Wearable interface with embedded sensors and fabrication method

Abstract

Examples described herein relate to wearable interfaces with embedded sensors and methods for fabricating the same. A method comprises receiving a digital file representing a contour of a body part or a modified contour of the body part for fabrication of the wearable interface, executing a computational algorithm to determine locations for at least one recess and routing features based on landmark data, and creating an inner structure with an internal surface configured to interface with the body part and an external surface comprising the at least one recess and routing features. A sensing system is placed onto the external surface with at least one sensor positioned within the at least one recess. An outer layer encapsulates the sensing system such that the at least one sensor is sub-surface embedded and protected from wear. A sensor harness is dimensioned for placement within the at least one recess prior to application of the outer layer.

Description

WEARABLE INTERFACE WITH EMBEDDED SENSORS AND FABRICATION METHODCROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority to U.S. Provisional Application No. 63 / 779,051, titled “Embedded-Sensor Sockets that Incorporate Advanced Fabrication,” filed March 27, 2025, which is hereby incorporated by reference in its entirety.STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH

[0002] This invention was made with government support under Grant No. R01HD 103815 awarded by the National Institutes of Health (NIH). The government has certain rights in the invention.FIELD OF INVENTION

[0003] The present disclosure relates to wearable interfaces with embedded sensors for monitoring variables at a body-device interface, and more particularly to methods and systems for fabricating wearable interfaces incorporating computationally determined inner structures with engineered recesses and routing features for integration of sensing systems encapsulated beneath an outer structural layer.BACKGROUND

[0004] Wearable interfaces such as prosthetic sockets and orthotic devices serve as the mechanical connection between assistive devices and the human body. In prosthetic applications, the socket interfaces with a residual limb and transfers motion and stress between the prosthesis and the person with limb loss. The quality of this interface affects comfort, gait stability, and limb health. Socket fit remains a primary concern for prosthesis users and influences overall satisfaction with the prosthesis. Similar interface challenges exist in orthotic devices, helmets, braces, exoskeleton interfaces, seating surfaces, shoes, casts, finger prostheses, upper limb prostheses and other wearable structures where monitoring of conditions at the body-device interface is desired.

[0005] Clinicians and researchers have pursued various approaches to monitor conditions at the interface between wearable devices and the body. Pressure sensing technologies including thin piezoresistive sensors, piezoelectric sensors, capacitive sensors, strain-gagesensors, load cells, textile-based sensors, MEMS pressure sensors, vacuum sensors, and bubble sensors, as well as distance and motion sensing technologies including inductive sensors and proximity sensors, have been applied to residual limbs or to the inside surfaces of sockets after fabrication. Ultrasound, laser, optical, radar infrared sensors, and tactile feedback sensors are also possible. While such approaches may be practical for in-clinic assessments or short-term monitoring, maintaining sensor functionality during extended use presents challenges, in part due to mechanical damage to sensing elements exposed at the interface surface.

[0006] Prior approaches to structural integration of sensors have included drilling holes in sockets to support and protect sensors, which may restrict sensor placement to relatively flat locations and extend fabrication time. Other approaches have involved scanning a body part to create a three-dimensional digital representation and then machining sensor locations directly into a liner or interface component during manufacturing. While such approaches may enable customized sensor placement, they may not provide structural integration of sensors within the wall of the wearable interface itself, and the sensors may remain exposed at the interface surface where they are subject to mechanical damage during use.

[0007] There remains a need for approaches that protect sensors from mechanical or chemical damage during extended use while enabling monitoring of conditions at the bodydevice interface during both active and inactive phases of use, such as during both stance and swing phases of gait in prosthetic applications and during standing and sitting. Similar monitoring needs exist for the other wearable interfaces described above.

[0008] Conventional socket fabrication methods involve multiple lamination steps and manual placement of components. For example, sensors may be placed on a cured inner resin layer and then covered by a second lamination, requiring two separate curing steps and increasing the risk of sensor damage during the second layup. Wiring and electronic connections placed manually during layup can be difficult to organize and protect, potentially leading to damage or malfunction. Individual sensor assembly during socket fabrication, including soldering, crimping, and routing each sensor one at a time, compounds these risks. The time and skill required for such fabrication can limit the practical adoption of instrumented sockets and other instrumented wearable interfaces in clinical settings.

[0009] Three-dimensional printing technologies have been applied to prosthetic socket fabrication, enabling the creation of custom-shaped structures from digital files. Three-dimensionally printed inserts with recesses for sensor placement have been developed forinstallation inside existing sockets. However, such inserts add thickness to the socket interior, may alter the socket shape experienced by the user, and require a separate socket to already be fabricated. Integrating sensing systems into three-dimensionally printed socket structures while maintaining reliable sensor placement, protecting electronic components, and achieving efficient fabrication workflows presents ongoing challenges. Furthermore, sensor placement locations in existing approaches are typically determined manually by a clinician or technician, which may introduce variability and may not account for local surface geometry that affects sensor conformance and signal quality. For specific intended uses of the data like a detailed characterization of activity that depends on compliance with sensor placement guidelines, analysis algorithms may not function properly if sensor locations are determined manually.

[0010] Accordingly, there remains a general interest in approaches for fabricating wearable interfaces with embedded sensors that can automate sensor placement determination, reduce fabrication time and manufacturing variability, and protect sensing components from damage during both fabrication and extended use.SUMMARY

[0011] This summary is provided to introduce a selection of concepts in a simplified form that are further described below in the detailed description. This summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used as an aid in determining the scope of the claimed subject matter.

[0012] According to an aspect of the present disclosure, a method for fabricating a wearable interface with embedded sensors is provided. The method comprises receiving a digital file representing a contour of a body part or a modified contour of the body part, the digital file being for fabrication of the wearable interface. The method further comprises executing a computational algorithm to determine locations for at least one recess and routing features based on landmark data within or calculated from the digital file. The method further comprises creating an inner structure based on the digital file, wherein the inner structure comprises an internal surface configured to interface with the body part and an external surface comprising the at least one recess configured to receive at least one sensor and the routing features configured to guide electrical connections. The method further comprises placing a sensing system onto the external surface of the inner structure, wherein the sensing system comprises at least one sensor positioned within the at least one recess and electrical connections routed through the routing features. The method further comprises applying an outer layer overthe inner structure and the sensing system to encapsulate the at least one sensor and the electrical connections.

[0013] This method provides technical advantages including reduced fabrication time compared to conventional methods involving multiple lamination steps. The computational determination of recess and routing feature locations based on landmark data enables repeatable sensor placement without relying on manual positioning. The encapsulation of sensors and electrical connections beneath the outer layer protects the sensing components from mechanical, electrical or chemical damage during use.

[0014] According to another aspect of the present disclosure, the inner structure may be fabricated using additive manufacturing comprising at least one of selective laser sintering (SLS), stereolithography (SLA), multi -jet fusion (MJF), fused deposition modeling (FDM), lubricant sublayer photo-curing (LSPC), photopolymerization (DLPs, LEDs), direct energy deposition (DED), electron beam melting (EBM), carbon digital-like synthesis (DLS), or material or binder jetting and the inner structure may be made of a glass-filled, carbon-filled or ceramic-filled polymer. Additive manufacturing enables precise fabrication of the inner structure with complex geometries including the recesses and routing features. Glass-filled, carbon-filled or ceramic-filled polymers provide mechanical strength and thermal resistance suitable for subsequent outer layer application processes.

[0015] According to another aspect of the present disclosure, creating the inner structure may further comprise forming a connector enclosure within the external surface configured to receive a connector of the sensing system, wherein the connector enclosure is positioned such that a bottom surface of the connector enclosure is flush with a distal end of the inner structure. Positioning the connector enclosure such that its bottom surface is flush with the distal end of the inner structure places the connector in the same plane as the mounting adapter for prosthetic componentry, enabling access to the connector from outside the socket. This configuration reduces the risk of damage when the socket is separated from the prosthetic componentry.

[0016] According to another aspect of the present disclosure, the method may further comprise executing the computational algorithm to optimize placement of the recesses based on local surface contour of the inner structure, including adjusting locations to avoid local surface regions exhibiting combined concavity and convexity, and minimizing intersecting paths of the routing features across the external surface of the inner structure. Optimizing recess placement based on local surface contours improves sensor conformance and signal quality byavoiding regions where sensors cannot seat properly. Minimizing intersecting routing paths reduces the risk of signal interference between electrical connections and simplifies the fabrication process. The computational algorithm may also execute rules for sensor placement for specific purposes such as activity categorization or socket fit assessment.

[0017] According to another aspect of the present disclosure, placing the sensing system may comprise placing a pre-assembled sensor harness, the pre-assembled sensor harness comprising the at least one sensor with electronic components encapsulated in a protective material and the electrical connections pre-installed within a single connector housing, and the method may further comprise testing the sensing system for functionality prior to applying the outer layer. The use of a pre-assembled sensor harness reduces the risk of damage during fabrication and enables bulk manufacturing separately from wearable interface fabrication. Testing prior to applying the outer layer enables identification and correction of defects before permanent encapsulation. The sensing system may further include a capacitor configured to tune a resonant frequency of the at least one resonant frequency sensor (e.g., an inductive sensor, MEMS pressure sensor, RFID sensor, infrared sensor, bioimpedance sensor) and a thermistor configured to measure temperature at a location of at least one sensor.

[0018] According to another aspect of the present disclosure, the outer layer may comprise a structural lamination, coating or shell that provides mechanical support and protects the sensing system from damage during use. It may provide support for structural elements of the adjustment mechanism or actuator.

[0019] According to another aspect of the present disclosure, when the outer layer of the wearable interface comprises a conductive material such as carbon fiber, a material that is magnetically permeable and electrically resistive sufficient to limit eddy current losses when a magnetic field is applied may be disposed over the at least one sensor between the at least one sensor and the outer layer, and a ground wire from the sensing system may be woven into the outer layer to electrically isolate the at least one sensor from conductive materials in the outer layer. The material limits eddy current losses when a magnetic field is applied. The material and ground wire provide electrical isolation between the sensors and the conductive carbon fiber material of the outer layer.

[0020] According to another aspect of the present disclosure, the method may further comprise smoothing the internal surface of the inner structure. Vapor smoothing and other smoothing techniques may be used to lower surface roughness while maintaining dimensionalaccuracy. The resulting friction characteristics may be selected based on patient and / or prosthetist preference. Media tumbling, media blasting, ironing, chemical treatment and epoxy coating or other smooth durable material coating may also be used.

[0021] According to another aspect of the present disclosure, a wearable interface with embedded sensors is provided. The wearable interface comprises an inner structure having an internal surface configured to interface with a body part and an external surface, wherein the external surface comprises a predefined layout including at least one recess configured to receive at least one sensor and routing features configured to guide electrical connections. The wearable interface further comprises a sensing system comprising at least one sensor positioned within the at least one recess, electrical connections extending from the at least one sensor through the routing features, and a connector configured to receive the electrical connections. The wearable interface further comprises an outer layer disposed over the inner structure and completely encapsulating the at least one sensor and the electrical connections, wherein the at least one sensor is sub-surface embedded on the external surface of the inner structure and protected from wear by the outer layer. On the inside surface, the continuous inner structure protects the at least one sensor.

[0022] The sub-surface embedding of sensors on the external surface of the inner structure protects the sensors from wear during extended use. The predefined layout enables repeatable sensor placement and organized routing of electrical connections.

[0023] According to another aspect of the present disclosure, the inner structure may be fabricated using additive manufacturing comprising at least one of selective laser sintering (SLS), stereolithography (SLA), multi -jet fusion (MJF), fused deposition modeling (FDM), lubricant sublayer photo-curing (LSPC), photopolymerization (DLPs, LEDs), direct energy deposition (DED), electron beam melting (EBM), carbon digital-like synthesis (DLS), or material or binder jetting. Additive manufacturing enables fabrication of the inner structure with complex geometries tailored to the body part contour, supporting customization of recesses and routing features for each wearable interface.

[0024] According to another aspect of the present disclosure, the inner structure of the wearable interface may be made of a glass-filled, carbon-filled or ceramic-filled polymer providing mechanical strength and thermal resistance suitable for the wearable interface application.

[0025] According to another aspect of the present disclosure, the inner structure may be made of glass-filled blended nylon 12 or another printed material capable of undergoing vapor smoothing and the internal surface may comprise a vapor-smoothed finish providing a smooth interface with the body part comparable to traditional socket materials.

[0026] According to another aspect of the present disclosure, the inner structure may further comprise structural elements configured to support at least one of adjustable socket panels, vacuum or suction mechanism, adjustable cabling mechanism, fluid-filled mechanism, air-filled mechanism, stiffness adjustment mechanism, frictional adjustment mechanism, socket length adjustment mechanism, manual mechanisms for adjustment of the wearable interface, electronic actuators for auto-adjustment of the wearable interface, a release-relock mechanism, vents, a cooling mechanism or a grip control mechanism. The structural elements enable integration of adjustment mechanisms within the wearable interface. The adjustable elements may enable dynamic fit adjustment based on changes in body part volume or position.

[0027] According to another aspect of the present disclosure, the wearable interface may further comprise an elastomeric liner configured to be worn between the body part and the internal surface of the inner structure. The elastomeric liner includes a magnetically permeable or conductive target material configured to interface with the at least one sensor. The magnetically permeable or conductive target material comprises at least one of a full magnetically permeable or conductive layer within the elastomeric liner, targeted areas of magnetically permeable or conductive material positioned at locations corresponding to the at least one recess, magnetically permeable or conductive material integrated within a fabric backing of the elastomeric liner, magnetically permeable or conductive sections molded within a silicone, polyurethane, or thermoplastic layer of the elastomeric liner, or disks or bands of magnetically permeable or conductive material disposed on a textile, polymer, or other material affixed to an outer surface of the elastomeric liner. The target may be an electrode that includes a conductive or magnetically permeable material, for example a myoelectric electrode to detect user intent or to communicate feedback. The elastomeric liner with magnetically permeable or conductive target material enables inductive distance sensing between the liner and the sensors embedded in the inner structure. The various configurations of magnetically permeable or conductive material within the liner provide flexibility in target material placement and integration.

