Systems and methods for fluid access control in skin graft systems

Abstract

A skin grafting system includes a handheld device, a cassette, and a device shield. The handheld device includes a device housing that forms an interior of a fixed drive system. The cassette includes a plurality of hollow microneedles that are surrounded by a peripheral housing and are configured to be operated by the drive system to extend and retract during a skin grafting procedure, pass through the peripheral housing into a subject to harvest tissue. The device shield is formed of a polymer extending from an interior opening to an exterior edge, the interior opening being sized to extend around the peripheral housing to position the exterior edge above the device housing, thereby controlling the entry of fluid from the periphery of the cassette into the interior of the device housing during a skin grafting procedure performed using the skin grafting system.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to U.S. Application No. 16 / 592,312, filed on October 3, 2019, the entire disclosure of which is incorporated herein by reference for all purposes. Technical Field

[0003] The disclosed subject matter relates generally to a skin grafting system and, more particularly, to a system that may include a device for harvesting and disseminating dermal micro-columns. Background Art

[0004] An autologous graft may refer to tissue that is transplanted from one site (e.g., a "donor site") to another site (e.g., a "recipient site") of an individual's body. For example, autologous grafts may be used to replace missing skin and other tissue and / or to accelerate healing resulting from trauma, injury, burns, surgery, and birth defects. The availability of tissue for autologous transplantation may be limited by the characteristics of the candidate donor sites, including the number and / or total area of ​​tissue grafts, the healing performance of the donor site, the similarity of the donor site and the recipient site, aesthetic considerations, etc.

[0005] Skin grafts can be performed surgically. For example, a traditional autologous transplant procedure may include: excision or surgical removal of burned tissue; selection of a donor site, which may be an area from which healthy skin is removed to serve as a covering for the cleaned burned area; and harvesting, in which the graft may be removed from the donor site (e.g., using an instrument similar to an electric razor). Such an instrument (e.g., a dermatome) may be configured to gently scrape a thin piece of tissue (e.g., about 10 / 1000 of an inch thick for a split-thickness skin graft) from the skin at an undamaged donor site for use as a skin graft. The skin graft may then be placed over the cleaned wound for healing. The removal of donor skin tissue to such a depth allows the donor site to heal on its own, a process similar to the healing process of a second-degree burn.

[0006] Traditionally, sheet grafts and mesh grafts are two types of autologous grafts that are often used for permanent wound coverage. A sheet graft may refer to a piece of skin tissue removed from an undamaged donor site of the body, a process that may be referred to as harvesting. The size of the donor skin piece used may be approximately the same as the size of the damaged area. A sheet graft may be overlaid on the excised wound and stapled or otherwise secured in place. The donor skin tissue used for a sheet graft may not stretch significantly, and a sheet graft that is slightly larger than the damaged area to be covered may be obtained because the transplanted tissue may often shrink slightly after harvesting.

[0007] Sheet grafts can provide an improved appearance to the repaired tissue area. For example, if large areas of the face, neck, and hands are damaged, sheet grafts may be used on these areas so that these more visible parts of the body do not appear as scarred after healing. Sheet grafts may be used to cover the entire burned or damaged area of ​​skin. Small areas of the sheet graft may be lost after placement because fluid accumulation (such as a hematoma) may occur under the sheet graft after placement.

[0008] Meshed skin grafts can be used to cover larger open wounds that may be difficult to cover using a sheet graft. Meshing of the skin graft can help skin tissue from the donor site expand to cover a larger area. It can also facilitate drainage of blood and fluids from underneath the skin graft when the skin graft is placed over the wound, which can help prevent loss of the graft. The expansion ratio (e.g., the ratio of unstretched graft area to stretched graft area) of a mesh graft can generally be between about 1:1 and 1:4. For example, donor skin can be meshed at a ratio of about 1:1 or 1:2, while larger expansion ratios may result in a more fragile graft, scarring as the mesh graft heals, and / or prolonged healing time.

[0009] Traditional graft meshing procedures may involve passing donor skin tissue through a machine that cuts slits through the tissue, which may facilitate expansion in a fashion similar to a fishnet or chain-link fence. Healing occurs when the spaces, also referred to as gaps or interstices, between the meshes of the stretched graft are filled with new epithelial skin growth. However, mesh grafts may be less durable grafts than sheet grafts, and large mesh grafts may result in permanent scarring after the graft has healed.

[0010] Xenograft or alloplastic graft may refer to skin taken from one of a variety of animals, such as a pig. Alloplastic skin tissue may also be used to temporarily cover excised wounds prior to placement of a more permanent autologous graft, and alloplastic skin tissue may be used due to limited availability and / or high cost of human skin tissue. Covering a wound with a xenograft or allograft is usually a temporary procedure that may be used until harvesting and placing an autologous graft is feasible.

[0011] Retrieving transplanted tissue from a donor site generally results in undesirable extensive tissue damage to the donor site. On the other hand, small skin injuries adjacent to healthy tissue are well tolerated and may heal quickly. The healing of such small wounds can be performed by techniques such as "focal photothermolysis" or "focal skin reconstruction," in which a small-sized injury pattern can be produced in the skin tissue. These exemplary techniques are described, for example, in U.S. Patent No. 6,997,923. Small-scale injury patterns can heal quickly through the regrowth of healthy tissue and can further provide desirable effects, such as tightening the skin without noticeable scars.

[0012] The mechanism of tissue transplantation provides the opportunity for the transplant tool to come into contact with clinical "soil" (e.g., blood, tissue, hair, etc.) from the patient. In split-thickness and full-thickness skin transplants (both of which harvest tissue that extends below the epidermis), localized damage to capillaries and / or blood vessels often results in bleeding. The extent of bleeding can be affected by patient factors, such as anticoagulant medications.

[0013] Therefore, it would be advantageous to have further systems and methods to protect reusable clinical tools from clinical soils without sacrificing the functionality of the skin harvesting process. Summary of the invention

[0014] In one aspect, the present disclosure provides a skin graft system having a handheld device, a cassette, and a disposable device shield. The handheld device includes a device housing that forms an interior of a fixed drive system. The cassette includes a plurality of hollow microneedles that are surrounded by a peripheral housing and configured to be operated by a drive system to extend and retract during a skin grafting process, past the peripheral housing into an object to collect tissue. The device shield is formed of a polymer extending from an interior opening to an exterior edge, the interior opening being sized to extend around the peripheral housing to position the exterior edge above the device housing, thereby preventing fluid from the periphery of the cassette from entering the interior of the device housing during a skin grafting process performed using the skin graft system.

[0015] On the other hand, the present disclosure provides a skin graft system having a handheld device, a box and a device shield. The handheld device includes a device housing having an engagement groove formed therein and forming an interior of a fixed drive system. The box is removably engaged with the handheld device through the engagement groove and includes a plurality of hollow microneedles surrounded by a peripheral shell and configured to be operated by the drive system to extend and retract during the skin grafting process, passing through the peripheral shell into the object to collect tissue. The device shield is formed by a flexible membrane extending from an internal opening to an external edge, and the size of the internal opening is designed to extend around the peripheral shell and move along it to form a barrier above the engagement groove when the external edge is arranged to extend above the device housing.

[0016] The following description and the accompanying drawings set forth in detail certain illustrative embodiments of the present disclosure. However, these embodiments illustrate only a few of the various ways in which the principles of the present disclosure may be used. Other embodiments and features will become apparent from the following detailed description of the present disclosure when considered in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The following description is provided with reference to the drawings, wherein like reference numerals refer to like elements.

[0018] Figure 1 is a top perspective view of a skin graft system including a cassette according to some embodiments of the present disclosure.

[0019] Figure 2A yes Figure 1 Front view of the system.

[0020] Figure 2B According to some embodiments of the present disclosure, Figure 2A An overhead view of the user interface in the system.

[0021] Figure 3A According to some embodiments of the present disclosure Figure 2A A cross-sectional view of a handheld device.

[0022] Figure 3B According to some embodiments of the present disclosure, Figure 2A A cross-sectional view of a housing of a handheld device.

