SPHERULE INSERTION TOOLS
20220362534 · 2022-11-17
Inventors
Cpc classification
A61M37/0069
HUMAN NECESSITIES
A61B2017/00411
HUMAN NECESSITIES
International classification
A61M37/00
HUMAN NECESSITIES
Abstract
Described are surgical tools to facilitate the proper implantation beneath the outer layer of tubular anatomical structures, or ductus, to include vessels, the trachea, esophagus, gut, and ureters, as well as the outer layer or within the parenchyma of organs, glands, or other tissue, of medicinal, magnetically susceptible, magnetized, and/or radiation-emitting spherules sized in proportion to the substrate structure. Spherule insertion tools expedite insertion transluminally to implant the wall surrounding a lumen making possible therapy and/or extraluminal stenting which leaves the lumen clear for subsequent passage. Spherules can also be introduced into deeper tissue through a ‘keyhole’ incision at the body surface. For evolving methods calling for the placement of numerous ‘seeds’ and/or boluses, eliminated are the need for more extensive incision with increased trauma, procedural duration, and healing time. Avoidance of the lumen is augmented by placing the magnets subcutaneously rather than using a magnetized perivascular collar, or stent-jacket.
Claims
1. An extension for the barrel of a variable discharge-pressure medical interventional airgun for use as a hand tool for the insertion into tissue and the introduction into, passage through, and discharge within the lumen of a tubular anatomical structure of medicinal and magnetically susceptible spherules into the wall surrounding said tubular anatomical structure as a means for the delivery of interventional therapy and an aid to imaging.
2. An extension for the muzzle, that is the distal terminus from which the spherules are discharged, from a variable discharge pressure operated airgun as defined in claim 1 wherein at least one tractive electromagnet is mounted proximal thereto so that energizing said electromagnet allows a misplaced spherule to be recovered.
3. An extension for the barrel of a variable discharge-pressure medical interventional airgun for use as a hand tool as defined in claim 1 with an unobstructed passageway entirely through its longitudinal central axis to allow different miniature cabled devices such as scopes, lasers, intravascular ultrasound probes, a rod to deploy an embolic filter at the distal end of said extension, and a rod with a pressure sensor which the operator can view to test the force of expulsion needed to insert the spherule implant into that tissue, each such longitudinally configured device insertable interchangeably during an interventional procedure thereby imparting considerable imaging and therapeutic capability.
4. An extension for the barrel of a variable discharge pressure operated airgun as set forth in claim 1 wherein the current conducted through the coil of said tractive electromagnet can be increased causing the temperature of said coil to be increased to a level suitable for thermal angioplasty and ablation of atheromatous, infected, and malignant tissue.
5. An apparatus for stenting a tubular anatomical structure whereby a variable discharge pressure medical interventional airgun as set forth in claim 1—is used to implant ferromagnetic spherules within the tissue lining the lumen of said tubular structure, said spherules susceptible to a magnetically generated tractive force in relation to magnetized material about the external surface of said tubular anatomical structure.
6. An extension for the barrel of a variable discharge-pressure medical interventional airgun used as a hand tool for the insertion into tissue of small therapeutic, magnetically susceptible, and radiopaque spherules.
7. A medical interventional airgun incorporating a rotary spherule airgun loading magazine clip whereby each in a plurality of spherules is released into a different discharge tube for simultaneous expulsion and insertion at a different radial angle into the surrounding wall of a tubular anatomical structure.
8. A medical interventional airgun barrel incorporating radially outward thermal expansion wire-projectable lift platforms which in order to medically treat a tissue surface, lift interchangeable tool inserts into working contact with said tissue surface such as that of the wall surrounding a lumen obstructed by a deposition of crystal or an atheromatous lesion.
9. A therapeutic spherule containing magnetically susceptible matter exclusively matched to and limited to implantation by a corresponding dedicated medical interventional airgun such that said airgun and said spherule stand in a reciprocal relation as to define a unit invention.
Description
DESCRIPTION OF THE DRAWING FIGURES
[0049]
[0050]
[0051]
[0052]
[0053]
[0054]
[0055]
[0056]
[0057]
[0058]
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0059] The finer details of spherule implant insertion tool or discharge device structure are set forth in parent application Ser. No. 15/932,172, entitled Integrated System for the Infixion and Retrieval of Implants, which is readily available online. This divisional application will review the features of spherule implant insertion tool components to include pipe and torpedo-configured spherule implant discharge devices, or barrel-assemblies with the omission of the fine details thereof. Figure numbers higher than 10 appear in the parent application.
