背景技术：
[0006]There have been many developments in additive manufacturing in recent years, and three dimensional fabrication or “printing” systems have become an increasingly practical means of manufacturing organic and inorganic materials from a digital model. Three dimensional fabricators are often referred to as additive manufacturing devices or 3D Printers. Such devices have also been adapted to work as part of, or in conjunction with, traditional computer numeric control (CNC) systems and other robotic motion or robotic arm systems, which have motions systems similar to those usable in additive manufacturing, but do not always include a deposition tool. A description of some exemplary 3D fabrication systems and recent developments in the art can be found in U.S. Pat. No. 7,625,198 to Lipson et al., and the patents and publications referenced therein. Commonly used 3D Printing technologies include Stereolithography (SLA), Fused Deposition Modeling and Free Form Fabrication, Ink jetting Processes, and Selective Laser Sintering (SLS).
[0007]The manufacturing and production of customized parts has traditionally been accomplished by manual labor, using both hand tools and larger scale machines to produce customized parts or prototype parts for small-scale production runs. Recent advances in 3D Printing technology have provided a new means of creating customized parts and prototypes; however, there is a limit to the type and quantity of products that can be produced with 3D Printers given their narrow materials set and the high cost of ownership and operation. More recently, reductions in the cost of three-axis robotics systems have provided new opportunities to utilize novel additive manufacturing techniques in low cost devices, and make them accessible to previously underserved or unserved users.
[0008]Particularly in the medical field, where custom medical products are not usually available on demand, there exists a need for a 3D Printing technology to manufacture custom medical devices that will provide physicians and others the ability to prescribe a custom medical device, create it immediately, and test its efficacy on patients in real time, rather than waiting weeks for custom manufacturers to complete manual processes. The term medical device as used herein is not limited to that which is prescribed by a physician or used to treat a particular ailment, but also extends to include any article which is created with respect to a biological feature, attribute, or requirement. For example, this could include orthotics/prosthetics, implantables, prescription, custom orthotic insoles, as well as specialized non-medical gear used in sporting, such as customized helmets and padding.
[0009]By way of example, orthotic is a term that can be used with regard to the design, manufacture and application of orthoses, also referred to generally as an orthotic or orthotics. (Prosthetics are closely related to orthotics and often function similarly.) Custom orthotic shoe insoles are also often referred to simply as orthotics. Generally, orthotics are externally applied devices used to modify the structural and functional characteristics of the neuromuscular and skeletal system, and are typically used to: (1) control, guide, limit and/or immobilize an extremity, joint or body segment for a particular reason; (2) restrict movement in a given direction; (3) assist movement generally; (4) reduce weight bearing forces for a particular purpose (5) aid rehabilitation from fractures after the removal of a cast; or (6) otherwise correct the shape and/or function of the body, to provide easier movement capability or reduce pain.
[0010]The current process for producing a custom orthotic is slow, expensive and subject to flawed results. For example, with respect to a custom insole, a clinician may take an impression of a patient's foot, using either a plaster cast or a foam impression (in rare instances, complicated hand-held 3D Scanners are used to digitally perform the same function). The impressions are then sent to an offsite orthotics lab which produces the orthotic by hand using the impression and a basic prescription as a guide. The process usually involves hand casting, vacuum forming, or milling from a solid piece, and subsequent manual assembly of several components, such as padding. The process will often take two weeks or more. The clinician must then test the orthotic on the patient to ensure it functions properly, and accurately reflects the prescription. It is difficult and often impractical to make further modifications to the costly orthotic that would enhance efficacy or comfort for the patient. In some instances, the patient (or some other non-professional) may take the place of a clinician and alternative means of capturing the patient impression (such as foot pressure mapping) may be used. Likewise, pre-fabricated orthotics may be “matched” to patients by some means, such as using pressure map data, to achieve approximately custom results.
[0011]Traditionally-manufactured orthotics are necessarily limited by the technologies used to create them. The main corrective part of the orthotic, its shell, is typically a rigid piece made from a single solid/uniform material, although padding can be added by subsequent manual assembly. Because traditional manufacturing works by sculpting or forming the shell from a uniform bulk material, it typically exhibits no internal variation in geometry or mechanical properties, only a simple external geometric shape with a clinically and usually functionally arbitrary interior substructure. In other words, the entirety of the shell is made from a material that is fashioned in a particular shape, and limited to the intrinsic characteristics of the material from which it is made. The same is true of any additional components, such as padding or posting, which are cut from uniform materials. Notably, these components are manufactured by a different process on a different machine from the shell, and often both fabricated and assembled by hand.