[0028] According to another aspect of the present disclosure, the at least one sensor may comprise inductive distance sensors. The inductive distance sensors may be arranged as asingle sensor, in a sensor array of more than one sensor, or a fusion of multiple sensors configured to determine at least one position of a target relative to the inner structure. A sensor array includes sensors configured into a group of at least two sensors. A fusion of multiple sensors is a group of separate individual sensors, whether local or at different locations, that may use a weighted combination of data from different sensors to calculate a distance or rotation of interest. A fusion of multiple sensors may include sensor arrays. The known positions and orientations of the sensors from the inner structure digital file support accurate position determination. The sensing system may further include a capacitor configured to tune a resonant frequency of the at least one inductive sensor antenna and a thermistor configured to measure temperature at a location of the at least one inductive sensor antenna.

[0029] According to another aspect of the present disclosure, the wearable interface may further comprise a processor configured to receive data from the single sensor, sensor array or fusion of multiple sensors and to determine a socket fit metric and from that determine a device adjustment, and the inner structure may further comprise mounting features for at least the one actuator configured to adjust a dimension of the wearable interface or a dependent feature based on a command from the processor. The processor enables open-loop or closed-loop control of the wearable interface based on sensor data from the inductive distance sensors. The mounting features for the actuator enable dynamic adjustment of the wearable interface dimension without manual intervention.

[0030] According to another aspect of the present disclosure, the external surface of the wearable interface may further comprise a connector enclosure configured to receive the connector, wherein the connector enclosure is positioned such that a bottom surface of the connector enclosure is flush with a distal end of the inner structure. The connector enclosure provides a protected receptacle for the electrical interface between the sensing system and electronics or another external device.

[0031] According to another aspect of the present disclosure, the outer layer of the wearable interface may comprise a vacuum-assisted carbon-fiber lamination, and a material that is magnetically permeable and electrically resistive sufficient to limit eddy current losses when a magnetic field is applied is disposed over the at least one sensor between the at least one sensor and the outer layer, and a ground wire from the sensing system may be woven into the outer layer to electrically isolate the at least one sensor from conductive materials in the outer layer. The material and ground wire provide electrical isolation between the sensors and the conductive carbon fiber material of the outer layer.

[0032] According to another aspect of the present disclosure, a digital file representing a contour of the body part may be used to determine an active region and sensitivity distribution of the at least one sensor based on the known position and orientation of the at least one sensor within the inner structure, enabling characterization of sensing performance at each sensor location.

[0033] According to another aspect of the present disclosure, the inner structure of the wearable interface may have a variability in stiffness or a gradient in stiffness from the internal surface to the external surface, enabling a compliant interface with the body part while providing structural support for the recesses, routing features, and outer layer.

[0034] According to another aspect of the present disclosure, the sensing system of the wearable interface may be a pre-assembled sensor harness that is a standalone subassembly physically separable from the inner structure prior to integration, enabling testing for functionality prior to permanent encapsulation.

[0035] According to another aspect of the present disclosure, a sensor harness for integration with a wearable interface inner structure is provided. The sensor harness comprises at least one sensor element, the at least one sensor element having associated electronic components. The sensor harness further comprises a single connector housing. The sensor harness further comprises lead wires pre-installed within the single connector housing and extending to the at least one sensor element. The sensor harness further comprises a protective encapsulation disposed over the electronic components of the at least one sensor element. The protective encapsulation may comprise at least one of hot melt glue, epoxy, silicone potting compound, UV-curable resin or conformal coating. The sensor harness is dimensioned and configured for physical placement within predefined recesses on an external surface of a wearable interface inner structure prior to application of an outer structural layer. The preassembly reduces the risk of damage during fabrication and enables bulk manufacturing. The protective encapsulation shields the electronic components from mechanical damage during handling.

[0036] According to another aspect of the present disclosure, the lead wires may be arranged in a zigzag or serpentine configuration with an elastic element in parallel to accommodate varying distances between the at least one sensor element and the single connector housing. The zigzag or serpentine configuration accommodates varying distanceswithout requiring custom wire lengths. The elastic element provides strain relief and reduces tensile stress in the lead wires.

[0037] According to another aspect of the present disclosure, when the sensor harness comprises a plurality of sensor elements, adjacent sensor elements may be connected through a flexible joint formed in a flexible circuit backing material to maintain sensor organization during placement while allowing the sensor elements to conform to curved surfaces of the wearable interface inner structure. The flexible joint maintains sensor organization during placement, reducing the risk of misalignment. The flexible circuit backing material allows the sensor elements to conform to curved surfaces while keeping the sensors organized. Alternatively, a flexible joint may be put in place after flexible circuit fabrication.

[0038] According to another aspect of the present disclosure, the at least one sensor element may comprise at least one inductive sensor antenna or antenna array, and the associated electronic components may include a capacitor and a thermistor for the at least one inductive sensor antenna or antenna array. The inductive sensor antennae enable distance sensing to a magnetically permeable or conductive target material. The capacitor tunes the resonant frequency of the corresponding antenna, and the thermistor enables temperature measurement for thermal compensation.

[0039] According to another aspect of the present disclosure, the sensor harness may be a standalone subassembly physically separable from the wearable interface inner structure prior to integration, enabling quality control testing and removal or replacement if testing reveals a defect.

[0040] According to another aspect of the present disclosure, the digital file may be obtained from at least one of a scan of a socket shape, a scan of a residual limb, medical imaging data, a computational model, or a database of body part contours, enabling the fabrication methodology to be applied to new patients, existing patients, and standardized configurations.

[0041] According to another aspect of the present disclosure, the wearable interface may be at least one of a prosthetic socket, an orthotic device, a helmet, a brace, an exoskeleton interface, a seating surface, a shoe, a cast, a finger prosthesis or an upper limb prosthesis.

[0042] According to another aspect of the present disclosure, the at least one sensor may comprise at least one inductive sensor antenna or antenna array configured to sense distance to a magnetically permeable or conductive target material, enabling non-contact distance sensingbetween the inner structure and a target within an elastomeric liner or other interface component.

[0043] According to another aspect of the present disclosure, the method may be implemented at least in part via software executed by a processor, the software being stored on a non-transitory computer-readable medium. The software implementation enables automation of the computational algorithm for determining recess and routing feature locations and may support control adjustment and analytics during use.

[0044] According to another aspect of the present disclosure, the at least one sensor of the wearable interface may comprise at least one inductive distance sensor antenna, and the sensing system may further comprise a capacitor configured to tune a resonant frequency of the at least one inductive sensor antenna and a thermistor configured to measure temperature at a location of the at least one inductive sensor antenna. The capacitor enables optimization of sensor sensitivity, and the thermistor enables compensation for temperature-dependent variations.

[0045] According to another aspect of the present disclosure, the protective encapsulation of the sensor harness may comprise at least one of hot melt glue, epoxy, polyurethane, acrylic, dielectric adhesive, rubber adhesive, silicone potting compound, UV-curable resin or a conformal coating with high dielectric strength. The protective encapsulation shields the electronic components from mechanical damage during handling and fabrication.

[0046] According to another aspect of the present disclosure, the sensor harness may include sensor elements of different types configured to monitor different variables at a bodydevice interface, enabling simultaneous monitoring of multiple variables such as distance, force, pressure, shear stress, temperature, humidity, oxygen concentration, sweat, hydration, muscle function, energy levels, skin health, blood flow, vessel density, collagen density, heart rate, heart rate variability, blood pressure, respiration, electrolyte concentration, metabolite concentration, and analyte concentration.

[0047] According to another aspect of the present disclosure, the sensor harness may be available in standard sizes configured to cover a patient population without requiring custom dimensions, enabling bulk manufacturing while accommodating the range of wearable interface geometries encountered in clinical practice.

[0048] According to another aspect of the present disclosure, the lead wires of the sensor harness may have lengths calculated from a digital model of the wearable interface inner structure, enabling precise dimensioning for physical placement within the predefined recesses.

[0049] According to another aspect of the present disclosure, a wearable interface system is provided comprising the sensor harness integrated with the wearable interface, wherein the at least one sensor element of the sensor harness is positioned within the at least one recess on the external surface of the inner structure of the wearable interface, and the lead wires are routed through the routing features on the external surface of the inner structure. The integration enables precise sensor placement within the predefined recesses and organized routing of electrical connections. The wearable interface system may include more than one sensor harness configured with different sensor types or different numbers of sensor elements.

[0050] According to another aspect of the present disclosure, a wearable interface with embedded sensors made by the method described herein is provided, incorporating the computational determination of recess and routing feature locations, the inner structure with engineered recesses and routing features, and the encapsulation of the sensing system beneath the outer layer.

[0051] According to another aspect of the present disclosure, the method may further comprise receiving sensor data from the sensing system indicating motion of an underlying anatomical structure relative to the inner structure, for example a bony structure, using the sensor data with the digital file and a computational model to determine tissue stresses at the body-device interface, and computationally testing adjustments to at least one actuator dependent on the wearable interface based on the determined tissue stresses. The computational model may be a finite element model.

[0052] According to another aspect of the present disclosure, the sensing system may be three-dimensionally printed directly onto the inner structure during fabrication of the inner structure. Three-dimensional printing of the sensing system onto the inner structure eliminates or simplifies the sensor harness by forming the sensing elements as part of the inner structure fabrication process.

[0053] According to another aspect of the present disclosure, the processor of the wearable interface may be further configured to receive sensor data indicating motion of an underlying anatomical structure relative to the inner structure, for example a bony structure, use the sensor data with the digital file and a computational model such as a finite element model to determine tissue stresses at the body-device interface, and computationally test adjustments to at least one actuator dependent on the wearable interface based on the determined tissue stresses. Theprocessor may further use patient characteristics, prosthesis characteristics, and patient medical history and imaging data in determining the device adjustment.

[0054] According to another aspect of the present disclosure, the processor of the wearable interface may be further configured to use activity data to calculate the socket fit metric. Activity data may include information about the current activity mode of the user, such as walking, standing, sitting, or other activities, enabling the processor to adapt the socket fit metric calculation to the demands of the current activity.

[0055] According to another aspect of the present disclosure, the processor of the wearable interface may be further configured to use sensor data history to calculate the socket fit metric. Using sensor data history enables the processor to identify trends and patterns in socket fit over time, supporting predictive adjustment strategies and longitudinal monitoring of interface conditions.

[0056] According to another aspect of the present disclosure, the processor of the wearable interface may be further configured to receive data from at least one additional sensor comprising at least one of a pressure sensor, a capacitive sensor, a strain-gage sensor, a piezoelectric sensor, a textile-based sensor, a MEMS sensor, a vacuum sensor, a proximity sensor, an ultrasound sensor, a laser sensor, an optical sensor, a radar infrared sensor, or a tactile feedback sensor, and to use data from the at least one additional sensor in calculating the socket fit metric. Incorporating data from additional sensor types enables the processor to calculate the socket fit metric based on a broader set of interface conditions, improving the accuracy and robustness of the fit determination.

[0057] According to another aspect of the present disclosure, a non-transitory computer-readable medium storing instructions that, when executed by one or more processors, cause the one or more processors to perform the fabrication method described herein is provided. The computer-readable medium enables automation of the fabrication methodology including the computational algorithm for determining recess and routing feature locations.

[0058] According to another aspect of the present disclosure, a system for fabricating a wearable interface with embedded sensors is provided, the system comprising a processor and memory coupled to the processor and storing instructions that, when executed by the processor, cause the processor to execute the computational algorithm and perform the fabrication method described herein. The system enables integrated computational design and fabrication of the wearable interface with embedded sensors.

[0059] According to another aspect of the present disclosure, the at least one sensor of the method may be selected from the group consisting of an inductive sensor, a pressure sensor, a capacitive sensor, a strain-gage sensor, a piezoelectric sensor, a textile-based sensor, a MEMS sensor, a vacuum sensor, a proximity sensor, an ultrasound sensor, a laser sensor, an optical sensor, a radar infrared sensor, and a tactile feedback sensor. The variety of sensor types enables the fabrication methodology to be applied to different monitoring applications and sensing modalities.

[0060] According to another aspect of the present disclosure, the wearable interface fabricated by the method may comprise at least one of a prosthetic socket for a transtibial, transfemoral, or upper-limb amputation, an orthotic device, a helmet, a brace, an exoskeleton interface, a seating surface, a shoe, a cast, a finger prosthesis, an upper limb prosthesis, or a veterinary prosthetic or orthotic device for an animal. The fabrication methodology may be applied to any wearable structure where the inner structure conforms to the contour of a body part and monitoring of conditions at the body-device interface is desired.

[0061] According to another aspect of the present disclosure, the outer layer of the method may be selected from the group consisting of a structural lamination, a coating, a three-dimensionally printed shell, a vacuum-assisted carbon-fiber lamination, and a non-conductive polymer layer. The selection of outer layer type enables the fabrication methodology to be adapted to different structural requirements and manufacturing processes.

[0062] According to another aspect of the present disclosure, the at least one sensor of the wearable interface may be three-dimensionally printed directly onto the external surface of the inner structure. Three-dimensional printing of the sensor directly onto the inner structure eliminates or simplifies the sensor harness by forming the sensing elements as part of the inner structure fabrication process. In another embodiment, electrical connections may be three-dimensionally printed directly on the external surface of the inner structure.

[0063] According to another aspect of the present disclosure, the sensor harness may comprise sensor elements of different types configured to monitor different variables selected from distance, force, pressure, shear stress, temperature, humidity, oxygen concentration, sweat, hydration, muscle function, energy levels, skin health, blood flow, vessel density, collagen density, heart rate, heart rate variability, blood pressure, respiration, electrolyte concentration, metabolite concentration, and analyte concentration. The use ofdifferent sensor element types within a single sensor harness enables simultaneous monitoring of multiple variables at the body-device interface.

[0064] The foregoing general description of the illustrative embodiments and the following detailed description thereof are merely example aspects of the teachings of this disclosure and are not restrictive.BRIEF DESCRIPTION OF FIGURES

[0065] Non-limiting and non-exhaustive examples are described with reference to the following figures.

[0066] FIG. 1 illustrates a block diagram of a wearable interface with embedded sensors, according to aspects of the present disclosure.

[0067] FIG. 2 illustrates a node diagram of a sensor harness for integration with a wearable interface inner structure, according to aspects of the present disclosure.

[0068] FIG. 3 illustrates a system diagram of a control system environment for a wearable interface with embedded sensors, including a dynamic response path, according to aspects of the present disclosure.

[0069] FIG. 4 illustrates perspective views of an initial socket shape of a wearable interface inner structure showing the inner structure as one continuous piece, according to aspects of the present disclosure.