[0023] Figure 4A According to some embodiments of the present disclosure Figure 2A A rear perspective view of the internal drive assembly and related components corresponding to the handheld device.

[0024] Figure 4B According to some embodiments of the present disclosure Figure 4A A right side perspective view of the left frame assembly corresponding to the internal assembly of the device.

[0025] Figure 4C According to some embodiments of the present disclosure Figure 4A A right perspective view of the right frame assembly corresponding to the internal components of the device.

[0026] Figure 4D According to some embodiments of the present disclosure Figure 4A A rear perspective view of a horizontal component assembly corresponding to the internal components of the device.

[0027] Figure 4E According to some embodiments of the present disclosure Figure 4A A rear perspective view of a vertical component assembly corresponding to the internal components of the device.

[0028] Figure 5A is a perspective view of a case assembly including a removable cover according to some embodiments of the present disclosure.

[0029] Figure 5B According to some embodiments of the present disclosure Figure 5A A three-dimensional diagram of a box piece corresponding to the box piece.

[0030] Fig. 6A is an example of a microneedle and pin assembly capable of harvesting tissue according to some embodiments of the present disclosure.

[0031] Figure 6B is a perspective view of a microneedle and pin assembly capable of retrieving tissue according to some embodiments of the present disclosure.

[0032] Figure 6C is a plan view of a microneedle array according to some embodiments of the present disclosure.

[0033] Figure 7 is a flowchart illustrating a method of collecting and disseminating tissue according to some embodiments of the present disclosure.

[0034] Figure 8 is a front view of a device shield applied to a cassette according to some embodiments of the present disclosure.

[0035] Fig. 9 According to some embodiments of the present disclosure, the present invention is applied to a skin transplantation system. Figure 8 A three-dimensional view of the device shield.

[0036] Fig.10 According to some embodiments of the present disclosure, the present invention is applied to a skin transplantation system. Figure 8 A cross-sectional view of the device shield. DETAILED DESCRIPTION

[0037] The following discussion is provided to enable those skilled in the art to make and use the systems and methods of the present disclosure. Various modifications to the illustrated embodiments will be apparent to those skilled in the art, and the above principles herein may be applied to other embodiments and applications without departing from the embodiments of the present disclosure. Therefore, the embodiments of the present disclosure are not intended to be limited to the illustrated embodiments, but are to be accorded the widest scope consistent with the principles and features disclosed herein.

[0038] The detailed description should be read with reference to the accompanying drawings. The accompanying drawings depict selected embodiments and are not intended to limit the scope of the embodiments of the present disclosure. Those skilled in the art will recognize that the examples provided herein have many useful alternatives and that they fall within the scope of embodiments of the present invention. Moreover, it should be understood that the wording and terminology used herein are for descriptive purposes and should not be considered as limiting. As used herein, "includes," "comprising," or "having" and variations thereof are intended to include the items listed thereafter and their equivalents as well as additional items.

[0039] Unless otherwise specified or limited, the terms "mounted," "connected," "supported," and "coupled" and variations thereof are used broadly and include direct and indirect mountings, connections, supports, and couplings. Further, "connected" and "coupled" are not limited to physical or mechanical connections or couplings. As used herein, unless expressly stated otherwise, "connected" means that one element / feature is directly or indirectly connected to another element / feature, and not necessarily electrically or mechanically. Similarly, unless expressly stated otherwise, "coupled" means that one element / feature is directly or indirectly coupled to another element / feature, and not necessarily electrically or mechanically.

[0040] Embodiments of the present disclosure may be described herein in terms of functional and / or logical block components and various processing steps. It should be understood that such block components may be implemented by any number of hardware, software, and / or firmware components configured to perform a specified function. For example, embodiments may employ various integrated circuit components, such as digital signal processing elements, logic elements, diodes, etc., which may perform various functions under the control of one or more processors or other control devices. Other embodiments may employ program code, or code in combination with other circuit components.

[0041] As described above, the present disclosure generally relates to a skin graft system, and more specifically, to a system that may include a device for collecting and spreading skin microcolumns. In some cases, the process of collecting skin microcolumns may include penetrating donor site tissue. Although usually rare, collecting microcolumns often causes local bleeding. The amount of blood at the donor site may depend on a variety of factors, such as the number of tissue punctures / penetrations, the number of collection processes performed in a single tissue area, the number of collection processes performed using a single cassette (as described below), patient blood pressure, platelet counts, medications, donor site treatments, and / or complications. In some cases, it may be advantageous to prevent blood from contacting and / or entering components of the skin graft system. Specifically, it may be advantageous to prevent blood from entering reusable elements of the skin graft system.

[0042] For example, medical institutions typically have standard cleaning, disinfection, and / or sterilization procedures that must be followed when an instrument is reusable between patients. Specifically, to minimize the risk of infection transmission, all blood and body matter should be handled as potentially infectious. For complex instruments, blood entering the instrument housing can result in procedural delays, lengthy sterilization processes, and / or instrument replacement (and associated costs), among other things. Accordingly, the present disclosure includes a system for preventing blood from entering a handheld device (e.g., a reusable handheld device) corresponding to a skin graft system.

[0043] Reference now Figure 1 , shows a skin graft system 3000 according to some embodiments of the present disclosure. In some configurations, the skin graft system 3000 can be configured to collect and spread donor tissue. As shown, the skin graft system 3000 can include a handheld device 1000 (reusable) and a box assembly 2000. As will be described in more detail below, the box assembly 2000 can include a box 2002 and a box cover 2004. According to some configurations, the box 2002 can include a microneedle and pin array 2006. Notably, the box 2002 can include a simplified microneedle array 2006 (i.e., without pins).

[0044] like Figures 1 to 2B As shown, the handheld device 1000 may include an engagement slot 1002 configured to receive the cassette assembly 2000. The loading door 1004 can be in an "open" position (see, for example, Figure 1 ) and the "off" position (see e.g. FIG. 2A to FIG. 2B) between. In some configurations, loading door 1004 can be hinged and further configured to open and close over loading aperture 1006. Handheld device 1000 can include a door sensor that can determine the position of loading door 1004. Depending on the needs of the user, loading aperture 1006 can be sized to enable cassette assembly 2000 to slide into and out of engagement slot 1002. Advantageously, cassette assembly 2000 can be single-use and / or disposable (e.g., including multiple uses on a single patient), while handheld device 1000 can be designed for multiple uses. Figure 2A As shown, the handheld device 1000 may also include a trigger 1014. The trigger 1014 may be configured to activate the collection process and / or the dispensing process in response to a selection via the user interface 1008 and / or a trigger input by a user. In some configurations, the handheld device 1000 may include an indicator light 1016. The indicator light 1016 may be positioned so that the user can easily view the indicator light 1016 during collection and / or dispensing.

[0045] In some configurations, the handheld device 1000 may include a user interface 1008. As shown, the user interface 1008 may include a ready input 1018, an indicator light 1020, and / or a spread input 1022. In some configurations, the indicator light 1020 may operate the same or similarly to the indicator light 1016 (described above). As the skin graft system 3000 is used in accordance with a skin grafting procedure such as will be described, the ready input 1018, the indicator lights 1016, 1020, and the spread input 1022 may provide visual feedback to the user corresponding to the current operation of the skin graft system 3000.

[0046] Reference now FIG. 3A to FIG. 3B , a cross-sectional view of a handheld device 1000 constructed in accordance with the present disclosure is shown. The handheld device 1000 is shown as including various internal controllers. In some configurations, the handheld device 1000 may include a power module 1028, a solenoid controller 1030, and / or a main controller 1032. The power module 1028 may be in electrical communication with a power input 1038. In some configurations, the drive system may include a solenoid in communication with the solenoid controller 1030.