[0060] Open Monobarrel, or Simple Pipe Type Barrel-Assembly, with Bounce-Plate
[0061] A barrel-assembly for use in the vascular tree must present a smooth and slippery surface, allow quick operation as one means for minimizing hypoxia, and incorporate features that minimize if not eliminate the need for withdrawal and reentry. This fact and the need to avoid any projections prompts enclosing the barrel-tubes of a radial discharge barrel-assembly in a slippery torpedo-shaped shell such as shown in
[0062] Compared to the structurally differentiated trachea with its cartilage rings, the relatively undifferentiated gross structure of vascular, gastrointestinal, urogenital (urinogenital, genitourinary) and gamete transmitting ductus which pulsate or forcibly undulate during peristalsis can be secured by a larger number of miniballs at each level placed at different radial angles with less regard for precise placement. While a simple pipe or open barrel-assembly such as that shown in
[0063] By contrast, the placement of miniballs in the trachea must be discretionary such that each miniball can be aimed at a specific point. This is more easily accomplished using a single barrel single discharge tool such as the simple pipe or open barrel-assembly shown in
[0064] FIG. 31 in the parent application shows a simple pipe type barrel-assembly without a bounce-plate (deflection-plate, ricochet-plate; rebound-tip; rebound-plate, rebound deflection-plate, rebound angle deflection plate), and
[0065] Where to rotate the tool might injure tissue near the discharge end or muzzle of the tool, a bounce-plate allows the trajectory of a miniball to be reversed. Whereas the positioning of miniballs along the intima of an artery with its lack of distinguishable structure from one level to the next is noncritical, to place miniballs in a structured ductus must be undertaken with precision. For this reason, unless preceded with considerable practice, the use of a bounce-plate inside a structured milieu is to be discouraged.
[0066] In
[0067] In a barrel-assembly for use without a bounce-plate or with a bounce-plate attachment described below, rotatory or swivel joint 133 must be placed at a level sufficiently proximal to allow muzzle-head 45 to be rotated in relation to the barrel-catheter. In a barrel-assembly with an intracorporeally controllable bounce-plate mechanism described below, rotatory joint 133 must also be placed sufficiently proximal to allow clear access to the bounce-plate mechanism controls, which must be mounted to the top of muzzle-head 45 with which the mechanism rotates.
[0068] Provided muzzle-head 45, which is inflexible from the distal (front) end to rotary joint 133 and includes a moderate curvature toward the front end with recovery electromagnet 46 shown in FIG. 33 of the parent application within magnet housing 56 nested therein can be passed through the vocal folds and larynx, for example with little risk of injury, rotary joint 133 will join muzzle-head 45 to barrel-catheter 44. However, if the inflexibility of the muzzle-head interferes with safe clearance, then a tool of the same kind having a working end with a less pronounced curvature is used.
[0069] Provided the ductus can be negotiated from within the lumen without injury and the implants properly positioned, to approach from outside the ductus through one or more small incisions at the body surface in order to use stays is to be discouraged. For use in an open surgical field, a simple pipe type or open monobarrel barrel-assembly such as shown in
[0070] Omitted here but shown in detail in FIGS. 35 thru 37 of the parent application, the materials of a bounce-plate mechanism must be flexible to comply with that of the barrel-catheter, which is readily accomplished with many different materials using a bevel gear but not a pulley arrangement within control tube 135 shown in FIG. 37. The division of the control sleeve into a proximal control slide-box portion 134 and distal controlled slide-box portion 140 is due to the requirement for control rod 135 to be rotatable, hence, cylindrical, whereas the distal bounce-plate 53 must have bilateral extension. Continuous sleeve or separate slide boxes 134 and 140 can be made of any suitable nonmagnetic metal or plastic with all corners and edges rounded or blunted.
[0071] Control slide-box 134 in FIGS. 35 and 36 of the parent application Ser. No. 15/932,17, is lined with a material such as felt that imparts a smooth sliding action to slide-block 137, while controlled slide-box 140 is lined with an absorbent material such as gauze or a nonallergenic foam which can be wetted with a mucolytic such as acetylcysteine or a mucinolytic (mucinase, mucopolysaccharidase). The absolute amount of acetylcysteine is too small to cause stomatitis or induce nausea or rhinorrhea; however, to prevent bronchospasm, only light wetting is used in the distal airway. When made continuous, the proximal lumen must be circular to allow control tube 135 to be rotated, while the lumen of the distal controlled slide-box 140 must be horizontal to accommodate bounce-plate 53.
