1. Field of Invention This invention relates to a tissue treatment system including a radio frequency (r.f.) generator and a treatment instrument connectible to the generator and to a source of ionisable gas for producing a plasma jet. The primary use of the system is skin resurfacing. The invention also relates to a method of regenerating the reticular architecture of the dermis.
A tissue-treatment system is disclosed in related U.S. Pat. No. 6,629,974, filed Feb. 13, 2002 and U.S. Pat. No. 6,723,091, filed Feb. 22, 2001. The complete disclosures of U.S. Pat. No. 6,629,974 and U.S. Pat. No. 6,723,091, including the specifications, drawings, and claims are incorporated herein by reference in their entirety.
In the system disclosed in the above patents and applications, a handheld treatment instrument has a gas conduit terminating in a plasma exit nozzle. There is an electrode associated with the conduit, and this electrode is coupled to a separate r.f. power generator which is arranged to deliver r.f. power to the electrode for creating a plasma from gas fed through the conduit. The delivered radio frequency power is typically at UHF frequencies in the region of 2.45 GHz and the instrument includes a structure resonant in that frequency region in order to provide an electric field concentration in the conduit for striking the plasma upstream of the exit nozzle, the plasma forming a jet which emerges from the nozzle and which can be used to effect local heating of a tissue surface.
It has been found that the clinical effect caused through energy delivered by the pulsed plasma instrument is, for a given instrument design and generator energy setting, dependent, firstly, on the distance of the plasma exit nozzle from the tissue to be treated; as the distance increases the plasma jet beam or plume becomes more diffuse, causing the energy and the energy per unit area to decrease, so reducing the heating effect. Secondly, the clinical effect is dependent on the angle of the direction of the plasma jet (in the known system the jet is coaxial with the longitudinal axis of the instrument) with respect to the tissue to be treated. It will be appreciated that, as the angle becomes more extreme then, for an otherwise circular distribution of energy, the distribution becomes elliptical or oval with differing concentration of energy per unit area at either end of the long axis of the oval.
It is desirable to indicate to the user the area of the tissue that will be heated to produce desirable clinical effects so that the user may accurately target areas of tissue. More accurate overlapping of adjacent treatments can be achieved, giving an overall uniform delivery of energy to the patient's tissue to be treated.
According to a first aspect of this invention, a tissue treatment system includes a treatment instrument in the form of a handpiece which is arranged to direct a beam of treatment energy from a distal end of the handpiece for treating a tissue surface spaced from the distal end, the treatment energy being produced by a treatment energy emitter, wherein the handpiece incorporates at least part of an optical target marking projector for projecting a visible target marker onto a plane at a predetermined spacing from the handpiece distal end. The invention has particular application to a tissue treatment system which operates by delivering thermal energy to a tissue surface such as human skin. Such thermal energy treatment may be performed by a treatment energy emitter in the form of a gas plasma generator, the above-mentioned handpiece having a nozzle at its distal end for directing a thermal energy beam in the form of a plasma jet outwardly from the nozzle.
Preferably, the target marking projector has a light exit aperture at the distal end of the handpiece, the exit aperture being offset from a treatment beam axis of the handpiece.
In the preferred handpiece, light for the visible target marker is projected from the distal end of the handpiece and centred on a projection axis which is inclined towards the treatment beam axis so as to intersect the latter approximately at the said predetermined spacing from the handpiece distal end.
The projected target marker preferably defines an area indicative of the tissue area which will be subjected to thermal treatment when the distal end of the handpiece is located at the predetermined spacing from a tissue surface. Thus, for instance, a circular treatment area may be indicated by a target marker in the form of a generally circular ring of projected light. Other markers can be used, such as a plurality of light dots arranged in a suitable pattern, a square, parts of a circle, and so on.
The projector typically comprises a light source and an optical fibre light guide, at least a distal portion of the light guide being housed in the handpiece and terminating in the exit aperture.
The light source itself may be formed in the shape of the required marker and may be an illuminated mask having a marker aperture of the required shape. Thus, for a ring marker, the mask may have an annular aperture or an aperture forming a part or parts of an annulus. Alternatively, the light source may be a light emitter which is, itself, in the form of an annulus.
The projector preferably includes at least one lens for concentrating light from the light source onto a proximal end of the fibre guide, light reaching the end of the fibre guide at an angle within the acceptance angle for the material of the fibre or fibres. Under such conditions, light incident at a given angle on the proximal end of the fibre is emitted from the distal end at the same angle with respect to the fibre axis. This property of optical fibres may, therefore, be used to form an image of the light source in the projection plane.
