Abstract:
The present invention relates to devices for dermatology and more particularly to fluid enhanced skin treatment system for skin rejuvenation that can optionally use an abrasive probe for removing epidermal layers while contemporaneously providing for the infusion of therapeutic fluids into the skin.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
       [0001]    This application claims benefit of priority to U.S. Provisional Application No. 62/209,641 filed Aug. 25, 2015, the contents of which is herein incorporated by reference in its entirety. 
     
    
     FIELD OF THE INVENTION 
       [0002]    The present invention relates to devices for dermatology and more particularly to fluid enhanced skin treatment system for skin rejuvenation that can optionally use an abrasive probe for removing epidermal layers while contemporaneously providing for the infusion of therapeutic fluids into the skin. 
       BACKGROUND OF THE INVENTION 
       [0003]    Dermatologists and plastic surgeons have used various methods for removing superficial skin layers to cause the growth of new skin layers (i.e., commonly described as skin resurfacing techniques) since the early 1900&#39;s. Early skin resurfacing treatments used an acid such as phenol to etch away surface layers of a patient&#39;s skin that contained damage to thereafter be replaced by new skin. The term damage when referring to a skin disorder is herein defined as any cutaneous defect, e.g., including but not limited to rhytides, hyperpigmentation, acne scars, solar elastosis, other dyschromias, stria distensae, seborrheic dermatitus. 
         [0004]    Following the removal of surface skin layers at a particular depth, no matter the method of skin removal, the body&#39;s natural wound-healing response begins to regenerate the epidermis and underlying wounded skin layers. The new skin layer will then cytologically and architecturally resemble a younger and more normal skin. The range of resurfacing treatments can be divided generally into three categories based on the depth of the skin removal and wound: (i) superficial exfoliations or peels extending into the epidermis, (ii) medium-depth resurfacing treatments extending into the papillary dermis, and (iii) deep resurfacing treatments that remove tissue to the depth of the reticular dermis. 
         [0005]    Modern techniques for skin layer removal include: CO 2  laser resurfacing which fails into the category of a deep resurfacing treatment; Erbium laser resurfacing which generally is considered a medium-depth treatment; mechanical dermabrasion using high-speed abrasive wheels which results in a medium-depth or deep resurfacing treatment; and chemical peels which may range from a superficial to a deep resurfacing treatment, depending on the treatment parameters. A recent treatment, generally called micro-dermabrasion, has been developed that uses an air-pressure source to deliver abrasive particles directly against a patient&#39;s skin at high-velocities to abrade away skin layers. Such a micro-dermabrasion modality may be likened to sandblasting albeit at velocities that do no cause excess pain and discomfort to the patient. Micro-dermabrasion as currently practiced falls into the category of a superficial resurfacing treatment. 
         [0006]    A superficial exfoliation, peel or abrasion removes some or all of the epidermis may be suited for treating very light rhytides. Such a superficial exfoliation is not effective in treating many forms of damage to skin. A medium-depth resurfacing treatment that extends into the papillary dermis can treat many types of damage to skin. Deep resurfacing treatments, such as CO 2  laser treatments, that extend well into the reticular dermis causes the most significant growth of new skin layers but carry the risk of scarring unless carefully controlled. 
         [0007]    It is useful to briefly explain the body&#39;s mechanism of actually resurfacing skin in response to the removal of a significant depth of dermal layers. Each of the above-listed depths of treatment disrupts the epidermal barrier, or a deeper dermal barrier (papillary or reticular), which initiates varied levels of the body&#39;s wound-healing response. A superficial skin layer removal typically causes a limited wound-healing response, including a transient inflammatory response and limited collagen synthesis within the dermis. In a medium-depth or a deep treatment, the initial inflammatory stage leads to hemostasis through an activated coagulation cascade. Chemotactic factors and fibrin lysis products cause neutrophils and monocytes to appear at the site of the wound. The neutrophils sterilize the wound site and the monocytes convert to macrophages and elaborate growth factors which initiate the next phase of the body&#39;s wound-healing response involving granular tissue formation. In this phase, fibroblasts generate a new extracellular matrix, particularly in the papillary and reticuilar dermis, which is sustained by angiogenesis and protected anteriorly by the reforming epithelial layer. The new extracellular matrix is largely composed of collagen fibers (particularly Types I and III) which are laid down in compact parallel arrays. It is largely the collagen fibers that provide the structural integrity of the new skin—and contribute to the appearance of youthful skin. 
         [0008]    All of the prevalent types of skin damage (rhytides, solar elastosis effects, hyperpigmentation, acne scars, dyschromias, melasma, stria distensae) manifest common histologic and ultrastructural characteristics, which in particular include disorganized and thinner collagen aggregates, abnormalities in elastic fibers, and abnormal fibroblasts, melanocytes and keratinocytes that disrupt the normal architecture of the dermal layers. It is well recognized that there will be a clinical improvement in the condition and appearance of a patient&#39;s skin when a more normal architecture is regenerated by the body&#39;s wound-healing response. Of most significance to a clinical improvement is skin is the creation of more dense parallel collagen aggregates with decreased periodicity (spacing between fibrils). The body&#39;s wound-healing response is responsible for synthesis of these collagen aggregates. In addition to the body&#39;s natural wound healing response, adjunct pharmaceutical treatments that are administered concurrent with, or following, a skin exfoliations can enhance the development of collagen aggregates to provide a more normal dermal architecture in the skin—the result being a more youthful appearing skin. 