[0012]Some do manufacture the shell component of the orthotic with computer-aided design and manufacturing (“CAD/CAM”) techniques, particularly CNC milling machines, which supplement the remaining, subsequent manual aspects of the process. These “subtractive manufacturing” milling techniques produce orthotics inherently limited to the characteristics of the solid blocks of typically uniform material from which they carve a shell. While additive manufacturing could be used to fabricate an orthotic shell, the current state-of-the-art technology has not been adopted by orthotics labs, as milling is, by most criteria, a superior technique for this application. Fabricating an orthotic shell using currently available 3D printers relying on conventional printing techniques that are, by default, limited to mono-material prints using a uniform (non-functional) fill pattern, would yield a shell of equal or lesser quality to a milled one. A fill pattern can refer to, among other meanings, the ‘internal geometry’ created within a 3D Printed structure by the “filling in” (printing) of the area inside the outer margins of a 2D layer slice. Indeed, the current methods of 3D printing a “closed” geometry (as would generally be used for an orthotic) provide limited benefits over milling from a solid block, since printing a single, uniform fill pattern is functionally equivalent (or inferior) to milling a solid block of uniform material. Indeed, a 3D Printed object is typically more costly, time intensive, and less durable than a milled one, due to the laminated structure imposed on objects made with many 3D printing techniques. Thus, the use of 3D printing technology in the medical device field has generally been limited to complex external shape matching, with little to no perceived advantage over pre-existing manufacturing techniques for most common applications.
[0013]Traditional orthotic manufacturing requires that a user selects a base shell material in advance, limiting the user to that material's intrinsic mechanical properties for the orthotic's principal structural component. While the addition of exterior padding or the removal of material (i.e., drilling) could be used to further modify the orthotic, this requires additional manual processing steps and separate components must be (manually) glued together, reducing product quality. Traditional manufacturing generally limits orthotic design to a single (usually hard) material cast of, e.g., a foot, which may then be supported by various padding (on the dorsal aspect of the orthotic) and angled into a “biomechanically neutral” position by the addition of postings (glued on platforms on the plantar aspect of the orthotic). The dorsal aspect of an orthotic is described herein as the surface, which comes into contact with the plantar aspect of the foot. These constraints necessitate a multi-step manufacturing process with manual inputs at various points in the process. Manufacturing orthotics with common milling techniques also limits the creation of the main structure (e.g., foot mold) to a solid, uniform material—a derivative of the solid block of material used as a starting point in the milling process. Even if an injection molding processes was used (prohibitive cost notwithstanding), the results would still be uniform or at least standardized.
[0014]Generally, orthotics manufacturing, particularly with respect to insoles, is limited to manual or partially manual processes. These processes limit the features and quality of the orthotics which can be created for patients. Achieving beneficial variation in mechanical properties in an orthotic is difficult, and often impractical, if not impossible. Attempting to fabricate orthotics which exhibit various mechanical properties to correspond to practical or clinical needs requires the manual labor-intensive combination of many custom components. It would be desirable to have a means to fabricate multi-property orthotics with little or no manual labor to increase usability, clinical efficacy, the feasible feature set, and decrease cost and lead time. Current technologies cannot fabricate an entire orthotic without manual assembly steps, nor can they effectively create a shell with properties different from those intrinsic to the inputted bulk material, necessarily requiring that a top coat (padding and other components) be glued onto a shell. These limitations are inherent in the current orthotics fabrication process, regardless of how the shell is fabricated.
