Medical Tool for Reduced Penetration Force with Feedback Means
A medical device for reducing the force necessary to penetrate living being tissue using a variety of reciprocating motion actuators, including piezoelectric, voice coil, solenoids, pneumatics or fluidics. The reciprocating actuator drives a penetrating member through the tissue at a reduced force while the device detects the passage of the penetrating member through the tissue. Upon passage of the penetrating member through the tissue, electrical power to the reciprocating actuator is automatically terminated. A fluid-containing syringe may be coupled to a channel within the penetrating member. Once the penetrating member tip has passed through the living tissue, the fluid within the syringe no longer experiences any pressure and a plunger within the syringe displaces indicating passage of the penetrating member tip. This motion can provide direct tactile feedback to an operator of the medical device or can automatically open a switch providing electrical power to the medical device.
This non-provisional application claims the benefit under 35 U.S.C. §119(e) of Provisional Application Ser. No. 61/089,756 filed on Sep. 15, 2008 entitled MEDICAL TOOL FOR REDUCED PENETRATION FORCE WITH FEEDBACK MEANS and also is a Continuation-in-Part application and claims the benefit under 35 U.S.C. §120 of application Ser. No. 12/163,071 filed on Jun. 27, 2008 entitled MEDICAL TOOL FOR REDUCED PENETRATION FORCE which in turn claims the benefit under 35 U.S.C. §119(e) of Provisional Application Ser. No. 60/937,749 filed on Jun. 29, 2007 entitled RESONANCE DRIVEN VASCULAR ENTRY NEEDLE and all of whose entire disclosures are incorporated by reference herein.
BACKGROUND OF THE INVENTION1. Field of the Invention
The present invention generally pertains to handheld medical devices, and more specifically to electrically driven lancets; epidural catheter inserters; biopsy medical instruments, such as bone biopsy medical devices; vascular entry penetrating members, spinal access needles and other catheterization needles. The invention is applicable to the delivery and removal of blood, tissues, medicine, bone marrow, nutrients or other materials within the body.
2. Description of Related Art
Epidural anesthesia is a form of regional anesthesia involving injection of drugs directly into the epidural space. To begin the procedure, a needle is inserted from the outer layer of skin, through several layers of tissue and finally placed within the epidural space, through which a catheter is optionally passed. Local anesthetics are injected into the epidural space causing temporary loss of sensation and pain by blocking the transmission of pain signals through nerves in or near the spinal cord. The procedure can be unpleasant to the patient because of the high force levels required for the relatively dull epidural needle to penetrate the supraspinous ligament, interspinous ligament and ligamentum flavum. One complication is that a clinician will accidently overshoot and puncture the dura because of this high force of penetration and an almost-instantaneous change in resistance upon passing the needle into the epidural space (i.e., high forward momentum followed by instantaneous minimization of force). Upon puncturing the dura, the cerebrospinal fluid can leak into the epidural space causing the patient to experience severe post dural puncture headache, lasting from days to possibly years. Significant leakage can cause enough intracranial hypotension as to tear veins, cause subdural hematoma, and fraction injuries to the cranial nerves resulting in tinnitus, hearing loss, dizziness, facial droop, or double vision.
A bone marrow biopsy is used for diagnosing tumors and a variety of bone diseases. The most commonly used site for the bone biopsy is the anterior iliac crest. A major disadvantage is the force required to penetrate the bone tissue, and the twisting motion often used to force the needle inward, which results in patient discomfort as well as possible healing complications from damaged tissues. The penetration force can also be tiring for clinicians and lead to multiple sampling attempts. Complications are rare but can include bleeding, pain, and infection. Pain is minimized with proper local anesthesia, though the patient still experiences a pressure sensation during insertion and retraction during some procedures. Another problem is crushing the sample or being unable to retrieve part of all of it, limiting the ability to diagnose. As shown in
Currently, to minimize the possibility of a dura puncture, the epidural catheter insertion process is typically performed very slowly and with a 16-18 gauge, specially designed, relatively dull needle PA2, such as the one shown in
Several alternate technologies have been developed that attempt to minimize the dura puncture risk, while also giving the clinician indication of successful epidural placement. For example, the detection method and apparatus disclosed in U.S. Patent Application Publication No. 2007/0142766 (Sundar, et al.), the contents of which are incorporated by reference, relies on a spring-loaded plunger pushing a fluid into the epidural space upon successful entry. Accordingly, the clinician is given a visual indicator (i.e., the movement of the plunger as the fluid experiences a loss of resistance at the needle opening), and would cease applying forward force. Similarly, U.S. Pat. No. 5,681,283 (Brownfield) also relies on a visual indicator to communicate successful entry of a needle into a cavity to the clinician. Unfortunately, while a visual indicator is a positive advancement, the actual cause of the accidental dural wall puncture—that is, the high force applied by the clinician against the needle to pass through the various tissue layers and then stop—is not taught or suggested.