         [0009]    The deeper skin resurfacing treatments, such as laser ablation, chemical peels and mechanical dermabrasion have drawbacks. The treatments are best used for treatments of a patient&#39;s face and may not be suited for treating other portions of a patient&#39;s body. For example, laser resurfacing of a patient&#39;s neck or decolletage may result in post-treatment pigmentation disorders. All the deep resurfacing treatments are expensive, require anesthetics, and must be performed in a clinical setting. Perhaps, the most significant disadvantage to deep resurfacing treatments relates to the post-treatment recovery period. It may require up to several weeks or even months to fully recover and to allow the skin the form a new epidermal layer. During a period ranging from a few weeks to several weeks after a deep resurfacing treatment, the patient typically must wear heavy make-up to cover redness thus making the treatment acceptable only to women. 
         [0010]    Conventional dry microdermabrasion uses a hand held device to jet dry abrasive particles against the skin to remove cells from the epidermis to provide a younger and healthier looking appearance, remove wrinkles and improve skin tone. The superficial treatment offered by dry microdermabrasion has the advantages of being performed without anesthetics and requiring no extended post-treatment recovery period. However, such dry microdermabrasion systems do not treat deep wrinkles and dehydrates the patient&#39;s skin. 
       SUMMARY OF THE INVENTION 
       [0011]    The fluid skin treatment systems and methods corresponding to the invention relate in general to the field of skin care, and the systems may be used by an individual to treat his or her own skin or can be used by a practitioner to treat a patients skin. The systems may be used to perform dermabrasion, skin rejuvenation, cleansing and the infusion of treatment fluids into the skin. 
         [0012]    In one variation, the system provides new modalities of fluid enhanced dermabrasion which improve upon the devices and methods disclosed by the author in U.S. Pat. Nos. 6,644,591; 7,678,120; 7,789,886, 8,066,716 and 8,337,513, all of which are incorporated herein by this reference. A fluid enhanced microdermabrasion system includes a probe with an abrasive skin-contact surface, a negative pressure source and a treatment fluid source both in communication with the skin-contact surface. The operator translates the abrasive skin-contact surface over the patient&#39;s skin to remove an epidermal layer, and the negative pressure source suctions the skin-contact surface against the skin while at the same time drawing the treatment fluid from a source to the abraded skin surface. A combination of surface features of the skin-contact surface and the negative pressure allows the treatment fluid to penetrate surface skin layers. Such a fluid-assisted microdermabrasion treatment can remove visible lines and allow for improved absorption of topical skin treatment products. 
         [0013]    A variation of a microdermabrasion system for treating a tissue includes a device body having an applicator end, the applicator end comprising a tissue contact surface being recessed within the applicator end; at least one fluid opening configured to deliver a fluid from the fluid source to the skin contact surface; at least one negative pressure opening configured to apply the negative pressure source therethrough to draw the tissue against the tissue contact surface, wherein, when the tissue is positioned against the applicator end, the negative pressure source pulls the fluid from the at least one fluid opening; and at least one vibratory element positioned in the device body, where actuation of the vibratory element causes a vibratory motion of the applicator end. The tissue contact surface can comprises an abrasive surface. Alternatively or in combination, the tissue contact surface comprises a plurality of annular ridges and a plurality of recesses. 
         [0014]    In one variation, the at least one vibratory element comprises at least one vibratory element that produces vibration in a single direction relative to the device body. For example, the at least one vibratory element produces vibration the single direction that is perpendicular to an axis of the applicator end or where the at least one vibratory element produces vibration the single direction that is parallel to an axis of the applicator end. 
         [0015]    Variations of the system can include at least a second vibratory element that produces vibration in a direction perpendicular to the single direction of the at least one vibratory element. 
         [0016]    In another example, a microdermabrasion system can include a device body having an applicator end, the applicator end comprising a tissue contact surface comprising an abrasive finish and being recessed within the applicator end; at least one fluid opening configured to deliver a fluid from the fluid source to the tissue contact surface; at least one negative pressure opening configured to apply the negative pressure source therethrough to draw the tissue against the tissue-contact surface, wherein when the tissue is positioned against the applicator end, the negative pressure source pulls the fluid from the at least one fluid opening; and at least one vibratory element positioned in the device body, where actuation of the vibratory element configured to vibrate in a single axis, where the vibratory element causes a vibratory motion of the applicator end. 
         [0017]    The present disclosure also includes methods for treating skin and/or tissue. For example, such a method can include advancing a device body having an applicator end against tissue, the applicator end comprises a recessed tissue contact surface; drawing suction through at least one negative pressure opening located in the recessed tissue contact surface which pulls the skin within the applicator end; and producing a first vibratory motion within the device body, where the first vibratory motion is limited to a first directional axis and where the first vibratory motion causes an abrasion on the skin resulting from the skin contacting the recessed tissue contact surface. 
         [0018]    In one variation, drawing suction pulls a fluid through at least one fluid. 