[0015]Unlike what is taught with respect to the present invention, existing 3D Printing systems do not specify variations in fill pattern, material, etc. in a manner that addresses clinical considerations or practical patient needs. As such, using existing 3D Printer technology would only support fabrication of the orthotic's shell—the piece typically milled from a solid block. The 3D Printed shell would be created using a single rigid material (e.g., Acrylonitrile butadiene styrene (“ABS”)/Polylactic acid (“PLA”)) with a fill pattern dictated by a non-clinical concern, such as reducing print time or saving material; typically a by-product of a 3D Printer's default material deposition pathing algorithm, which is created without any consideration for clinically or functionally relevant patterning. Such a fabricated shell, like its milled counterpart, would require manual processing to add layers of padding to accommodate the printed shell, and would not generally confer many benefits over traditional orthotic manufacturing techniques. Producing orthotics “in-office” represents a largely unmet need as current technologies such as noisy, debris-generating milling machines (and were they to be used, traditional 3D Printers) produce a raw product—a simple shell—unacceptable to clinicians, who have not adopted milling machines for in-office use in large number due to the requirement to adding a second top coat material (and possibly additional padding) which necessarily involves significant manual labor and skill. Moreover, an in-office medical device production system would need to perform a variety of tasks, such as scanning anatomies and fabricating multiple orthotics in a reasonable work flow.
[0016]It would be desirable, however, to have manufacturing devices and methods that could combine one or more materials and arrange them in various shapes and internal patterns such that a custom medical device could be created with less manual input and digitally and precisely exhibit varied properties, as dictated by the biomechanical or practical needs of the patient. This would allow the creation of more effective orthotics and likely help increase patient compliance by adding precision and flexibility to the orthotics which could be easily created for patients.
具体实施方式：
[0077]Before detailing particular embodiments of the present invention, it may be helpful to further describe various limitations of the prior art and the corresponding features in embodiments of the present invention that can overcome those limitations.
[0078]Unlike the prior art, and as described further herein, embodiments of the present invention can support the creation of a fully functional custom medical device with regions of varied mechanical properties, without multiple manual assembly steps, and in more variety and precision than could be practically created manually. Certain existing methodologies do exist for altering mechanical properties in 3D-printed objects by using combinations of two materials in a grid-based ink jetting processes or by using material combinations in extrusion deposition processes. Additionally, mechanical variation in 3D-printed products has been accomplished in single-material objects by using air voids via a handful of unique patterning methods. However, these techniques have not been adopted for use in custom medical devices such as orthotics, nor have any such techniques been further developed to reflect clinical concerns, clinical data, or practical considerations particular to custom medical devices such as orthotics. Further, these technologies, while all labeled 3D Printing, are not currently available in integrated devices.
[0079]For example, 3D Printers can generate functional fill patterns, such as described in U.S. Pub. No. 2012/0241993 entitled “SYSTEMS AND METHODS FOR FREEFORM FABRICATION OF FOAMED STRUCTURES” and published on Sep. 27, 2012 (filed as U.S. application Ser. No. 13/356,194 on Jan. 23, 2012); however, these techniques have not previously been used to print custom medical devices such as orthotics in accordance with pertinent clinical data. Several techniques for printing functional patterns have been created for general purpose printing, but until now, no method or system for implementing functional material deposition patterns or material combinations in view of clinical data has been introduced. Moreover, no device or comprehensive system exists to automate the entire process of manufacturing custom medical devices such as orthotics using additive manufacturing (3D Printing) technology.
[0080]3D Printing has in certain instances been used to create unique external geometries based on patient-specific geometries. For example, printers have been used to create parts which conform to the external shape of a patient's anatomy. But only embodiments of the present invention utilize 3D Printing technology to create functional mechanical variations in custom medical devices such as orthotics based on clinical requirements or practical patient needs. This enables a physician or clinician to benefit from unique attributes of 3D Printing technology to manufacture custom medical devices such as orthotics with a desired external geometry (shape), as well control the processes by which that shape is generated, such that it has regions of varying mechanical properties based on clinical considerations or practical patient needs.