Therefore, there exists a need for a tool that reduces the puncture force of a needle, such as a Tuohy needle, and enables a clinician to perform a more controlled entry into the epidural space, thereby reducing the possibility of an accidental dura puncture.
While accidental dura puncture is a concern, simply locating the epidural space may pose a challenge even to the most skilled physicians. Therefore, when a needle such as a Tuohy needle is passed through the ligamentum flavum and into the epidural space, it is helpful for a clinician to receive immediate feedback indicating successful penetration and the location of the tip of the needle. A basic conventional feedback device such as the one in
Some advancements have also attempted to provide an automatic biasing element to act against the plunger of an epidural syringe while also providing visual indication or feedback, rather than tactile response, of successful puncture of various internal target areas in the human body. For example, in U.S. Patent Publication No. 2007/0142766 (Sundar et al.), a spring is utilized to act with a biasing force against the syringe plunger. When the epidural needle attached to the syringe passes through into the dural space, the pressure drop allows the spring to bias the plunger. As the plunger moves, the stem provides at least some visual indication as it moves with the plunger. Similarly, U.S. Pat. No. 5,024,662 (Menes et al.), which is hereby incorporated by reference, provides visual indication by utilizing an elastomer band to provide the biasing force against the plunger stem. In U.S. Pat. No. 4,623,335 (Jackson) which is hereby incorporated by reference, an alternative device assists in visually indicating a pressure to identify the location of the needle tip. In addition, U.S. Pat. No. 7,297,131 (Call) which is hereby incorporated by reference, uses a pressure transducer to translate a pressure change into an electronic signal. The electronic signal is then converted to a visual display indicator, for example by activating a light emitting diode to emit.
Therefore, a need exists to overcome the challenges not addressed by conventionally available technologies that reduces the force necessary for penetration of a sharp medical element of a medical device through tissue and also has the ability to deliver (e.g., deliver saline solution, or drugs, etc.) or retrieve materials subcutaneously (e.g., bone biopsy, etc.).
A need also exists to provide visual, tactile, electrical or additional indication to a clinician that the penetrating member has successfully penetrated the specific body space such as the epidural space, especially when the force to enter such a space has been substantially reduced. And this same force reduction must be either controlled or shut off immediately upon entry into the epidural space to avoid (easier) penetration of the dura.
Specifically, a need exists in the medical device art for an improved medical device having a penetrating element that is vibrated at a frequency that thereby reduces the force required to penetrate tissue, reduces the amount of resulting tissue damage and scarring, improving body space or vessel access success rate, minimizes introduction wound site trauma and, most importantly, improves patient comfort while minimizing potential complications.
A need exists for a clinician to be able to use less force to penetrate hard tissue such as the cortical bone during bone biopsy, which would reduce clinician fatigue, patient discomfort, and tissue damage while improving the sampling success rate and quality. There is a need to sense proper location, stop forward motion and collect the sample. There is a further need to turn device on after collection and to reduce force and patient discomfort as the penetrating member is being retracted from the body.
There is also a need for spinal access procedures where a clinician would want a reduction of force as well as to know the location of the needle tip but applied to a relatively-sharp penetrating member, such as a pencil point tip, as the clinician does not want to core tissue.
There is also a need for performing nerve block procedures where a clinician would want a reduction of force as well as to know the location of the needle tip. And this same force reduction must be either controlled or shut off immediately upon entry into the desired location.
All references cited herein are incorporated herein by reference in their entireties.
SUMMARY OF THE INVENTIONThe basis of the invention is a handheld medical device, (e.g., epidural needle, bone biopsy device, spinal needle, regional block needle, catheter introducer needle, etc.) having a penetrating member (e.g., an introducer needle, Tuohy needle, pencil point tipped needle, trocar needle (e.g., JAMSHIDI® biopsy needle), etc.), at a distal end, for use in procedures, (e.g., vascular entry and catheterization, single shot or continuous epidurals, spinal access, regional blocks, or bone biopsy, etc.), wherein the medical device comprises at least one driving actuator, (e.g., a piezoelectric, voice coil, solenoid, pneumatic, fluidic or any oscillatory or translational actuator etc.) attached to the penetrating member (e.g., at a proximal end of the penetrating member), and wherein the driving actuator translates the penetrating member, causing it to reciprocate at small displacements, thereby reducing the force required to penetrate through tissues.
Additionally, the invention comprises a means for providing feedback, either visually, audibly, or by tactile response, using a variety of detection mechanisms (such as, but not limited to, electrical, magnetic, pressure, capacitive, inductive, etc. means), to indicate successful penetration of various tissues, or of voids within the body such as the epidural space so that the clinician knows when to stop as well as to limit power to the driving mechanism.
Actuator technologies that rely on conventional, single or stacked piezoelectric material assemblies for actuation are hindered by the maximum strain limit of the piezoelectric materials themselves. Because the maximum strain limit of conventional piezoelectric materials is about 0.1% for polycrystalline piezoelectric materials, such as lead zirconate titanate (PZT) polycrystalline (also referred to as ceramic) materials and 0.5% for single crystal piezoelectric materials, it would require a large stack of cells to approach useful displacement or actuation of, for example, a handheld medical device usable for processes penetrating through tissues. However, using a large stack of cells to actuate components of a handpiece would also require that the tool size be increased beyond usable biometric design for handheld instruments.