[0047] Still reference FIG. 3A to FIG. 3BIn some configurations, the handheld device 1000 may include a housing 1036. The housing 1036 may include a left half housing and a right half housing. In some configurations, each of the left half housing, the right half housing, the loading door 1004, and the housing mounting cover may be injection molded separately. The left half housing and the right half housing may be composed of a hard plastic substrate, and in some configurations, may be composed of a softer elastic molded section. Similarly, the loading door 1004 and the housing mounting cover may be composed of a hard plastic substrate. In some configurations, the interior of the housing 1036 may interface with the internal components. As an example, the ribs may be attached to the interior of the housing 1036 and may be configured to support various printed circuit boards (PCBs). The ribs may be able to separate the PCBs (e.g., the power module 1028, the solenoid controller 1030, and the main controller 1032) from the internal moving parts. In addition, in some configurations, the housing 1036 may be able to support the internal subassembly 1034 via pins and vibration-damping boots. This can attenuate operational shocks to the internal subassembly 1034 (eg, from a user, from internal moving parts), and protect the internal subassembly 1034 from damage caused by external shocks (eg, from dropping the handheld device 1000).

[0048] Reference now FIG. 4A to FIG. 4E , showing various internal components corresponding to handheld device 1000 according to some configurations. Figure 4A An internal subassembly 1034 is shown, which may include a left frame assembly 1040a, a right frame assembly 1040b, a horizontal component assembly 1044, and / or a vertical component assembly 1046. Each of the left frame assembly 1040a and the right frame assembly 1040b may include a corresponding flipper assembly (e.g., a left flipper assembly 1048a, a right flipper assembly 1048b). In some configurations, the horizontal component assembly 1044 may include a horizontal motor 1050. Additionally, the vertical component assembly 1046 may include a solenoid 1052.

[0049] Still reference FIG. 4A to FIG. 4E , especially FIG. 4B to FIG. 4C, further exemplary details of the left frame assembly 1040a and the right frame assembly 1040b according to some configurations are shown. In some configurations, the left frame assembly 1040a and the right frame assembly 1040b can be identical or substantially similar (e.g., symmetrical). As shown, the left frame assembly 1040a can include a left flipper assembly 1048a attached to a first side of the left frame. In addition, the left frame assembly 1040a can include marker sensors 1060a, 1060b attached to a second side of the left frame. The marker sensors 1060a, 1060b can communicate with the position sensing linear slide 1054 and the position sensing marker 1062. In some configurations, the left frame assembly 1040a can include position sensing springs 1056a, 1056b, which can contact the tissue interface 1058a. The tissue interface 1058a can be located on a third side of the left frame. In some configurations, the left frame assembly 1040a can be attached to a portion of the vertical member assembly 1046 via screws and alignment pins or other attachment system.

[0050] In some configurations, the right frame assembly 1040b may include marker sensors 1060c, 1060d attached to a first side of the right frame. The marker sensors 1060c, 1060d may communicate with the position sensing linear slide 1054 and the position sensing marker 1062. In addition, as shown, the right frame assembly 1040b may include a right flipper assembly 1048b attached to a second side of the right frame. In some configurations, the right frame assembly 1040b may include position sensing springs 1056c, 1056d, which may contact the tissue interface 1058b. The tissue interface 1058b may be located on a third side of the right frame. In some configurations, the right frame assembly 1040b may be attached to a portion of the vertical component assembly 1046 via screws and alignment pins.

[0051] The flipper assembly 1048a, 1048b may include a flipper mounting block 1066 and a flipper motor 1068. In some constructions, the flipper mounting block 1066 may be constructed of a dielectric material. The flipper motor 1068 may be connected to (and control) a flipper drive pulley 1070a, 1070b. A bearing (e.g., a thrust bearing) 1072 may support an axial load applied to the flipper 1074 by a needle ejector plate (e.g., needle ejector plate 1112 as described below). The flipper 1074 may rotate in response to motor actuation, while the flipper drive pulleys 1070a, 1070b may prevent any downward movement of the flipper 1074 during operation of the handheld device 1000. In some constructions, the flipper 1074 may include two connected components, such as two brass components brazed together. The primary function of the flipper 1074 is to retract the spring when the needle is loaded. Figure 4EThe needle ejector plate 1112 is held in place. Subsequently, during the remainder of normal operation, the flipper 1074 is moved out of the needle ejector plate 1112. In some configurations, the flipper mounting block 1066 may be used as Figure 4E A guide for the solenoid plunger rod 1106 (eg, to maintain proper alignment).

[0052] Still reference FIG. 4A to FIG. 4E , especially Figure 4D , further exemplary details of the horizontal component assembly 1044 according to some configurations are shown. The horizontal component assembly may include sensors, actuators and / or guides for positioning the horizontal carriage assembly 1082, and thereby include hammers 1098a, 1098b for driving the microneedle into the tissue (described below). In some configurations, the horizontal mark sensor 1064 can be used to position the horizontal component assembly 1082. As shown, the horizontal component assembly 1044 may include a horizontal carriage assembly 1082, which may be configured to mount a horizontal motor 1050. In some configurations, a horizontal chassis 1084 may support the horizontal carriage assembly 1082. Additionally, the right frame assembly 1040b and the left frame assembly 1040a may be attached to opposite sides of the horizontal chassis 1084, for example, using rivets. According to some configurations, a ground connection 1080 may be attached to the horizontal chassis 1084.

[0053] In some configurations, the horizontal member assembly 1044 may further include a retractable sliding door 1090. When the cartridge 2002 has not yet been inserted into the engagement slot 1002, the sliding door 1090 may extend across the loading aperture 1006. Thus, the user may be prevented from placing anything into the handheld device 1000 without the cartridge 2002. The sliding door 1090 may be secured to a sliding door mount 1086, which may be attached to the horizontal chassis 1084. Additionally, a sliding door spring 1088 may be secured to the sliding door mount 1086 and biased such that the sliding door 1090 remains in a "closed" position (i.e., extending across the loading aperture 1006) when no cartridge is loaded.

[0054] As shown, according to some configurations, the horizontal carriage assembly 1082 may include hammers 1098a, 1098b, corresponding hammer return springs 1092a, 1092b, and corresponding hammer guides 1094a, 1094b. Typically, the horizontal carriage assembly 1082 may be configured to position and guide the hammers 1098a, 1098b to drive the microneedles into the tissue. In some configurations, the hammer guides 1094a, 1094b may be made of bronze, which helps to maintain the bearing surface during many collection and dissemination cycles. In addition, in some configurations, the hammers 1098a, 1098b may be hardened 17-4 stainless steel, which may provide excellent wear characteristics while maintaining anti-corrosion properties. Alternatively, the hammers 1098a, 1098b may be different bearing materials. The horizontal carriage assembly 1082 may also include a horizontal lead screw drive nut 1096. Additionally, the horizontal lead screw assembly 1096 can be a Teflon coated lead screw and an acetal drive nut designed to reduce friction. Alternatively, the horizontal lead screw assembly 1096 can include other material types. The horizontal lead screw assembly 1096 can provide a pitch sufficient to meet positioning resolution and linear force. The horizontal carriage assembly 1082 can additionally use motor pauses to sense whether a cassette has been loaded, or whether there is a device jam.

[0055] Still reference FIG. 4A to FIG. 4E , especially Figure 4E , further exemplary details of the vertical component assembly 1046 according to some configurations are shown. As shown, the vertical component assembly 1046 may include a solenoid 1052 and a corresponding solenoid plunger rod 1106. In addition, the vertical component assembly 1046 may include a vertical motor 1100, corresponding unlocking cams 1102a, unlocking cams 1102b, and vertical lead screws 1104a, 1104b. In some configurations, the vertical position of the vertical carrier subassembly 1108 can be controlled by moving up and down on the vertical lead screws 1104a, 1104b (e.g., using the vertical motor 1100). As will be described, the vertical positioning can move each microneedle corresponding to the box 2002. Generally, the vertical component assembly 1046 can be configured to interface with the box 2002 and its related components and manipulate them during the collection and / or dissemination of tissue. In some configurations, the vertical motor 1100 is sized to fit within the vertical member assembly 1046 while still providing the torque and speed required to manipulate the position of the microneedles.