Although the projector may be battery-powered and may be contained entirely within the handpiece, the preferred embodiment has the light source in the same housing as the treatment energy power source (which may be a radio frequency generator housing) and light radiation is transmitted via an optical fibre contained within a cord connecting the handpiece to the power source housing. In the case of a gas plasma system this cord also contains a coaxial cable and a gas supply tube.
Projecting a target marker as described onto the tissue surface indicates the area on the tissue surface that will be treated. The size of the marker indicates the spacing of the handpiece from the tissue surface since, with diverging light emitted from the exit aperture, the size of the marker increases as the distance of the tissue surface from the handpiece increases. In general terms, because the size of the marker varies as the distance varies, the marker size indicates the distance.
The shape of the marker indicates the angle at which the instrument is held with respect to the target tissue surface. Thus, if the light source is circular, a circular marker image indicates that the treatment beam axis is approximately perpendicular to the target tissue surface. If the marker image is elliptical, then this is an indication of an inclined target beam axis.
According to a second aspect of the invention, a tissue treatment instrument for tissue treatment system comprises a handpiece which is arranged to direct a beam of treatment energy from a distal end thereof for treating a tissue surface spaced from the said distal end, wherein the handpiece incorporates optical means for projecting a visible target marker onto a plane spaced from the handpiece distal end.
Human skin has two principal layers: the epidermis, which is the outer layer and typically has a thickness of around 120μ in the region of the face, and the dermis which is typically 20-30 times thicker than the epidermis, and contains hair follicles, sebaceous glands, nerve endings and fine blood capillaries. By volume the dermis is made up predominantly of the protein collagen.
Ageing and exposure to ultraviolet (UV) light result in changes to the structure of the skin, these changes including a loss of elasticity, sagging, wrinkling and a pallor or yellowing of the skin consistent with reduced vascularity. The background to these effects is explained in our co-pending patent application entitled “Method of Regenerating the Reticular Architecture of the Dermis” filed on even date herewith, the disclosure of which is incorporated herein by reference.
According to a third aspect of the present invention, there is provided a cosmetic method of regenerating the reticular architecture of tissue using a handheld tissue treatment instrument as a source of thermal energy, wherein the method comprises locating the instrument over the tissue to be treated whilst illuminating the surface of the tissue with a visible target marker projected from the instrument, the position of the instrument with respect o the tissue surface being selected according to the appearance of the marker, and operating the thermal energy source whilst the instrument is in the said position.
Preferably it is the spacing of the instrument from the tissue surface which is selected according to the appearance of the marker. In addition, the angle of the instrument with respect to the tissue surface may be selected in this way.
The instrument nozzle may be used as a size reference feature, the method including comparing the marker size with the nozzle diameter to achieve optimum instrument spacing. The selected spacing of the nozzle from the tissue surface is preferably in the range of from 2 mm to 10 mm and, most normally, in the range of from 4 mm to 7 mm.
In the preferred method, the thermal energy source is operated to form first and second adjacent regions of thermally-modified tissue in the region of the DE Junction, the first region overlying the second region and being thermally modified to a greater extent than the second region.
In particular, the thermal energy source may be operated to direct thermal energy at the surface of human skin to form first and second adjacent regions of thermally-modified tissue in the region of the epidermis and dermis of the skin, the first region overlying the second region and being thermally modified to an extent that it separated from the second region some days after the delivery of thermal energy, the depth of the separation being dependent on the amount of energy delivered and the thermal capacity of the skin.
In a preferred embodiment, the thermal energy source is operated for a single pass over the skin surface, the thermal energy source being arranged to have an energy setting dependent on the desired depth of effect. Alternatively, the thermal energy source is operated over at least two passes over the skin surface, the energy levels of the passes being chosen dependent on the desired depth of effect.
In either case, the energy setting of the thermal energy source may be such as to create vacuolation on the first pass. In the latter case, the energy setting of the thermal energy source may be such as not to create vacuolation on the first pass, thereby enabling a second pass without removing the treated skin.
Preferably, the energy setting of the thermal energy source is such as to preserve the integrity of the epidermis as a biological dressing.