[0070] FIG. 5 illustrates a flowchart of a method for fabricating a wearable interface with embedded sensors, according to aspects of the present disclosure.

[0071] FIG. 6 illustrates perspective views of a wearable interface at successive stages of fabrication, according to aspects of the present disclosure.

[0072] FIG. 7 illustrates a flowchart of a method for computationally determining sensor placement locations on a wearable interface inner structure, according to aspects of the present disclosure.

[0073] FIG. 8 illustrates a flowchart of a method for assembling a sensor harness for integration with a wearable interface inner structure, according to aspects of the present disclosure.

[0074] FIG. 9 illustrates perspective views of sensor harness fabrication components and assembly stages, according to aspects of the present disclosure.

[0075] FIG. 10 illustrates a close-up view of an external surface of a wearable interface inner structure with a sensor positioned adjacent to a recess prior to placement, according to aspects of the present disclosure.

[0076] FIG. 11 illustrates a close-up view of a distal end of a wearable interface inner structure during fabrication, according to aspects of the present disclosure.

[0077] FIG. 12A illustrates a perspective view of an inner structure of a wearable interface with a sensing system installed showing electrical connections with an elastic element, according to aspects of the present disclosure.

[0078] FIG. 12B illustrates a perspective view of an inner structure of a wearable interface with a sensing system installed showing ferrite patches applied over sensor antennae, according to aspects of the present disclosure.

[0079] FIG. 13 illustrates close-up views of a ground wire being woven into an outer layer during wearable interface fabrication, according to aspects of the present disclosure.

[0080] FIG. 14 illustrates a flowchart of a method for operating a wearable interface with embedded sensors in a closed-loop monitoring and adjustment cycle, according to aspects of the present disclosure.

[0081] FIG. 15 illustrates schematic views of sensor array configurations for a wearable interface, including a sensor array including three uniformly sized circular inductive sensor antennae, an array including sensors of different size, and an overlapping array, according to aspects of the present disclosure.

[0082] FIG. 16 illustrates perspective views of a wearable liner system configured for use with a wearable interface having embedded sensors, according to aspects of the present disclosure.DETAILED DESCRIPTION

[0083] The following description sets forth example aspects of the present disclosure. It should be recognized, however, that such description is not intended as a limitation on the scope of the present disclosure. Rather, the description also encompasses combinations and modifications to those example aspects described herein.

[0084] As used herein, the term “wearable interface” refers to a structure configured to interface with a body part. A wearable interface may comprise a prosthetic socket, an orthoticdevice, a helmet, a brace, an exoskeleton interface, a seating surface, a shoe, a cast, a finger prosthesis, an upper limb prosthesis or another structure configured to contact or surround a body part. The body part may be a body part of a human user or an animal, such as a companion animal, service animal, or other animal requiring a prosthetic, orthotic, or other wearable interface. The wearable interface may include one or more sensors configured to monitor motion, position, distance, stress, displacement, temperature, humidity, oxygen concentration, sweat rate and composition or other variables at an interface between the wearable interface and the body part.

[0085] As used herein, the term “recesses” refers to depressions, debosses, cutouts, or other features formed in a surface and configured to receive components such as sensors. Recesses may be shaped to match the geometry of a sensor element so that the sensor element sits flush within or below the surface.

[0086] As used herein, the term “routing features” refers to channels, pathways, grooves, visual indicators such as ink pathways or printed markings, or other features formed in or placed on a surface and configured to guide mechanical or electrical connections such as lead wires, conductive traces, or other conductors from sensors to a connector or other termination point. Routing features may be physical structures formed in the surface of the inner structure, visual guides placed on the surface to indicate where a technician should route wires, or a combination thereof.

[0087] As used herein, the term “sensor elements” refers to sensing components configured to detect a variable at an interface between a wearable interface and a body part. Sensor elements may include inductive sensor antennae, pressure sensors, capacitive sensors, strain-gage sensors, piezoelectric sensors, textile-based sensors, MEMS pressure sensors, vacuum sensors, proximity sensors, ultrasound sensors, laser sensors, optical sensors, radar infrared sensors and tactile feedback sensors, or other sensing modalities. In some aspects, sensor elements may include inductive sensor antennae configured to sense distance to a magnetically permeable or conductive target.

[0088] As used herein, the term “digital file” refers to an electronic data file representing a contour of a body part or a modified contour of the body part. The digital file is for fabrication of the wearable interface. Contour files of body parts are often modified by practitioners into wearable interfaces so as to redistribute stress to load tolerant regions of the body part. The digital file may include a socket shape file, a scan of a body part, a scan of an existing socketor interface, or a computationally generated model of a body part contour. The digital file may include anatomical landmark data such as patellar tendon location, tibia axis, tibial tubercle, fibular head location, anterior distal end of tibia location, distal end of fibula or other anatomical features. As used herein, the term “landmark data” encompasses both anatomical landmark data and practitioner-placed landmark data. Anatomical landmark data refers to locations of identifiable anatomical features such as the patellar tendon, tibial tubercle, fibular head, anterior distal end of tibia, or other bony or soft tissue features. Practitioner-placed landmark data refers to digitization marks placed by a clinician or technician during scanning or digital file creation to indicate locations of clinical interest, such as preferred sensor locations, regions requiring monitoring, areas at risk for skin breakdown, or other locations the practitioner identifies as important for the wearable interface. Landmark data may be included in the digital file by a clinician or technician during scanning, may be added to the digital file after scanning, or may be automatically identified from a scan of the body part or existing interface. For non-prosthetic applications, the anatomical landmark data may include other anatomical features relevant to the body part of interest, such as cranial suture locations for helmet applications, rib or spine locations for back brace applications, or bony prominence locations for orthotic or seating surface applications. The digital file may contain further parameters for actuator mounting locations, vent placements, or stiffness variability or gradients within the inner structure.

[0089] As used herein, the term “lookup table” refers to a data structure that stores precomputed values relating sensor signals to physical variables such as distance, position, or other measurable quantities. A lookup table may enable rapid conversion of sensor measurements during operation by retrieving stored values rather than performing real-time calculations, as done when using a complex computational model, for example. Interpolation between points in a lookup table may be executed quickly. In some aspects, a lookup table may be generated during a calibration process and may include correction factors for sensor-specific characteristics such as active region and sensitivity distribution.

[0090] The present disclosure provides a fabrication methodology centered on an inner structure that replaces conventional inner lamination layers with a structure explicitly engineered with recesses, routing features, and connector enclosures for reliable and fast integration of sensors. The inner structure may be fabricated based on a digital file representing a contour of a body part or a modified contour of the body part, the digital file being for fabrication of the wearable interface, using additive manufacturing techniques, machining,molding, or other manufacturing methods. A computational algorithm may determine locations for the recesses and routing features based on landmark data within the digital file or landmarks calculated from the socket shape digital file. A sensing system comprising a pre-assembled sensor harness may then be placed onto the external surface of the inner structure, with sensors positioned within the recesses and electrical connections routed through the routing features. An outer layer such as a structural lamination, coating, or three-dimensionally printed shell may be applied to encapsulate the sensors and electrical connections, with the sensors subsurface embedded on the external surface of the inner structure and protected from wear. On the inside surface, the continuous inner structure protects the sensors.

[0091] The inner structure may include a single recess or a plurality of recesses depending on the monitoring application. Multiple recesses may accommodate sensor arrays for position determination, overlap arrays for extended coverage, or fusions of multiple sensors from different locations to determine position, orientation, or motion of large regions or structures. The inner structure may be configured with the appropriate number of recesses and routing features based on the clinical monitoring objectives and the complexity of the sensing system to be integrated.

[0092] In some implementations, the fabrication methodology disclosed herein may be applied to prosthetic sockets for transtibial, transfemoral, or other amputations, where the inner structure is shaped based on the contour of a residual limb for fabrication of the wearable interface. The methodology may also be applied to orthotic devices such as lower-limb orthosis cuffs or back braces, helmets for cranial management or concussion monitoring, exoskeleton interfaces, seating surfaces, shoes, casts, finger prostheses, upper limb prostheses, or other wearable structures where the inner structure conforms to the contour of a body part and monitoring of conditions at the body-device interface is desired. Outside of rehabilitation applications, the methodology may be applied to motion capture for animation or filmmaking, robotic training and control systems, sports performance monitoring in athletic equipment interfaces, ergonomic assessment of workplace equipment, or testing and monitoring any condition in which position and movement between a custom-shaped inner structure and a nearby surface is of interest.

[0093] The methodology may also be applied to veterinary applications, where the inner structure conforms to the contour of an animal body part such as a limb of a companion animal, service animal, or working animal. Prosthetic and orthotic devices for animals may benefit from the same embedded sensor capabilities described herein, including monitoring ofconditions at the body-device interface and open-loop or closed-loop adjustment based on sensor data. The following description with reference to the accompanying figures provides additional detail regarding the structure and fabrication of the wearable interface with embedded sensors.

[0094] Referring to FIG. 1, a wearable interface 100 with embedded sensors is shown in block diagram form. Wearable interface 100 represents an example embodiment, and other configurations are possible. Wearable interface 100 may be a prosthetic socket, an orthotic device, a helmet, a brace, an exoskeleton interface, or another structure configured to interface with a body part.

[0095] Wearable interface 100 includes an inner structure 102 having an internal surface 104 configured to interface with the body part of a user and an external surface 106. Internal surface 104 may be configured to contact a residual limb, a liner worn over the residual limb, a sock, a pad, a flexible inner or another body surface. Inner structure 102 may be fabricated from a digital file representing a contour of a body part or a modified contour of the body part, the digital file being for fabrication of the wearable interface, using additive manufacturing techniques, machining, molding, lamination, blister forming, a hybrid approach, or other manufacturing methods. Inner structure 102 may be fabricated from materials having variability or a gradient in stiffness from internal surface 104 to external surface 106. A variability or gradient in stiffness from the internal surface to the external surface may enable the internal surface to provide a compliant interface with the body part while the external surface provides structural support for the recesses, routing features, and outer layer. A computational algorithm may determine the locations for recesses 108 and routing features 110 based on landmark data within the digital file or the contour within the digital file.

[0096] With continued reference to FIG. 1, external surface 106 includes a predefined layout with at least one recess 108 and routing features 110. Recesses 108 are debosses formed in external surface 106 and shaped to receive sensor elements and other components, such as socket adjustment components. Routing features 110 are channels, grooves, visual indicators, or pathways formed in or on external surface 106 that guide sensing or adjustability components, such as lead wires from the sensors to a connector or cable housings to an adjustment machanism, as described previously with respect to the definition of “routing features.” External surface 106 further includes a connector enclosure 112 configured to receive a connector of a sensing system. Connector enclosure 112 is positioned such that a bottom surface of connector enclosure 112 is flush with a distal end of inner structure 102.

[0097] External surface 106 may also include structural elements 114 configured to support adjustable socket panels; vacuum or suction mechanism; adjustable cabling mechanism; fluid-filled enclosure; air-filled enclosure; stiffness adjustment mechanism; frictional adjustment mechanism; socket length adjustment mechanism; manual mechanisms for adjustment of the wearable interface; electronic actuators for auto-adjustment of the wearable interface; a release-relock mechanism; vents; a cooling mechanism; or a grip control mechanism; or other device. Structural elements 114 may be formed integrally with inner structure 102 during fabrication of the inner structure and sized to receive the selected adjustment mechanisms while maintaining structural integrity of recesses 108 and routing features 110. In some aspects, the adjustable elements supported by structural elements 114 may not be exclusively fastened to inner structure 102. The adjustable elements may alternatively be fastened to or integrated with outer layer 124, whether the outer layer is a lamination, a three-dimensionally printed shell, or another structural covering.

[0098] As further shown in FIG. 1, wearable interface 100 includes a sensing system 116 comprising at least one sensor positioned within recesses 108. The sensors may be inductive sensor antennae, pressure sensors, capacitive sensors, strain-gage sensors, piezoelectric sensors, shear sensors, textile-based sensors, MEMS pressure sensors, vacuum sensors, proximity sensors, ultrasound, laser, optical, radar infrared sensors and tactile feedback sensors or other sensor elements. In the embodiment shown, sensing system 116 includes multiple inductive sensor antennae 118, electrical connections 120 extending from inductive sensor antennae 118 through routing features 110, and a connector 122 configured to receive electrical connections 120. Inductive sensor antennae 118 are coil antennae configured to sense distance to a magnetically permeable or conductive target. The sensors may be configured to track stress, displacement, and other metrics when a target material is embedded and properly constrained. Sensing system 116 may be a pre-assembled sensor harness that is a standalone subassembly physically separable from inner structure 102 prior to integration. The sensors may be arranged as a single sensor, in a sensor array, or as a fusion of multiple sensors configured to determine the position of a target relative to the inner structure 102 or multiple target locations relative to the inner structure 102. Sensing system 116 may further include a capacitor configured to tune a resonant frequency of the at least one resonant frequency sensor and a thermistor configured to measure temperature at the location of the at least one sensor.

[0099] Wearable interface 100 further includes an outer layer 124 disposed over inner structure 102 and sensing system 116. Outer layer 124 may completely or partially encapsulatethe sensors and electrical connections 120. In some embodiments, outer layer 124 completely encapsulates the sensors such that the sensors are sub-surface embedded on external surface 106 of inner structure 102 and protected from wear by outer layer 124. Outer layer 124 may be a structural lamination such as a vacuum-assisted carbon-fiber lamination, a coating, a three-dimensionally printed shell, or another structural covering applied over inner structure 102 and sensing system 116. When outer layer 124 includes a conductive material such as carbon fiber or another material that may distort the electromagnetic field, a material that is magnetically permeable and electrically resistive sufficient to limit eddy current losses when a magnetic field is applied may be applied over each sensor prior to applying outer layer 124, and a ground wire from sensing system 116 may be woven into outer layer 124 to electrically isolate the sensors from conductive materials in outer layer 124.