[0081]By using clinical data and varying the material properties in a 3D printer's output, one can manufacture custom medical devices such as orthotics having unique properties that are customized for the intended user (i.e., patient). It is also possible to manufacture functionally-novel device geometries because alteration of both geometry and material compression properties can be used to replace the need for traditional posting and padding of manufactured devices. For example, in cases where bunion joint pain would necessitate manual removal of a portion of an orthotic to alleviate pain (pressure), embodiments of the invention would allow one to simply alter the fill pattern or materials at certain areas (or implement another 3D Printing process variation, such as the level heating or other changes possible even within a single material). Of course, printing the necessary hole is also possible. In addition, in accordance with embodiments of the invention, padding and structural support (e.g., an orthotic shell) can be modified across a controlled, continuous spectrum to achieve patient specific results, as opposed to the discrete combinations possible when using mass produced padding to supplement a rigid orthotic device manufactured in the traditional manner. This is now possible because the effective change in Young's Modulus (i.e., compression or stiffness), traditionally achieved by manually combining a particular shell material and pads, can instead be achieved by 3D printing a single structure (of one or more materials) that utilizes available processes, patterns, materials, or combinations thereof to achieve the desired mechanical properties. The embodiments introduce use of the combination of one or more materials in one or more processes and/or in one or more patterns to fabricate medical devices using additive manufacturing. Some limited mechanical property modification might be provided using external geometric features (such as an orthotic with externally printed springs) and a 3D Printed topcoat of a different material, thereby incorporating a multi-material feature into such embodiments of the invention. Mechanical properties can refer to Young's Modulus, Sheer Modulus, Coefficient of Friction, and a host of other properties. As used herein, the term “mechanical properties” can extend beyond its traditional meaning to encompass any property that can be manipulated by the printing process/technology or materials, including, among others, properties traditionally classified as material, bulk material, porosity, optical, thermal, or electrical properties.
[0082]Embodiments of the invention can also provide a single integrated system for the entire process, from initial input of the orthotic geometry through final manufacturing of custom medical devices such as an orthotic. Embodiments of the invention also offer the ability to vary and combine functional patterns and/or processes to respond to clinical demands, as well as practical needs such as producing an orthotic that accurately grips a shoe or foot. This unification of the prescription process and the creation of a custom medical device enables a physician to directly customize and control the medical device production (i.e., the 3D Printing process including deposition, materials, fill patterns, etc.) in order to more accurately and efficiently address a clinical diagnosis and need. By using an embodiment of the present invention, a physician could select a particular mechanical property (which could be presented as choices among familiar materials whose properties would be mimicked or by selection from any other scale) and the 3D Printer could manufacture a custom medical device reflecting the desired mechanical property in a particular selected region by configuring the printing processes as necessary. This process of creating an orthotic to correspond to a clinical or practical need (e.g., shoe shape or usage) could be automated using inputted data and decision algorithms.
[0083]Embodiments of the present invention also introduce a system and method for using a single material or single manufacturing process (e.g., 3D Printing) to manufacture all the components of custom medical device—such as the shell, posting, padding, gripping, etc. of an orthotic product—and where all such components could be customized by direct manipulation of the printing process. For example, even if one could print the complete external shape of an orthotic using existing techniques for a 3D Printer, the medical device resulting from that uniform production process would not function correctly because it would not contain different components or regions having distinct mechanical properties. But as noted above, embodiments of the present invention enable a user to customize and alter various aspects of the printing process, such as the fill pattern and materials, in order to accommodate mechanical variations in the different functional aspects of the medical device, as customized for use by a particular patient. Embodiments of the present invention offer additional features benefiting the patient, but not related to the medical purpose of the device (i.e., in embodiments having a classically defined medical purpose). For example, with respect to a foot orthotic, it would be advantageous to impregnate materials with antimicrobial or odor fighting properties at specific areas in the orthotic. Similarly, it would be advantageous to create orthotics which can fold along the long axis and spring back to fit into a difficult shoe geometry.
[0084]While the methodology and exemplary embodiments for altering the 3D Printing process to create custom medical devices with varying regions of functional internal structure or material combination in response to clinical concerns is primarily discussed herein with respect to orthotic insoles, the same techniques can be applied with respect to other products created to interact with the human body, including a wide array of medical devices, prosthetics, orthotics, and non-clinical devices customized to anatomy. As such, while the exemplary embodiments relate primarily to the customized manufacturing of orthotic insoles, one skilled in the art will appreciate how the present invention applies to other medical devices and products. Likewise, the exemplary embodiments presented herein focus primarily on additive manufacturing systems such as 3D Printers, and in particular on solid free form fabrication using deposition tool heads, but it should be understood and appreciated that the present invention can be implemented in a wider variety of embodiments and robotic devices.
[0085]Given the limitations of the current systems and the inconvenience they impose on clinicians, it is desirable to have a system of more efficiently producing superior customized medical devices such as orthotics and other fabricated articles. This is especially the case where it is preferably to have a single device capable of performing many tasks, such as laser scanning and fabricating orthotics.