Flextensional actuator assembly designs have been developed which provide amplification in piezoelectric material stack strain displacement. The flextensional designs comprise a piezoelectric material driving cell disposed within a frame, platen, endcaps or housing. The geometry of the frame, platten, endcaps or housing provides amplification of the axial or longitudinal motions of the driver cell to obtain a larger displacement of the flextensional assembly in a particular direction. Essentially, the flextensional actuator assembly more efficiently converts strain in one direction into movement (or force) in a second direction. Flextensional piezoelectric actuators may be considered mid-frequency actuators, e.g., 25-35 kHz. Flextensional actuators may take on several embodiments. For example, in one embodiment, flextensional actuators are of the Cymbal type, as described in U.S. Pat. No. 5,729,077 (Newnham), which is hereby incorporated by reference. In another embodiment, flextensional actuators are of the amplified piezoelectric actuator (“APA”) type as described in U.S. Pat. No. 6,465,936 (Knowles), which is hereby incorporated by reference. In yet another embodiment, the actuator is a Langevin or bolted dumbbell-type actuator, similar to, but not limited to that which is disclosed in U.S. Patent Application Publication No. 2007/0063618 A1 (Bromfield), which is hereby incorporated by reference.
In a preferred embodiment, the present invention comprises a handheld device including a body, a flextensional actuator disposed within said body and a penetrating or “sharps” member attached to one face of the flextensional actuator. In the broadest scope of the invention, the penetrating member may be hollow or solid. The actuator may have an internal bore running from a distal end to a proximal end or may have a side port located on the penetrating member attachment fitting. Therefore for single use penetrating members there is no need to sterilize the penetrating member after use. Where the penetrating member is hollow, it forms a hollow tubular structure having a sharpened distal end. The hollow central portion of the penetrating member is concentric to the internal bore of the actuator, together forming a continuous hollow cavity from a distal end of the actuator body to a proximal end of the penetrating member. For example, the flextensional actuator assembly may utilize flextensional Cymbal actuator technology or amplified piezoelectric actuator (APA) technology. The flextensional actuator assembly provides for improved amplification and improved performance, which are above that of a conventional handheld device. For example, the amplification may be improved by up to about 50-fold. Additionally, the flextensional actuator assembly enables handpiece configurations to have a more simplified design and a smaller format.
One embodiment of the present invention is a resonance driven vascular entry needle to reduce insertion force of the penetrating member and to reduce rolling or collapsing of vasculature.
An alternative embodiment of the present invention is a reduction of force epidural needle that provides the clinician a more controlled entry into the epidural space, minimizing the accidental puncturing of the dural sheath. In this embodiment, an actuator, for example, a Langevin actuator (more commonly referred to as a Langevin transducer), has a hollow penetrating member, for example a hollow needle, attached to a distal portion of the actuator. The Langevin actuator in this embodiment may be open at opposite ends. The openings include a hollow portion extending continuously from the distal end of the actuator to a proximal end of the actuator. The distal opening coincides with the hollow penetrating member. A plunger, having a handle, a shaft and a seal is also attached to the actuator at an opposite end of the sharps member. The plunger's shaft is slidably disposed within the continuous, hollowed inner portion of the actuator. The seal is attached to a distal portion of the plunger's shaft and separates a distal volume of the hollowed inner portion of the actuator from a proximal volume of the hollowed inner portion. Because the plunger's shaft is slidably disposed, the plunger is also slidably disposed and, in response to a motion of the shaft in a distal direction, reduces the distal volume of the hollowed inner portion and increases the proximal volume. Conversely, in response to a motion of the shaft in a proximal direction, the seal also moves in a proximal direction, thereby reducing the proximal volume of the hollowed portion and increasing the distal volume. The motion of the plunger's shaft, and, effectively, the plunger's seal, is actuated by an external force acting on the plunger's handle. When electrically activated, the actuator transfers compression and expansion of the piezoelectric material portion to a hollow and penetrating tip of the hollow needle. Langevin actuators may be considered high frequency actuators, e.g., >50 kHz.
Another embodiment of the invention provides a bone marrow biopsy device having an outer casing, an actuator, for example, a Langevin actuator (e.g., see, for example, U.S. Pat. No. 6,491,708 (Madan, et al.), whose entire disclosure is incorporated by reference herein), including a first body portion and a second body portion of the actuator, with piezoelectric material formed between the first and second body portions, wherein the actuator is disposed at least partially within the casing. The invention further includes a handle, an outer cannula, such as a needle, having an open distal end and an open proximal end with the cannula positioned at a distal portion of the actuator. In one aspect of the present embodiment, the invention further comprises a stylet having a penetrating distal tip attached to the handle at a portion opposite the distal tip, wherein the stylet is slidably disposed through a center cavity of the body and cannula. The actuator is formed with a distal opening formed at a distal end of the actuator, and a proximal opening formed at a proximal end of the actuator with a centralized hollow bore extending from the distal opening to the proximal opening, thereby defining a hollow channel.