[0100] With continued reference to FIG. 1, wearable interface 100 may be used with an elastomeric liner 126 configured to be worn between the body part and internal surface 104 of inner structure 102. For inductive sensor embodiments, elastomeric liner 126 may include a magnetically permeable or conductive target material 128 configured to interface with inductive sensor antenna 118. Magnetically permeable or conductive target material 128 may be integrated into elastomeric liner 126 in various configurations, including a full magnetically permeable or conductive layer, targeted areas of magnetically permeable or conductive material at locations corresponding to recesses 108, magnetically permeable or conductive material within a fabric backing, magnetically permeable or conductive sections molded within the elastomer liner which may include a silicone, polyurethane, or thermoplastic layer, or disks or bands of magnetically permeable or conductive material on a textile or polymer affixed to an outer surface of elastomeric liner 126. A ferrous material is used in the description below though other magnetically permeable or conductive materials besides iron powder may be used. In some aspects, magnetically permeable or conductive sections may be molded within the elastomer liner which may include a silicone, polyurethane, or thermoplastic layer during liner fabrication, enabling integration without separate attachment steps. For non-inductive sensor embodiments, elastomeric liner 126 may not include magnetically permeable or conductive target material or may include different target materials appropriate to the sensing modality.

[0101] Wearable interface 100 further includes a processor 130 configured to receive data from inductive sensor antenna 118. Processor 130 may determine a socket fit metric based on the data received from sensing system 116 and from that determine a device adjustment. As used herein, a device adjustment refers to a modification to a dimension of the wearable1interface or to a feature of the prosthesis or assistive device dependent on the wearable interface, including but not limited to socket size, componentry stiffness, surface friction, socket length, suspension height, or other adjustable parameters. Processor 130 may issue commands to an actuator configured to adjust a dimension of wearable interface 100 or other parts of the prosthesis dependent on the wearable interface application based on the sensor data. A dependent feature refers to a component or parameter of the prosthesis or assistive device that is functionally related to the wearable interface, such as foot stiffness, knee stiffness, ankle stiffness, alignment, knee flexion, ankle flexion, range of motion, foot length, temperature, joint power, energy storage and return properties, socket length, or other componentry characteristics that may be adjusted in response to sensor data from the wearable interface.

[0102] Inner structure 102 may include mounting features for the actuator within structural elements 114. Processor 130 may present information showing locations of recesses 108 relative to anatomical landmarks to allow prosthetists to view data at locations collected relative to areas at risk for injury. Processor 130 may integrate a patient’s liner type and thickness, componentry models and settings, prosthetist information from patient treatment history, and medical information from a primary care provider available in a digital record. Prosthetists may add selections for data collection locations to an inner structure file as landmarks, and such landmarks may become locations for deboss fabrication in inner structure 102.

[0103] Processor 130 may be a microprocessor, a microcontroller, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA), or another processing device configured to execute instructions for analyzing sensor data and controlling actuator 304. In some embodiments, multiple processors may be used, where a first processor performs real-time signal processing of sensor data and a second processor performs higher-level analysis such as pattern recognition or machine learning inference. Processor 130 may be located within wearable interface 100, within a separate housing attached to wearable interface 100, or within a remote device that communicates with sensing system 116 via wired or wireless connection.

[0104] Referring to FIG. 2, a node diagram of a sensor harness 200 for integration with inner structure 102 of wearable interface 100 is shown. Sensor harness 200 may be a standalone subassembly physically separable from the inner structure prior to integration. Sensor harness 200 may include a single sensor element or multiple sensor elements depending on the monitoring application. In alternative embodiments, the sensing system may be assembleddirectly onto inner structure 102 during fabrication rather than as a pre-assembled standalone subassembly, or the sensor elements and electrical connections may be three-dimensionally printed directly onto inner structure 102.

[0105] In some implementations, wearable interface 100 may include more than one sensor harness. For example, a first sensor harness may include inductive sensor antennae for distance sensing, and a second sensor harness may include pressure sensors for interface stress monitoring. Multiple sensor harnesses may be used where different sensor types require different electronic components, different protective encapsulation materials, or different connector configurations, or where a large number of sensors makes a single harness impractical for assembly or placement. Each sensor harness may be independently tested for functionality prior to integration with inner structure 102. The multiple sensor harnesses may share a single connector enclosure 112 or may each have a separate connector enclosure on the inner structure.

[0106] Prior to integration, sensor harness 200 may be held in place within recesses 108 by an adhesive such as double-sided tape and is not permanently bonded to inner structure 102 until outer layer 124 is applied. The physical separability of sensor harness 200 from inner structure 102 prior to application of outer layer 124 enables removal and replacement of sensor harness 200 if testing reveals a defect. In other implementations, sensor harness 200 may be permanently integrated with inner structure 102 during placement, such as through automated assembly processes or direct bonding methods. Sensor harness 200 is dimensioned and configured for physical placement within the predefined recesses on the external surface of the inner structure prior to application of an outer structural layer.

[0107] Sensor harness 200 includes one or more sensor elements, each having associated electronic components. The sensor elements may include inductive sensor antennae, pressure sensors, capacitive sensors, strain-gage sensors, piezoelectric sensors, shear sensors, textilebased sensors, MEMS, vacuum sensors, proximity sensors, ultrasound, laser, optical, radar infrared sensors and tactile feedback sensors, or other sensing components. Sensor harness 200 may include sensor elements of different types to monitor multiple variables at the body-device interface. In embodiments where the sensing system includes sensors of different modalities, the inner structure digital file may be configured with recesses and routing features dimensioned for each sensor type, with separate routing paths that maintain electrical isolation and minimize crosstalk between different sensor modalities.

[0108] In the embodiment shown in FIG. 2, the sensor elements are inductive sensor antennae 202 or antenna arrays. Each of the inductive sensor antennae 202 or antenna arrays may be a coil antenna or group of coil antennae configured to sense distance to the magnetically permeable target or conductive material. The associated electronic components may include a capacitor 204 and a thermistor 206 for each inductive sensor antenna. Electronic components may be attached to inductive sensor antennae 202 by soldering, conductive adhesive, or other attachment methods. Capacitor 204 may be configured to tune the resonant frequency of the corresponding inductive sensor antenna to optimize sensor sensitivity for the expected distance range. Thermistor 206 may be configured to measure temperature at the corresponding inductive sensor antenna location, enabling compensation for temperature-dependent variations in sensor response or providing additional clinical data regarding conditions at the body-device interface. For non-inductive sensor embodiments, the associated electronic components may include signal conditioning circuitry, amplifiers, or other components appropriate to the sensing modality.

[0109] With continued reference to FIG. 2, sensor harness 200 includes a single connector housing 208 and lead wires 210 pre-installed within single connector housing 208 and extending to each of inductive sensor antennae 202, sensor array, or fusion of sensors. In alternative embodiments, sensor harness 200 may include multiple connector housings or may use wireless connections where each sensor element includes a wireless transmitter configured to communicate with processor 130.

[0110] Lead wires 210 may be pre-installed within single connector housing 208 before assembly of sensor harness 200, which may reduce the risk of damage during fabrication and speed up installation. Lead wires 210 may be arranged in a zigzag or serpentine configuration with an elastic element in parallel to accommodate varying distances between inductive sensor antennae 202 and single connector housing 208. In alternative embodiments, lead wires 210 may be arranged in a straight configuration with slack, a coiled or helical configuration, or a flat ribbon cable configuration. The lead wire configuration may be selected based on the geometry of the inner structure, the number of sensor elements, and the routing path lengths determined by the computational algorithm.

[0111] The lengths of lead wires 210 may be calculated from the digital model generated by the computational algorithm described with respect to method 500 by adding a margin (e.g., 2-5 centimeters) to the routing path length from the antenna to the connector plug, ensuring that lead wires 210 are not too taut when adhered to the external surface. Alternatively, astandard wire length for each region of the wearable interface (proximal, mid-limb, and distal for a prosthetic socket, or other regions for non-prosthetic applications) may be used, with excess wire bundled in a crevice next to the connector. Sensor harness 200 may be available in standard sizes (such as small, medium, and large) with corresponding wire lengths to cover the patient population rather than requiring custom dimensions for each configuration.

[0112] Sensor harness 200 may be dimensioned based on the inner structure geometry using a digital model such as a CAD model, a parametric model, a scan-derived model, or another computational representation. Recess dimensions from the digital model, including the depth, inner diameter, outer diameter, and tail dimensions of each recess, may inform the sizing of the corresponding sensor elements. Routing path lengths from the digital model may inform lead wire lengths by determining the routing path length from each recess to the connector enclosure and adding a margin. The digital model may output dimensional parameters for the sensor harness including sensor element sizes, lead wire lengths, and connector housing position, enabling vendor fabrication of sensor harnesses dimensioned for physical placement within the predefined recesses of the corresponding inner structure.

[0113] Sensor harness 200 further includes a protective encapsulation 212 disposed over the electronic components of each sensor element. Protective encapsulation 212 may be hot melt glue placed at a midpoint of a tab of each of inductive sensor antennae 202 and compressed into an even layer over the electronic components using a mold with a closable lid. Protective encapsulation 212 may alternatively be epoxy, polyurethane, acrylic, dielectric adhesive, rubber adhesive, silicone potting compound, UV-curable resin, or a conformal coating with high dielectric strength. Protective encapsulation 212 protects capacitor 204, thermistor 206, solder pads, and lead wires 210 from mechanical damage during handling and fabrication. For scale production, protective encapsulation 212 may be applied using automated dispensing systems, pick-and-place equipment, continuous flow encapsulation processes, injection molding, transfer molding, or overmolding techniques.

[0114] As further shown in FIG. 2, when sensor harness 200 includes multiple sensor elements, adjacent sensor elements may be connected through a flexible joint 214. Flexible joint 214 may be formed in a flexible circuit backing material such as polyimide, polyester, liquid crystal polymer, or another flexible substrate to maintain sensor organization during placement while allowing the sensor elements to conform to curved surfaces of the inner structure. Flexible joint 214 may include cutouts in the flexible circuit backing material that allow adjacent inductive sensor antennae 202 to flex relative to each other, enabling sensorarrays or fusions of multiple sensors to take on the shape of the wearable interface while keeping the sensors organized for the technician to apply into the recesses. In another embodiment, when the deboss for the sensors is relatively flat no cutouts are made in the flexible circuit backing material.

[0115] A support material such as peelable backing may be used to support inductive sensor antennae 202 during handling and later removed once the sensors are in place within the recesses. Alternative support methods such as rigid carriers, vacuum fixtures, or dissolvable materials may also be used. Sensor harness 200 may be prepared in bulk in a fabrication process separate from the wearable interface fabrication. Preparing sensor harness 200 in bulk may make the assembly durable and strain relieve lead wires 210, minimizing the risk of damage during subsequent fabrication steps.

[0116] Referring to FIG. 3, a system diagram of a control system environment 300 for wearable interface 100 with embedded sensors is shown. Control system environment 300 illustrates closed-loop control architecture for dynamic fit adjustment of wearable interface 100 based on sensor data. The control system architecture may be applied to prosthetic sockets, orthotic devices, helmets, exoskeletons, seating surfaces, shoes, casts, finger prostheses, upper limb prostheses or other wearable interfaces where dynamic adjustment based on sensor feedback is desired.

[0117] In control system environment 300, processor 130 receives sensor data from sensing system 116. As shown in FIG. 3, sensing system 116 is represented as sensing system 302 to illustrate the sensor configuration within the control system environment. Sensing system 302 may include a single sensor, a sensor array, or a fusion of multiple sensors. A fusion of multiple sensors may include sensor arrays. The positions and orientations of the sensors relative to each other are well-controlled and well known from the inner structure digital file used to fabricate inner structure 102. This enables the computational algorithm to combine the sensor positions and orientations with calibration data, for example lookup table data for each sensor, to characterize the active region and sensitivity distribution of sensors in sensing system 302, which improves the resolution and quality of the data.

[0118] The active region of a sensor refers to the spatial area over which the sensor can detect the target material. The sensitivity distribution describes how the sensor’s responsiveness varies across the active region. Characterizing the active region and sensitivity distribution enables correction of sensor measurements based on the known position andorientation of each sensor within the inner structure. Sensors that are part of sensing system 116, for example inductive distance sensors, may be positioned within recesses 108 on external surface 106 of inner structure 102 and configured to sense distance to magnetically permeable or conductive target material 128 within elastomeric liner 126.

[0119] For a sensor array that includes three or more antennae and a magnetically permeable or conductive target of approximately comparable size to the antennae, measurements from these three sensor antennae 118 may be used to estimate the three-dimensional position of the target relative to the array. In one method, the distance of the target from each antenna is inferred from the sensor data and a geometric calculation such as trilateration is implemented to estimate the position. In another method, interpolation of data in a pre-determined lookup table is used to estimate the position.

[0120] Alternatively, for a sensor array that includes at least two antennae and a magnetically permeable or conductive target larger than the antennae, the measurements from each antenna may be processed independently to determine the sensed distance of a few locations corresponding to the number of antennae. This configuration is effective when monitoring locations where the sensor planes are misaligned or of different curvatures, for example a bony area of the limb such as the anterior distal end of the tibia. Other areas with an underlying anatomical structure of interest may also be monitored. Each sensor measures the perpendicular distance to a different point on magnetically permeable or conductive target material 128. Because the positions and orientations of the sensors relative to each other are well-controlled and well known from the inner structure digital file, processor 130 may determine the perpendicular distance for each sensor to magnetically permeable or conductive target material 128. From this data, processor 130 may determine the motion and orientation of the underlying bone relative to the reference frame of inner structure 102. By monitoring at other bony locations, processor 130 may measure the angulation of the bony structures in the residual limb relative to inner structure 102. Incorporation of a scan of the limb bony structures into the inner structure digital file may allow processor 130 to track the motion of all bony structures.

[0121] With continued reference to FIG. 3, processor 130 determines a socket fit metric from the data received from sensing system 302. The socket fit metric may be an average of multiple sensor readings, data from multiple sensors combined in an equation, or another computation derived from the sensor data. The socket fit metric may reflect bony structure motion relative to the inner structure, such as the motion and orientation of underlying bone orangulation of bony structures determined from the sensor data. Processor 130 then determines prosthesis adjustments based on the relationship between adjustments and sensor data, which has been previously measured and characterized. Because the relationship between specific adjustments and their effect on sensor data is known, processor 130 may work backwards from the current sensor data to identify the adjustment that will bring the socket fit metric toward a desired value.

[0122] Processor 130 may analyze the sensor data to identify sources of change in socket fit, for example changes in limb volume, limb shape, limb-socket alignment, position changes of the residual limb within the socket in multiple directions, sweat buildup, gait, terrain, temperature, or other variables. Processor 130 may also determine activity modes including walking bouts, low locomotion, standing stationary, standing weight shifting, sitting still, sitting weight shifting, partial doff (partial removal of the wearable interface from the body part), and full doff (complete removal of the wearable interface from the body part) based on the sensor data, and may adapt the control strategy accordingly. Processor 130 may use sensor data history to identify trends and patterns in socket fit over time. Processor 130 may store sensor data for later analysis or may transmit sensor data to remote devices or services for further processing and clinical review.