[0056] In some configurations, the solenoid 1052 can deliver an operating force to the hammers 1098a, 1098b during retraction. As a non-limiting example, the solenoid 1052 can be activated by a half-wave alternating current. The force delivered by the solenoid 1052 increases sharply as it approaches the end of its stroke. In some configurations, the mass of the solenoid plunger rod 1106 and the solenoid plunger can be selected based on the energy required to drive the microneedle into the tissue. In some configurations, a stopper (e.g., a brass stopper) can be integrated into the solenoid 1052, which can enable extension control of the solenoid plunger rod 1106 and absorb residual kinetic energy at the end of the stroke.

[0057] In some configurations, the vertical component assembly 1046 may include a vertical carriage assembly 1108. As shown, the vertical carriage assembly 1108 may include a needle retraction slide 1110 with a top plate 1112. In some configurations, the opposite end of the vertical carriage assembly 1108 may include needle retraction slide latches 1116a, 1116b with corresponding latch plates 1122a, 1122b. The latch plates 1122a, 1122b may define the maximum position of the needle retraction slide 1110. In addition, the needle retraction spring 1120 may be integrated into the vertical carriage assembly 1108, so that effective retraction of the microneedle on the pin can be achieved. The needle retraction slide latches 1116a, 1116b can be used to lock the needle retraction slide 1110 in preparation for collection. The vertical carriage assembly 1108 can also move the needle and the pin (e.g., the pin in the microneedle) simultaneously.

[0058] In some configurations, the vertical carriage assembly 1108 may include a cartridge latch 1114 that may be configured to secure the cartridge 2002 when inserted into the loading aperture 1006. Additionally, according to some configurations, a vertical flag 1118 may be attached to the exterior of the vertical carriage assembly 1108. As shown, the needle retraction slider 1110 may also include guide rods 1124a, 1124b that may be configured to guide the needle retraction slider 1110 during vertical movement. In some configurations, the needle retraction slider 1110 may include a locking latch 1126 that may contact the guide rods 1124a, 1124b and may be configured to engage and disengage the microneedle during operation of the handheld device 1000. The needle retraction slider 1110 may be a spring-loaded subassembly that serves at least two purposes. First, the slider 1110 may lock the needle module (after being driven into tissue). Secondly, the slide 1110 can retract the needle. In some configurations, the needle retraction slide 1110 can only retract the needle, but cannot move the needle forward. In addition, in some configurations, the locking latch 1126 can only work after the skin graft system 3000 is initialized. Further details about the skin graft system 3000 are provided below.

[0059] Reference now FIG. 5A to FIG. 5B, shows a box 2002 and a box assembly 2000 according to some configurations. As shown, the box assembly 2000 may include a box 2002 and a box cover 2004, and the box cover 2004 is removably attached to a microneedle chamber 2018. The microneedle chamber 2018 can enclose a plurality of microneedles 2006. In some configurations, the microneedles 2006 can be arranged in an array within the microneedle chamber 2018. Figure 5A As shown, the combination of the cartridge cover 2004 and the microneedle chamber 2018 can form an enclosure for the microneedle 2006. The cartridge cover 2004 can include release levers 2016a, 2016b, which a user can press simultaneously to remove the cartridge cover 2004 from the cartridge 2002.

[0060] In some configurations, the cassette 2002 may include a tissue stabilizer 2014 that forms a peripheral housing and may be configured to stabilize the tissue during collection. That is, the tissue stabilizer 2014 forms a wider peripheral housing than the microneedle chamber 2018, allowing for greater distribution of force during use of the skin graft system 3000 on the tissue. As shown, the tissue stabilizer 2014 may also include outwardly extending loading tabs 2012a, 2012b. In some configurations, during loading of the cassette assembly 2000 into the loading hole 1006, the loading tabs 2012a, 2012b are in sliding contact with the engagement slot 1002.

[0061] Reference now FIG. 6A to FIG. 6C , showing a microneedle 2050 and a microneedle array 2006 of a configuration according to the present disclosure. The microneedle 2050 can assist in harvesting tissue from a donor site. In some configurations, the microneedle 2050 can include a hollow tube 2054 that can include a plurality of points 2056 at its distal end. In some non-limiting examples, needle systems such as those described in U.S. Pat. Nos. 9,060,803, 9,827,006, 9,895,162; and U.S. Patent Application Publication Nos. 2015 / 0216545, 2016 / 0015416, 2018 / 0036029, 2018 / 0140316 and / or combinations or components thereof can be used.

[0062] In some configurations of the present disclosure, the hollow tube 2054 can be provided with two points 2056, which can be at a sufficient angle to penetrate and cut biological tissue, thereby removing small micrografts from biological tissue. Such a hollow tube 2054 can be provided with two points 2056, and a "narrow heel" portion located between the two points 2056. According to some embodiments, the narrow heel portion can be sharpened to form a cutting edge corresponding to the hollow tube 2054.

[0063] In some configurations, the hollow tube 2054 can be slidably attached to the base plate 2058 so that the hollow tube 2054 can pass through a hole provided in the base plate 2058, such as Fig. 6A The position of the hollow tube 2054 relative to the base plate 2058 can be controlled by translating the hollow tube 2054 relative to the base plate 2058, for example, substantially along the longitudinal axis of the hollow tube 2054. In this way, the distance that the distal end of the hollow tube 2054 protrudes beyond the lower surface of the base plate 2058 can be controllably changed.

[0064] The microneedle 2050 may also include a pin 2052 disposed in the central lumen or opening of the hollow tube 2054. The diameter of the pin 2052 may be substantially the same as or slightly smaller than the inner diameter of the hollow tube 2054, so that the hollow tube 2054 can be translated along an axis corresponding to the pin 2052 while the pin 2052 fills or occludes most or all of the lumen of the hollow tube 2054. The pin 2052 may be formed of a low friction material or coated with a low friction material such as Teflon® or the like to facilitate movement of the hollow tube 2054 relative to the pin 2052 and / or inhibit accumulation or adhesion of biological material to the pin 2052. The distal end of the pin 2052 may be substantially flat to facilitate displacement of the tissue micrograft within the hollow tube 2054 as the hollow tube 2054 translates relative to the pin 2052.

[0065] The hollow tube 2054 can translate relative to the pin 2052, for example, substantially along the longitudinal axis of the hollow tube 2054. In this manner, the position of the distal end of the hollow tube 2054 relative to the distal end of the pin 2052 can be controllably changed. For example, the position of the distal end of the hollow tube 2054 and the distal end of the pin 2052 can both be controllably and independently selected and changed relative to the position of the lower surface of the base plate 2058.

[0066] Figure 6B One configuration of the present disclosure is shown in which the pin 2052 can be positioned relative to the hollow tube 2054 so that the distal ends of the two are substantially aligned. In another configuration, the pin 2052 can extend slightly beyond the distal end of the hollow tube 2054 so that the sharp portion of the hollow tube 2054 can be shielded from undesired contact with objects and / or users. Portions of the pin 2052 and / or the hollow tube 2054 can optionally be provided with a coating or surface treatment to reduce friction between them and / or between either component or biological tissue.

[0067] As described herein, a plurality of microneedles (eg, microneedles 2050 ) may form microneedle array 2006 . Figure 6CA top view of an exemplary microneedle array 2006 of a configuration according to the present disclosure is shown. In some configurations, the microneedle array 2006 can be substantially circular. The microneedle array 2006 can be formed by assembling multiple rows of needles (horizontal rows or vertical rows). The design can be modular, and the configuration can take any shape or size using rows of various sizes as modules. In some configurations, all microneedles can be actuated simultaneously, such as inserted into tissue. In other configurations, multiple groups or multiple sections can be actuated sequentially. For example, the microneedle array 2006 can be divided into multiple quadrants, and each quadrant can be actuated sequentially. Sequentially can refer to actuating each row in a linear order (such as row 1, row 2, row 3) or a non-linear order (such as row 1, row 10, row 3). Alternatively, each row of microneedles can be actuated sequentially separately. In addition, each single microneedle can be actuated sequentially separately. In some configurations, a row can be actuated at a time, for example, 20 rows can be actuated individually in sequence, while in other configurations, two, three, four, or more rows can be actuated at a time. An advantage of sequentially actuating segments of the microneedle array 2006 is that less force is required to insert a segment at the donor site than to insert the entire microneedle array 2006. In some configurations, a solenoid (e.g., solenoid 1052) can be used to drive the microneedle array 2006. Multiple actuations of the solenoid can be used to insert rows in sequence.