More precisely, the outer cannula is a hollow tube fixedly attached at the distal end of the actuator such that the open proximal end of the cannula coincides with the distal opening of the actuator distal end. The stylet is slidably and centrally disposed within the actuator from the proximal end through the hollow channel and through the distal end. The stylet is also of predetermined length such that it is slidably and centrally located through the outer cannula, with the distal tip of the stylet protruding past the open distal end of the cannula.
The various actuators of the present invention must be connected electrically to an external electrical signal source. Upon excitation by the electrical signal, the actuators convert the signal into mechanical energy that results in vibratory motion of an end-effector, such as an attached needle or stylet. In the case of a Langevin actuator, the vibratory motion produced by the piezoelectric materials generates a standing wave through the whole assembly such as that in graph in
Accordingly, an alternative embodiment, the actuator may be formed with a distal opening formed at the distal end of the actuator, a port opening on at least a portion of the actuator, and a hollow bore extending from the distal opening to and in communication with the port opening. Preferably, the port opening may be a side port on a horn side of the actuator. More preferably, the port opening is generally located (preferably centered) at a zero node location of the actuator, and most preferably centered at a zero node location on a horn side of the actuator. Additionally, a means for providing feedback, for example any of those conventional feedback devices disclosed above used for indication of successful body location such as the epidural space penetration is in communication with the present embodiment by attachment at the port opening location, or preferably at the side port. Alternatively, any means capable of delivering fluid, such as a catheter tube or conventional syringe can be attached at the port opening location, or preferably at the side port.
The present invention relates generally to oscillatory or translational actuated handheld device for penetration through various tissues within a body for the delivery or removal of bodily fluids, tissues, nutrients, medicines, therapies, placement or removal of catheters, etc. For example for piezoelectric devices, the present invention is a handpiece including a body, at least one piezoelectric element disposed within the body, and a sharps member for tissue penetration, such as a syringe, epidural needle or biopsy needle located at a distal portion of the handheld device, having a feedback means capable of indicating successful penetration of the body space, such as epidural space by providing visual, audible or tactile indications using any well-known detection mechanisms such as but not limited to electrical, magnetic, pressure, capacitive, inductive, etc. means.
Additionally, with the use of proper circuitry the handheld medical device comprising an actuator is provided with a means for shutting off external power to the driving actuator (e.g., one or more of piezoelectric elements, voice coil, solenoid, other oscillatory or translational actuator, etc.) upon penetration of a particular tissue or internal portion of a body such as the epidural space. The means for shutting off external power to the driving actuator may be implemented as part of the aforementioned means for providing visual, audible or tactile indications or may be a separate means altogether. Preferably the means for shutting off external power to the driving actuator upon penetration of a particular tissue or internal portion of for example, the epidural space, may be accomplished by incorporating proper circuit configurations to aforementioned electrical means to trigger a switching means in order to cut off power to the driving actuator. Such a means is described in U.S. Pat. No. 5,575,789 (Bell et al.) whose entire disclosure is incorporated by reference herein. By providing such electrical cut-off means, upon successfully penetrating the epidural space for example, a clinician receives one or more of a visual, audible, and tactile indications as well as a loss of power to the device as a secondary indication that a particular internal portion of a body has been penetrated. Furthermore, with a loss of power to the device by cutting off electrical power to the driving actuator, the force or forward momentum necessary for further penetration of tissue will cease and in turn, will decrease the potential for unwanted body area puncture such as accidental dural puncture.
Additionally the invention with specific control electronics will provide reduction of force as the penetrating member is retracted from the body.
In one embodiment, the penetrating or sharp tubular member is a part of a vascular entry needle.
In another embodiment, the penetrating sharp tubular member is a Tuohy needle.
In yet another embodiment, the penetrating or sharp tubular member is a trocar and stylet assembly, such as a JAMSHIDI® biopsy needle.
In yet another embodiment, the penetrating or sharp tubular member is a pencil point tipped needle.
In yet another embodiment, the penetrating or sharp tubular member is part of a trocar access port.
These and other features of this invention are described in, or are apparent from, the following detailed description of various exemplary embodiments of this invention.
Exemplary embodiments of this invention will be described with reference to the accompanying figures.
The preferred embodiments of the present invention are illustrated in
The effectiveness of the invention as described, for example, in the aforementioned preferred embodiments, utilizes reduction of force to optimize penetrating through tissue or materials found within the body. Essentially, when tissue is penetrated by the high speed operation of a penetrating member portion of the device, such as a needle, the force required for entry is reduced. In other words, a reduction of force effect is observed when a penetrating member (also referred to as a “tubular member”), for example a needle, is vibrated axially (e.g., reciprocated) during the insertion process and enough mechanical energy is present to break adhesive bonds between tissue and the penetrating member. The threshold limits of energy can be reached in the sonic to ultrasonic frequency ranges if the necessary amount of needle displacement is present.