In a preferred embodiment, the thermal energy source is operated so that a line of cleavage occurs within the skin 2 to 5 days following treatment, the line of cleavage occurring between said first and second regions. In one particular case, the operation of the thermal energy source may be such as to form a line of cleavage from 2 to 3 cells deep in the stratum corneum of the superficial epidermis and the upper dermis.
Advantageously, the operation of the thermal energy source is such that the tissue in the first region is sloughed tissue. In this case, the sloughed tissue is removed once a new epidermis has been substantially generated in the region of the line of cleavage.
Preferably, the tissue below the line of cleavage in said second region includes the lower epidermis, the basal membrane and the DE Junction. More preferably, at least the thermally-modified basal membrane and the DE Junction are regenerated.
In one particular case, the line of cleavage forms below areas of solar elastosis, such that the solar elastosis and deranged fibroblasts are sloughed.
Preferably, the operation of the thermal energy source is such as to denature dermal collagen in the second region.
In a preferred embodiment, the tissue in said second region undergoes a regenerative process following regeneration of the epidermis.
In this case, the reticular architecture of the dermis is regenerated in whole, or in part, by fibroblasts less exposed to the effects of UV radiation.
The collagen architecture and/or elastin architecture and/or the GAGS of the dermis is regenerated in whole, or in part, by fibroblasts less exposed to the effects of UV radiation.
Preferably, the healing process is such that risk of scarring and hypo pigmentation is substantially eliminated.
Advantageously, a progressive improvement in skin changes associated with ageing and photodamage occur over a period of between 6 and 12 months following treatment.
In a preferred embodiment, the source of thermal energy is an instrument having an electrode connected to a power output device, and wherein the power output device is operated to create an electric field in the region of the electrode; a flow of gas is directed through the electric field to generate, by virtue of the interaction of the electric field with the gas, a plasma; the plasma is directed onto the tissue for a predetermined period of time; and the power transferred into the plasma from the electric field is controlled so as to desiccate at least a portion of the dermis with vapour pockets formed in dermis cells.
Preferably, the power output device is operated to deliver discrete pulses of heat of millisecond duration.
Advantageously, the pulses have a duration in the range of from about 0.5 to about 100 milliseconds, and preferably a duration in the range of from about 4.5 to about 15.4 milliseconds.
Conveniently, the power output device is operated to deliver energy in the range of from about 1 Joule to about 4 Joules for an instrument having a first predetermined nozzle diameter, and to deliver energy in the range of from less than 0.5. Joules to about 2.0 Joules for an instrument having a second predetermined diameter that is less than the first predetermined diameter.
Preferably, the first predetermined diameter is substantially 5 mm and the second predetermined diameter is substantially 1.5 mm.
The thermal energy may be delivered to the tissue from a thermal energy source as a jet of fluid having stored heat energy at the tissue surface, the jet of fluid typically comprising a jet of ionised diatomic gas.
The invention also includes a cosmetic method of regenerating the reticular architecture of the dermis using a tissue treatment system including a treatment instrument in the form of a handpiece having a gas plasma generator, wherein the method comprises locating the instrument over the tissue to be treated and projecting a visible marker from the instrument onto the tissue surface beneath the instrument and positioning the instrument to cause the marker to adopt a required configuration associated with predetermined position of the instrument with respect to the tissue surface, and operating the gas plasma generator whilst the instrument is in the predetermined position to direct a gas plasma jet onto the tissue surface.
According to another aspect of the invention, a cosmetic method of regenerating the reticular architecture of tissue using a handheld tissue treatment instrument as a source of thermal energy comprises locating the instrument over the tissue to be treated, illuminating the surface of the tissue with a visible target marker projected from the instrument, and using the marker as a positioning aid. Typically, this method includes operating the thermal energy source with the instrument located at a plurality of different positions to produce a graduated clinical effect at the periphery of a treated tissue area. The instrument positions may be selected by locating the instrument so as to produce different respective marker configurations on the tissue surface.
The gradation of effect may be produced by positioning the instrument at different spacings or at different angles with respect to the tissue surface. Thus, the gradation of effect may be produced by increasing the spacing on each successive pass of the instrument from treated to untreated areas of tissue, using the projected marker as a spacing guide or by angling the instrument at a greater angle in respect of the perpendicular at the boundaries of a treated area, the angle being selected by observing the shape of the marker. In the case of a marker which is generally circular when the instrument is perpendicular to the tissue surface, the instrument may be increasingly inclined by selecting orientations which produce a marker shape which is increasingly elliptical.