         [0019]    In another example, the method further comprises producing a second vibratory motion, where the second vibratory motion is limited to a second directional axis that is different than the first directional axis. The second directional axis can be perpendicular to the first directional axis. The first directional axis is parallel to a central axis of the applicator end (where the central axis extends perpendicularly to the surface of the tissue). 
         [0020]    There remains a need for a skin treatment system that can effectively rejuvenate a patient&#39;s skin, that can optionally use abrasives for removing epidermal layers and that provides an effective means for the infusion of therapeutic fluids into the skin. Further, there is a need for a system that allows for use by aestheticians in an office setting and for use at home by the patient. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0021]      FIG. 1  is a perspective view of an embodiment of the treatment device in use being held by a human hand in relation to a patient&#39;s skin. 
           [0022]      FIG. 2  is a perspective view of a working end of a device similar to that of  FIG. 1  showing the location and orientation of linear actuators, fluid inflow ports and a central suction passageway in the working end. 
           [0023]      FIG. 3  is a sectional view of a working end similar to that of  FIG. 2  showing the orientation of linear actuators, fluid inflow ports and a central suction passageway. 
           [0024]      FIG. 4A  is an illustration of a vibration device comprising an eccentric rotating mass (ERM) motor. 
           [0025]      FIG. 4B  is an illustration of a vibration device comprising a linear resonant actuator (LRA). 
           [0026]      FIG. 5A  is a front elevation view of the working end of  FIG. 2  again showing the location and orientation of linear actuators, fluid inflow ports and a central suction passageway in the working end. 
           [0027]      FIG. 5B  is a front elevation view of another variation of a working end similar to that of  FIG. 5A  showing the location and orientation of linear actuators, fluid inflow ports and a central suction passageway. 
           [0028]      FIG. 5C  is a front elevation view of another variation of a working end showing the location and orientation of linear actuators, fluid inflow ports and a central suction passageway. 
           [0029]      FIG. 6A  is a perspective view of another variation of working end with the linear actuators configured to impart vibrational mechanical energy longitudinally relative to the longitudinal axis of the device shaft. 
           [0030]      FIG. 6B  is a perspective view of another embodiment of the skin treatment device and linear actuators in use being held by a human hand in relation to a patient&#39;s skin. 
           [0031]      FIG. 7A  is a sectional view of an initial step of using the working end of  FIG. 6A  to treat a patient&#39;s skin. 
           [0032]      FIG. 7B  is a sectional view similar to  FIG. 7A  showing subsequent step of actuating the negative pressure source, the fluid source and the linear actuators to treat the patient&#39;s skin. 
           [0033]      FIG. 8  is a sectional view of another variation of working end with multiple linear actuators configured to selectively impart vibrational energy to skin in a first axis and/or a second axis. 
           [0034]      FIG. 9  is a sectional view of another variation of working end with a fluid trap and fluid recirculation mechanism. 
           [0035]      FIG. 10  is a perspective view of another variation of working end that includes a microfabricated microfluidic elastomer block with integrated channels for fluid flows and further configured with elastomeric actuators for treating a patient&#39;s skin. 
           [0036]      FIG. 11A  is a sectional view of the working end of  FIG. 10  in a first position showing fluid inflow channels and the suction channels with the elastomeric actuators in a repose or non-actuated position. 
           [0037]      FIG. 11B  is a sectional view as in  FIG. 11A  in a second position showing the elastomeric actuators in an actuated position. 
           [0038]      FIG. 12A  is a sectional view of a working end similar to that of  FIGS. 11A-11B  with a microfabricated elastomeric valve operated by a controller to control fluid inflows, with the valve in a normally open position. 
           [0039]      FIG. 12B  is a sectional view of the working end of  FIG. 11A  with the valve in a closed position. 
           [0040]      FIG. 13A  is a schematic view of another variation of a working end with a floating component for maximizing the delivery of vibrational forces to a patients skin. 
           [0041]      FIG. 13B  is an end view of the working end of  FIG. 13A . 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0042]      FIGS. 1 and 2  illustrate an embodiment of the invention wherein the fluid skin treatment system  50  includes a treatment device  100  comprising a hand held unit with an elongated shaft or body  105  that can be gripped by the operator&#39;s hand and a working end or applicator tip portion  110  with a skin contact surface  122  configured to engage a patient&#39;s skin  124  ( FIG. 1 ). The body  105  can have any suitable dimension along axis  111  and any shape suited for gripping with a human hand or fingers, and the surface area of the skin contact surface  122  can range from about 20 mm 2  to 100 cm 2 . Devices with smaller dimension skin contact surfaces  122  are suited for treating facial skin, and the larger skin contact surfaces  122  are adapted for treating a patient&#39;s torso, arms or legs. In one variation described below, a practitioner may use a large surface area device (see, e.g.,  FIG. 6B ) to treat a skin of a patient&#39;s arms, legs, torso or back in a form of fluid infusion into the epidermis, skin cleansing or a chemo-detoxification therapy. 