[0123] Sensor data from sensing system 302 may inform adjustments to prosthetic componentry including foot, knee, and ankle stiffness, socket surface roughness and frictional coefficient, knee motion characteristics, energy storage and return properties of prosthetic componentry, and socket length. For example, sensor data indicating excessive limb pistoning within the socket may suggest a need for increased socket friction, and sensor data indicating restricted limb motion may suggest a need for reduced stiffness in foot, knee, or ankle componentry. Such adjustments may be implemented by a clinician or user based on sensor data analysis or may be implemented automatically by processor 130 through electronic actuators or adjustable componentry.

[0124] Actuator 304 is configured to adjust one or more dimensions of wearable interface 100 or other parts of the prosthesis dependent on the wearable interface application based on commands from processor 130. Actuator 304 may be a motor-driven mechanism configured to move adjustable socket panels radially inward and outward through a lead screw or through an adjustable cabling mechanism or other mechanism coupled to the panels. Actuator 304 may alternatively include ratcheted dials, lever mechanisms, straps, grids of fluid-filled bubbles, grids of air-filled bubbles, pumps, threaded inserts, flexible panels, or other adjustmentmechanisms Actuator 304 may alternatively adjust a vacuum or suction setting, a fluid-filled enclosure, air-filled enclosure, a stiffness adjustment mechanism, frictional adjustment mechanism, a release-relock mechanism, vents, a cooling mechanism, a grip control mechanism, or other manual or electronic adjustments in the prosthesis.

[0125] Inner structure 102 may include mounting features for actuator 304 within structural elements 114. The mounting features provide physical support for the adjustment mechanisms and position them at predetermined locations on inner structure 102. Because the positions of recesses 108 and structural elements 114 are known from the inner structure digital file, the control system can correlate sensor measurements with the physical locations of the adjustment mechanisms, enabling processor 130 to issue targeted commands to actuator 304 in response to changes detected by sensing system 302.

[0126] The release-relock mechanism supported by structural elements 114 may include an electronic configuration in which a motor drives the release-relock mechanism, providing an electronic means to control the release and relock distances when connected to a microcontroller or processor 130. Buttons or other user input devices to control the release action and relock action may be incorporated into the inner structure’s support surface within structural elements 114. Release-relock is a method that allows users to temporarily release socket structures to facilitate recovery of limb fluid volume, by moving the structures radially outward or in another direction, or by releasing a pin or tether through the bottom of the socket so that the prosthesis wearer may partially doff the prosthesis. Releasing socket structures during rest periods may allow fluid that has been displaced from the residual limb during weight-bearing to return, improving comfort and tissue health. The release-relock mechanism may be part of an adjustable panel system, such as a cabled system, supported by structural elements 114.

[0127] The adjustment mechanism may further include a manual safety release separate from the primary adjustment mechanism. The manual safety release may be fastened to the mounting structures of the adjustment system and configured to allow the adjustable elements such as panels to fold outward or release tension in the event of motor failure, battery depletion, or other loss of powered adjustment capability, enabling the user to remove the body part from the wearable interface without powered assistance. The manual safety release may be a mechanical latch, a spring-loaded release, a breakaway fastener, or another mechanism configured to override the powered adjustment system.

[0128] Structural elements 114 may also support an adjustment mechanism that changes the height of the suspension mechanism or the length of the wearable interface perceived by the user. Such height adjustment may enable the user or clinician to modify the effective socket depth in response to changes in conditions at the body-device interface or to accommodate different activity levels. The inner structure may be designed with sensors and appropriate mounting structures to support automated adjustment.

[0129] In some implementations, panel debossments may be formed around the edges of adjustable panels on external surface 106 so that the technician can identify where to cut during fabrication. Rectangular debossments may also be formed to hold cables or other adjustment hardware. These visual and tactile guides on the inner structure may reduce fabrication errors by providing the technician with clear indications of panel boundaries, cable routing paths, and hardware mounting locations during the assembly process.

[0130] As further shown in FIG. 3, a dashed dynamic response path extends from wearable interface 100 back to sensing system 302. The dashed dynamic response path illustrates that sensor data from sensing system 302 is continuously fed back to processor 130, which in turn commands actuator 304 to adjust wearable interface 100, creating a closed-loop control cycle. This closed-loop control architecture may enable automatic adjustment of the prosthesis based on the embedded sensor data without manual intervention.

[0131] In some implementations, auto-adjustments performed by processor 130 may be dependent on patient-specific attributes in addition to the sensor measurements. For example, the auto-adjustment strategy may differ based on residual limb length. At certain anatomical locations such as the anterior distal region, short limbs and long limbs may exhibit opposite patterns of sensed distance change in response to changes in interface friction. In some aspects, short limbs may show decreased pistoning when interface friction increases, while long limbs may show increased pistoning under the same conditions. This difference may be due to variations in limb depth and a coupling action between anatomical sites such as the anterior distal and posterior mid-limb regions that influences how the limb moves within the socket. Accordingly, short limbs and long limbs may require different adjustment responses to maintain optimal fit. Processor 130 may receive patient attribute data such as residual limb length, limb circumference, or tissue composition from the digital file or from clinical records and may adjust the control algorithm accordingly. The auto-adjustment strategy is linked to the inner structure fabrication because the sensor positions, structural element positions, and patient-specific attributes are all derived from the inner structure digital file.

[0132] Processor 130 may use computational analysis techniques on data collected from prosthesis users to establish patterns in data. The patterns established by the computational analysis may be used to create algorithms that inform new design processes and improve the workflow for future wearable interface fabrication. Computational strategies may include machine learning algorithms, statistical analysis, rule-based systems, or other data analysis techniques applied to data collected from the sensors to inform the performance and clinical utility of the sensor locations and to improve the design optimization of future inner structures.

[0133] Referring to FIG. 4, two perspective views of an initial socket shape 400 of a wearable interface inner structure are shown. While FIG. 4 illustrates a prosthetic socket embodiment, the inner structure shape may be configured for other wearable interface applications such as orthotic devices, helmets, a brace, an exoskeleton interface, a seating surface, a shoe, a cast, a finger prosthesis, an upper limb prosthesis, or a veterinary prosthetic or orthotic device for an animal, where the inner structure conforms to the contour of the corresponding body part or a practitioner-modified contour for the wearable interface.

[0134] A first view on the left depicts inner structure 402 from a first angle, showing the anatomically contoured socket body with proximal opening 404 at the top configured to receive a residual limb. Proximal opening 404 defines the entry point through which the residual limb or a liner worn over the residual limb is inserted into the wearable interface. A second view on the right depicts inner structure 402 from a second angle, showing proximal opening 406 at the proximal end. Inner structure 402 and proximal opening 406 are one continuous piece, together forming the inner structure at the outset of fabrication.

[0135] The hole 406 may simplify pouring plaster or other structural support material or frame into inner structure 402 to provide mechanical support during fabrication of outer layer 124. Inner structure 402 exhibits a tapered profile narrowing from proximal opening 404 toward the distal end, conforming to the anatomical contour of some residual limbs. Residual limbs with a more cylindrical shape may exhibit less taper, and the inner structure profile may be adjusted accordingly. For non-prosthetic applications, the opening and profile of the inner structure may be configured to conform to the contour of the corresponding body part, such as a head for a helmet application or a limb segment for an orthotic application.

[0136] Inner structure 402 may be fabricated from a digital file representing a contour of a body part or a modified contour of the body part, the digital file being for fabrication of the wearable interface, as described previously with respect to FIG. 1. The digital file may beimported into a computer-aided design (CAD) package where the shape may be outward projected or otherwise processed to create a solid model of inner structure 402 with a defined wall thickness. Inner structure 402 may have sufficient thickness to form the recesses on external surface 106 to support sensor elements. The thickness and projection distance may be selected based on the outer layer type, the sensor element dimensions, and the structural requirements of the wearable interface application. Inner structure 402 may be fabricated using additive manufacturing techniques as described previously with respect to FIG. 1, or alternatively using machining, molding, or other manufacturing methods.

[0137] The materials of inner structure 402 may differ within examples. In one embodiment, inner structure 402 may be made of a glass-filled, carbon-filled polymer, ceramic-filled polymer having a glass transition temperature, Young’s modulus, and tensile strength suitable for the intended outer layer application. For example, when heated lamination is applied as the outer layer, the material should have a glass transition temperature above the lamination processing temperature and mechanical properties comparable to materials used in traditional socket fabrication. For applications where heated lamination is not used, such as when the outer layer comprises a coating, a three-dimensionally printed shell, or another nonheated structural covering, materials with lower glass transition temperatures or different mechanical properties may be used, including standard polymers, flexible thermoplastics, or elastomeric materials.

[0138] A hole may be designed through distal opening 610 centered about a mounting adapter to ensure proper alignment between inner structure 402 and prosthetic componentry during use. In one embodiment, the hole may have a sufficient diameter to accommodate a four-hole adapter. Material may be added around distal opening 610 to create a lip and support for the mounting adapter, providing structural support for load transfer and allowing the top of the adapter to line up properly with inner structure 402 when the technician begins the layup process. If a suspension method is used that does not require a distal hole, such as suction, vacuum, or sleeve suspension, the distal end of inner structure 402 may be continuous. In such configurations, sensor antennae may be positioned in the distal region, covered, and then the distal hardware added within a recess created to hold the structure of interest. The method may also be applied to side of socket suspension, for example in a blade prosthesis configuration, where the attachment point is located at a side of the socket rather than at the distal end.

[0139] At the brim of the CAD model for inner structure 402, a flat plate may be added above the brim line. The flat plate may be extended outward, and a hole may be placed throughthe flat plate connecting to the inside of inner structure 402. The hole may simplify pouring plaster or other structural support material or frame into inner structure 402 to provide mechanical support during fabrication of outer layer 124. In some implementations, when the inner structure material has sufficient strength and thermal resistance, the structural support material may not be needed.

[0140] Referring to FIG. 5, a flowchart of method 500 for fabricating wearable interface 100 with embedded sensors is shown. Method 500 provides an overview of the fabrication process for integrating sensing system 116 into inner structure 102. While method 500 is described with reference to a prosthetic socket embodiment, the steps of method 500 may be applied to fabrication of other wearable interfaces such as orthotic devices, helmets, exoskeleton interfaces, a seating surface, a shoe, a cast, a finger prosthesis, an upper limb prosthesis or other structures configured to interface with a body part. Method 500 may be implemented as a whole or in part via software executed by a processor or computer system, the software being stored on a non-transitory computer-readable medium. For example, steps 502 and 504 involving receiving the digital file and executing the computational algorithm may be performed by software running on a computer workstation, a cloud-based computing platform, or another processing system. Each of the methods disclosed herein, including method 500, method 700, method 800, and method 1400, may be implemented in whole or in part via software, firmware, or a combination thereof, executed by one or more processors and stored on one or more non-transitory computer-readable media.

[0141] Method 500 begins at step 502 with receiving a digital file representing a contour of a body part or a modified contour of the body part, the digital file being for fabrication of the wearable interface. The digital file may comprise a socket shape file that includes anatomical landmark data as described previously with respect to the definition of “digital file.” The digital file may be obtained from a scan of a socket shape, a traditional socket shape, or a direct scan of the residual limb, from medical imaging data such as CT orMRI, from a computational model, or from a database of body part contours. If no digital file is available, an industrial scanner and software may be used to scan the socket shape, add landmarks, and create the digital file.

[0142] At step 504, a computational algorithm is executed to determine locations for recesses 108, routing features 110, connector enclosures, support structures for adjustment mechanisms, and other elements to be designed into the inner structure based on landmark data within the digital file. The computational algorithm may use anatomical features andpractitioner-placed digitization marks to determine sensor placement locations. In some cases, the computational algorithm may adjust sensor locations based on local surface contour of inner structure 102, including adjusting locations to avoid local surface regions that are not flat or of one curvature, for example regions exhibiting multiple directions of curvature or combined concavity and convexity. The computational algorithm may also determine an optimal wiring routing strategy that uses the least amount of wire, maintains sufficient distance from locations that could damage the wires, such as near adjustable panels or other socket hardware, and ensures that wires from different sensors do not cross. In some cases, if a wire crossing is implemented, shield material may be placed between the wires during fabrication to reduce noise.

[0143] At step 506, inner structure 102 is generated based on the digital file. Inner structure 102 comprises internal surface 104, external surface 106 with recesses 108, routing features 110, connector enclosures, and support structures as described previously with respect to FIG.1. Inner structure 102 may be fabricated using additive manufacturing techniques, machining, molding, or other manufacturing methods. The recesses 108, routing features 110, connector enclosures, and support structures may be formed in external surface 106 based on the locations determined by the computational algorithm at step 504. A connector enclosure may be united with inner structure 102 within the CAD model using a combine feature so that there is continuous material between the connector enclosure and inner structure 102.

[0144] At step 508, sensing system 116 is placed onto external surface 106 of inner structure 102, with sensors positioned within recesses 108 and electrical connections 120 routed through routing features 110. Placing sensing system 116 may include placing sensor harness 200, which is a pre-assembled sensor harness including the sensors with electronic components encapsulated in protective encapsulation 212 and electrical connections 120 preinstalled within single connector housing 208. When wearable interface 100 includes more than one sensor harness, each sensor harness may be placed sequentially onto external surface 106. A technician or automated placement system may position sensor harness 200 onto external surface 106 with each sensor element aligned over its corresponding recess. The sensor elements may be pressed into recesses 108 so that each sensor sits flush within or below external surface 106. Sensors may be placed into recesses 108 using an adhesive such as double-sided tape, a mechanical fastener, a friction fit, or another attachment method. Lead wires 210 may be secured at intervals along routing features 110 using hot-melt adhesive or another securing method to maintain the determined wire route.

[0145] At step 510, sensing system 116 is tested for functionality prior to applying outer layer 124. Each sensor may be tested to verify proper signal response. For inductive sensor embodiments, testing may include placing a section of magnetically permeable or conductive target material over the sensor and verifying that the signal changes in response to the presence and removal of the target material. For temperature sensing components such as thermistor 206, testing may include applying a thermal stimulus and verifying that the signal responds to the temperature change. For non-inductive sensor embodiments, testing methods appropriate to the sensing modality may be used. Testing may be performed manually by a technician, using a dedicated test fixture, or using an automated test system that evaluates each sensor against predefined acceptance criteria. Improper function may indicate mechanical failure at a connection point, and sensor harness 200 may be repaired or replaced prior to applying outer layer 124.