[0072] Thus, a lumen uniform in diameter or gauge from end to end would have to equal the width of bounce-plate 53, which will most often equal the diameter of exit-hole 55. This would double the cross-sectional area of muzzle-head 45 and bounce-plate mechanism combination. Fundamental objects being to minimize the muzzle-head to miniball diameter ratio and cost, separate proximal and distal lumina or slideways are provided as control slide-box 134 and controlled slide-box 140. The proximal end of bounce-plate control slide-box 134 then spans across a nonrotatable and intracorporeal joint between the inflexible muzzle-head 45 and the distal end of the barrel-catheter 44. Rotary joint 133 must then be sufficiently proximal to allow the barrel-assembly distal to it to be rotated and the bounce-plate to be controlled.
[0073] Since the bounce-plate mechanism does not span over rotary joint 133, the muzzle-head remains endlessly rotatable. Bounce-plates range in cost of manufacture and precision from a simple attachment to a built in precision mechanism that allows the discharge to be redirected without the need to move, much less remove, the muzzle-head from the body. Unless the insertion tool is completely straight, located in the concavity on the underside of the muzzle-head in
[0074] Enclosed Multiple Barrel Barrel-Assembly
[0075] Insertion thus seeks to wedge the miniball in place and avoid pull-through or delamination of tunic layers which may have been weakened by disease. In the data gathering through actual testing such as described in section XVII of the parent application entitled Testing and Tests that precedes any such procedure with an enclosed multibarrel muzzle-head as shown in
[0076] In
[0077] Relegating a more detailed description of the structure to the parent application, only the distal segment of barrel-catheter 44 separated to create a rotary joint and journaled within through-bore rotor 60 of the turret-motor rotates with rotor 60, and since muzzle-spindle 77 is attached to the distal end of the distal end of the distal segment, spindle 77 is rotated. Part number 111 is a flex joint to divert the muzzle-head when continued advancement directly forward would injure the endothelial or urothelial lining if not the intima of the surrounding luminal wall, and 174 is a token radial projection unit with any of the tools having interchangeable working tips such as those suggested in
[0078] Not shown here are radial projection catheters, angioplasty tools without spherule ejection capability that incorporate many radial projection units with various tool inserts to treat the luminal wall. For a more detailed description of both barrel-assemblies such as that shown here in
[0079] For structured lumina or where for any reason it is advisable to reverse the direction of miniball entry, such as when entry orients the muzzle-head retrograde so that the passage of contents might eventually urge the miniball back into the lumen, a means for reversing the direction of entry is desirable. While in some instances, such as for treating the trachea in a very small or ‘teacup’ sized dog where a simple pipe is too large for safe passage, an endoluminally deployable and retractable bounce-plate mechanism of a types now to be described can be added to a small gauge monobarrel radial discharge barrel-assembly.
[0080] However, radial discharge barrel-assemblies are ordinarily intended for implanting substantially uniform gross anatomy as in virtually every other type of ductus (ureters, gastrointestinal tract, arteries) where exactitude in aiming is noncritical and multiple miniballs can be discharged simultaneously. To allow a clearer view of the exit-hole (muzzle), aiding aiming accuracy in relation to the differentiated structure within the trachea, simple pipes omit a shell (body, enclosure).
[0081] Barrel-assemblies for use within vessels, for example, provide a shell about the muzzle-head to protect the lumen wall, and are intended primarily for veterinary use to alleviate tracheal collapse, although the same conformation makes simple pipes more suited to applications outside of lumina than radial discharge barrel-assemblies. Since a simple pipe barrel-assembly with the endoluminally deployable bounce-plate mechanism shown in
[0082] Simple pipes can be made 1. To accept a simple bounce-plate attachment that to slip on and off requires removal from the patient and to change the vertical angle (elevation) requires bending and the rotational angle requires rotation of the muzzle-head; 2. With a substantially fixed rebound angle bounce-plate that can be slid forward into position or deployed and rotated while endoluminal whenever needed; or 3. So that vertical and rotational angular adjustments are under positive or direct mechanical control and calibrated for precision. The latter two are adjustable in downward inclination (elevation) of the bounce plate and thus the angle of rebound along the vertical axis of the muzzle-head.
[0083] By providing a calibrated control arm, that rotatable thus allows fine adjustment in the angle of discharge through a wide radially and longitudinally arcuate volume to its underside. When the muzzle-head can be long enough to extend outside the body, the forcibly bendable metal muzzle-head of the barrel-assembly is joined at its proximal end to the barrel-catheter by an internally smooth rotary joint for rotation as a handpiece. The intracorporeally adjustable bounce-plate configurations shown in FIGS. 35 thru 37 in the parent application are then mounted to the upper surface of the muzzle-head. If not, the control spans over the junction between the muzzle-head and barrel-catheter. Either configuration allows the bounce-plate to be controlled while the barrel-assembly is in use to more quickly achieve fine control over the angle of discharge.