         [0043]    The components of device  100  as can be understood from  FIGS. 1-3  include a variation of the device body  105  being fabricated of a molded plastic, metal, a combination of plastic and metal or other suitable materials. The body  105  can be disposable or re-useable, or can be a combination of disposable and non-disposable components. In the illustrated variations, the working end or applicator tip portion  110  is detachable from the device body  105  and can be coupled to the body  105  by a slip fit or friction fit with or without an O-ring  128  as can be understood from  FIG. 3 . Any means of detachably coupling the applicator tip  110  to the body  105  may be suitable, such as screw thread or quick-connect type fittings. In one variation, the applicator tip  110  is a substantially rigid plastic material and can be disposable. In another variation, the tip  110  is configured with at least the skin contact surface  122  comprising a soft silicone or other rubber-like material that can flex and/or compress slightly when engaging a patient&#39;s skin as will be described below. 
         [0044]    Now referring to  FIGS. 1-3 , it can be seen that a variation of the system  50  includes a negative pressure source  140  that communicates with an aspiration channel  142  in the device  100  that terminates distally in an opening  144  in the skin contact surface  122 . In the variation of  FIG. 2 , the aspiration channel  142  terminates in opening  144  in the center of skin contact surface  122 , but it should be appreciated that the opening  141  can be singular or multiple and can be located or distributed anywhere in the skin contact surface  122 . 
         [0045]    The system  50  can further optionally includes a fluid source  145  that communicates with at least one flow channel  146  in the device body  110  which extend through the applicator tip  110  and terminate in a plurality of ports  148  in the skin contact surface  122  ( FIG. 2 ). As can be seen in  FIG. 2 , the ports  148  are distributed around an outer perimeter of the skin contact surface  122 . In this variation, the skin contact surface  122  is concave which is adapted for suctioning tissue into the concavity of the applicator tip  110 . In one variation, the skin contact surface  122  can carry abrasive elements, such as diamond particles  132  embedded into the surface  122 . One or more such tips  110  with abrasives can be used during a treatment of a patient&#39;s skin, with different size diamond particles in different tips for more aggressive and less aggressive dermabrasion. In a method of making an applicator tip  110 , such a tip can be injection molded of a rigid plastic. Thereafter, the skin contact surface  122  can be heated to be slightly melted and then impressed within a form against diamond particles  132  which then can be somewhat embedded in the skin contact surface  122  as the plastic cools and resets. In another variation method of making an applicator tip  110 , the skin contact surface  122  can be an elastomer (e.g., silicone) which can be molded into a form that carries the diamond particles will then be bonded to the surface  122 . In another method, the diamond particles can be mixed with a polymer or elastomer and following a molding process, a thin layer of the polymer or elastomer can be removed (by chemical etching, sand blasting, etc) to expose the diamond particles. In another method, the diamond particles can bonded to a molded applicator tip  110  with adhesives or bonding agents. 
         [0046]      FIG. 1  shows the fluid source  145  being remote from the handheld device  100 , but it should be appreciated that the device body  105  can be dimensioned to carry a cartridge fluid source indicated at  148  in  FIG. 1 . 
         [0047]    In  FIG. 1 , it can be seen about the plane of the skin contact surface  122  is angled about 30 to 45° from the longitudinal axis  111  of the body  105 . It should be appreciated that the plane of the skin contact surface  122  can vary from about 45° to 90° from said axis  111 . For convenience,  FIGS. 2-3  show the skin contact surface  122  as being perpendicular to the axis  111 . 
         [0048]    In the variation in  FIG. 3 , it can be seen that the skin contact surface  122  in configured with a plurality of annular ridges  149   a  and recesses  149   b  which are adapted for engaging and tensioning the patient&#39;s skin under when the device is used to abrade skin, as disclosed in the author&#39;s previous patents, for example, U.S. Pat. No. 6,641,591. The ridges may be provided with sharp edges or abrasive diamond particles  132  or other abrasive elements for abrading skin. 
         [0049]    Referring to  FIGS. 1-3 , the system  50  further includes an electrical source  150  and controller  155  for actuating a mechanism to impart vibratory forces from the skin contact surface  122  to the patient&#39;s skin. In  FIGS. 2-3 , a device  100  corresponding to the invention includes the distal portion  170  of body  105  carrying at least one linear actuator or linear resonant actuator  175  which is adapted to provide mechanical vibratory force in a particular ‘single’ direction (or vector). In  FIG. 2 , the body  105  carries two actuators  175  which are configured to produce vibratory motion as shown by arrows AA that is perpendicular to the plane of the skin contact surface  122 . The variations of  FIGS. 2 and 3  show first and second linear resonant actuators (LRAs)  175  carried within non-disposable body  105  closely adjacent to the disposable applicator tip  110  so that vibratory forces are transmitted directly to the applicator tip  110  and skin contact surface without any significant energy losses. To enhance coupling of vibratory forces between the device body  105  and the applicator tip  110 , that can be engagement features such as keys, pins, or cooperating male-female elements and the like to effectively couple motion from the LRAs  175  to the skin contact surface  122  and then to the patients skin. 
         [0050]    As background, the forces produced by vibration motors are actually vectors, with both a direction and a magnitude. In the configurations of skin treatment devices disclosed herein corresponding to the invention, the direction of vibratory motion provide by LRAs is designed to achieve certain objectives, which can be (i) to enhance abrasion with an abrasive applicator tip  110 , or (ii) to enhance fluid infusion into the patient&#39;s skin, for example, following dermabrasion. 