[0146] At step 512, outer layer 124 is applied over inner structure 102 and sensing system 116 to encapsulate the sensors and electrical connections 120. Outer layer 124 may be a structural lamination, a coating, a three-dimensionally printed shell, or another structural covering that mechanically supports inner structure 102 and protects sensing system 116 from mechanical damage during use. Prior to applying outer layer 124, a material that is magnetically permeable and electrically resistive sufficient to limit eddy current losses when a magnetic field is applied may be applied over each sensor to shield the sensor from conductive materials. A shielding material may be added as a layer of a sensor made from a multilayer circuit board. When outer layer 124 includes a conductive material such as carbon fiber, a ground wire from sensing system 116 may be woven into outer layer 124 to electrically isolate the sensors from the conductive outer layer material and may serve as a Faraday cage for both the target and sensor. For non-conductive outer layer materials or environments where an external e-field or electromagnetic interference is not expected, the electrical isolation steps may not be required. The internal surface 104 of inner structure 102 may be vapor smoothed prior to or after application of outer layer 124 to lower surface roughness. The application of outer layer 124 completes the fabrication of wearable interface 100 with embedded sensors.

[0147] Referring to FIG. 6, three views of wearable interface 100 at successive stages of fabrication are shown. The three views illustrate the progression from an inner structure (preassembly) 600 through placement of sensing system 116 to completion with outer layer 124. While FIG. 6 illustrates a prosthetic socket embodiment, the three-stage fabrication process may be applied to other wearable interfaces as described previously.

[0148] A first view on the left of FIG. 6 depicts inner structure (pre-assembly) 600 prior to sensor placement. Inner structure (pre-assembly) 600 is the socket body fabricated as described previously with respect to inner structure 102. Inner structure (pre-assembly) 600 includes a connector enclosure 606 at a distal end configured to receive connector 122 of sensing system 116. A bottom surface of connector enclosure 608 is visible in the first view and may be positioned such that bottom surface of connector enclosure 608 is flush with a distal end of inner structure (pre-assembly) 600. The bottom surface may be above the distal end of the inner structure if it is more convenient to position the electronics enclosure above the bottom surface, or if the distal location interferes with componentry or function. Inner structure (pre-assembly) 600 further includes a distal receptacle 610 at the top of the image with a central opening configured to receive a mounting adapter for prosthetic componentry. Distal receptacle 610 may be the lip and support structure for a mounting adaptor as described previously. Inner structure (pre-assembly) 600 also includes a recess 612 on external surface 106 configured to receive a sensor element such as inductive sensor antenna 118 or a sensor array. In one embodiment, a routing region may be debossed into the external surface above the electrical connector position for wire routing, with dimensions adjusted to accommodate the size of the wearable interface and the number of sensors.

[0149] As further shown in FIG. 6, a second view in the center depicts an intermediate assembly 602 after placement of sensing system 116. Placing sensing system 116 may include placing sensor harness 200 as described previously with respect to FIG. 2. Intermediate assembly 602 includes distal hardware 614 and a former plate and cap 616 assembled at distal receptacle 610. Distal hardware 614 may be a four-hole locking pin adapter or other mounting hardware secured to the distal end of inner structure 102 and serving as the mechanical interface between the socket and prosthetic componentry. For non-prosthetic applications, the distal hardware may be a hinge, bracket, or other attachment hardware appropriate to the wearable interface application. Former plate and cap 616 extends upward from distal hardware 614.

[0150] Intermediate assembly 602 further includes an electronics enclosure 618 positioned adjacent to connector enclosure 608, receiving electrical connector cable 620. Alternatively, electronics enclosure 618 may be fastened to componentry below the socket or at other locations. Electronics enclosure 618 provides the electrical interface between sensing system 116 and external devices and may include processor 130 and a data storage or transfer unit. Electrical connector cable 620 may be routed along external surface 106 through routing features 110. Alternatively, electrical connector cable 620 may be routed along outer layer 124.Alternatively, electronics enclosure 618 may be plugged into the connector enclosure 608, eliminating the need for the electrical connector cable 620. A sensor (seated in recess) 622 is positioned within recess 612 on external surface 106. A sensor (conforming to curved surface) 624 conforms to a lower curved region of inner structure 102. Sensor (conforming to curved surface) 624 may include a hole punched through the center of the antenna so that sensor (conforming to curved surface) 624 better conforms to the shape of the curved region.

[0151] Following placement of sensing system 116, sensing system 116 may be tested for functionality as described previously with respect to step 510 of method 500. If testing reveals a defect, sensor harness 200 may be removed and replaced prior to application of outer layer 124. Prior to placement of sensing system 116, external surface 106 of inner structure 102 may be roughened using sandpaper or other abrasive to facilitate a strong bond to the outer layer material. Inner structure 102 may be filled with plaster, other material, or a frame that provides structural support to prevent deformation under vacuum during lamination. In some aspects, when the inner structure material has sufficient strength and thermal resistance, the structural support material may not be needed.

[0152] Prior to applying outer layer 124, a material that is magnetically permeable and electrically resistive sufficient to limit eddy current losses when a magnetic field is applied, for example a ferrite patch, may be applied over each sensor to electrically isolate the sensor from conductive materials in outer layer 124. When outer layer 124 includes a conductive material such as carbon fiber, a ground wire from sensing system 116 may be woven into outer layer 124 to electrically isolate the sensors from the conductive outer layer material. In the completed wearable interface, the material may be disposed over each sensor between the sensor and outer layer 124.

[0153] With continued reference to FIG. 6, a third view on the right depicts a completed interface 604 after application of an outer layer 626. Outer layer 626 is a structural lamination, coating, three-dimensionally printed shell, or another structural covering encapsulating inner structure 102 and sensing system 116. In the embodiment shown, outer layer 626 may be a vacuum-assisted carbon-fiber lamination that mechanically supports inner structure 102 and protects sensing system 116 from mechanical damage during use. Former plate and cap 616 is a temporary component used during fabrication to create a flat surface for lamination and is removed after application of outer layer 626. After removal of the temporary components, permanent prosthetic componentry such as a four-hole locking pin adapter may be installed at the distal end of completed interface 604. The application of outer layer 626 completes thefabrication of wearable interface 100 with embedded sensors, with sensor (seated in recess) 622 and sensor (conforming to curved surface) 624 sub-surface embedded on external surface 106 and protected from wear by outer layer 626.

[0154] Referring to FIG. 7, a flowchart of method 700 for computationally determining sensor placement locations on inner structure 102 is shown. Method 700 provides a computational approach for automatically determining locations for recesses 108 and routing features 110 based on landmark data and other information within a digital file representing the contour of a body part. The other information may include the type of socket, socket stiffness, liner type and thickness, insert material and shape, bone shapes, scans of limb bony structures, practitioner-noted problematic regions, patient treatment history, medical information from a primary care provider, computational modeling results such as finite element analysis identifying at-risk locations including areas of high pressure, high shear stress, or slip, patient health variables, activity data, socket fit data, and other information about the wearer and prosthesis. While method 700 is described with reference to a prosthetic socket embodiment, the computational approach may be applied to determine sensor placement locations for other wearable interfaces as described previously.

[0155] Method 700 begins at step 702 with receiving landmark data from a digital file representing a contour of a body part or a modified contour of the body part. The digital file is for fabrication of the wearable interface or calculating landmark locations based on the shape of the digital file. Landmark data may include sensor location data. The landmark data may include features as described previously with respect to the definition of “digital file.” Landmark data may be included in the digital file by a clinician or technician or may be automatically identified from a scan of the body part or existing interface.

[0156] At step 704, candidate sensor locations are identified based on the landmark and other data about the patient, their prosthesis, prosthesis use, and prosthesis history. The computational algorithm may identify candidate locations based on clinical monitoring objectives. For example, the computational algorithm may implement a prosthesis use configuration where sensors are placed at posterior distal and anterior proximal locations to determine activity modes as described previously with respect to FIG. 3. The computational algorithm may alternatively implement a prosthetic fit configuration where sensors are placed at posterior midlimb and anterior distal locations and may include other locations or additional information described above to determine sources of change in socket fit as described previously with respect to FIG. 3. Alternatively, a clinician or clinical care team may selectlocations of interest for data collection and add their selections to the inner structure digital file as landmarks, and such landmarks may become locations for recess fabrication in inner structure 102. Computational modeling such as finite element analysis may also be used to identify at-risk locations on the body part, such as areas of high pressure, high shear stress, or slip. Finite element models may be created from the inner structure model, and the analysis results may be used to further facilitate both the selection of sensor locations and the design of the inner structure.

[0157] At step 706, the local surface contour at each candidate location is evaluated. The computational algorithm may adjust sensor locations based on local surface contour of inner structure 102. Regions exhibiting only concavity or only convexity are generally acceptable for sensor placement, as sensors can conform to surfaces with a single direction of curvature. However, regions exhibiting combined concavity and convexity are less favorable and may be avoided because sensors placed in such regions may not conform to the surface contour, may not sit properly within the recesses, and may produce degraded signal quality. When two sensors are near an edge, such as near the anterior distal tibia, the computational algorithm may move the sensors so that the edge is between them, which may improve conformance of each sensor to the local surface and may reduce mechanical stress on the sensor elements. Additional optimization criteria may include maintaining sufficient distance from adjustment mechanisms or other socket hardware and minimizing wire length.

[0158] At step 708, routing paths for electrical connections 120 are optimized to minimize intersecting paths across external surface 106 of inner structure 102. The computational algorithm may determine an optimal wiring routing strategy that uses the least amount of wire, maintains sufficient distance from locations that could damage the wires, and ensures that wires from different sensors do not cross. If a wire crossing must be implemented, shield material may be placed between the wires during fabrication to reduce noise. The computational algorithm may also calculate wire lengths for each sensor by determining the routing path length from each recess to the connector enclosure and adding a margin to ensure the wires are not taut when adhered to external surface 106.

[0159] At step 710, deboss geometry, cutouts, support structures, and other elements are generated in the CAD model based on the optimized sensor locations and routing paths. Each recess may be shaped to match the geometry of the corresponding sensor element so that the sensor element sits flush within or below external surface 106. The recesses may have an annular shape with a central opening and a tail extending from the outer edge of the antennatoward connector 122. The depth, inner diameter, outer diameter, and tail dimensions of each recess may be determined based on the size and geometry of the corresponding sensor element. Sensor elements of different sizes may be used together depending on the clinical need, and the recess dimensions may be adjusted accordingly. Cutouts for adjustable panels, support structures for adjustment mechanisms, and connector enclosures may also be generated in the CAD model at this step. The path of the wires into connector 122 may be smoothed to ensure there are no sharp edges that may damage lead wires 210. The sensor location coordinates may be added to the inner structure digital file to facilitate visualization and interpretation of the data collected by sensing system 116.

[0160] Referring to FIG. 8, a flowchart of method 800 for assembling sensor harness 200 for integration with inner structure 102 is shown. Method 800 provides a process for preparing sensor harness 200 as a standalone subassembly prior to integration with inner structure 102. While method 800 is described with reference to inductive sensor antennae, the assembly process may be adapted for other sensor element types by substituting the appropriate sensor elements and electronic components.

[0161] Method 800 may begin with preparatory steps including removing inductive sensor antennae or antenna arrays from flexible circuit sheets and punching out the centers of the antennae to improve conformance to curved surfaces. The antennae may be manufactured as part of a flexible circuit panel or flexible polymer substrate and separated from the panel or surrounding polymer substrate prior to assembly for example along perforation lines made during printing. The center punch-out may be performed using a die, a laser cutter, or a manual punch tool. Punching a hole through the center of the antenna allows the antenna to flex more readily when placed on a curved surface, reducing the tendency of the antenna to buckle or lift from the recess. In some aspects, the center hole technique may be particularly useful in regions of the inner structure exhibiting higher curvature, such as the distal region of a prosthetic socket. The center hole may also reduce mechanical stress on the antenna coil traces during placement and during use of the wearable interface. The size of the center hole may be selected based on the curvature of the target region and the flexibility requirements of the antenna material.

[0162] Method 800 then proceeds at step 802 with attaching electronic components to inductive sensor antennae 202 or antenna arrays. The electronic components may be attached by soldering, conductive adhesive, or other attachment methods. The electronic components may include capacitor 204 and thermistor 206 for each of the inductive sensor antennae 202.Solder pads on inductive sensor antennae 202 may receive electronic components and lead wires 210. For non-inductive sensor embodiments, the electronic components may include signal conditioning circuitry, amplifiers, or other components appropriate to the sensing modality.

[0163] With continued reference to FIG. 8, at step 804, the electronic components and connections are encapsulated in a protective material. Protective encapsulation 212 may be hot melt glue placed at the midpoint of a tab of each of the inductive sensor antennae 202 and compressed into an even layer over the electronic components using a mold with a closable lid, as described previously with respect to FIG. 2. Protective encapsulation 212 may alternatively be epoxy, silicone potting compound, UV-curable resin, conformal coating, or another protective material. With capacitor 204, thermistor 206, solder pads, and lead wires 210 encased in protective encapsulation 212, the risk of mechanical damage during subsequent handling and fabrication steps may be minimized.

[0164] At step 806, lead wires 210 are pre-installed within single connector housing 208. Lead wires 210 may be cut, stripped, and crimped prior to placement into single connector housing 208. Pre-installing lead wires 210 within single connector housing 208 before assembly of sensor harness 200 may reduce the risk of damage during wearable interface fabrication and speed up installation. Lead wires 210 may be arranged in a zigzag or serpentine configuration with an elastic element in parallel as described previously with respect to FIG.2.

[0165] As further shown in FIG. 8, at step 808, inductive sensor antennae 202 or antenna arrays are threaded through single connector housing 208. Inductive sensor antennae 202 or antenna arrays may be gathered into a stack and encased in a protective sleeve to safely thread through single connector housing 208. Once connector 122 is fully seated into connector enclosure 112, the protective sleeve may be removed.