[0086]Currently, additive manufacturing devices are generally limited to producing one object at a time, or producing a series of objects simultaneously on a single work surface. For example, a 3D Printer being used to fabricate toys would be limited to fabricating only as many toys as could fit within the confines of its single work surface. In most cases, the fabrication of the toys would need to be simultaneous (i.e., each layer from two distinct objects would need to be deposited in succession), whereby layer one of object one would be followed by layer one of object two, and layer two of object one, and layer two of object two, and so on. If this was not the case, and two objects were being fabricated on one work surface sequentially (or with any substantial lag), a larger work surface would be required so that the tool fabricating the second object would not make contact with the first object (at a later or completed stage of fabrication) while printing. However, a user of an additive manufacturing system may wish to fabricate multiple items of varying geometry within a short period of time. For example, the current approach of using a single work surface would not allow someone who is fabricating one object of reasonable size to easily fabricate a second object of shorter print time (e.g., smaller size) while the first object is fabricated. Previously, there was no effective means of “interrupting” a fabrication process to perform another task. In the context of an additive manufacturing system, this second task may be the fabrication of a second item, as described above. However, it is also possible that the interrupting task may be a non-printing task.
[0087]As will be discussed herein, embodiments of the present invention may be used for both 3D Printing and laser scanning, such as first laser scanning an impression of a foot and then fabricating a corresponding orthotic. In the past, a hypothetical machine with such dual capability would generally not be able to pause the fabrication of an object being printed in order to laser scan a second object (e.g., a second impression). Reasons for this incapability could be the inability to fit both objects on a single work surface, and the risk that introducing a second object for scanning to the work surface might result in damage to the first object being fabricated. This is just one of many illustrative scenarios in which embodiments of the present invention would be desirable.
[0088]Generally, as single- and multi-function robotically controlled motion systems (such as 3D Printers) become more commonplace, particularly in home and office scenarios, it is likely that users will wish to switch among various tasks and tools. It is therefore desirable that a multi-function machine, or more generally a machine used to perform multiple tasks, be able to separate various functions and/or tasks onto different work surfaces, which would provide many benefits such as hygiene, quality, efficiency, and space saving.
[0089]Due to the inherent complexities of additive manufacturing, CNC, and similar systems and the shortcomings in currently known techniques, existing systems may fail to provide users with a means to efficiently multi-task. Current products limited to single work surfaces do not make them amenable to the performance of multiple tasks of varying duration on objects of varying geometry. In particular, it is desirable to have robotic systems and techniques that allow a user to deploy multiple work surfaces, wherein several tasks and tools can be used sequentially or simultaneously. This is especially true in the fabrication of orthotics, particularly in an in-office setting, where a compact machine capable of multi-tasking between printing and scanning jobs would have clear benefits in terms of cost, training, office space, and efficiency.
2. Description of Prior Art Systems and Methods
[0090]In order to provide some background regarding three dimensional robotic motion systems in general and illustrate common components in such devices that may be used in connection with embodiments of the present invention, FIG. 1 provides a perspective view of a prior art three dimensional fabricating system. It should be understood that embodiments of the present invention are not limited to a three dimensional fabricating system as shown in FIG. 1 and could be implemented by properly adapting other systems with robotic arms or computer-controlled motion, which may or may not resemble the system shown in FIG. 1. In FIG. 1, fabrication system 100 includes fabricator 101 with material deposition tool head 102 (also referred to herein as deposition tool or deposition head), control unit 103 having one or more actuators and sensors configured to control operating characteristics of material deposition tool 102, and build tray (i.e., build surface, work surface, or fabrication surface) 104. Fabrication command unit 105 may be coupled to fabricator 101 as a component physically inside fabricator 101, or it may be coupled as an external device (e.g., computer) via a wired or wireless connection.
[0091]Notably, in some other robotic systems which could be used to implement embodiments of the invention, material deposition tool 102 might be replaced with another type of tool, or a combination of tools, or an interchangeable tool (deposition or otherwise). Embodiments of the invention could also be implemented with machines not specifically known or used as “fabrication” systems, such as “scanning” systems (like those using a laser scanner) or by other robotic machines.