         [0051]    A typical type of vibration motor is an eccentric rotating mass (ERM) motor  176  as shown in  FIG. 4A . This type of vibration motor operates on a direct current and carries an offset mass or non-symmetric mass  177  attached to the motor shaft. In operation, the motor rotates the eccentric weight and the centrifugal or centripetal forces are unbalanced which causes a rapid displacement of the motor resulting in as vibration. This ERM type of motor essentially then vibrates in two directions X and Y with no direct movement in the direction of the axis Z of the motor shaft. A ‘coin’ vibration motor works on the same principle as an article ERM motor except it is flatter and compact. The author believes that such ERM vibration motors would not be particularly effective in the present application, and therefore the use of an ERM motor is not proposed herein for several variations of skin treatment devices. 
         [0052]    With the above background in mind, the invention herein can use one or more linear resonant actuators or LRA  175  as shown in  FIG. 4B  that allows for control of the vectors (direction and magnitude) of vibratory forces applied to a patient&#39;s skin. Of particular interest, the LRAs produce vibrations much differently than ERM or eccentric rotating mass motors. An LRA comprises a magnet, a spring and a voice coil that are adapted for motor displacement. The magnet is actuated by an electromagnetic field in the voice coil, and the spring enables the magnet (that has a selected mass) to oscillate back and forth around a normal rest position maintained by the spring. Thus, it can easily understood that the magnet can be restricted to move back and forth along only one axis Z in  FIG. 4B . Such an LRA is adapted to be driven by an AC drive signal. Thus, in one variation described above and shown in  FIGS. 2 and 3 , the LRA is mounted to generate vibratory motion substantially parallel to the patient&#39;s skin (and the skin contact surface  122 ) in an “abrasion mode” to move the abrasive applicator tip  110  across the surface of the skin. This form of motion parallel to the skin is advantageous compared the type of motion provided by a typical ERM motor that is not capable of generating vibratory forces in a single plane. 
         [0053]    As can be understood from  FIG. 1 , the device  100  and it applicator tip  110  are also adapted to be manually moved or translated across the patient&#39;s skin at the same time the LRAs provide vibratory motion. In one variation, the device includes directions for use wherein the practitioner is instructed to move the applicator tip  110  in directions perpendicular to the direction of vibratory motion provided LRAs  175 . Thus, the combination of manual translation and vibratory motion allows for very effective removal of epidermal layers. As an example in  FIG. 1 , the directions of vibratory motion are indicated by arrows AA, and the direction of manual translation indicated by arrows BB. 
         [0054]      FIGS. 5A-5B  illustrate end view of other variations of skin contact surfaces  122  with outlines of LRAs and the direction of vibratory forces.  FIG. 5A  is a view of an applicator tip  110  as in  FIGS. 2 and 3  and shows the direction vibratory forces AA.  FIG. 5B  shows a variation  110 ′ in the shape of the skin contact surface  122  and again shows the direction of vibratory motion provided by the LRAs with arrows BB indicating the intended direction manual translation.  FIG. 5C  shows another variation  110 ″ in which the LRA provides vibratory motion in multiple directions perpendicular to the axis of the device and there would not be a preferred direction of manual translation. Linear resident actuators of the type useful for the present invention can be obtained from Precision Microdrives Ltd. 105 Canterbury Court, 1 Brixton Road, London, SW9 6DE, United Kingdom. 
         [0055]    Referring again to  FIGS. 1-3 , it can be understood further that the controller  155  can be configured to control the electrical source  150  that drives the LRAs, while contemporaneously controlling fluid flows from the fluid source  145  and the negative pressure source  140 . In general, the variation shown in  FIGS. 2 and 4  provides LRAs that can enhance skin abrasion with an abrasive applicator tip  110 . The LRAs can provide sonic motion which may be in the range of 50 Hz to 1000 Hz for a skin abrasion mode of operation. The range of amplitude of the LRA can be from 0.005″ to 0.25″. 
         [0056]    Now turning to  FIGS. 6A and 6B , another applicator tip variation  180  is shown which uses LRAs  175  to provide a different mode of operation. In the variation shown in  FIG. 6A , two LRAs are oriented substantially parallel to the axis  111  of the device body  105 , or generally perpendicular to the skin contact surface  122 . This applicator tip  180  may or may not have abrasive elements in the skin contact surface  122 . In this variation, the LRAs  175  are adapted to operate in an “infusion mode” to infuse fluid from fluid source  145  into the patient&#39;s skin by means of vibratory forces being applied substantially perpendicular to a tensioned skin surface along with the fluid flows.  FIG. 6B  shows a handheld device  185  with a different form factor having a much larger skin contact surface  122 ′ that again has at least one LRA  175  are oriented perpendicular to the skin contact surface  122 ′. The devices of  FIGS. 6A-6B  may be used following an abrasive skin treatment wherein these devices may be dedicated for use in enhancing fluid penetration into the patient&#39;s epidermis. 