[0084] To reduce the risk of injury, permanent endoluminal bounce-plate control mechanisms must be as little protrusive as possible and have outer edges and corners that are blunted (rounded, curved). The use of a bounce-plate pertains only to simple pipe, not radial discharge type barrel-assemblies. The forward edge or rim of the pipe is generally cut an angle to allow flush placement against tissue to be implanted. The overhang generally accommodates the reverse discharge of miniballs when a bounce- or rebound deflection plate is attached. To minimize accidental injury, the tip of a simple pipe is covered with an elastomer guard. Protruding beyond the tip of the simple pipe, an overhang or roof-configured bounce-plate especially requires a protective guard.
[0085] Likewise for flush abutment, the tip of a walled-around bounce-plate is angled with the tip directed in the opposite direction. Walled-around, Krummlauf-type continuously curved barrels, and hybrid versions of the two for reversing the direction of discharge would allow good control over the trajectory but are impractical because of the enlargement if not hook conformation at the distal end of the pipe. Such ends make insertion and withdrawal difficult and more prone to cause laryngeal injury. The bounce-plate can be a friction-fitting attachment or a permanent feature. Because to observe the muzzle-port or ports is unintended and more difficult with a barrel radial discharge barrel-assembly, the simple pipe is preferred for use in the anatomically differentiated airway.
[0086] A torpedo-enclosed single barrel radial discharge barrel-assembly is used only in the airway of the smallest dogs with collapsed trachea where there is not the space to manipulate an open simple pipe such as shown in
[0087] This capability can be beneficial, for example, in the trachea to introduce implants into the posterior junction of each successive cartilage ring with the annular ligament, as described below. Published testing results on specimens having just died are consulted before engaging upon such use. The avoidance of withdrawal and reentry in the airway is not onerous as it is in the bloodstream, and such a capability is often unnecessary. The single barrel radial discharge barrel-assembly and not the simple pipe is recommended when space is lacking to insert and withdraw the simple pipe without risk of injury to the larynx.
[0088] In smaller patients, a simple pipe barrel-assembly may be usable for a distance towards the bronchi, down to which the diameter of the lumen becomes so restrictive that it becomes necessary to withdraw and replace the simple pipe with a single barrel radial discharge barrel-assembly. The bounce-plate is thus incorporated into a second simple pipe rather than as an option that would be opened or closed in a single embodiment. Under such circumstances, withdrawal and reentry is preferable or essential, so that a single embodiment capable of discharge both distad and proximad, which to provide entails additional complexity and cost greater than the sum for separate barrel-assemblies where one does and the other does not have a bounce-plate, is not preferred.
[0089] Accordingly, a simple pipe barrel-assembly that reverses the direction of the trajectory is provided in a separate barrel-assembly. FIGS. 32 and 34 of the parent application show a simple pipe barrel-assembly with a manually attached bounce-plate at the distal end of the muzzle-head. An attachable bounce-plate is not deployable or retractable with the muzzle-head intracorporeal and is suitable only for occasional or isolated use for directional reversal of the trajectory when laryngeal clearance to admit the tip with bounce-plate is adequate.
[0090] Bounce-plates that allow insertion through the larynx then extension of the bounce-plate into position during use and retraction before withdrawal are described below in this section and shown in FIGS. 35 thru 37. Except for the addition of bounce-plate 53 and a soft protective annulus 52 adapted for the change in configuration of the muzzle-head that results from the bounce-plate, the simple pipe is the same as that shown in FIG. 31 with only a soft rubbery protective ring 52 surrounding the tip. Since the front portion of a full circle protective annulus 52 interferes with mounting bounce-plate 53, a hybrid annulus consisting of a soft or rubbery portion at the rear and bounce-plate portion at the front provided.
[0091] The bounce-plate portion may consist of bare metal or metal with an outer rubbery coat, which is then preferably unitary with the rubbery rear portion. A detailed view of the tractive electromagnet 46 mounted in the concavity on the underside of the simple pipe barrel-assembly in the curve 45 approaching its distal end is shown in FIGS. 31 thru 34. The loss of a miniball in the airway being unlikely and posing little risk even were it to occur, an antemagnet chamber as seen in magnet assemblies used in radial discharge barrel-assemblies for use in the bloodstream described below, is not used. In FIG. 33, recovery electromagnet 46 is enclosed within electromagnet housing 56 made of any hard plasticizer free resin and bonded in position by means of an adhesive that is pliable after curing as discussed in the preceding section.