[0068] Reference now Figure 7, some non-limiting examples of the steps of a process 4000 for collecting and spreading tissue according to a configuration of the present disclosure are shown. In some configurations, as described above, the skin graft system 3000 can be used to implement the process 4000. As shown, the process 4000 includes powering a handheld device (process block 4002). In some configurations, the handheld device can be the same or similar to the handheld device 1000. The process 4000 shown also includes loading a cassette into the handheld device (process block 4004). In some configurations, the cassette can be the same or similar to the cassette 2002 or the cassette assembly 2000. Further, the process 4000 is shown as including activating a collection mode (process block 4006). According to some configurations, the activation can be initiated via the user interface 1008, as will be described below. Alternatively, the activation can be initiated via contact with a donor site. The process 4000 is shown as including applying a skin graft system (e.g., skin graft system 3000) to a donor site (process block 4008). The donor site may correspond to a healthy area of ​​tissue of the patient. Next, process 4000 is shown as including initiating a collection process (process block 4010). In some configurations, the initiation may be performed via the trigger 1014 described above. Process 4000 is shown as also including removing the skin graft system from the donor site (method block 4012). Next, process 4000 is shown as including activating a spreading mode (process block 4014). In some configurations, the activation may be performed via the user interface 1008, as described below. Process 4000 is shown as also including positioning the skin graft system above the recipient site (process block 4016). In some configurations, the recipient site may correspond to a damaged area of ​​tissue of the patient. Next, process 4000 is shown as including initiating a spreading process (process block 4018). In some configurations, the initiation may be performed via actuating the trigger 1014 described above. As shown, process 4000 may end after the spreading process (process block 4018), or may return to process block 4006 to reactivate the collection mode. In some configurations, a single cartridge (e.g., cartridge 2002) can be used multiple times on the same patient. Advantageously, if the recipient site is relatively large, a single cartridge can be used for multiple collections and dispensings. Thus, process 4000 can continue processing blocks 4006 to 4018 until the user is ready to dispose of the cartridge.

[0069] According to the configuration of the present invention, both a harvesting process and a spreading process may be performed using the skin graft system 3000. Thus, a non-limiting description of the internal functions of the handheld device 1000 and the cartridge 2002 is disclosed herein.

[0070] user interface

[0071] refer to Figure 2BAs a non-limiting example, an example of using the user interface 1008 to control the above process is provided. When power is supplied to the handheld device, the ready input 1018 may flash green when the handheld device 1000 is first powered on (e.g., approximately 8 seconds upon initial startup). This may inform the user that the handheld device 1000 is performing a startup self-test or other operation. As another non-limiting example, the ready input 1018 may produce steady green illumination when the handheld device 1000 is turned on and ready for subsequent use. In some constructions, pressing the ready input 1018 for a predetermined amount of time (e.g., 3 seconds, 5 seconds, etc.) may cause the handheld device 1000 to enter a standby mode. Continuing with this non-limiting example, the ready input 1018 may stop emitting light when the handheld device 1000 is in standby mode. Other lighting colors, patterns, and timings may be implemented according to various constructions and preferences.

[0072] As another non-limiting example, as will be described in the skin grafting process, when the handheld device 1000 is in the harvesting mode, but sufficient pressure has not yet been achieved against the donor site, the indicator light 1020 may emit a steady white light. Additionally, when the handheld device 1000 is in the harvesting mode, and sufficient pressure has been achieved against the donor site (and the trigger 1014 is disengaged), the indicator light 1020 may emit a steady green light. When the handheld device 1000 is in the harvesting process, the indicator light 1020 may emit a flashing green light. If during the harvesting process, the pressure drops below a threshold, the indicator light 1020 may emit a flashing white light. Additionally, when the handheld device 1000 experiences a fault condition, the indicator light 1020 may emit a flashing white light.

[0073] In another non-limiting example, when the collection process is complete, the scatter input 1022 may emit a steady white light. In some constructions, subsequently pressing the scatter input 1022 may cause the handheld device 1000 to enter the scatter mode. When the handheld device 1000 is in the scatter mode, the scatter input 1022 may emit a steady green light. Similar to the indicator light 1020, the scatter input 1020 may emit a flashing white light when the handheld device 1000 experiences a fault condition. In some constructions, the scatter input 1022 may emit a flashing white light during the collection process, which may indicate that a withdrawal recovery is required. Subsequently pressing the scatter input 1022 may activate the withdrawal recovery process. Once the withdrawal recovery process is complete, the scatter input 1022 may emit a steady white light. The withdrawal recovery process is described in detail below.

[0074] In some configurations, similar to indicator light 1020, indicator light 1016 can emit a continuous green light when handheld device 1000 is in the collection mode and sufficient pressure against the donor site has been reached (and trigger 1014 is disengaged). In addition, according to some configurations, indicator light 1020 can emit a flashing green light during the collection process.

[0075] Skin graft system operation position

[0076] In some configurations, multiple operating positions can be defined corresponding to skin graft system 3000. Notably, skin graft system 3000 can be operated using additional operating positions that are not expressly defined.

[0077] Some configurations of the present disclosure include a horizontal carriage home position, where the horizontal carriage assembly 1082 may be in a position to obstruct the horizontal mark sensor 1064. This position may be a "safe" position to keep the carriage away from other moving parts.

[0078] Some configurations of the present disclosure include a vertical carriage home position corresponding to the calibration position, wherein the vertical carriage assembly 1108 can be aligned with the corresponding components for loading or receiving. This position can be below the vertical mark sensor shielding point. From the user's perspective, the vertical carriage assembly 1108 appears to be closest to the engagement slot 1002 of the handheld device 1000.

[0079] Some configurations of the present disclosure include a vertical carriage unlock / disperse position corresponding to the calibration position, wherein the vertical carriage assembly 1108 unlocks the needle retraction slide 1110 by pushing the needle retraction slide latches 1116a, 1116b above their respective unlocking cams 1102a, 1102b. This can be the highest position to which the vertical carriage assembly 1108 will travel. From the user's perspective, the vertical carriage assembly 1108 appears to be standing upright inside the handheld device 1000.

[0080] Some configurations of the present disclosure include a "flipper in" position and a "flipper out" position. Each flipper 1074 may have two defined positions that the handheld device 1000 detects via a marker sensor that can provide positive feedback that each position has been reached. The "flipper in" or retracted position may correspond to when the flipper 1074 is safely away from the moving parts. The "flipper out" or extended position may correspond to when the flipper 1074 blocks the top plate 1112. The "flipper out" position may be used for initialization when the needle retraction slide 1110 (and thus the cassette 2002) is locked.

[0081] Some configurations of the present disclosure include a vertical carriage locked position corresponding to the calibration position, to which the vertical carriage assembly 1108 can be moved (with the flipper 1074 extended) to compress the needle retraction spring 1120 and lock the needle retraction slide latch 1116. This "locking" can allow the needle to be retracted later, while also locking the cartridge 2002 inside the handheld device 1000.

[0082] Some configurations of the present disclosure include a vertical carriage lock release position, which can be a position that deviates from the calibrated lock position, where the properly locked needle retraction slide top plate 1112 will no longer exert pressure on the flippers 1074, so the flippers 1074 can be safely retracted. Conversely, if the needle retraction slide top plate 1112 is not properly locked, this position can be designed to maintain sufficient pressure on the flippers 1074 so that these flippers will not retract. This position can enable the handheld device 1000 to clearly sense the correct locking of the needle retraction slide 1110.

[0083] Some configurations of the present disclosure include a vertical carrier withdrawal position, which may be a position that is offset from the calibrated unlocked position, where the needle retraction slider 1110 will not be unlocked and the extended needle may be behind the tissue stabilizer 2014. After retraction, this position is where the vertical carrier assembly 1108 may withdraw the needle (containing the tissue graft) from the tissue prior to dissemination. Advantageously, since the needle remains extended, the tissue graft may be exposed in this position.