To exploit the reduction of force effect, the medical device of the present invention is designed such that the penetrating distal tip portion attains a short travel distance or displacement, and vibrates sinusoidally with a high penetrating frequency. Utilizing the various device configurations as described in the aforementioned embodiments, it has been determined that the sinusoidal motion of the sharp distal tip must include a displacement for piezoelectric tools of between 35-100 μm, more preferably between 50-100 μm, at a frequency of between 20-50 kHz, but most preferably at 20-25 kHz. This motion is caused by the penetrating member 20 being attached to an actuating piezoelectric actuator operated at 50-150 Vpp/mm, but most preferably at 90 Vpp/mm where Vpp is known as the peak-to-peak voltage.
For example,
By way of example only, referring to
It should be understood that the number of piezoelectric elements 114 does not form a limitation on the present invention and that it is within the broadest scope of the present invention to include one or more piezoelectric elements 114.
According to an alternative embodiment, a side port (not shown) may be formed at the horn 110 side of the actuator and the continuous bore 126 extends from a distal opening 122 at distal face 121 and in communication with this side port. The functional performance of the medical device is driven by the piezoelectric elements section. Piezoelectric elements 114, such as each of one or more piezoelectric material rings are capable of precise, controlled displacement and can generate energy at a specific frequency. The piezoelectric materials expand when exposed to an electrical input, due to the asymmetry of the crystal structure, in a process known as the converse piezoelectric effect. Contraction is also possible with negative voltage. Piezoelectric strain is quantified through the piezoelectric coefficients d33, d31, and d15, multiplied by the electric field, E, to determine the strain, x, induced in the material. Ferroelectric polycrystalline materials, such as barium titanate (BT) and lead zirconate titanate (PZT), exhibit piezoelectricity when electrically poled. Simple devices composed of a disk or a multilayer type directly use the strain induced in a material by the applied electric field. Acoustic and ultrasonic vibrations can be generated by an alternating field tuned at the mechanical resonance frequency of a piezoelectric device. Piezoelectric components can be fabricated in a wide range of shapes and sizes. In one embodiment, piezoelectric component may be 2-5 mm in diameter and 3-5 mm long, possibly composed of several stacked rings, disks or plates. The exact dimensions of the piezoelectric component are performance dependent. The piezoelectric single or polycrystalline materials may be comprised of at least one of lead zirconate titanate (PZT), multilayer PZT, lead magnesium niobate-lead titanate (PMN-PT), multilayer PMN-PT, lead zinc niobate-lead titanate (PZN-PT), polyvinylidene difluoride (PVDF), multilayer PVDF, and other ferroelectric polymers. These materials also can be doped which changes properties and enhances the performance of the medical device. This list is not intended to be all inclusive of all possible piezoelectric materials. For example there is significant research into non-lead (Pb) containing materials that once developed will operate in this invention.
In the embodiment shown in
Referring now to
Referring now to
In the most preferred embodiment, the side port is located on the penetrating member hub 525 at the end attachment point
Referring now to
Returning to
Referring to
In an alternate embodiment of the present invention, the penetrating introducer 201 of
A more preferred embodiment 202b is shown in
In the most preferred embodiment 202c is shown in
Now referring to
Referring now to
In an alternate embodiment, an advanced bone biopsy device, generally indicated as 400, shown in
While the previous embodiments have been described with respect to a Langevin actuator 100 as the actuating mechanism, the invention is not so limited. For example, as shown in
In operation, the piezoelectric material 514 expands during the AC voltage cycle, which causes the frame's proximal and distal faces 512a, 512b formed opposite of one another to move inward toward each other. Conversely, when piezoelectric material 514 compresses during the opposite AC cycle, an outward displacement of the frame's proximal and distal faces 512a, 512b away from one another occurs. However, in the present embodiment, the proximal face 512a of the frame is fixedly attached to body's 518 attachment point 516 so that any movement in the piezoelectric material stack will result in only a relative motion of distal face 512b and, thereby, a motion of the penetrating member 513.
Two examples of applicable amplified piezoelectric actuators (APAs) are the non-hinged type, and the grooved or hinged type. Details of the mechanics, operation and design of an example hinged or grooved APA are described in U.S. Pat. No. 6,465,936 (Knowles et al.), which is hereby incorporated by reference in its entirety. An example of a non-hinged APA is the Cedrat APA50XS, sold by Cedrat Technologies, and described in the Cedrat Piezo Products Catalogue “Piezo Actuators & Electronics” (Copyright© Cedrat Technologies June 2005).
Preferably, the APAs of the present invention are operated at frequencies in the range of 100 Hz to 20 kHz, more preferably 100 Hz to 1 kHz.