[0092] When the airway is large enough that withdrawal of a muzzle-head without bounce-plate as shown in FIGS. 31 and 33 and reentry with a rebound muzzle-head or muzzle-head having a bounce-plate, such as those shown in FIGS. 32 and 34 poses minimal risk of injury, the separate embodiments are used. When the airway is not so small as to necessitate the use of a radial-discharge barrel-assembly, a simple pipe with a bounce-plate is used. The bounce-plate is a distal tip cap (crown, ferrule) friction-secured fitting that to attach or replace necessitates removal and reintroduction of the pipe; a bounce-plate that is endoluminally deployable and retractable addressed in the next section, and one that is endoluminally adjustable in angle addressed in the section following that.
[0093] If, for example, the simple pipe is polypropylene on the outside and the nonferrous metal of the bounce-plate is an alloy of aluminum, the adhesive, which must remain pliant after cured, is preferably a two part polyurethane, such as Loctite U-05FL, mentioned above in the preceding section entitled Simple Pipe Barrel-assembly. The angle of rebound equal and opposite to the angle at which the miniball strikes the bounce-plate upon exiting the original muzzle-port, seen in FIG. 34 as 55, the angle described between the trajectory upon colliding and rebound off of the bounce-plate is usually 45 degrees.
[0094] If nonrotatably mounted to the airgun muzzle at the twist-to-lock connector, then rotary joint 133 shown here in
[0095] Whether along a longer muzzle-head, the junction between barrel-catheter and muzzle-head, or at a level along the barrel-catheter, rotary joint 133 must be positioned sufficiently proximal along the barrel-assembly that it remains extracorporeal and accessible for manual adjustment. Since the bounce-plate mechanism must be continuous and its push-pull handle and rotation lever or arm 138 shown in FIGS. 35 thru 37 must also remain accessible, rotary joint 133 must be positioned proximal to the proximal end of the bounce-plate mechanism. Control slide-box or sheath 134 is ordinarily extended up to controlled slide-box or sleeve 140. Controlled slide-box 140 is advantageously identical to distinct bounce-plate 53 housing when bounce-plate 53 is of a shape that would result in added expense were it unitary or continuous with the bounce-plate mechanism proximal to it.
[0096] Rebound dissipates the kinetic energy and momentum or propulsive force imparted to the miniball necessitating adjustment of the airgun setting. Since the simple pipe barrel-assembly is intended for use in the trachea and the single-barrel radial discharge barrel-assembly for use in the tracheobronchial tree when the lumen diameter is confining, sections to follow the description of these single barrel barrel-assemblies will be directed to the application of these barrel-assemblies for use in the airway. Multiple discharge barrel-assemblies, which are not used in the airway but rather in vessels and ducts are described later.
[0097] The simplest type of rebound deflection plate, shown in
[0098] Closed Multiple Barrel Barrel-Assembly Radial Projection Tools
[0099] Indicated as part number 174 in
[0100] Tool-inserts can deploy variously configured curettage (evidement, scraper abrader-type) working tips for dislodging and relegating to the embolic filter 173 atheromatous or adherent crystalline matter or injectors, for example, four working tips diagrammatically represented in
[0101] Enclosed Multiple Barrel Barrel-Assembly with Integral Embolic Filter
[0102] The closed multiple barrel barrel-assembly shown in
[0103] In
[0104] Angioplasty and Stenting Control Panel
[0105] In barrel-assemblies for use in lumina that are less restrictive, the primary can include electrically and fluid controlled heat-windows and tool-inserts, and tool-inserts of either type may incorporate internal functions such as warming the contents of an injection syringe, which require additional circuits. Accordingly, the specific controls and the apportionment of these in ablation or angioplasty control panels of different barrel-assemblies and radial projection catheters vary considerably. For this reason, the control panel shown in
[0106] Positional and Therapeutic Control Components in a Fully Capable Barrel-Assembly
[0107]
[0108] In
[0109] A fully featured barrel-assembly control system fully automates lumen preparation and therapy such as thermal, as well as exercise positional control of the barrel-assembly antegrade-retrograde, the rotational angle of the muzzle-head turret motor, and the deployment of accessories such as an embolic filter and radial projection tools. Automatic control in this regard is always semiautomatic in that control overall is never entrusted to the control system but rather administered by the operator or an assistant through the use of a joystick such as shown in
[0110] Interventional Airguns
[0111] Whereas barrel-assemblies conduct miniballs to the target and usually incorporate additional means for treating the internal surface of the lumen, the force to propel the miniballs is provided by a CO.sub.2 or compressed air-powered, specially designed, that is, dedicated, interventional airgun such as those shown in FIG. 81, reproduced here as
[0112] In a simple embodiment intended for use with a refillable cylinder of compressed air that has been pressurized for use with a tissue of certain properties as shown here in
[0113] A dedicated interventional airgun can be a gravity fed monobarrel such as those shown here in
[0114] A control knob is provided to adjust the voltages that regulate the extent and duration that the electropneumatic valve opens to the pressurized gas. Providing dedicated interventional airguns with an additional foot control switch to trigger discharge is not preferred. A conventional electrical foot-switch must be adapted to incorporate a safety pin that must be released by depressing a lever with the toe of the opposite foot, and limited to triggering only, the foot switch is too limited. The incorporation into a foot operated control panel of all the controls necessary to use the apparatus is rejected as inviting unintended actuation.