The invention will be described below by way of example with reference to the drawings in which:
FIGS. 11 to 13 show the process of reticular regeneration at the day of treatment, at four days after treatment, and at ten days after treatment respectively.
Referring to
The generator housing 12 has an instrument holder 20 for storing the instrument when not in use.
Within the cord 18 there is a coaxial cable for conveying r.f. energy from the generator 10 to the instrument 16, and a gas supply pipe for supplying nitrogen gas from a gas reservoir or source (not shown) inside the generator housing 12. The cord also contains an optical fibre line for transmitting visible light to the instrument from a light source in the generator housing. At its distal end, the cord 18 passes into the casing 22 of the handpiece body 16A
In the re-usable handpiece body 16A, the coaxial cable 18A is connected to inner and outer electrodes 26 and 27, as shown in
A resonator in the form of a helically wound tungsten coil 31 is located within the quartz tube 29, the coil being positioned such that, when the disposable nose assembly 16B is secured in position on the handpiece body 16A, the proximal end of the coil is adjacent the distal end of the inner electrode 26. The coil is wound such that it is adjacent and in intimate contact with the inner surface of the quartz tube 29.
In use of the instrument, nitrogen gas is fed by a supply pipe to the interior of the tube 29 where it reaches a location adjacent the distal end of the inner electrode 26. When an r.f. voltage is supplied via the coaxial cable to the electrodes 26 and 27, an intense r.f. electric field is created inside the tube 29 in the region of the distal end of the inner electrode. The field strength is aided by the helical coil 31 which is resonant at the operating frequency of the generator and, in this way, conversion of the nitrogen gas into a plasma is promoted, the plasma exiting as a jet at a nozzle 29A of the quartz tube 29. The plasma jet, centred on a treatment beam axis 32 (this axis being the axis of the tube 29), is directed onto tissue to be treated, the nozzle 29A typically being held a few millimetres from the surface of the tissue.
The handpiece 16 also contains an optical fibre light guide 34 which extends through the core 18 into the handpiece where its distal end portion 34A is bent inwardly towards the treatment axis defined by the quartz tube 29 to terminate at a distal end which defines an exit aperture adjacent the nozzle 29A. The inclination of the fibre guide at this point defines a projection axis for projecting a target marker onto the tissue surface, as will be described in more detail below.
Following repeated use of the instrument, the quartz tube 29 and its resonant coil 31 require replacement. The disposable nose assembly 16B containing these elements is easily attached and detached from the reusable part 16A of the instrument, the interface between the two components 16A, 16B of the instrument providing accurate location of the quartz tube 29 and the coil 31 with respect to the electrodes 26, 27.
Referring to
The magnetron 200 operates in the high UHF band, typically at 2.475 GHz, producing an output on an output line which feeds a feed transition stage 213 for converting the magnetron output to a coaxial 50 ohms feeder, low frequency AC isolation also being provided by this stage. Thereafter, a circulator 214 provides a constant 50 ohms load impedance for the output of the feed transition stage 213. Apart from a first port coupled to the transition stage 213, the circulator 214 has a second port 214A coupled to a UHF isolation stage 215 and hence to the output terminal 216 of the generator for delivering RF power to the handheld instrument 16 (
The controller 210 also applies via line 219 a control signal for opening and closing a gas supply valve 220 so that nitrogen gas is supplied from the source 221 to a gas supply outlet 222 from where it is fed through the gas supply pipe in the cord 18 to the instrument 16 (
The controller 210 is programmed to pulse the magnetron 200 so that, when the user presses a footswitch (not shown in the drawings), r.f. energy is delivered as a pulsed waveform to the UHF output 216, typically at a pulse repetition rate of between about 1 Hz and about 4 Hz. A single pulse mode is also provided. The controller 210 also operates the valve 220 so that nitrogen gas is supplied to the handheld instrument simultaneously with the supply of r.f. energy. The light source 224 can be actuated independently of r.f. energy and nitrogen gas supply. Further details of the modes of delivery of r.f. energy are set out in the above-mentioned U.S. Pat. No. 6,723,091.
The optical fibre light guide 34 and the light source 224 form part of an optical target marker projector which is shown as a whole in
The distal end portion 34A of the optical fibre guide is supported within the disposable nose section 16B by an elongate rigid fibre guide support 40, as shown in the exploded view of the handpiece appearing in
Referring to
The LED 232 is chosen to produce a blue light since this colour has the advantage of being easily seen on a range of skin colours from light to dark. Other colours may, of course, be used.