Alternatively, the actuator of the present invention may be a Cymbal actuator. For example, in
The Cymbal actuator 610 drives the penetrating member 513. When activated by an AC current, the Cymbal actuator 610 vibrates sinusoidally with respect to the current's frequency. Because endcap 612a is fixed to an inner sidewall of body 518, when Cymbal actuator 610 is activated, endcap 612b moves with respect to the body in a direction parallel to the hypothetical long axis of the medical device. Further, the displacement of penetrating member 513 is amplified relative to the displacement originating at piezoelectric material 514 when it compresses and expands during activation due in part to the amplification caused by the design of endcaps 612. For example, the piezoelectric material 514 alone may only displace by about 1-2 microns, but attached to the endcaps 612, the Cymbal actuator 610 as a whole may generate up to about 1 kN (225 lb-f) of force and about 80 to 100 microns of displacement. This motion is further transferred through the penetrating member 513 as an amplified longitudinal displacement of 100-300 microns. For cases requiring higher displacement, a plurality of Cymbal actuators 610 can be stacked endcap-to-endcap to increase the total longitudinal displacement of the penetrating member 513.
In alternate embodiments of the present invention, an additional port opening is formed in communication with a channel formed within the body of the actuator, for example a Langevin actuator. In particular,
Because the port opening is provided so as to attach a means for providing visual, audible or tactile feedback response (e.g., using any well-known detection mechanisms such as but not limited to electrical, magnetic, pressure, capacitive, inductive, etc. means) to indicate the successful penetration of the specific tissue such as the epidural space, it must be formed at a location which will be least detrimental to such means. In other words, because the actuator vibrates at high frequencies, each point along the actuator experiences a different displacement defined by a standing wave. In
In a more preferred embodiment,
In
In a seventh embodiment of the present invention shown in
Alternatively, as shown in an eighth embodiment of the invention in
Alternatively, as shown in an eighth embodiment of the invention in
In a ninth embodiment of the present invention shown in
In a most preferred embodiment of the present invention shown in
Another embodiment described in
By way of example only, the following is an exemplary method of using the present invention, whereby a clinician uses the present invention for an epidural procedure. When performing an epidural procedure, the clinician first fills syringe PA3 with a fluid, such as a saline solution or air. The clinician then inserts the front portion 9 of the syringe into the side port SP of the actuator 700b. Upon electrically activating the actuator, the clinician holds actuator 700b with a first hand while pressing the distal end 130a of the hollow needle against a patient's back. The clinician continues to provide forward momentum, while also providing a biasing force against biasing element 11, advancing hollow needle 130. With continued forward momentum, the hollow needle punctures the supraspinous ligament, the instraspinous ligament, and the ligamentum flavum (see
It should be further noted that it is within the broadest scope of the present invention to include syringes or other mechanisms which provide automatic biasing, such that the clinician does not have to apply a biasing force against the biasing element 11 prior to entry into, for example, the epidural space. In particular, the automatic biasing force (implemented, for example, via a spring, an elastomer, or any other well-known biasing mechanism such as, but not limited to, those described in U.S. Patent Publication No. 2007/0142766 (Sundar, et al.)) maintains an equal resistance as the needle is moved through the supraspinous ligament, the instraspinous ligament, and the ligamentum flavum. Upon entry into the epidural space, the biasing force is no longer resisted and this can be manifested in a variety of ways to the clinician, but not limited to, movement of the biasing element, or any other visual, audible or tactile indication using any well-known detection mechanisms such as but not limited to electrical, magnetic, pressure, capacitive, inductive, etc. means. For example, a pressure signal indicative of a loss of solution resistance automatically cuts off power to the driver actuator (e.g., piezoelectric elements, voice coil, solenoid, etc.).
While feedback means have been coupled to the side port SP, the invention is not so limited to feedback means. Any device may be coupled to a port location of the actuator, or ideally at the side port SP location even those devices simply being a means for providing or removing liquid, gas or other material such as a conventional syringe.
While the above-described embodiments of the present invention are made with respect to a handheld medical tool having a vibrating penetrating member and utilizing a Langevin actuator, Cymbal actuator, or APA for actuation, as mentioned earlier, the present invention is not limited to these actuator assemblies. Generally, any type of motor comprising an actuator assembly, further comprising a mass coupled to a piezoelectric material, or a voice coil motor, or solenoid, or any other translational motion device, would also fall within the spirit and scope of the invention. Furthermore, where the actuator assembly comprises a mass coupled to a piezoelectric material, the actuator assembly having a geometry which, upon actuation, amplifies the motion in a direction beyond the maximum strain of the piezoelectric material, would also fall within the spirit and scope of the present invention.
A first attachment point 916a fixes the distal end of the coil support tube 906 to the body 910. A second attachment point 916b fixes the proximal end of the coil support tube 906 to the body 910. The conducting coil may be made of different configurations including but not limited to several layers formed by a single wire, several layers formed of different wires either round or other geometric shapes. In a first embodiment of the conducting coil shown in
An alternative voice coil embodiment 900b is shown in
An electrical signal is applied at the conductive attachment sites 918 and 920 and causes the formation of the Lorentz force to form in an alternating direction that moves the conductive coil 902 and extension member 914 reciprocally along the longitudinal axis of the device. The conductive coils are physically in contact with the driving tube in this embodiment.