         [0057]    As can be seen in  FIGS. 6A and 7A , the applicator tip again has a central aspiration channel  142  communicating with central opening  144 . In addition, the negative pressure source  140  communicates with a peripheral annular channel  188  (or set of ports). Thus, the patient&#39;s skin can be suctioned against the skin contact surface  122  at both the periphery and the center of the working end to capture and tension the skin surface. The central aspiration opening  144  and the peripheral aspiration channel  188  can be coupled to the same negative pressure source  140  or the controller  155  can control valves in the aspiration channels to modulate suction pressure in the ports  111  and  188 . In one variation, referring to  FIG. 7A , the controller  155  operates the system so that initially suction is applied through the perimeter aspiration channel  188  to engage the skins surface as shown in  FIG. 7A . Thereafter, the controller  155  actuates the negative pressure source  140  to provide suction through the central opening  144  which results in stretching the skin into the concavity of the applicator tip  110  as shown in  FIG. 7B . The controller  155  then further can operate an optional valve to allow fluid to flow from fluid source  145  through ports  148  to interface with the skin. The fluid flows can be provided by a positive pressure pump or can be influenced by the negative pressure at the skin surface through aspiration port  144 . Finally, the controller  155  can actuate the LRAs contemporaneous with fluid flows to the skin interface, which provide mechanical force to infuse fluids into the stretched and abraded skin surface. The operator can actuate the system by a switch on the hand held device  100  or by means of a foot switch, or another suitable switching mechanism. Thus, in  FIG. 7B  can be seen by picturing motion of the LRA&#39;s assistant driving fluids perpendicularly into the epidermis. It is believed that they are between motion are useful for that influence the epidermis, for example from 500 Hz to 4000 Hz. 
         [0058]    It can be understood from the  FIGS. 2-7B  that the LRAs  175  are carried in the device very close to the distal end of body  105  to allow the transmission of forces directly to and through the applicator tip  180  to the patient&#39;s skin. The device is designed so that a disposable applicator tip  180  can be attached to body  105  so that surface  190  of the tip  180  interfaces with surface  192  of body  105  to allow effective force transmission from the LRAs through the tip (see  FIGS. 7A-7B ). 
         [0059]    In another variation shown in  FIG. 8 , a device body  205  can be configured with multiple LRAs with at least one LRA  175  oriented to provide vibratory motion parallel to the skin surface for causing abrasion in an “abrasion mode” with at least one another LRA  175  oriented to provide vibratory motion substantially perpendicular to the skin surface to enhance fluid penetration into the patient&#39;s epidermis in an “infusion mode” as described above. In one system variation, the operator can select activation of the skin-parallel LRA motion or the skin-perpendicular LRA motion. In another system variation, the controller  155  can operate each LRA in pulsed intervals ranging from 0.1 seconds or more. Further, the controller  155  can be adapted to operate “abrasion mode” LRAs in a timed sequence with the “infusion mode” LRAs. The controller  155  can have presets or can be programmable to provide various overlapping or non-overlapping abrasion and infusion modes. 
         [0060]      FIG. 9  another embodiment another variation of an applicator tip  210  that includes a fluid trap for allowing the recirculation of therapeutic fluids. The applicator tip  210  of  FIG. 9  is similar to the  FIG. 7A , with central aspiration channel  142 , peripheral aspiration channel  188  and a plurality of fluid inflow channels  148  in a concavity of the tip  210 . The tip  210  can be disposable, and includes an interior collection chamber  215 . As can be seen, the aspiration channel  142  extends partway through the collection chamber  215  and a gap  218  in the channel allows fluids in the outflows to separate from the aspirated gas flows. Thus, gravity will cause fluid droplets  220  to fall out of the aspiration pathway into chamber  215 . The fluid droplets can pass through a filter indicated at  225  and then fall to the bottom  228  of chamber  215  and then through channels  240  back in the fluid inflow channels  148 . By this means, therapeutic fluids that were not absorbed by the patient&#39;s skin may be re-introduced in to the interface with the skin for infusion therein. In one variation, shown in  FIG. 9 , the collection chamber  215  includes one-way valves  244 , such as flaps in a silicone sheet  245  wherein aspiration pressure from negative pressure source  140  closes the valves  244  to prevent fluids or gas from being suctioned through recirculation channels  240 . It can be understood that when the collected fluid reaches a certain weight in the chamber and when the operator intermittently stops operating the negative pressure source  140 , then the captured fluids will fall through the one-way valves  244  into the bottom  228  of the collection chamber  215 . In another variation, the controller  155  can intermittently turn off the negative pressure source  140  which will then allow the captured fluid volume to fall through the one-way valves  244  to the bottom  228  of the collection chamber  215 . It can be seen in  FIG. 9  that the LRAs  175  can be positioned proximate to the applicator tip  210  to provide vibratory motion as described previously. It should be appreciated that the applicator tip  210  of  FIG. 9  can have any suitable dimensions to position the LRAs  175  into close proximity to the skin contact surface  122 . 