A laser diode light source may also be used.
Referring to
Multiple internal reflections, the length of the fibre, and bending of the fibre, amongst other effects, tend to spread the incident rays to some degree. The mask 224M is located in a collimated beam of light produced between the two lenses 234, 236 of the light source. Accordingly, with an annular aperture 224A, a cylindrical annulus of light is incident upon the second lens 236. The image of the annulus is transmitted through the fibre guide with a fidelity dependent on the quality of the fibre, its length, and its degree of bending. A low cost polymer fibre may be used. The best results, however, are obtained with a silica fibre, which has lower losses and distortion. Polymer fibres typically have a numerical aperture in the range of from 0.3 to 0.75, while silica fibres have a numerical aperture generally within the range 0.12 to 0.48.
The projection of the annular image 260 onto a target tissue surface will now be described with reference to
Large deviations of the treatment beam axis 32 from the preferred perpendicular orientation with respect to the tissue surface 250 are indicated by a pronounced elliptical image (as opposed to a circular or near-circular image).
By actuating the light source before treatment begins, the user can position the handpiece 16 at the required spacing from the tissue surface and can identify the area of clinical effect before the gas plasma is actuated.
Variations to the system include the following.
With appropriate modification to the mask 224M of the light source 224, a solid circle of light may be projected on the tissue surface rather than an annulus.
In the preferred embodiment, the exit aperture formed by the distal end 34D of the fibre guide 34 is radially offset with respect to the treatment beam axis, the distal end portion 34A of the fibre guide being bent to project the annulus of light such that the centre of the projected annulus is centrally positioned with respect to the centre of the zone of treatment produced by a gas plasma jet from the nozzle 29A. Alternatively, the distal face of the fibre may be processed such that it is not perpendicular to the fibre axis. In this case, the light is projected at an angle with respect to the fibre axis at its exit aperture and may, thereby, be used to modify the shape of the image and its spacing from the nozzle 29A.
In another embodiment, at least one additional fibre guide may be employed between the light source 224 and the distal end of the handpiece. For example, part of the marker image may be transmitted by one fibre guide and another part of the image by another fibre guide. In particular, half of the image may be projected by a fibre guide offset on one side of the plasma exit nozzle and the other half of the image may be projected by a fibre guide terminating on the diametrically opposite side of the nozzle, the respective projection axes intersecting at the required tissue treatment spacing from the nozzle. In this way, the image appears disjointed or mis-shapen at spacings of the instrument greater or less than the optimum spacing.
In yet a further alternative of the embodiment, the quartz tube 29 itself may be used as a light guide for projecting the marker.
It is possible to mount the projector completely within the handset, powering the light source from a battery.
Systems within the broader scope of the invention may include systems in which heating energy is delivered to the tissue from a source having a low thermal time constant. Typically, treatment energy can be delivered in pulses of very short duration (typically 0.5 to 100 ms) and without reliance on an intermediary conversion from one kind of energy to another such as a chromophore in laser energy and tissue resistivity in radio frequency energy.
In use, the instrument 16 is passed over the surface of tissue to be cosmetically treated, with the nozzle 29a typically being held a few millimetres from the surface of the tissue. The pulse duration and energy levels are chosen so as to form first and second adjacent regions of thermally-modified tissue in the region of the DE Junction. The first, upper region is termed a zone of thermal damage, having a thermal modification which is greater than that of the second, lower region. The thermally damaged zone is thermally modified to an extent that it separates from the second region some days after the delivery of the thermal energy. Following separation of the first damaged region, the epidermis and the upper region of the dermis regenerate naturally.
A benefit of using a diatomic plasma is that it is able to deliver a relatively large amount of energy which causes heating in a short period of time. This enables delivery in discreet pulses of millisecond duration, and is in contrast to heat conduction from a merely hot gas. In the preferred embodiment, energy from 1 Joule to 4 Joules is delivered in a period of 4.5 to 15.4 milliseconds respectively for a nozzle with an exit diameter of 5 millimetres, and delivers from less than 0.5 Joules up to 2 Joules in the same period for a nozzle with an exit diameter of less than 1.5 millimetres. Experiments have shown that useful clinical effects are achieved with yet longer pulses extending to 50 milliseconds, and further analysis shows extension up to 100 milliseconds or more will provide useful effects. In addition, the pulse width may be shortened to deliver the same, or otherwise similar, useful heating energy. Plasma pulses as short as 0.5 milliseconds have been produced with the system described above.