In all of the voice coil actuator configurations described, springs may be used to limit and control certain dynamic aspects of the penetrating member 20.
From the above description, it may be appreciated that the present invention provides significant benefits over conventional medical devices. The configuration of the actuating means described above, such as embodiments comprising a Langevin actuator, Cymbal actuator, or an APA, accommodates the use of piezoelectric actuating members in a medical instrument by enabling the displacement of the penetrating sharps member or needle to such frequencies that cause a reduction of force needed for penetrating through tissue during procedures such as bone biopsy, epidural catheterization or vascular entry. Electrical signal control facilitated by an electrically coupled feedback system could provide the capability of high oscillation rate actuation, control over penetration depth, electrical cut off (faster response than human) and low traction force for these procedures.
Another electrical power cut off implementation detects a forward motion of the biasing element 11 discussed previously. In particular, once the penetrating member 20 passes through the last tissue layer, pressure on the biasing element 11 is relieved and the incremental movement of the biasing element 11 into the body 10 is detected by a sensor which instantly opens the switch S and thereby cuts off electrical power to the present invention.
Additionally, the feedback control of the electronics enables the device to be vibrated in such a way that the force is also reduced as the penetrating member is retracted from the living being as would be necessary in bone biopsy after the tissue is extracted.
Now that exemplary embodiments of the present invention have been shown and described in detail, various modifications and improvements thereon will become readily apparent to those skilled in the art. While the foregoing embodiments may have dealt with the penetration through skin, bone, veins and ligaments as exemplary biological tissues, the present invention can undoubtedly ensure similar effects with other tissues which are commonly penetrated within the body. For example there are multiplicities of other tools like central venous catheter introducers, laparoscopic instruments with associated sharps, cavity drainage catheter kits, and neonatal lancets, as well as procedures like insulin administration and percutaneous glucose testing, to name a few, where embodiments disclosed herein comprising sonically or ultrasonically driven sharps members may be used to precisely pierce or puncture tissues with minimal tinting. Accordingly, the spirit and scope of the present invention is to be construed broadly and limited only by the appended claims, and not by the foregoing specification.
REFERENCE LABELS
-
- A Static needle force curve
- B Vibrating needle force curve
- G1 Displacement Graph
- LT Langevin actuator (also known as Langevin transducer)
- PA1 Conventional biopsy needle
- PA2 Conventional epidural needle
- PA3 Conventional Syringe
- PT Pressure transducer
- S Switch
- SP Side Port
- ZN Zero node
- 1 Cannula
- 1′ Cannula distal end
- 2 Stylet
- 3 Distal tip
- 4 Stylet tip angled face
- 5 Tuohy needle
- 6 Tuohy curved tip
- 7 Tip opening
- 9 Front portion
- 10 Tubular body
- 11 Biasing element
- 12 Plunger
- 14 Inner Stylet
- 15 Outer trocar tube
- 16 APA needle
- 16b Alternate embodiment
- 20 Penetrating member
- 100 Langevin actuator
- 110 Horn
- 111 Support wings
- 112 Rear mass
- 114 Piezoelectric elements
- 114b Electrical conductors
- 115 Sterilization sleeve
- 116 Bolt
- 117 Battery & inverter compartment
- 118 Handle
- 120 Seal
- 121 Distal face
- 122 Distal opening
- 123 Luer taper nose
- 124 Proximal opening
- 126 Bore
- 126a Short bore
- 128 Attachment fitting
- 129 Catheter
- 130 Hollow needle
- 130a Distal end of hollow needle
- 130b Proximal end of hollow needle
- 132 Plunger handle
- 134 Plunger shaft
- 134a Proximal end of plunger shaft
- 134b Distal end of plunger shaft
- 136 Plunger seal
- 142 Inner stylet handle
- 144 Inner stylet shaft
- 146 Inner stylet tip
- 148 Trocar attachment fitting
- 150 Outer trocar body
- 152 Distal trocar opening
- 154 Distal trocar tip
- 200 Penetrating introducer
- 202b More preferred embodiment
- 202c Most preferred embodiment
- 201 Supported introducer
- 202 Catheterization introducer
- 300 Bone biopsy device
- 400 Advanced bone biopsy device
- 500 APA syringe
- 500b Alternate embodiment
- 510 Amplified piezoelectric actuator (APA)
- 512 Frame
- 512a Proximal end of frame
- 512b Distal end of frame
- 513 Penetrating member
- 513a Proximal end of penetrating member
- 513b Distal tip of penetrating member
- 514 Piezoelectric material
- 516 APA attachment point
- 518 Handle
- 521 Handle distal opening
- 524 Handle proximal opening
- 525 Penetrating member hub
- 526 APA bore
- 600 Cymbal syringe
- 600b Alternate embodiment
- 610 Cymbal actuator
- 612 Endcap
- 612a Proximal endcap
- 612b Distal endcap
- 626 Cymbal bore
- 616 Cymbal attachment point
- 700 General side port configuration
- 700a First side port configuration
- 700b Second side port configuration
- 800 Feedback capable reduction of force tool
- 900 Medical tool using voice coil actuator
- 900b Alternate voice coil embodiment
- 902 Conducting coil