[0115] Accordingly,
[0116] Such an embodiment, using a single cylinder of compressed gas without the additional expense of a regulator, is suitable for use where the a range of exit velocities or forces of penetration is required, as when treating a single tissue to a single depth. Under normal circumstances, a disposable delivery catheter designed for the particular application is provided. A device as shown above and in the following FIG. 82 allows continuous variability in the force impact, which expedites testing tissues for the purpose of disposable catheter design. The compressed gas can be supplied, for example, from either an internal prefilled disposable CO.sub.2 or by means of piping from an external CA compressed air cylinder.
[0117] Whereas CO.sub.2 delivers 837 psi at 70 degrees Fahrenheit, a compressed air cylinder can be filled to a preferred pressure. With the interposition of a small adaptor, either a CO.sub.2 or CA cylinder can be connected to the valve body inlet. Using a single source of compressed gas without regulator keeps the design simple and economical. A small CO.sub.2 cylinder inserted within the enclosure makes the single-purpose airgun self-contained and compact. Containing nonliquified gas, a compressed air cylinder is larger and therefore connected from outside through a hose but can be filled to any pressure within its design specification. With or without a regulator, control with a single source of compressed gas is limited to reduction in the outlet pressure (also referred to as a canister or tank).
[0118] With this basic design, variability in shot impact force is limited to adjustment in the field strength and duration of plunger solenoid actuation. Preserving this simplicity and economy limits the pressure-reducing features that can be built into the airgun. Nevertheless, by connecting compressed air cylinders filled to different pressures, even the simple airgun can be used to treat different tissues to different depths of penetration. In such use, multiple cylinders of compressed air are connected and switched among manually by means of a pneumatic or electronically by means of an electropneumatic station valve.
[0119] This can be done at no great expense when switching is manual; however, the parts necessary to switch among different cylinders with electronic valves loses the economic edge over a design that affords continuous variability in pressure through the use of a regulator. A warming jacket containing a heating element or coil about the gas delivery tube with thermostat or pyrometer control can be used to change the temperature and so adjust the pressure.
[0120] Since conventional CO.sub.2 cylinders are rated for up to 1800 pounds per square inch (psi), the range of pressure control gained in this manner is much less than it is with compressed gas cylinders, which can withstand pressure of thousands of pounds per square inch. For clarity,
[0121] Continuing with
[0122] Whereas an enclosure-mounted manually operated potentiometer is less costly and assumes operation by an assistant, an electronic potentiometer in the remote hand control affords the operator direct control; both can be connected in series. Depressing the remote control ‘dead-man’ or plunger type trigger switch at the top of the joystick control connects the power supply through the EPOT and VCTDR to the undamped direct current powered plunger solenoid, energizing the solenoid coil. This causes the solenoid plunger (slug, armature) to strike or punch the spring-loaded valve inlet pin forcing open the valve within the valve body for the interval set by the VCTDR.
[0123] Use of the plunger switch trigger requires release of the safety by retracting a pin intromitted into the side of the control button or key which is placed at one end of a spring-loaded lever retracted by pressing the opposite end with the ball of the index finger. The gas thus admitted to the rear of the mini ball implant in the receiver propels the implant as a projectile through the barrel and delivery tube at the target tissue.
[0124] Adjustment in the output of the power supply through the potentiometer varies the actuation field strength of the solenoid, varying the punching force of the solenoid plunger against the valve pin.
[0125] Increasing the force of plunger impact upon the valve pin also slightly increases pin excursion, hence, valve open-time. Valve open-time is thus determined both by the interval that the switch connects the solenoid to the power supply and by the voltage. This timing may be controlled as a structural or mechanical feature of the switch contacts or through a separate electronic time-delay relay. Absent such a solenoid actuation time mechanism, the solenoid plunger would not retract until the switch was released, which interval is too long.