[0084] Some configurations of the present disclosure include a collection recovery mode that can occur during the collection process. The collection recovery mode can include attempting to continue deploying the needle module into the tissue. In addition, the collection recovery mode can be automatic and completely controlled by onboard software (i.e., without user interaction). In some embodiments, the collection recovery mode can include reversing the movement of the horizontal carriage assembly 1082 for a predetermined distance or time interval. Subsequently, the horizontal carriage assembly 1082 can advance and attempt to deploy the needle module into the tissue again.

[0085] Some configurations of the present disclosure include a withdrawal recovery mode that can occur after the needle has been deployed (and the handheld device 1000 is attempting to return the horizontal carriage to its original position). In some configurations, the horizontal carriage assembly 1082 may become stuck due to increased friction from the needle module. If this occurs, the handheld device 1000 can cause the spread light (on the spread input 1022) to flash white, indicating that withdrawal recovery is required. The user can then relieve the downward force on the tissue and press the spread input 1022, which will allow the handheld device 1000 to continue withdrawing the needle from the tissue.

[0086] Vertical manipulation of skin graft components

[0087] According to some configurations, the various components corresponding to the handheld device 1000 and the cartridge 2002 may have predefined operations based on the current mode of the handheld device 1000 (eg, initialization, collection mode, dispensing mode, etc.).

[0088] In some configurations, the vertical member assembly 1046 can have a predefined "loaded" configuration that corresponds to loading the cartridge 2002 into the handheld device 1000. For example, during loading, the solenoid plunger rod 1106, each flipper 1074, and the needle retraction slide 1110 can be retracted (retracting the needle). The vertical carriage assembly 1108 can be set to a home position (as described above).

[0089] In some configurations, the vertical member assembly 1046 may have a predefined "initialization" configuration. For example, during initialization, each flipper 1074 may be extended (flipper out), the needle retraction slide 1110 may be locked, and the needle retraction spring 1120 may be loaded (needle remains retracted). The vertical carriage assembly 1108 may be set to a locked position (as described above). As each flipper 1074 is extended, the vertical carriage assembly 1108 may move upward to the locked position. The extended flipper 1074 may hold the needle retraction slide 1110 in place. When the vertical carriage assembly 1108 reaches the locked position, the needle retraction slide latch 1116 may lock the top plate 1112 in place, and the needle retraction spring 1120 is loaded. In some configurations, this does not move the needle from its retracted state.

[0090] In some configurations, the vertical member assembly 1046 can have a predefined "initialized" configuration that can correspond to a skin graft system 3000 that is ready to be collected. For example, in the initialized configuration, each flipper 1074 can be retracted (flipper in), the needle retraction slide 1110 can be locked, and the needle retraction spring 1120 is loaded. In some configurations, this does not move the needle from its retracted state. According to some configurations, the vertical carriage assembly 1108 can be moved downward back to the original position.

[0091] In some configurations, the vertical component assembly 1046 may have a predefined "collection" configuration corresponding to the user force applied. For example, in the collection configuration, the needle retraction slide 1110 may remain locked, and the needle retraction spring 1120 is loaded and the needle retracts. According to some configurations, the vertical carriage assembly 1108 may remain in the collection position. When the user positions the skin graft system 3000 at the donor site and applies a downward force, the user will perceive that the tissue stabilizer 2014 moves a small amount in the direction opposite to the applied force, causing the indicator light 1016 and the indicator light 1020 to light up, indicating to the user that there is correct collection alignment. In some configurations, the indicator light 1016 may light up green to provide visual confirmation of force to the user.

[0092] In some configurations, the vertical member assembly 1046 may have a predefined "collection" configuration corresponding to the needle deployment. For example, in this collection configuration, the solenoid plunger rod 1106 can be advanced, and the needle retraction slide 1110 can remain locked, and the needle retraction spring 1120 is loaded. Notably, the needle (e.g., the needle from the microneedle array 2006) can be deployed into the tissue. According to some configurations, the vertical carriage assembly 1108 can remain in the original position, and the user force can still be applied via the handheld device 1000. When the user pulls the trigger 1014, the skin graft assembly 3000 can begin the collection sequence. Therefore, the skin graft assembly 3000 can advance each row of needles in the microneedle array into the tissue by striking the hammer 1098a, hammer 1098b with the solenoid plunger rod 1106.

[0093] In some configurations, the vertical component assembly 1046 may have a predefined "extraction" configuration. For example, in this extraction configuration, the solenoid plunger rod 1106 may be retracted, and the needle retraction slide 1110 may remain locked, and the needle retraction spring 1120 may be loaded. The needle (e.g., from the microneedle array 2006) may remain deployed in the tissue at the beginning of extraction. The vertical carriage assembly 1108 may be moved to the extraction position (as described above). In some configurations, after collection is complete, the skin graft system 3000 may extract the needle by lifting all the needles in the microneedle array 2006 at once. The needle may be lifted to the extraction position, and the user force may be removed. In some configurations, the needle may remain advanced relative to the pin (e.g., pin 2052), and when the needle is retracted, the tissue stabilizer 2014 may remain stationary.

[0094] In some configurations, the vertical component assembly 1046 can have a predefined "scattering" configuration. For example, in the scattering configuration, the needle retraction slide 1110 can be in a retracted position and the needle can be similarly retracted. In some configurations, the vertical carriage assembly 1108 can be moved from a withdrawal position. When the user activates the scattering sequence, the skin graft system 3000 can move the vertical carriage assembly 1108 from the extraction position, which can release the loaded needle retraction spring 1120 and the needle retraction slide 1110. Thus, this movement can retract the needle relative to the pin (e.g., pin 2052), thereby exposing the graft and positioning the components for the scattering sequence.

[0095] In some configurations, the vertical member assembly 1046 can have a "scatter" configuration corresponding to an advanced needle position. For example, in the scatter configuration, the solenoid plunger rod 1106 can be advanced, and the needle retraction slide 1110 can be advanced (similarly, the needle can be advanced). According to some configurations, the solenoid plunger rod 1106 can be advanced, first striking the top plate 1112, and then striking the needle module (e.g., within the microneedle array 2006). This can push the top plate 1112 in front of the needle carrier, thereby preventing damage to the carrier. Advancement of the needles, followed by rapid retraction of the needles (via the unlocked top plate 1112), can disperse the graft into the recipient site.

[0096] Power-on self-test

[0097] In some configurations, the handheld device 1000 can perform a self-test at startup (e.g., when the handheld device 1000 is first powered on). In some configurations, the self-test can be performed when the handheld device 1000 is plugged in to receive power and the ready input 1018 is pressed and released. According to some configurations, the ready input 1018 can flash green throughout the self-test. Next, the horizontal carriage assembly 1082 can move forward a very small amount, thereby clearing the horizontal mark sensor 1064. The horizontal carriage assembly 1082 can then return to the original position.

[0098] During the self-test, the vertical carriage assembly 1108 can be moved upward by a very small amount so that the vertical mark 1118 is away from the sensor. Subsequently, the vertical carriage assembly 1108 can be returned to the original position. In some configurations, the vertical carriage assembly 1108 can be moved upward to an unlocked position, and the needle retraction slide latch 1116 can be moved in the unlocked position before returning to the original position. For example, if the needle retraction slide 1110 is locked (e.g., the cassette 2002 is locked), the needle retraction slide 1110 can be released.

[0099] In some configurations, the horizontal carriage assembly 1082 can be moved to a predetermined position (e.g., approximately two-thirds of the full range), which can verify the absence of a cassette (e.g., cassette 2002). Subsequently, the horizontal carriage assembly 1082 can be returned to the original position.

[0100] During the self-test process, the flipper 1074 can extend and then retract. In addition, in some configurations, some or all lights on the handheld device 1000 can flash (e.g., indicator lights 1016, 1020, scatter input 1022, etc.). After the self-test is completed, the ready input 1018 can light up continuously green, for example, which can indicate that the self-test was successful.