[0092]With respect to FIG. 1, fabrication command unit 105 includes processor 106, memory 107, and fabrication software application 108 that can be stored in memory 107 and executed by processor 106. It should be appreciated that control unit 103 of fabricator 101 may be configured to receive instructions from fabrication command unit 105 such that fabricator 101 can fabricate an output product on build surface 104 from materials dispensed by material deposition tool 102.
[0093]The fabricated output product can be a three dimensional structure comprising a plurality of deposition layers. Material deposition tool 102 typically deposits material in viscous form and the material can be designed to solidify after being deposited to form an output product on build surface 104. Alternatively, the material may require a separate curing process to solidify it, or may remain in a viscous form capable of maintaining a three dimensional structure. Output products are generally three dimensional structures created by a plurality of deposition layers. Fabrication software application 108 can generate tool path information for fabricator 101 and delineate how material can be used to generate shapes with entrapped air. Complex CAD programs may also be used to generate the intended geometry.
[0094]Embodiments of the present invention may be implemented in any suitable three-dimensional fabricating system (i.e., additive manufacturing device or 3D Printer), for example, as illustrated in FIG. 1 and described above, or in a combination of systems. Some other exemplary three-dimensional fabricating systems or components thereof are described in U.S. Pub. No. 2012/0241993 entitled “SYSTEMS AND METHODS FOR FREEFORM FABRICATION OF FOAMED STRUCTURES” and published on Sep. 27, 2012 (filed as U.S. application Ser. No. 13/356,194 on Jan. 23, 2012) and U.S. Pat. No. 7,625,198 to Lipson et al.
[0095]FIG. 2 provides exemplary process 200 for 3D Printing. Computer aided design (CAD) data generated by a user and/or software 201 can be provided as input to 3D printing software 202 which typically “slices” the CAD data into multiple (z-axis) layers 203 and generates fabrication directions or commands for each layer 204 which are transmitted to the fabrication components in a 3D Printer 205 to fabricate an object 206. Depending on the particular 3D printing technology employed, the layer fabrication commands may consist of x-y motion (typically tool head ‘pathing’) instructions and deposition/sintering/light curing instructions. Also, depending on the particular 3D Printer being used, it is possible that the pathing motion in the x-y-z axis may be achieved by motion of either a tool head and/or a build surface. One of ordinary skill in the art will recognize that there are many possible variations and configurations of the 3D printer (FIGS. 1) and 3D printing procedure (FIG. 2) described herein that may be used in systems for additive manufacturing, but the above description should provide sufficient background of available systems that can be used in connection with embodiments of the invention.
[0096]FIG. 3 provides an introductory understanding of orthotic construction. Foot 301 is shown atop traditional custom orthotic insole 302. Insole 302 is shown as having a shell 303 which is typically made of a rigid material (e.g., plastic) that is milled or vacuum formed to correspond to the impression taken by the clinician. Several accommodative pads or shell modifications (e.g., drilled holes) of the type shown in FIG. 4 may be used to alter the shell. The shell is typically then affixed to a top coat 304, which may extend past the length of the shell 303, at which point is it often referred to as a forefoot extension. Such top coats or coverings exhibit various degrees of padding. Clinical concerns including the adjustment of the plane in which the foot is positioned may call for angled rearfoot posting 305 and/or forefoot posting 306.
[0097]FIG. 4 provides illustrations of exemplary pads or holes 400 which may be prescribed by a clinician to address common clinical conditions using well known orthotic prescriptions. Traditionally, these pads (or holes) 400 would be placed on top of (or through) a milled or handcrafted orthotic shell molded to fit a patient's foot, sometimes reducing contact with the fitted shape and foot and increasing the ability for the patient to slide off the orthotic. Moreover, the variety of pads 400 are typically mass produced, limiting the mechanical properties which a clinician can offer a patient to the specific predetermined offerings of pad manufacturers. If a patient desired a custom pad, it would be expensive, time-consuming, and require a great deal of manual labor. Further, the manual nature of traditional orthotic construction does not provide a digital model for quantitatively assessing the mechanical property effects of padding and shell construction, as is possible using the present invention.