Another benefit is that oxygen is purged from the skin surface by the plasma and flow of inert gas that follows immediately following a plasma pulse. As a result, the oxidative carbonisation that often occurs at the skin surface on application of thermal energy is avoided, leaving a desiccated intact epithelium with minor structural alteration.
This minor structural alteration is nonetheless important in providing yet another benefit of the invention, as it changes the thermal characteristics of the epidermis at higher energy settings. Following a single pass of plasma over the skin surface at an energy setting greater than 2 Joules, the epidermal cells at the basal membrane are heated to a degree that produces vacuolation of the cellular contents. This produces a natural insulator limiting the absorption and depth of penetration of energy from subsequent passes. This is a beneficial safety feature that avoids the risk of excessive damage by inadvertent application of multiple passes to the same site on the skin surface.
Alternatively, when using energy pulses at or below 2 Joules, then the vacuolation is not observed, and the treated skin is still capable of absorbing the thermal energy of a second pass, by changing the energy in the second pass using either a narrow nozzle to focus the plasma or a higher energy setting will have an additive effect. The benefit of using a narrow nozzle embodiment is that the focused energy can be directed onto specific areas of the skin surface such as deeper wrinkles.
For example, if the skin is subjected to two passes of 4 Joules, then the depth of thermal effect is only 10-20% greater than with a single pass of 4 Joules. Alternatively, if the skin is first treated with 2 Joules, then with a second pass of 4 Joules then the effect will be consistent with a single pass with 6 Joules. Part of this benefit also relates to the water content of the skin, particularly the upper layers of the epidermis following pre-treatment with a topical anaesthetic.
Through experimentation with the invention, it has become clear that the depth of effect changes by up to 50% depending on the hydration of the upper layers of the epidermis following application of a topical anaesthetic. Topical anaesthetics include a hydrating component, as they rely on hydration of the superficial epidermis for the penetration of the anaesthetic agent through the skin. This changes the absorption of pure thermal energy, whereby a larger proportion of the energy is dissipated in the superficial epidermis, reducing the depth of penetration into the dermis. If no anaesthesia or tumescent subcuticular anaesthesia is employed, then the depth of dermal penetration for a given energy setting can be doubled. A pre-treatment with 2 Joules produces sufficient desiccation of the superficial epidermis, following use of topical anaesthesia, that an equivalent depth of effect can be produced with the second pass to that achieved with no anaesthesia or tumescent subcuticular anaesthesia.
The reason for using a diatomic plasma which delivers a relatively large amount of energy in a short period of time is that the irreversible clinical effects (the thermal modification and thermal damage of the tissue) occur over tissue depths that result in the desired clinical effects, whilst avoiding any undesired clinical effects. If the heating energy is delivered over too long a time, the effects of convection from the skins surface and conduction into the underlying tissue will be such that no significant temperature rise results. On the other hand, if the time is too short, then irreversible effects (such as water vaporising) at or near the skins surface will carry away otherwise useful heating energy.
As mentioned above, the use of a topical anaesthetic modifies the effect of the treatment. Thus, as shown in
Referring again to
This application claims priority of U.S. Provisional Patent Application No. 60/653,481, filed Feb. 17, 2005. This application is a Continuation-in-Part of U.S. patent application Ser. No. 10/792,765, filed Mar. 5, 2004 that is a Continuation-in-Part Application of U.S. patent application Ser. No. 09/789,500, filed Feb. 22, 2001, that in turn claims the benefit of priority of U.S. Provisional Patent Application No. 60/183,785, filed Feb. 22, 2000. The complete disclosures of U.S. Provisional Patent Application No. 60/653,481, U.S. patent application Ser. No. 10/792,765, U.S. patent application Ser. No. 09/789,500, and U.S. Provisional Patent Application No. 60/183,785, including the specifications, drawings, and claims are incorporated herein by reference in their entirety
Number | Date | Country | |
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60653481 | Feb 2005 | US | |
60183785 | Feb 2000 | US |
Number | Date | Country | |
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Parent | 10792765 | Mar 2004 | US |
Child | 11225215 | Sep 2005 | US |
Parent | 09789550 | Feb 2001 | US |
Child | 10792765 | Mar 2004 | US |