[0101] Loading and initializing the cartridge

[0102] In some configurations, the skin graft system 3000 can have a predefined cartridge loading and initialization process. The user can open the loading door 1004 and then slide the cartridge assembly 2000 (i.e., including the cartridge cover 2004) into the engagement slot 1002. The cartridge latch 1114 can lock onto the cartridge 2002. The user can then remove the cartridge cover 2004 and close the loading door 1004, which can activate the internal loading door switch.

[0103] The initialization process may also include moving the horizontal carriage assembly 1082 from the home position so that it can detect the presence of the box by pausing on the first box section. Subsequently, the horizontal carriage assembly 1082 may return to the home position. In addition, the vertical carriage assembly 1108 may be moved in small amounts so that the vertical mark 1118 leaves the sensor, and then the vertical carriage assembly 1108 may return to the home position.

[0104] In some configurations, the flipper 1074 can extend above the top plate 1112. The vertical carriage assembly 1108 can be moved to a locked position. When moved to the locked position, the flipper 1074 can hold the top plate 1112 in place while the needle retraction slide latch 1116 moves out and eventually locks on the top plate 1112. Therefore, the needle retraction spring 1120 can remain in a compressed state. For example, when this happens, the locking latch 1126 can pop up under the needle segment (e.g., the needle segment within the microneedle array 2006) to prepare to lock the needle segment during the collection sequence. In some configurations, the vertical carriage assembly can be moved downward a small amount to move into the locked relaxed position (as described above). In addition, the flipper 1074 can be retracted.

[0105] The initialization process may also include returning the vertical carriage assembly 1108 to the collection position. The horizontal carriage assembly 1082 may engage the first needle segment (within the microneedle array 2006) by pausing against it and then backing off a predetermined small distance. The handheld device 1000 may then calculate the position of each needle segment. After the initialization process is complete, the indicator light 1020 may illuminate white to indicate that the handheld device 1000 is ready for the collection sequence.

[0106] Collection and extraction methods

[0107] In some configurations, the user can use the harvesting process to harvest and extract the tissue column. The user can position the handheld device 1000 at the donor site and press the tissue stabilizer 2014 against the skin. The user can use one or both hands to apply force to the skin via the handheld device 1000. The tissue stabilizer interface component can move upward, compressing the position sensing spring 1056 until the position sensing mark 1062 blocks the mark sensor. In some configurations, the indicator lights 1016, 1020 can light up green to indicate that the trigger 1014 is active.

[0108] Once the trigger 1014 is activated, the user can pull the trigger 1014 (while maintaining force on the skin) and the handheld device 1000 can begin the collection sequence. In some configurations, the indicator lights 1016, 1020 can flash green throughout the collection and withdrawal period. The position sensing flag 1062 can be monitored throughout the collection period (between solenoid activations) to ensure that sufficient force is maintained. The solenoid 1052 can quickly advance the solenoid plunger rod 1106, which can advance the two hammers 1098a, 1098b and insert the first needle module into the tissue. When the needle module is inserted, the needle module travels through the needle module locking latch. Subsequently, the solenoid 1052 and hammers 1098a, 1098b can be retracted, and the needle segment can remain locked in the tissue.

[0109] In some configurations, the horizontal carriage assembly 1082 can advance to the next calculated needle segment position. Alternatively, the next needle segment position can be recalculated or otherwise revalidated throughout the retrieval process. The solenoid 1052 can rapidly advance the solenoid plunger rod 1106, which can advance the two hammers 1098a, 1098b and insert the next needle module into the tissue. When inserting the needle module, the needle module can travel past the locking latch 1126. The locking latch 1126 can rebound, and the solenoid 1052 and hammers 1098a, 1098b can retract. The insertion process can be repeated until all needle segments are inserted into the tissue.

[0110] According to some configurations, after all segments have been inserted, the horizontal carriage assembly 1082 can be returned to its original position. The vertical carriage assembly 1108 can be moved upward to a withdrawal position, withdrawing the needle from the tissue and positioning the needle securely upright within the tissue stabilizer 2014. The indicator lights 1016, 1020 can stop flashing green and turn off. In addition, the spreading input 1022 can illuminate white, indicating that the handheld device 1000 is ready for the spreading process. After the collection process is completed, the user can remove the force on the tissue and lift off the handheld device 1000.

[0111] Spread method

[0112] In some configurations, the user can spread the tissue column after the harvesting process. Once the user removes the handheld device 1000 (with the harvested tissue column) from the donor site, the needle can be safely erected within the cassette 2002 (e.g., within the tissue stabilizer 2014). With the recipient site ready for the tissue column, the user can activate the spreading mode by pressing the spreading input 1022. In some configurations, the spreading input 1022 can change from being illuminated white to green.

[0113] In some configurations, the user can position the cassette 2002 directly over the recipient site. The user can then pull the trigger 1014 and the vertical carriage assembly 1108 can move out of the withdrawn position, which can release the needle retraction slide 1110 and pull the needle back behind the pin (e.g., pin 2052). The handheld device 1000 can rapidly advance the solenoid plunger rod 1106, thereby pushing the needle retraction slide 1110 and the needle module. The needle retraction slide 1110 can be kept pushed in front of the needle module to prevent damage to the needle module. Subsequently, the solenoid plunger rod 1106 can be retracted, which can cause the needle retraction slide 1110 to retract (pulling the needle module back with the needle retraction slide 1110). The process of rapidly advancing the solenoid plunger rod 1106 can be repeated several times, which can ensure that as much graft as possible is deposited into the recipient site. In some configurations, the solenoid 1052 may be activated six times. After the dispensing process is completed, the vertical carriage assembly 1108 can be returned to the original position and the needle retraction slide 1110 is unlocked.

[0114] Remove the box

[0115] In some configurations, once the user completes the collection and spreading process, the user can open the loading door 1004, press the cartridge latch 1114, and slide out the cartridge 2002. In some configurations, if the user wishes to complete another collection with the same cartridge 2002, the user can open and close the loading door 1004 (i.e., without removing the cartridge 2002). This can initiate another initialization process via the handheld device 1000. Alternatively, the user can initiate another initialization process via an input on the user interface 1008 (not shown).

[0116] Fluid Ingress Protection

[0117] As described above, the cartridge 2002 can be used for multiple collection and dissemination processes (for a single patient) before being removed from the handheld device 1000 and subsequently disposed of. In some cases, repeated puncture of tissue via the microneedle array 2006 may cause localized bleeding. In addition, repeated deployment and retraction of the needle module may cause blood or other fluids to be dispersed. Since the cartridge 2002 can be disposable, it may not matter if blood is dispersed to the outside of the microneedle chamber 2018, for example. However, the handheld device 1000 can be reused. Therefore, it may be advantageous to prevent blood from entering the housing 1036. For example, if blood penetrates the housing 1036, an extensive cleaning and disinfection process may be required.

[0118] The present disclosure includes systems and methods for preventing blood from entering. Specifically, the present disclosure provides a device shield that can protect the contact points between the engagement groove 1002 and the box 2002 (see, for example, Figure 1 ). In addition, the device shield of the present disclosure can be designed to protect the contact points existing between the loading door 1004 and the cassette 2002 (see, for example, Figure 1 ).

[0119] Reference now Figures 8 to 9 , shows a device shield 5000 constructed in accordance with the present disclosure. Generally, the device shield 5000 can be configured to removably protect the contact points between the case 2002 and the handheld device 1000. The device shield 5000 is formed of a liquid-impermeable material (or multiple materials) and extends from the interior opening 5002 to an outer edge 5004. At the outer edge, corner cutouts 5006 may be included. Thus, as will be described, the device shield 5000 forms a barrier to fluids surrounding or surrounding the interior opening 5002.

[0120] The opening 5002 can engage the microneedle chamber 2018. In this way, when the cartridge 2002 is engaged with the handheld device 100, the device shield 5000 extends from the opening 5002 above the handheld device 1000 to the outer edge 5004. In some configurations, a portion of the outer edge 5004 can contact the loading door 1004 (see, for example, Fig. 9 ). The loading door 1004 may optionally include a finger joint 1005 (eg Fig. 9 5004 ), which may contact a portion of the outer edge 5004. As shown, the finger engagement portion 1005 may extend beyond the device shield 5000 so that the loading door 1004 may be opened and closed even when the device shield 5000 is in place on the skin graft assembly 3000.

