Preferably, the dispenser is made of a metal, a ceramic, Nitinol or any sturdy material. In one embodiment, the penetrating section is defined by an opening which is opposite the base. In another embodiment, the penetrating section of the dispenser is substantially annular shaped or substantially conical shaped. In an alternative embodiment, the penetrating section is defined by an opening which extends through the side(s) of the piercing tip. In a further embodiment, the piercing tip is made of a porous material. Thus, the porous material defines the penetrating section of the dispenser, wherein the fluid medicament is forced through the pores of the porous tip section.
One aspect of the invention provides an injector device similar to a self-expandable stent or a multiple-arm probe.
Some aspects of the invention relate to a medical device with at least two expandable arms that self-expand radially outwardly when deployed, wherein at least one arm is equipped with probe/piercing elements and at least one arm has no piercing elements. In one embodiment, the at least one arm without piercing elements serves as the stabilizing or anchoring means for stabilizing and anchoring the medical device during the medical operations. In another embodiment, at least a portion of the exterior surface of the stabilizing arm comprises studded surface, textured surface, protrusion or dummy piercing tip without drug delivery capability.
As illustrated in
In one embodiment, a restrictor is placed within each piercing element 11, 21, 31, 41, or hollow fluid delivery passageway 55 or common passageway 57 to provide controlled fluid flow. By way of illustration, the restrictor may be a porous material that needs a predetermined pressure of the delivered fluid to open. Some aspects of the invention provide a medical device or an injector of the drug delivery device, wherein a restrictor or stopper 67 is placed on the piercing elements near a piercing tip to control the penetration depth of the piercing element into tissue of the human arteries or an internal organ. In one embodiment, the stopper is made from or comprises a radiopaque material selected from the group consisting of gold, platinum, rhenium, iridium, rhodium, tantalum, and tungsten. In still another embodiment, the stopper is made from a plastic filled with a radiopaque material, wherein the radiopaque material is selected from the group consisting of gold, platinum, rhenium, iridium, rhodium, tantalum, and tungsten.
The conduit of a portion of the hollow fluid delivery passageway 15, 45, 55 or the conduit of a portion of the piercing element 11, 21, 31, 41 with a hollow fluid delivery passageway may be collapsible and expandable. By ways of illustration, the conduit may be constructed of a material that is relatively flexible such as a polymer membrane, rubber, silicone or latex, which expands during delivery of the medicinal agent(s) through the conduit. After delivery of the medicinal agent(s), the conduit returns to the collapsed state. Alternatively, the collapsed conduit may be constructed with a material that is folded in the collapsed state and unfolds to allow delivery of the medicinal agent(s) through the conduit. After delivery of the medicinal agent, the conduit may return to a folded state.
In one embodiment, a stopper 67 is incorporated at about the distal section of the injector 64 to control penetration depth. In operations during a device delivery stage, the collapsible cap 61 may be folded or collapsed to a diameter D2, to prevent tissue from entering the injector 64. During delivery of medicinal agent(s) the cap 61 is unfolds or expands to a diameter D1 which is larger than the injector diameter D0, allowing fluid or drug to be injected to the target tissue site specifically in vivo.
Some aspects of the invention prevent tissue from obstructing the conduit during transit of the device through body tissue to the target delivery site since the conduit is collapsed during transit. Similarly, the device prevents contact between the medicinal agent and the tissue encountered during transit since the conduit is collapsed during transit toward target tissue and when withdrawn. In one embodiment, the device allows for delivery of medicinal agent(s) nearly coincident with the distal tip of the piercing element. In one embodiment, the expanded conduit conforms to anatomical restrictions, for example, when inserted through a narrow opening between relatively hard unyielding body structures. The medicinal agent(s) of the present invention may be in the form of liquid, gas, solids, suspensions, colloids, micro-spheres, nano-spheres, gels, or combinations thereof.
The major part of the piercing element is constructed with a suitably stiff material to enable it to pierce through body tissue. In one preferred embodiment, the piercing element could be constructed of a superelastic material such as nickel titanium, enabling it to undergo significant bending without permanent deformation. In another preferred embodiment, all or part of the piercing element may be constructed of a radiopaque material to facilitate imaging with fluoroscopy. It is anticipated that in most cases, the piercing element will be constructed of a metal but it could be constructed with any suitably rigid material.