[0166] At step 810, adjacent inductive sensor antennae 202 or antenna arrays are connected with flexible joints. Flexible joint 214 may be formed in a flexible circuit backing material by making cutouts into the flexible circuit backing material, as described previously with respect to FIG. 2. Connecting adjacent inductive sensor antennae 202 through flexible joint 214 may allow sensor arrays or fusions of multiple sensors to take on the shape of the wearable interface while keeping the sensors organized for the technician to apply into recesses 108.

[0167] At step 811, sensors are affixed in the recesses and lead wire is affixed to the inner structure. Sensors may be placed into recesses 108 using an adhesive such as double-sided tape, a mechanical fastener, a friction fit, or another attachment method as described previously with respect to step 508 of method 500. Lead wires 210 may be secured at intervals along routing features 110 on external surface 106 of inner structure 102 to maintain the determined wire route and prevent strains that may lead to mechanical failure.

[0168] At step 812, the completed harness is tested for functionality. Testing at this stage is performed because once outer layer 124 is applied, the sensors are permanently encapsulated, and repair or replacement becomes significantly more difficult. Each of the inductive sensor antennae 202 may be electrically tested using a section of magnetically permeable or conductive target material. When the target material covers inductive sensor antenna 118, signal values may change, and when the target material is removed, the signal may return to a baseline value. For temperature sensing components such as thermistor 206, testing may include applying a thermal stimulus and verifying that the signal responds to the temperature change. Testing may be performed manually by a technician, using a dedicated test fixture, or using an automated test system. Improper function may indicate mechanical failure at a connection point, including wire crimps and solder connections. Sensor harness 200 may be repaired prior to integration with inner structure 102.

[0169] Method 800 may be performed in bulk to prepare multiple sensor harnesses in a fabrication process separate from the wearable interface fabrication, as described previously with respect to FIG. 2. Different sensor harness configurations may be prepared for different sensor types, different numbers of sensor elements, or different wearable interface applications. For non-prosthetic applications, method 800 may be adapted by configuring sensor harness 200 with fewer or more sensor elements and with different lead wire lengths to accommodate the geometry of the corresponding inner structure.

[0170] Referring to FIG. 9, four views of sensor harness fabrication components and assembly stages are shown. FIG. 9 illustrates the components and processes used to prepare sensor harness 200 as a standalone subassembly prior to integration with inner structure 102. The mold and assembly components may be adapted for sensor arrays, fusions of multiple sensors, or other sensor element types by modifying the mold geometry and encapsulation materials.

[0171] View (a) of FIG. 9 depicts a mold assembly 900 showing a completed sensor harness including multiple inductive sensor antennae 202 connected by lead wires 210 bundled together and terminating at single connector housing 208. Electronic components including capacitor 204 and thermistor 206 are visible along the wire paths of mold assembly 900. Mold assembly 900 illustrates the final configuration of sensor harness 200 after completion of the assembly process described previously with respect to method 800.

[0172] With continued reference to FIG. 9, view (b) depicts a mold base 902 showing a mold apparatus with recesses configured to receive inductive sensor antennae 202 for potting electronic components in protective encapsulation 212. Mold base 902 may be a jig configured to hold inductive sensor antennae 202 in position during application of protective encapsulation 212. An antenna element and encapsulation material are positioned adjacent to mold base 902 in view (b).

[0173] As further shown in FIG. 9, view (c) depicts a mold lid 904 showing a two-piece mold assembly with multiple cavities for processing sensor elements. Mold lid 904 may be closed over mold base 902 to compress protective encapsulation 212 into an even layer over the electronic components of inductive sensor antennae 202, as described previously with respect to FIG. 2. A ferrous target material or supporting surface for the sensor antenna is seated within the mold base in view (c). Mold lid 904 may be configured to apply pressure to protective encapsulation 212 during curing, ensuring that capacitor 204, thermistor 206, solder pads, and lead wires 210 are encased in an even protective layer.

[0174] View (d) of FIG. 9 depicts a protective threading sleeve 906 showing the threading process in which sensor elements are placed within a protective sleeve and threaded through single connector housing 208. Protective threading sleeve 906 may be a tubular sleeve configured to gather inductive sensor antennae 202 into a stack for safe threading through single connector housing 208. Antennae within sensor arrays may be folded at the joints to fit into the protective sleeve. Protective threading sleeve 906 may protect inductive sensor antennae 202 and lead wires 210 from damage during the threading process. Once connector 122 is fully seated into connector enclosure 112, protective threading sleeve 906 may be removed.

[0175] The fabrication components shown in FIG. 9 may enable preparation of sensor harness 200 in bulk in a fabrication process separate from the wearable interface fabrication. For non-prosthetic applications, the fabrication components may be adapted to accommodatesensor harnesses configured with different sensor element types, quantities, or lead wire lengths.

[0176] Referring to FIG. 10, a close-up view 1000 shows a detailed view of external surface 106 of inner structure 102 with sensors positioned within recesses 108. Close-up view 1000 illustrates the configuration of sensing system 116 on external surface 1006 prior to application of outer layer 124. The sensors may be any of the sensor element types described previously. In the embodiment shown, the sensors are inductive sensor antennae. The sensors may be part of sensor harness 200, which is a pre-assembled standalone subassembly as described previously with respect to FIG. 2.

[0177] An inductive sensor antenna 1004 is seated within a recess on external surface 1006. Inductive sensor antenna 1004 includes concentric coil traces with a central opening configured to sense distance to magnetically permeable or conductive target material 128. Inductive sensor antenna 1004 may be placed into the recess using an adhesive such as doublesided tape or another attachment method as described previously with respect to step 508 of method 500. The recess is contoured to conform to the geometry of inductive sensor antenna 1004, allowing inductive sensor antenna 1004 to sit flush within or below external surface 1006 prior to application of outer layer 124. The recess geometry may be computationally determined by the algorithm described previously with respect to method 700, based on the size and geometry of inductive sensor antenna 1004 and the local surface contour at the recess location.

[0178] With continued reference to FIG. 10, electrical connections 1002 extend from connector 122 at a peripheral edge of inner structure 102 to inductive sensor antenna 1004. Electrical connections 1002 may be twisted-pair lead wires routed through routing features on external surface 1006, a ribbon cable, a printed flexible circuit material, a helical coil arrangement of wires or another architecture. Electronic components including capacitor 204 and thermistor 206 are visible along the wire paths of electrical connections 1002. Electrical connections 1002 may be secured at intervals along routing features 110 to maintain the determined wire route and prevent strains that may lead to mechanical failure.

[0179] As further shown in FIG. 10, an adjacent recess 1008 is visible below inductive sensor antenna 1004. Adjacent recess 1008 is shaped to receive a second sensor element and includes a smaller central opening indicating a different sensor size or configuration. Adjacent recess 1008 is contoured to conform to the geometry of the respective sensor element, allowingthe sensor to sit flush within external surface 1006. The different dimensions of adjacent recess 1008 compared to the recess holding inductive sensor antenna 1004 illustrate that recesses 108 may be individually sized and shaped based on the corresponding sensor element geometry.

[0180] When a sensor array is seated within a recess on external surface 1006, where the recess is shaped to include multiple antennae in the array and adjacent antennae are connected, the array is placed as a unit. A hole may be punched through the center of inductive sensor antenna 1004 in locations of high curvature so that inductive sensor antenna 1004 better conforms to the shape of external surface 1006 without buckling or lifting from the recess. As described previously with respect to step 706 of method 700, the computational algorithm may adjust sensor locations to avoid local surface regions exhibiting combined concavity and convexity. The center hole technique may be used where some curvature is present, but the location is otherwise suitable for sensor placement.

[0181] Prior to application of outer layer 124, a material that is magnetically permeable and electrically resistive sufficient to limit eddy current losses when a magnetic field is applied, for example a ferrite patch, may be applied over each sensor to electrically isolate the sensor from conductive materials in outer layer 124, as described with respect to FIG. 13.

[0182] Sensor elements of different sizes may be used together depending on clinical need. For example, different size sensors may be positioned in the space between adjustable panels of a wearable interface to track different regions of expected motion. The configuration shown in FIG. 10 with inductive sensor antenna 1004 and adjacent recess 1008 having different dimensions illustrates how varying spatial resolution may be achieved by combining sensors of different sizes within recesses 108 on external surface 1006.

[0183] Referring to FIG. 11, a distal assembly close-up 1100 shows a detailed view of the distal end of inner structure 102 during fabrication for a pin-lock suspension configuration. Distal assembly close-up 1100 illustrates the configuration of distal componentry and sensing system 116 at the distal end of inner structure 102 prior to application of outer layer 124. While FIG. 11 illustrates a prosthetic socket embodiment, the distal assembly configuration may be adapted for other wearable interfaces where a mounting point, hinge, or attachment interface is located at a terminal end of the inner structure.

[0184] Componentry may be attached to distal hardware 1104. Distal hardware 1104 is a four-hole locking pin adapter secured to the distal end of inner structure 102 and serves as the mechanical interface between wearable interface 100 and prosthetic componentry. A lockingmechanism 1102 within the four posts for the four-hole adapter may engage with the suspension pin fastener to the elastomeric liner 126 to provide suspension of wearable interface 100 on the residual limb. For non-prosthetic applications, the distal hardware may be other mounting or attachment hardware appropriate to the wearable interface application.

[0185] With continued reference to FIG. 11, a connector enclosure 1106 is integrated into inner structure 102 adjacent to distal hardware 1104, united with inner structure 102 within the CAD model as described previously with respect to FIG. 1. Connector enclosure 1106 is positioned such that the bottom surface of connector enclosure 1106 is flush with the distal end of inner structure 102. The connector enclosure may alternatively be positioned such that the bottom surface is proximal to the distal end of the inner structure, for example when a more proximal location better accommodates the electronics enclosure or when the distal location interferes with componentry or function.

[0186] As further shown in FIG. 11 , an inductive sensor antenna 1108 is positioned within a recess on external surface 106 of inner structure 102. The sensor may be any of the sensor element types described previously. Inductive sensor antenna 1108 may be a coil antenna configured to sense distance to magnetically permeable or conductive target material 128 within elastomeric liner 126. Inductive sensor antenna or sensor array 1108 may be placed into the recess using an adhesive or another attachment method as described previously with respect to step 508 of method 500. Inductive sensor antenna or sensor array 1108 may be part of sensor harness 200 as described previously with respect to FIG. 2.

[0187] Electrical connections 1110 extend from inductive sensor antenna 1108 toward connector enclosure 1106. Electrical connections 1110 are twisted-pair lead wires routed through routing features 110 on external surface 106 of inner structure 102. Electronic components including capacitor 204 and thermistor 206 may be visible along the routing path of electrical connections 1110.

[0188] Prior to application of outer layer 124, a material that is magnetically permeable and electrically resistive sufficient to limit eddy current losses when a magnetic field is applied, for example a ferrite patch, may be applied over inductive sensor antenna 1108 to electrically isolate inductive sensor antenna 1108 from conductive materials in outer layer 124, as described with respect to FIG. 13. Sensing system 116 may be tested for functionality at this stage as described previously with respect to step 510 of method 500.

[0189] Wearable interface 100 may be configured for side of socket suspension such as used with a blade prosthesis. In such configurations, distal hardware 1104 may be positioned at a side of inner structure 102 rather than at the distal end, and connector enclosure 1106 may be repositioned accordingly.

[0190] Referring to FIG. 12 A, a perspective view of inner structure 102 mounted on a stand is shown with sensing system 116 installed on external surface 106 prior to application of outer layer 124 for a pin-lock suspension configuration. FIG. 12A illustrates the configuration of electrical connections 120 routed along external surface 106 between sensors positioned within recesses 108 and connector enclosure 112. The sensors may be any of the sensor element types described previously. In the embodiment shown, the sensors are inductive sensor antennae 118. The sensors may be part of sensor harness 200 as described previously with respect to FIG. 2.

[0191] Connector enclosure 112 is visible at a distal end of inner structure 102, housing connector 122 for sensing system 116 as described previously with respect to FIG. 1.

[0192] With continued reference to FIG. 12 A, two inductive sensor antennae 118 are positioned within recesses 108 on external surface 106 of inner structure 102. A first of inductive sensor antennae 118 is positioned at an upper region of inner structure 102, and a second of inductive sensor antennae 118 is positioned at a lower region of inner structure 102. The positioning of inductive sensor antennae 118 at different regions of inner structure 102 may result in varying distances between each of the inductive sensor antennae 118 and connector enclosure 112. The routing paths for electrical connections 120 may have been determined by the computational algorithm described previously with respect to step 708 of method 700.

[0193] Electrical connections 120 extend from connector enclosure 112 along external surface 106 and are routed between inductive sensor antennae 118. Electrical connections 120 are arranged in a zigzag or serpentine configuration 1202 that accommodates the varying distances between inductive sensor antennae 118 and connector enclosure 112. Zigzag or serpentine configuration 1202 may allow lead wires 210 to lengthen or shorten to meet the length need as lead wires 210 span the curved external surface 106 of inner structure 102. Zigzag or serpentine configuration 1202 may be formed during assembly of sensor harness 200 as described previously with respect to step 806 of method 800.

[0194] As further shown in FIG. 12A, an elastic element 1204 is arranged in parallel with lead wires 210 of electrical connections 120. Elastic element 1204 provides strain relief and allows electrical connections 120 to flex as lead wires 210 span the curved external surface 106 of inner structure 102. Elastic element 1204 may be an elastomeric band, a spring element, a stretchable conductor, or another resilient material configured to accommodate changes in length as lead wires 210 are routed across curved surfaces. Elastic element 1204 may reduce tensile stress in lead wires 210 and may allow a wide range of wire lengths to be accommodated without requiring custom wire lengths for each wearable interface configuration. The combination of zigzag or serpentine configuration 1202 and elastic element 1204 may reduce bunching of lead wires 210 and may prevent strains that may lead to mechanical failure during use of wearable interface 100.

[0195] Referring to FIG. 12B, a perspective view of inner structure 102 mounted on a stand is shown with sensing system 116 installed on external surface 106 and ferrite patches 1206 applied over the sensor antennae prior to application of outer layer 124. Connector enclosure 112 is visible at a distal end of inner structure 102. Electrical connections 120 extend from connector enclosure 112 along external surface 106.