[0121] In some configurations, the device shield 5000 can include corner cutouts (e.g., corner cutouts 5006). As an example, the corner cutouts 5006 can be inverted and / or rounded to allow a user to easily grasp the device shield 5000 during application and removal of the device shield 5000 from the skin graft assembly 3000.

[0122] In some configurations, the device shield 5000 may extend from the outer periphery of the tissue stabilizing member 2014. The device shield 5000 prevents blood from flowing onto or into the handheld device 1000 by, for example, protecting or sealing any openings corresponding to the engagement slot 1002 in contact with the cartridge 2002 and the loading door 1004 in contact with the cartridge 2002.

[0123] According to some configurations, the device shield 5000 can be formed of a polymer that forms a barrier to fluids. Additionally, the device shield 5000 can be formed of a pliable or elastomeric material. The device shield 5000 can have a generally flat geometry. By having a generally flat geometry and being formed of a pliable or elastomeric material, the size of the device shield opening 5002 can be designed to be smaller than the outer perimeter of the microneedle chamber 2018 so that the device shield 5000 can be stretched onto the microneedle chamber 2018. The stretching of the device shield 5000 can form a seal that is designed to be impermeable to blood and other fluids that typically impinge on the device shield 5000, thereby preventing liquid from entering the handheld device 1000 along the tissue stabilizer 2014.

[0124] exist Fig. 9 In the non-limiting example shown, when the opening 5002 of the device shield 5000 is pulled down the tissue stabilizer 2014, the outer edge 5004 can be pulled and, depending on material selection and design, stretched away from the opening 5002 to extend toward the handheld device 1000. In this configuration, the device shield 5000 is no longer a default, generally flat geometry, but instead exhibits a slope or curved surface 5008 extending from the opening 5002 to the outer edge 5004.

[0125] The size of the device shield 5000 can vary, and in some embodiments, can be customized. As an example, the device shield 5000 can be cut into different shapes and sizes to customize the blockage of blood entry and the usability of the skin graft assembly 3000. According to some embodiments of the present disclosure, the device shield 5000 can be molded into a generally fixed shape and / or size. As a non-limiting example, the device shield 5000 can contact the outside of the microneedle chamber 2018 (e.g., the tissue stabilizer 2014) and can extend outward from it in other ways (e.g., at a 90-degree angle, a 45-degree angle, etc.). Therefore, the device shield 5000 can provide a non-contact barrier for the entry point on the housing 1036.

[0126] refer to Fig.10 , a vertical cross-sectional view of one non-limiting example of a device shield 5000 engaged with a tissue stabilizer 2014 and extending to a loading door 1004 and a housing 1036 is shown. In this example, the device shield 5000 has an interior opening 5002 that is sized to be slightly smaller than or match the exterior of the tissue stabilizer. In this manner, by pulling on the exterior edge 5004, the device shield 5000 extends downward onto the tissue stabilizer 2014, which stretches the device shield 5000 and, in this illustration, causes the interior surface 5010 of the device shield 5000 to form the interior opening 5002 when in the non-installed position to extend perpendicular to the interior normal position and the tissue stabilizer. That is, because the interior opening 5002 is sized to match the size of the tissue stabilizer 2014, the opening must stretch and deform to accommodate the extension on the tissue stabilizer 2014, which causes the interior surface 5010 to shift to the lateral position shown.

[0127] In some configurations, the device shield 5000 can be molded to provide a customized downward seal to the handheld device 1000 (and associated access points). As a non-limiting example, the device shield 5000 can be molded to align with the curvature of the tissue stabilizer 2014, the microneedle chamber 2018, and / or the loading door 1004. Fig.10 In the non-limiting example shown, the device shield assumes a recessed orientation that forms a tight seal with the tissue stabilizer 2014 at the interior opening 5002 and a tight seal with the housing 1036 and the loading door 1004 at the exterior edge 5004. In addition, the device shield 5000 can be designed to provide a pocket 5012 between the device shield 5000 and the engagement slot 1002. The pocket 5012 can be configured to hold an absorbent material 5014 that can further prevent blood from entering the handheld device 1000. As shown, the absorbent material 5014 can be arranged in an annular or rectangular shape that engages and surrounds the tissue stabilizer 2014 and resides in the pocket 5012 above the engagement slot 1002. Alternatively, as shown in dashed lines, the absorbent material 5014a can have any of a variety of cross-sectional geometries or thicknesses.

[0128] Although the present disclosure may be susceptible to various modifications and alternative forms, specific constructions have been shown by way of example in the drawings and described in detail herein. However, it should be understood that the present disclosure is not intended to be limited to the particular form disclosed. On the contrary, the present disclosure covers all modifications, equivalents and substitutes that fall within the spirit and scope of the present invention as defined by the following appended claims.

[0129] This written description uses examples to disclose the present disclosure, including the best mode, and also to enable those skilled in the art to practice the present disclosure, including making and using any device or system and performing any combined method. The patentable scope of the invention is defined by the claims, and may include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they have structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements that do not differ substantially from the literal language of the claims.

[0130] Finally, it is expressly contemplated that any process or step described herein may be combined, eliminated, or reordered. Therefore, this description is intended only as an example and does not otherwise limit the scope of the present disclosure.

Claims

1. A skin transplantation system, comprising: A handheld device, the handheld device comprising a device housing, the device housing forming an interior of a fixed drive system; a cartridge comprising a plurality of hollow microneedles surrounded by a peripheral housing and configured to be operated by the drive system to extend and retract during a skin grafting procedure, past the peripheral housing into a subject to harvest tissue; as well as and a device shield formed of a polymer extending from an interior opening to an exterior edge, wherein the interior opening is sized to extend around the peripheral shell to position the exterior edge above the device shell to prevent fluid ingress from fluid surrounding the peripheral shell of the cassette into the interior of the device shell during a skin grafting procedure performed using the skin grafting system.

2. The system according to claim 1, characterized in that The device shield is configured to form a barrier with the peripheral housing.

3. The system according to claim 2, characterized in that The device shield is configured to deform to extend over the peripheral shell to form the barrier with the peripheral shell.

4. The system according to claim 1, characterized in that The device housing forms an engagement slot for receiving the cartridge, wherein the device shield is configured to extend over the engagement slot to position the outer edge against the device housing to form a shield against fluid reaching the engagement slot.

5. The system according to claim 4, characterized in that The device shield forms a pocket around the engagement slot.

6. The system according to claim 5, characterized in that The system also includes an absorbent material disposed in the pocket.

7. The system according to claim 6, characterized in that The absorbent material is configured to surround the peripheral shell.

8. The system of claim 1, wherein: The device shield is formed from an elastomeric material.

9. A skin transplantation system comprising: a handheld device, the handheld device including a device housing having an engagement slot formed therein and forming an interior portion of a fixed drive system; a cartridge that is removably engaged with the handheld device through the engagement slot and includes a plurality of hollow microneedles surrounded by a peripheral housing and configured to be operated by the drive system to extend and retract during a skin grafting procedure, pass through the peripheral housing and enter a subject to harvest tissue; as well as A device shield is formed by a flexible membrane extending from an inner opening to an outer edge, wherein the inner opening is sized to extend around and move along the peripheral shell to form a barrier over the engagement slot when the outer edge is arranged to extend over the device shell.

10. The system according to claim 9, characterized in that The device shield forms a seal with the peripheral shell.

11. The system according to claim 10, characterized in that The device shield deforms to extend over the peripheral shell to form the seal with the peripheral shell.

12. The system according to claim 9, characterized in that The device shield forms a pocket around the engagement slot.

13. The system of claim 12, wherein: The system also includes an absorbent material disposed in the pocket.

14. The system of claim 13, wherein: The absorbent material is configured to surround the peripheral shell.

15. The system of claim 9, wherein: The device shield is formed from a liquid-impermeable polymer.

Images