- 904 Magnetic member
- 906 Coil support tube
- 910 Body
- 912 Driving tube
- 914 Extension member
- 916a First attachment point
- 916b Second attachment point
- 918 First conductive attachment site
- 920 Second conductive attachment site
- 922 Second conductive coil
- 1000 Medical tool using solenoid actuator
- 1002 Solenoid coil
- 1004 Magnets
- 1014 Spring
- 1020 Pressure feedback system
- 1021 Reservoir with integrated pump
- 1022 Flexible tubing
- 1023 Attachment fitting
- 1024 Base
- 1025 On/off switch
- 1026 Light emitting diode
Claims
1.-33. (canceled)
34. A medical device for penetrating living being tissue, said device comprising:
- a penetrating member which is vibrated to reduce the force needed to penetrate living being tissue;
- a driving actuator coupled to said penetrating member and causing said vibration when energized;
- an electrical power cut off automatically de-energizing the driving actuator when said penetrating member has passed through the living being tissue; and
- a side port through which fluid pressure is monitored to initiate the automatic electrical power cut off, wherein fluid is introduced through the side port and into the penetrating member, wherein a longitudinal axis of the side port intersects a longitudinal axis of a bore and is oriented at a non-parallel angle at the intersection to the longitudinal axis of the bore, wherein the longitudinal axis of the bore is in turn oriented at a parallel angle to a longitudinal axis of the penetrating member;
- wherein the fluid introduced through the side port and into the penetrating member is dispensed from a distal end of the penetrating member out of the medical device.
35. The medical device of claim 34 wherein said penetrating member is one of a hypodermic needle, catheterization needle, Tuohy needle, bone biopsy trocar, spinal needle, nerve block needle, trocar access ports and interventional radiology needle.
36. The medical device of claim 34 wherein a pressure transducer detects pressure within a channel of said penetrating member and activates said electrical power cut off.
37. The medical device of claim 34 wherein the vibrating penetrating member comprises a hollow needle disposed in an attachment fitting, the attachment fitting coupled to the driving actuator.
38. The medical device of claim 34 wherein said driving actuator comprises a voice coil coupled to said penetrating member.
39. The medical device of claim 38 wherein said voice coil comprises a coil surrounding permanent magnets and a portion of said penetrating member.
40. The medical device of claim 38 wherein said voice coil comprises a coil surrounding permanent magnets and a shaft, said shaft coupled to said penetrating member.
41. The medical device of claim 38 further comprising vibration amplifiers positioned on opposite sides of said coil.
42. The medical device of claim 41 wherein the vibration amplifiers comprise springs positioned on opposite sides of said coil.
43. The medical device of claim 34 wherein said driving actuator is one of a pneumatic or fluidic actuator.
44. The medical device of claim 34, wherein the penetrating member has a penetrating member hub, wherein the bore is in the penetrating member hub, and wherein the longitudinal axis of the bore is coaxial with a longitudinal axis of a channel of the penetrating member.
45. A medical device for penetrating living being tissue, said device comprising:
- a penetrating member which is ultrasonically vibrated to reduce the force needed to penetrate living being tissue;
- a driving actuator coupled to said penetrating member and causing said ultrasonic vibration when energized;
- an electrical power cut off automatically de-energizing the driving actuator when said penetrating member has passed through the living being tissue;
- a tubular body that has an interior;
- a biasing element that moves from an at rest position and upon so doing is sensed by a sensor to trigger the electrical power cut off to automatically de-energize the driving actuator, wherein the sensor senses movement of the biasing element relative to the tubular body to trigger the electrical power cut off; and
- a side port in fluid communication with the interior of the tubular body.
46. The medical device of claim 45, wherein said driving actuator comprises a Langevin actuator.
47. The medical device of claim 45, wherein said driving actuator comprises a Langevin transducer.
48. The medical device of claim 45, wherein said driving actuator comprises a flextensional actuator assembly.
49. The medical device of claim 48, wherein said driving actuator comprises a cymbal actuator.
50. The medical device of claim 48, wherein said driving actuator comprises an amplified piezoelectric actuator.
51. The medical device of claim 45, further comprising a penetrating member hub that carries the penetrating member, wherein the side port is located at the penetrating member hub.
52. The medical device of claim 45, wherein the side port is located at the driving actuator.
Type: Application
Filed: Jul 11, 2014
Publication Date: Oct 30, 2014
Inventors: Paul L. Frankhouser (Bellefonte, PA), Brian M. Park (Bellefonte, PA), Maureen L. Mulvihill (Bellefonte, PA)
Application Number: 14/329,177
International Classification: A61B 17/34 (20060101); A61B 19/00 (20060101); A61B 10/02 (20060101);