[0126] The discontinuous character of the function, which involves the intermittent discharge of sudden shots, does not lend itself to servomechanical control; instead, a V voltmeter indicating EPOT output on the enclosure serves to implement human feedback. The acrylonitrile butadiene styrene (ABS) enclosure with a thermal conductivity between 0.14 and 0.21 watts per meter-Kelvin (W/mK) and 97 cubic feet per minute (cfm) fan with plastic vanes and frame prevent the undesired buildup of heat that could materially alter the gas pressure and therefore terminal ballistics. Adjusting the fan speed and thus the volume of air moved through the enclosure by means of a thermostat is another way that the temperature of the gas can be controlled to obtain variability in pressure.
[0127] Conventional means exist for preventing the temperature to exceed a set limit, and even were such to malfunction, all compressed gas cylinders incorporate a pressure relief mechanism. Thus, even using a single cylinder, and even when the cylinder contains CO.sub.2, which is not normally viewed as affording variability in pressure, numerous variables are available to control the pressure and therefore the force of impact and depth to which the shot will penetrate given tissue. Of these, the least costly embodiment shown here employs those variables that govern valve open time. In an embodiment that must afford a wide range of penetration forces for a single procedure, a regulator capable of continuously adjusting the gas pressure is used.
[0128] Whereas a regulator and the control means shown allow pressures less than that to which the cylinder is pressurized, increasing the temperature allows the cylinder pressure to be exceeded. The power controlled from the remote control hand piece is represented as controlling both the output from the power supply through the electronic potentiometer and the input power proportional time delay. That is, the same potentiometer is used to vary the input to the solenoid and the time-delay relay to continuously vary the force and interval that the valve is held open, both of which factors increase valve open-time. Separate control of the time delay does not significantly extend control variability.
[0129] Whether manually adjusted in a simpler model or electronically in one more costly, a regulator is usually controlled separately. In such an embodiment, the regulator is in effect the gross adjustment, whereas the controls shown here serve for fine adjustment. To avert disruption due to malfunction, more than one such relatively simple apparatus, each adjusted to the same settings, should be present. If more than two are available, differently adjusting these in pairs allows treating different tissues. An interventional airgun for suitable for procedures involving the treatment of different tissues to different depths in quick succession with redundant points of control to adjust the exit velocity is described in section XIII3c and shown in FIG. 82 of the parent application.
[0130] Control of Translational Motion of the Airgun and Rotation of its Turret-Motor
[0131]
[0132] The turret-motor is incapable of significant abrasive action in its rotatory mode, so that in situations where the barrel-assembly is readily rotated by hand, this mode is not needed in the barrel-assembly as independent from the airgun. Since reciprocal transluminal action is manual as well, no joystick control as shown in
[0133] As shown in
[0134] Airgun 151 rests on and can be locked at any rotational angle coaxial to the long axis of airgun barrel 152 in compression or tightenable swing cradle bracket 149. The cradle allows adjustability in the angle of rotation in the same way as the elevation adjusting device of a spotlight, except that the spotlight has tightening knobs at both sides while swing cradle bracket 149 has only one tightening knob 154 at the rear. The front component of the airgun enclosure-divided shaft that allows long axis airgun barrel 152 coaxial rotation of airgun 151 consists of airgun barrel 152 itself, while the rear portion consists of male threaded short stud 153 with upward directed pointer, resistance or spot-welded to the back of airgun cabinet 151.
[0135] A round scale with the rotational angle marked off in degrees is affixed by means of an adhesive to the rear surface of the rear arm of swing cradle bracket 149 in surrounding relation to the stud hole. Airgun barrel 152 and stud 153 fit through airgun barrel long axis-centered holes toward the upper ends of the front and rear arms of cradle-bracket 149. Rear stud 153 having been passed through the hole in the rear arm of cradle bracket 149, a Belleville disk ring spring washer is placed over the stud, centered in the angle scale and flush against the rear side of cradle bracket 149. Rotating airgun 151 thus rotates the pointer mounted on stud 153 over the scale, indicating the angle of rotation of airgun 151. Tightening knurled knob threaded over stud 153 compresses together the arms of cradle bracket 149 against the front and back of airgun 151 enclosure, fixing the airgun in rotational angle.
[0136] When, as shown in
[0137] Turning now to
[0138] Transluminal runs consisting of translation by the linear stage, holding fast while the timing relay signals the airgun hammer direct current powered plunger solenoid to operate, then executes the following increment, are performed one at a time, direct observation and action cancellation or override by the operator taking precedence over any automatic function. The components shown in
[0139] There is, therefore, no stack or register to store successive transluminal discharge runs, and no provision for the programming of successive runs is allowed. When it is desired to induce oscillation in the translatory or transluminal axis, the linear stage is controlled in a closed loop that may be intentionally derivative gain overdriven or overly amplified. Unless made to progress at a very slow rate, continuous positional control, whether by direct analogy whereby the muzzle-head would be made to move say, one millimeter for each move at the control of a centimeter, or by continuous directional incrementing, so that the muzzle-head would continue to increment in the direction of the control until the control was retracted, are both subject to constant overshooting.