3. Description of the Preferred Embodiments
[0098]FIG. 5 provides workflow overview 500 to illustrate one possible embodiment of the present invention. In this embodiment of the invention, a clinician can capture the physical characteristics of a patient's anatomy (e.g., a mold) through a variety of means, including but not limited to foam or plaster 501. (Actions by a clinician as described herein could alternatively be taken by a physician, the patient, or some other user, or several users together.) A clinician can then scan the mold or impression with an orthotics manufacturing device or an imaging device (e.g., digital scanner or camera) 503 to create a digitized record of the patient's anatomy 504. Alternatively, the clinician can use another method such as imaging device (e.g., digital scanner or camera) to create a digitized record of the physical characteristics of a patient's anatomy without using a mold 502. The clinician may then process the digital record with specialized software 505. Software 505 can be configured to enable a clinician to design a custom medical device, such as an orthotic, in view of the digital record of the patient's anatomy. For example, with respect to a foot orthotic, the clinician may be able to specify a particular pad or shell and optionally modify the shape of the pad or shell, add a forefoot extension, change mechanical properties in different elements of the orthotic material, etc. in view of the clinical and practical needs of the patient. Specialized software 505 can be integrated into the orthotics manufacturing device, or may be available on a separate computer. Specialized software 505 may optionally be able to analyze the digital record of the patient's anatomy and recommend particular customizations to the clinician. In addition, specialized software 505 may optionally have access to one or more clinical or medical data repositories that it can reference to recommend particular customizations to the clinician. Specialized software 505 may also allow the clinician to directly access one or more clinical or medical data repositories to research potential customizations. Specialized software 505 can generate a three dimensional model or other instructions or data for a customized medical device, which can be transmitted directly (wired or wirelessly) or indirectly (e.g., via a USB flash drive) to a fabrication device which manufactures the custom medical device and allows for any needed curing of materials 506. The custom medical device, such as an orthotic, is then complete and can be provided to the patient 507.
[0099]As discussed above with respect to FIG. 5, embodiments of the invention may utilize specialized software to process digital (or digitized) records about the geometry of a patient's anatomy to render a custom medical device (e.g., an orthotic). The clinician can also use specialized software to further customize features of the medical device. For example, starting with an anatomy-based shell for a foot orthotic generated in response to the digitized record, a clinician can direct the specialized software to add a u-shaped pad. However, whereas a u-shaped heel pad would traditionally be a distinct component placed on top of an orthotic shell, the clinician could direct the specialized software to integrate the pad into the structure of the shell of the orthotic itself. The specialized software may also offer a clinician the option of raising the pad from the surface of the orthotic shell. (This is illustrated below in reference to FIGS. 12A-C.) The specialized software may also enable a clinician to change the mechanical properties for particular regions of the custom medical device. For example, the mechanical properties of a u-shaped region in a foot orthotic could be manipulated to be more compressive or less compressive under a patient's weight, relative to other regions of the foot orthotic.
[0100]Assignment of mechanical properties to various aspects of the medical device may be done by computer software using data such as the anatomical data, physical exam data, pressure data, CAT scan or MRI data, and data about the properties of any interfacing hardware like a patient's shoe. Different embodiments of the invention used may have varying degrees of clinician discretionary intervention, with some embodiments completely automating the process of assigning mechanical properties to the medical device based on the digital data available.
[0101]In this embodiment, the clinician would first determine if the u-shaped region should be raised (and/or recessed) from the foot's mold, and if yes, to what degree. Then the clinician could select the degree of resistance to compression of that region, as compared to other regions on the orthotic. These variations of compression properties (as well as other mechanical properties) could be created by manipulating the additive manufacturing process, for example, by altering the composition of different fabricating materials being used, and altering the deposition process. Another example where modifying mechanical properties might be beneficial could be trying to alter the orthotic's expected response to sheering forces, in order to accommodate a patient's gait or athletic needs.
[0102]In a simple example, a hard piece of the orthotic (with respect to Young's Modulus) and a soft piece—e.g., the shell and the pad, respectively—could be fabricated by one (or more) 3D printer(s) as a single physical object by utilizing two different printing processes, where one process produces the portion of the object that is hard like plastics or resins, and a second process produces the portion that is softer and more akin to silicones or thermoplastic elastomers. A wide array of materials, in conjunction with a wide array of processes, could be used to create a variety of mechanical properties in different regions (and at various ratios) within a custom medical device, in order to accommodate clinical and practical needs. Even with respect to a single material, additive manufacturing processing algorithms can be used to change the mechanical properties of that material in different regions of a custom medical device, such as an orthotic.