         [0061]      FIGS. 10 and 11A-11B  illustrate another variation of fluid-assisted microdermabrasion system  400  that utilizes a handheld device as described above with body  405  and an applicator tip  410  that utilizes a fluidic actuator instead of a linear resonant actuator or LRA  175  as describe above. In general, the applicator tip variations of  FIGS. 10 and 11A-11B  again are disposable tips with a central aspiration pathway passageway  415 , a peripheral aspiration ports  420 , and the plurality of fluid outflow ports  422  in the skin contact surface  424  as described previously. In addition, the applicator tip  410  includes one or more fluid actuators  425  which comprise pneumatic or hydraulic expandable interior chambers  428  that can actuate an elastomeric surface portion  440  of the applicator tip  410  as shown in  FIGS. 11A-11B . There may be a single annular actuator or up to 20 or more actuators  425  in the skin contact surface  424 . The actuators  425  of the type shown have “high amplitude” capabilities, when compared to amplitude of linear resonant actuators or sonic/ultrasonic skin treatment devices. Further, the frequency of actuation can be adjustable over a very wide range, for example from less than 1 Hz to 50 Hz or more. 
         [0062]    Of particular interest, the applicator tip  410  comprises a microfabricated microfluidic body which can be manufactured by “soft lithography” means as is known in the art. There are several different techniques of microfabricating fluidic devices—all collectively known as soft lithography. For example, microtransfer molding is used wherein a transparent, elastomeric polydimethylsiloxane (PDMS) stamp has patterned relief on its surface to generate features in the polymer. The PDMS stamp is filled with a prepolymer or ceramic precursor and placed on a substrate. The material is cured and the stamp is removed. The technique generates features as small as 250 nm. Replica molding is a similar process wherein a PDMS stamp is cast against a conventionally patterned master. A polyurethane or other polymer is then molded against the secondary PDMS master. In this way, multiple copies can be made without damaging the original master. The technique can replicate features as small as 30 nm. Another process is known as micromolding in capillaries (MIMIC) wherein continuous channels are formed when a PDMS stamp is brought into conformal contact with a solid substrate. Then, capillary action fills the channels with a polymer precursor. The polymer is cured and the stamp is removed. MIMIC can generate features down to 1 μm in size. Solvent-assisted microcontact molding (SAMIM) is also known wherein as small amount of solvent is spread on a patterned PDMS stamp and the stamp is placed on a polymer, such as photoresist. The solvent swells the polymer and causes it to expand to fill the surface relief of the stamp. Features as small as 60 nm have been produced (see Xia and Whitesides, Annu. Rev. Mater. Sci. 1998 28:153-84). 
         [0063]    Referring to  FIG. 11A , it can be seen that the disposable soft lithography applicator tip  410  includes a base portion  442  of a rigid plastic for coupling with a device body  405 , and plurality of microfabricated elastomer layers  444   a - 444   d  that include microfluidic channels, features, and components. In this variation, there are four elastomer layers  444   a - 444   d,  but it should be appreciated that there can be from 2 to 20 or more elastomer layers. As can be seen in  FIGS. 10 and 11A , the applicator tip  410  has male flow connectors  446   a - 446   c  that couple with flow channels  448   a - 118   c  in the device body  442 . For example, male connector  446   a  connects with flow channel  148   a  in body  405  that in turn communicates with the annular channel  450  and peripheral aspiration ports  420 .  FIG. 11A  further shows flow channel  418   a  extends through the device body  405  and is operatively coupled to the negative pressure source  140 . It can be understood that annular channel  450  in the fluidic tip  410  then communicates with a plurality of peripheral aspiration ports  420 . 
         [0064]      FIGS. 11A-11B  further shows that male flow connector  446   b  couples with flow channel  448   b  in the device body and fluid source  145  to provide fluid flows to the skin contact surface  424  through outflow ports  422 . Again, the male connector  446   b  connects with an annular channel  460  that extends around the applicator tip  410  to communicate with the ports  422 . 
         [0065]    Still referring to  FIGS. 11-11B , the system  400  includes a reversible pump system or positive and negative pressure source  470  for actuating the actuators  425 . In one variation, the pump system  470  can be an electro-mechanical pressure generator, such as an AC or a DC air pump. When operating to provide a vacuum or positive pressure, the source  470  can generate between 1 and 14 psi of force, for example. The pump system  470  can be a piston pump, or other pump type coupled to controller  155  that can deliver a precise limited volume of fluid pressure to the one more actuators  425 . In  FIGS. 11A-11B , the male flow connector  446   c  couples with flow channel  448   c  in body  442  and pressure source  470  to provide gas (or liquid) flows to chambers  428  of the actuators  425 . The actuation of pressure source  470  and the actuators  425  is controlled by controller  155 , which is synchronized with activation of the negative pressure source  140  and fluid source  145 . In one variation, the operator depresses a trigger and the controller  155  activates the negative pressure source  140  to suction the patient&#39;s skin against the skin contact surface  424 . The suction forces can draw fluid through ports  422  to the skin interface, or the controller  155  can release the fluid from source  145  a selected time interval later by controlling a valve. Thereafter, the operator can depress a trigger further (or actuate another trigger) to actuate the actuators  425 . In one variation, the actuators  425  are controlled by controller  155  to operate at a predetermined frequency and amplitude. In another variation, the controller  155  can be configured to allow the operator to select from a multitude of actuator frequencies and amplitudes, for example on a touch screen of the controller  155 . 