[0140] The form of control must not permit a condition such that every change in position requires to be corrected, much less several times. Wasted motion would soon fatigue, prompting sloppiness where this must not be tolerated. While the first of these forms of control is the most intuitive or consistent with spontaneous eye-hand coordination, and the second is more intuitive than control that is based upon strict adherence to a previous setting of controls to specify the number, size, and direction of the increments to be executed automatically, for interventional application, where losses in efficiency based upon essential design factors are unacceptable and impatience with constant overshooting might induce carelessness, the first of these forms of control is rejected and the second reserved for quickly positioning the muzzle-head at the starting position for automatic discharge.
[0141] Once initiated, however, the system requires that the number and size of the increments to comprise each movement be entered first and the joystick or cyclic used to indicate the direction of movement, the latter being singular in any one such discharge-run or compound action. The apparatus then automatically switches between the movers (turret-motor and linear stage) and the airgun direct current powered plunger solenoid used to strike the valve body pin, stopping long enough between increments to allow the implants to travel to the trajectory termini. Shifting the joystick forward moves the linear stage stepper motor distad, backward proximad, tilting to the right or rotating clockwise moves the turret-motor clockwise, and tilting to the left or rotating counterclockwise moves the turret-motor counterclockwise.
[0142] The joystick has a central null position through which changes from forward (distad) to backward (proximad) direction of the airgun mounting linear positioning table must pass, so that reversal cannot be immediate. Similarly, rotation of the turret-motor cannot be reversed immediately, because a null region separates clockwise from counterclockwise contact, and since forward-backward excursion passes through the rotatory null region, simultaneous actuation of the turret-motor and linear stage is impossible. Actuating the automatic discharge (autodischarge) rocker switch shown in FIG. 85 causes the time delay relay shown in FIG. 84 to alternately switch between either the linear stage stepper or turret-motor as mover to the airgun solenoid that when energized strikes the valve-body pin releasing CO.sub.2 into the airgun chamber causing the implants to be ejected.
[0143] The airgun is mounted on a linear positioning table that by moving the airgun bodily, transluminally advances or retracts (withdraws) the muzzle-head. The linear positioning table can be used to a. Accurately reposition the muzzle-head once the barrel-assembly has been inserted into the airgun barrel, which involves only control over the linear stage and turret-motor as movers, b. Reposition the muzzle-head and then effect discharge semiautomatically, the operator manually triggering each discharge, which alternates between positional control and discharge, or c. Direct automatic repositioning and discharge, in which compound action the muzzle-head is manually directed to reposition by uniform distances (increments, stretches) stop at each conjunction by a fixed time that is long enough for the airgun to discharge with the longest barrel-assembly, and then discharge automatically at each stop, which requires the automatic and coordinated control of the movers and the airgun.
[0144] Turning now to the airgun control panel shown in FIG. 85 of the parent application, once angioplasty has been completed, the barrel-assembly is inserted into the airgun. The power supply is activated by pressing the ON-OFF toggle switch to the ‘ON’ button. To bring the muzzle-head to the starting position for discharge, the joystick is held in the direction required until the linear stage and the turret-motor have incremented toward and positioned it thus. Semiautomatic discharge is appropriate for isolated discharge, but implantation for stenting demands a proximity and accuracy of adjacent placement that only machine controlled automatic discharge allows to be attained.
[0145] Once the starting position has been reached, the airgun can be a. Discharged manually or semiautomatically by releasing the safety on the dead-man trigger switch and depressing the trigger, or b. Semiautomatic discharge initiated by using the upper dial to set the number of increments and the lower dial to set the length in millimeters of each increment. To measure and render observable the extent of linear travel of the linear positioning table, horizontal joint between the base and moving platform of the linear positioning table 150 is calibrated in millimeters. A failure to discharge will be evidement and thus can be distinguished externally, as discussed in the section of the parent application entitled Modes of Failure.
[0146] Less desirably, the airgun discharge components proper—CO.sub.2 or compressed air cylinder, valve body, chamber, and barrel—can be separately mounted within the airgun cabinet for rotation on a U-bracket mounted on a linear positioning table, which then contained within the cabinet at the bottom, even when made of transparent polycarbonate plastic with a hinged or removable top that may be left open to allow access to allow adjustment to the valve body slide as described below, is then more likely to obscured from view by reflection.
[0147] Such an arrangement thus reduces the observable action of the linear positioning table shown in
[0148] The run-ahead downstream embolic or trap-filter, part number 173 in