[0103]For example, when employing extrusion-based 3D printing, the properties of a single material can be altered by introducing variations in the pattern of the deposition path of an extrusion head as it layers material on a work surface. Other techniques could also be employed, such as using overlapping loop-depositing paths (rather than straight lines) by varying both the tool head path and its deposition settings, as can be induced by phenomena such as viscous thread instability. (Aspects of this technique are described in U.S. patent application Ser. No. 13/356,194, referenced above.) These techniques enable the deposition of coiled paths of varying coil shape, size, and lateral and vertical overlap, creating various desired mechanical properties by a combination of several factors including density and number of node connections between loops. Techniques using non-looped strands or strands of varying shapes, thicknesses, and patterns can also be used. Other techniques could include linear stacking patterns where the fill is not solid—this can result in creating pockets of air in the custom medical device, or creating paths for air to pass through the custom medical device. These variations can be induced by several methods, including but not limited to: (1) altering a CAD file to introduce external or internal substructures (e.g., “springs”), (2) modifying height, speed, material calibration or other tool head settings, or (3) manipulating the pathing-patterning algorithm used to create motion and deposition instructions from the CAD layer slices. Another useful technique for creating custom mechanical properties is using coiled or other functional fill patterns that alone would introduce air voids, but depositing one or more other materials to fill in what would otherwise be air voids. This could be done by depositing the air-replacing material during or after the printing of the coiled pattern. Similarly, honeycomb or similar grid-like patterns can be created with one or more materials using a variety of well-known additive manufacturing technologies.
[0104]Various techniques can be used to achieve desired mechanical properties. FIG. 6 provides an illustrative custom medical device, in this instance foot orthotic 600, which could be manufactured by embodiments of the present invention as described herein. Orthotic 600 has a shell 601 that is fabricated by an extrusion process, optionally with an internal crisscross-style grid pattern 606 or another structural design (such as a honeycomb structure) in certain regions of orthotic 600, with said regions optionally being fabricated using hard plastic or soft (i.e., more compressive) materials like certain TPEs or silicones. Such patterns are beneficial when customizing a medical device to be lightweight, and used selectively, they can provide desired mechanical properties while minimizing the quantity of material used, as well as minimizing fabrication time. (With respect to FIG. 6, it should be understood that the dashed lines around crisscross pattern 606 represent an internal view of the pattern which may be fully enclosed within shell 601 or beneath the top coat 604.) Further, it should be understood that the grid pattern 606 could be oriented straight up and down or shifted ninety-degrees by printing the orthotic in embodiments of the invention using a specialized printing orientation detailed below. Products similar to orthotic 600 could also be manufactured with ink jetting, sintering, or comparable fabrication processes using a variety of materials. In addition to the hard (i.e., stiff) portion of orthotic shell 601, orthotic 600 may also comprise compressive padding material 608 in certain regions. A looped deposition pattern of a soft material such as silicone or thermoplastic elastomer can be deposited to form padding material 608 with a precise Young's Modulus that differs from the other regions of shell 601. A third material, or the same soft material as padding material 608—perhaps with a tighter pattern—may be deposited to form top coat 604. (As illustration of “tight” versus a “loose” pattern is provided can be visualized in the contrast between patterns 1215 and 1214 in FIG. 12A below.) Such patterning may impart various gripping textures to the orthotics, which can be prescribed, as well. In some embodiments, multiple materials may refer to multiple colors of a single material which could be used to delineate among regions representative of traditional components, e.g. shell and top coat. In the present example, orthotic shell 601 could be created with a patterned surface to allow mechanical interlock of a second (or third) material for top coat 604, should one be desired, or as a means to grip the foot. It is also possible for shell 601 and top coat 604 to be created with depositions at different resolutions, such that shell 601 could be created with a courser resolution at a quicker speed, while it can be coated with a finer resolution top coat 604, giving orthotic 600 an outward appearance and feel of a high resolution print.
[0105]Further, specialized techniques unique to the invention can be used in various embodiments to impart desired mechanical properties and geometric shapes and substructures. In particular, embodiments call for specialized printing orientations to create specific geometries to impart desired mechanical properties. Some methods of achieving this will first be described, followed by the purpose for the technique. For example, with respect to FIGS. 26A and 26B aspects of a novel method of producing an orthotic are illustrated. Typically, all 3-