Some aspects of the invention relate to methods of positioning the medical device or injector within various anatomies in a human body by inflating a side balloon or deploying a positioning member with shape memory features, wherein the positioning member is self-expandable radially outwardly when deployed from a constraint, such as a catheter sheath.
One example to make a collapsible (elastic or folded) injector is to take a pre-shaped shape memory needle and grind a distal segment axially of a length suitable for penetration, perhaps ⅔rd of the body diameter thus removed. An elastic or folded sleeve is then attached over the ground segment. This device is less occlusive within a vessel, with less blood flow impedance, versus a balloon device such as the Infiltrator. Thus, the device could be deployed for a longer time given a time sensitive procedure, for example in a coronary artery or in the atrium, than a balloon type device.
A catheter with the ability to deliver medicinal agents through a piercing tip to areas of a patient's body locally has advantages over a needle. For example, to deliver medicinal agents to the wall of a blood vessel or a small tumor, which are not readily accessible by a needle. The target area to which an agent is to be delivered may be quite localized and may be restricted. In the example of a blood vessel, it may be desirable to deliver the medicinal agent into the vessel wall at a depth of approximately 0.25 millimeters while limiting the depth of penetration to about this delivery depth to avoid perforation of the vessel wall. A traditional hypodermic needle tip does not meet this need.
In some devices disclosed herein for use in the present method, an open edge defines the penetrating section of the dispenser. In alternative devices useful for the present method and disclosed herein, each dispenser can include a porous section or an opening through the dispenser wall of the penetrating section.
Some aspects of the invention relate to a steerable needle to provide access through non-linear pathways, for example to bypass an obstruction. A steerable needle may be manufactured by incorporating a piezoelectric material on a side of the needle so to flex or bend the needle when an electromagnetic force is applied to the piezoelectric material. Some aspects of the invention provide a medical device with site-specific features comprising at least one self-expandable piercing element that is sized and configured for a site-specific activity selected from the group consisting of diagnosis, sampling, energy therapy, and drug delivery, wherein the piercing element comprises a piezoelectric material on a side of the piercing element so to flex or bend the element when an electromagnetic force is applied to the piezoelectric material.
Therapy on Benign Prostate Hyperplasia
The prostate is not round but more a dual-lobed organ with the urethra situated off center. In operations for local drug delivery in vivo, it is desirable to have a medical device with two or more elongate piercing elements positioned axially parallel to each other, wherein the two or more piercing elements protrude at approximately 120 degrees in a plane perpendicular to an axis of the device with a third positioning arm spaced at 120 degrees to the two piercing elements. The current practice enables an operator to visualize and orientate before deploying the device. The side injector (plus anchoring finger) design provides a site-specific device.
In some disease stages, such as in the prostate where deeper penetration is needed, the present invention provides easily adjustable injector length without adding crossing profile, whereas a conventional balloon based device is handicapped due to balloon size limitation. Similarly in diseases relating to an atrial fibrillation (AF) in pulmonary veins, the present invention provides easily adjustable injector length without adding crossing profile, whereas a conventional balloon catheter design is handicapped due to balloon size limitation. Other disease areas, such as a calcified peripheral or bifurcated artery are also not easily reachable by a conventional balloon catheter.
From the foregoing description, it will be appreciated that a medical device and methods for site-specific diagnosis, energy therapy, sampling, and drug delivery in vivo have been disclosed. While the components, techniques and aspects of the invention have been described with a certain degree of particularity, it is manifest that many changes may be made in the specific designs, constructions and methodology herein above described without departing from the spirit and scope of this invention.
Various modifications and applications of the invention may occur to those who are skilled in the art, without departing from the true spirit or scope of the invention. It should be understood that the invention is not limited to the embodiments set forth herein for purposes of exemplification, but is to be defined only by a fair reading of the appended claims, including the full range of equivalency to which each element thereof is entitled.