         [0066]    In use, the system  400  of  FIGS. 10-11B  would allow the operator to strongly suction the patient&#39;s skin against the skin, contact surface  424  which will tension and stretch the engaged skin, and then the actuation of the actuators  425  will further tension and stretch the skin in the presence 
         [0067]    In another variation, the skin contact surface  424  can have abrasive elements (e.g., diamond particles, and the actuation of the actuators can cause motion in the abrasive over the patient&#39;s skin. This can be done in combination with a fluid infusion treatment. 
         [0068]      FIGS. 12A-12B  illustrate another soft lithography applicator tip  475  that is similar to the embodiment of  FIGS. 10-11B  with actuators  425 . fluid infusion channels  422  and aspiration channels  420  and  440 . The tip  475  differs in that is includes an additional features comprising at least one fluidic valve  480  in elastomer layers  440   a - 440   e  of the tip. In  FIG. 12A , it ea be seen that a male flow connector  482   a  couples with flow channel  482   b  in the device body and communicates with pressure source  470  operated by the controller  155  to and open and close an elastomeric valve  480 . In this variation, the valve  480  opens and closes fluid flow channel  485  formed in the elastomer layers  440   c - 440   d  that communicates with fluid source  145 . More in particular, the valve  480  operates by fluid (typically air) being pumped into chamber  488  by pressure source  470  which expands chamber  488  to cause elastomer wall  490  of layer  440   d  to impinge on and close flow channel  485  which communicates with annular channel  460  and the flow ports  422  in the skin contact surface  424 .  FIG. 12A  shows valve  480  in an open position and  FIG. 12A  shows valve  480  in a closed position. In can be understood that controller  155  then operate the valve  480  to control delivery of therapeutics fluids from source  145  to the skin interface in cooperation with actuation of the actuators  425  and aspiration forces. The valve  480  can be used to conserve therapeutic fluids or to only introduce fluid when needed and can be operated manually or by the controller  155 . A sensor, such as capacitance sensor  495  shown in  FIGS. 12A-12B , can be coupled to controller  155  and can sense when whether the skin interface has adequate or inadequate fluid flows for a particular skin treatment. An applicator tip similar to that of  FIGS. 12A-2B  can be configured with a plurality of valves  480  or gates to direct flows from different fluid sources can be used, and such valves and gate can allow for computer control all operational parameters in all the channels. It should be appreciate that other forms of valves, normally open valves, normally closed valves, gates, one-way valves, check valves, pressure relief valves, flow control mechanisms and the like can be fabricated in an applicator tip  475  from elastomeric materials for obvious purposes of controlling and modulating flows in hydraulic and/or pneumatic circuits, and such elements can be of types used in fluidic chip fabrications and described in U.S. Pat. Nos. 6,951,632 6,953,058; 6,802,342; 8,590,573; 8,104,514; 7,640,947; 7,392,827 and 6,829,753 which are incorporated herein by this reference. 
         [0069]      FIGS. 13A-13B  illustrate another variation in which a hand held device  505  has a working end  510  that again carries at least one LRA  515  disposed around a central aspiration channel  518 . The disposable applicator tip  520  is fabricated of an elastomer with a skin contact surface  522  having abrasive elements  525  disposed thereon. The LRAs  515  are adapted to stretch and impart motion to the skin to skin contact surface  522  parallel to the surface of the skin. In this variation, the device body  526  includes a floating body component  528  that carries the LRAs. It can be seen in  FIG. 13A  that soft resilient O-rings  532  carry the floating, vibrating body component within the device body  526 . This allows for optimal transmission of vibration forces to the skin contact surface  522  and also prevents vibration of the device body  526 . 
         [0070]    In one variation shown in  FIGS. 13A-13B , the working end carries three LRAs  515  with fluid inflow ports  535  and the fluid outflow channel  518  as described previously. In another variation, the floating body component  528  can carry first linear actuators to deliver forces for abrasion parallel to the skin and second linear actuators for to deliver forces perpendicular to the skin for fluid infusion. For example, a device can be similar to that of  FIG. 8 , with two LRAs for providing the abrasion mode, and a single LRA (e.g., a coin LRA) can be used to drive fluids into the patient&#39;s skin. In a variation, the fluid reservoir also can be carried in the handle and the user can simply squeeze a flexible fluid reservoir to provide for fluid infusion pressure. In one variation, the aspiration source can be coupled to the handle to make the entire system portable. In this variation, the only umbilical that is needed is a conduit to the negative pressure source which is configured to suction the patient&#39;s skin into the skin contact surface. 
         [0071]    In another variation, an ultrasound wave generator such as a piezoelectric crystal can be provided in the working end to deliver waves at ultrasonic speeds to the skin, for example, in the range of 1 Mhz to 6 Mhz. 
         [0072]    In another variation, the working end can include components and electrodes for delivering electrical current to the skin of a patient. In a further variation, the working end can be provided with a source of light energy, such as an LED or a flash lamp ot deliver light energy to the patient&#39;s skin, for example visible or infrared light. 
         [0073]    Another variation can include a plurality of microneedles in the skin contact surface for creating microperforations in the skin, in order to deliver fluids or electrical currents into the patient&#39;s skin. 
         [0074]    It should be appreciated that the treatment fluids can consist of water or an aqueous solution containing medications, peeling agents, serums, nourishing agents, botanicals, plumping agents, vitamins, hormones and the like known for topical use.