[0196] Ferrite patches 1206 are disposed over three inductive sensor antennae arranged in a triangular sensor array on external surface 106 of inner structure 102. Ferrite patches 1206 are a material that is magnetically permeable and electrically resistive, applied over the sensor antennae to limit eddy current losses when a magnetic field is applied and to electrically isolate the sensors from conductive materials in outer layer 124. Each ferrite patch may be adhesive-backed and applied over the corresponding sensor coil, taking care to ensure the via to the electronic components including capacitor 204 and thermistor 206 is exposed. The triangular sensor array arrangement shown in FIG. 12B may correspond to sensor array 1502 described with respect to FIG. 15. Ferrite patches 1206 may alternatively be a continuous sheet of magnetically permeable and electrically resistive material cut to cover the sensor region, or individual patches sized to match each sensor element. Other materials that are magnetically permeable and electrically resistive may be used in place of ferrite, as described with respect to FIG. 13.

[0197] Referring to FIG. 13, a detailed view 1300 shows two views of a ground wire 1302 being woven into an outer layer 1304 during wearable interface 100 fabrication. Outer layer 1304 is a woven carbon fiber material with a tight, uniform braid pattern. The electrical isolation techniques described with respect to FIG. 13 may be applicable when outer layer 124includes a conductive material such as carbon fiber, a conductive composite, or a metal coating or in environments where electromagnetic interference is expected. For non-conductive outer layer materials or in environments where electromagnetic interference is not expected, the electrical isolation steps described herein may not be required.

[0198] A first view on the left of FIG. 13 depicts ground wire 1302 being threaded through outer layer 1304. Ground wire 1302 is inserted through the weaves of outer layer 1304. A second view on the right of FIG. 13 depicts a close-up of ground wire 1302 after being pulled through outer layer 1304. A portion of ground wire 1302 is visible extending through a woven interface 1306 where ground wire 1302 has been integrated into the weave pattern of the carbon fiber material.

[0199] With continued reference to FIG. 13, ground wire 1302 is woven into outer layer 1304 to electrically isolate the sensors from conductive materials in outer layer 1304 and prevent signal interference during operation of wearable interface 100. The carbon fiber material of outer layer 1304 is conductive and may otherwise distort the signals of interest from sensing system 116. Ground wire 1302 may originate from sensor harness 200 and may be routed along a path determined during the computational algorithm’s routing optimization described previously with respect to step 708 of method 700. In one embodiment, at least 3 cm of exposed ground wire 1302 may be woven into the carbon fiber tows of outer layer 1304 to maximize contact with the conductive carbon fiber material. Different lengths of exposed ground wire 1302 may be used depending on the size of the wearable interface and the conductivity of the outer layer material.

[0200] Prior to applying outer layer 124, a material that is magnetically permeable and electrically resistive sufficient to limit eddy current losses when a magnetic field is applied, for example a ferrite patch, may be applied over each sensor as described previously with respect to FIG. 12B. Each sensor coil may be covered with the material, taking care to ensure the via to the electronic components including capacitor 204 and thermistor 206 is exposed. The material electrically isolates the backs of the sensors from the conductive material of outer layer 1304. The material may include radial slits to improve flexibility and conformance to curved surfaces of inner structure 102. Alternative electrical isolation methods may include non-conductive barrier layers, shielding tape, or insulative coatings applied between the sensors and the conductive outer layer material. A shielding material may be added within a layer of the multilayer flexible circuit sensor. The electrical isolation method may be selectedbased on the sensor modality, the outer layer material, and the geometry of the wearable interface.

[0201] As further shown in FIG. 13 , the face of connector 122 may be potted with a potting material to prevent resin or other matrix material from entering connector 122 during application of outer layer 1304. The potting material may be platinum cure silicone, an epoxy, a wax, or another removable or dissolvable material. The potting material may be removed once wearable interface 100 is complete to expose connector 122 for connection to external devices such as processor 130 or a data storage and transfer unit.

[0202] Referring to FIG. 14, a flowchart of method 1400 for operating wearable interface 100 with embedded sensors is shown. Method 1400 provides a process for receiving sensor data, determining a socket fit metric, determining prosthesis adjustments, and commanding adjustments to the wearable interface or a dependent feature. While method 1400 is described with reference to a prosthetic socket embodiment, the monitoring and adjustment cycle may be applied to other wearable interfaces such as orthotic devices, helmets, exoskeleton interfaces, a seating surface, a shoe, a cast, a finger prosthesis or an upper limb prosthesis where dynamic adjustment based on sensor feedback is desired. Method 1400 may operate as an open-loop or closed-loop control cycle.

[0203] Method 1400 begins at step 1402 with receiving sensor data from sensing system 116. The sensor data may be received from a single sensor, a sensor array, or a fusion of multiple sensors, as described previously with respect to FIG. 3. In the embodiment shown, sensing system 116 may include inductive distance sensors arranged as a single sensor, in a sensor array of more than one sensor, or a fusion of multiple sensors configured to determine at least one position of a target relative to inner structure 102. Processor 130 may receive the sensor data from sensing system 116 via connector 122 and electrical connections 120. For non-inductive sensor embodiments, the sensor data may include pressure, strain, temperature, or other measurements appropriate to the sensing modality.

[0204] At step 1404, a socket fit metric is determined from the sensor data. The socket fit metric is a quantitative measure that characterizes the relationship between the body part and the wearable interface at any given time. The socket fit metric may be derived from sensor readings processed using calibration data, lookup tables, computational models, or other methods as described previously with respect to FIG. 3. Processor 130 may use the sensor data to calculate the socket fit metric based on previously established relationships between sensorreadings and socket fit conditions. The socket fit metric may reflect changes in limb volume, limb shape, limb-socket alignment, position changes of the residual limb within the socket, bony structure motion relative to the inner structure, sweat buildup, gait, terrain, temperature, or other variables. Processor 130 may also determine a current activity mode based on the sensor data, such as walking, standing, sitting, partial doff, or full doff, and may use the activity mode in calculating the socket fit metric. Processor 130 may use sensor data history to identify trends and patterns in socket fit overtime. Sensor data history may include previously collected sensor readings, socket fit metrics, activity mode data, adjustment commands, or other data stored over a period of use. Processor 130 may analyze the sensor data history to detect gradual changes in socket fit, predict future fit conditions, or adapt the control strategy based on patterns observed over multiple use sessions.

[0205] At step 1406, a prosthesis adjustment is determined based on the sensor data. Processor 130 determines what prosthesis adjustments should be made based on the relationship between adjustments and sensor data, which has been previously measured and characterized. The processor utilizes knowledge of how specific adjustments affect sensor readings to identify appropriate adjustments that will bring the socket fit metric toward a desired value. The prosthesis adjustments may include modifications to socket size, foot stiffness, knee stiffness, ankle stiffness, socket surface roughness and frictional coefficient, alignment, knee flexion, ankle flexion, range of motion, foot length, temperature, joint power, socket length, knee motion, energy transfer in componentry, socket length, vacuum or suction, cabling mechanism, fluid-filled enclosure, air-filled enclosure, stiffness, release-relock, vents, a cooling mechanism, a grip control mechanism, or another variable or dimension of wearable interface 100 or a feature dependent upon it. The fit adjustment strategy may be dependent on patient-specific attributes such as residual limb length, limb circumference, tissue composition, fatigue, gait, or prosthesis characteristics such as liner material, stiffness of prosthetic componentry, or environmental variables such as terrain and temperature, as described previously with respect to FIG. 3. Processor 130 may also use patient characteristics, prosthesis characteristics, and patient medical history and imaging data in determining the prosthesis adjustment. Prosthesis adjustment is an example of a device adjustment as defined herein. The prosthesis adjustment may alternatively include alerting a clinician, logging data for review, or transmitting data to a remote device for clinical analysis.

[0206] In some aspects, device adjustments may include additional modifications beyond those described above. Alignment adjustments, such as modifying socket alignment relative tothe prosthetic foot, may improve gait symmetry and reduce compensatory movements that could lead to joint strain or fatigue. Suspension tension or force adjustments may enhance security of the wearable interface on the body part while reducing pistoning or discomfort during ambulation. Interface pressure distribution modifications may redistribute loads across the body-device interface to reduce localized stress concentrations and minimize the risk of tissue breakdown. Thermal management settings, such as adjustments to cooling mechanisms or vent configurations, may improve user comfort during extended wear or in varying environmental conditions. Vibration or haptic feedback parameters may be adjusted to provide sensory information to the user regarding interface conditions or gait events. Gait timing parameters, such as swing phase duration or stance phase characteristics, may be modified based on sensor data to optimize energy efficiency and walking comfort. Each of these device adjustments may be determined by processor 130 based on sensor data, patient characteristics, prosthesis characteristics, patient medical history and data, or combinations thereof.

[0207] At step 1408, a command is issued to adjust a dimension of the wearable interface or a dependent feature. Processor 130 may issue a command to actuator 304 based on the prosthesis adjustment determined at step 1406. Actuator 304 may be a motor-driven mechanism configured to move adjustable socket panels radially inward and outward, ratcheted dials, lever mechanisms, pumps for fluid-filled elements, pumps for air-filled elements, or other adjustment mechanisms supported by structural elements 114 on inner structure 102, as described previously with respect to FIG. 3. Actuator 304 may adjust the dimension in response to the command from processor 130. The fit adjustment may include safety limits to prevent excessive adjustment that could compromise user safety or comfort. For example, the total adjustment in a rest mode may be limited to a predefined percentage of the fit value to reduce the risk of the wearable interface becoming too loose before the user resumes activity. A user or clinician may override the safety limits via a remote computing device if desired.

[0208] Method 1400 may operate as a continuous monitoring and adjustment cycle, with a dashed dynamic response path extending from step 1408 back to step 1402. Sensor data is continuously received at step 1402, and the socket fit metric, prosthesis adjustment, and adjustment command are updated in response to changing conditions at the body-device interface. Processor 130 may store sensor data and adjustment history for later analysis, may transmit sensor data to remote devices for clinical review, or may use the data in subsequent controller decision-making. The continuous monitoring and adjustment cycle of method 1400may enable dynamic fit adjustment of wearable interface 100 without manual intervention by the user or clinician.

[0209] Referring to FIG. 15, sensor layouts 1500 showing three antenna array configurations for wearable interface 100 are shown. Sensor layouts 1500 illustrate different arrangements of sensors within recesses 108 on external surface 106 of inner structure 102 for various monitoring applications. The array configurations may be applied to any of the sensor element types described previously. In the embodiment shown, the array configurations are described with reference to inductive sensor antennae 118. The computational algorithm described previously with respect to method 700 may determine which array configuration to use based on the clinical monitoring objectives and the anatomical landmark data within the digital file.

[0210] Part (a) of FIG. 15 depicts a sensor array 1502 including three uniformly sized circular inductive sensor antennae arranged in a triangular sensor array. Sensor array 1502 is configured to determine a position of a magnetically permeable target 128 relative to inner structure 102 through geometric calculation or using a lookup table as described previously with respect to FIG. 3, or the three inductive sensor antennae of sensor array 1502 may each measure distance to magnetically permeable target 128, and processor 130 may calculate the three distance measurements using the independent processing technique described previously with respect to FIG. 3. Sensor array 1502 may be positioned at a distal, mid-limb or proximal region of inner structure 102 where tracking of a single or multiple target points is desired. Sensor harness 200 may be configured with three sensors connected by flexible joints 214 for placement as sensor array 1502.

[0211] With continued reference to FIG. 15, part (b) depicts a sensor array 1504 including sensors of different sizes. Sensor array 1504 includes one larger circular sensor positioned adjacent to smaller circular sensors. Sensor array 1504 represents a configuration for monitoring motion between adjacent adjustable panels of a wearable interface where varying spatial resolution is desired. The different sizes of sensors within sensor array 1504 may be positioned in the space between adjustable panels supported by structural elements 114 on inner structure 102 to track different regions of expected motion.

[0212] The sensors within sensor array 1502 or 1504 may be configured to determine a position of a magnetically permeable or conductive target arranged in a cluster configuration where each sensor measures perpendicular distance to different points on magneticallypermeable or conductive target material 128. Processor 130 may determine motion and orientation of a body part or bone relative to the reference frame of inner structure 102 based on the perpendicular distance measurements, as described previously with respect to FIG. 3. The sensors may be configured to monitor angulation of a bone or body structure relative to inner structure 102 by incorporating sensors at a more proximal location on inner structure 102. A scan of bony structures or other anatomical features may be incorporated into the inner structure digital file to allow motion of the structures to be tracked by sensing system 116.

[0213] Part (c) of FIG. 15 depicts an overlapping array 1506 including multiple uniformly sized sensors arranged in a grid pattern. Overlapping array 1506 includes different groupings of three sensors each indicated by distinct line styles including solid, dotted, dashed, and patterned outlines. The overlapping groupings illustrate how different combinations of sensors may be selectively activated to track a target as it moves across the monitored region. As the target moves across the region monitored by overlapping array 1506, processor 130 may select different groupings of three sensors to perform single location or multiple location calculations based on the current target position. Processor 130 may determine which grouping to activate based on signal strength from each sensor, selecting the grouping that provides the strongest combined signal. Overlapping array 1506 enables continuous tracking over an extended area and may track multiple targets within a region. Sensor harness 200 may be configured with a larger number of single sensors or sensor arrays connected by flexible joints 214 for placement as overlapping array 1506, with lead wires 210 arranged in zigzag or serpentine configuration 1202 to accommodate the distances between the sensors and single connector housing 208.

[0214] Referring to FIG. 16, two views of a wearable liner system configured for use with wearable interface 100 having embedded sensors are shown. Wearable liner system 1600 illustrates the integration of magnetically permeable or conductive target material 128 into elastomeric liner 126 for use with sensing system 116. While FIG. 16 illustrates a liner system for inductive distance sensing, for non-inductive sensor embodiments, the liner may include different target materials appropriate to the sensing modality or may not require a target material.

[0215] View (a) of FIG. 16 depicts a fabric backing construct 1602 in a flat, unformed state. Fabric backing construct 1602 is an elongated piece with a rounded top edge configured to conform to the contour of a body part. A magnetically permeable or conductive target material 1604 is visible as a circular element positioned on fabric backing construct 1602. Magnetically permeable target material 1604 is configured to interface with inductive sensorantennae 118 embedded within wearable interface 100. Magnetically permeable or conductive target material 1604 may be positioned at a location corresponding to recesses 108 on external surface 106 of inner structure 102. The locations of magnetically permeable or conductive target material 1604 on fabric backing construct 1602 may correspond to the recess locations determined by the computational algorithm described previously with respect to method 700, so that each target area aligns with a corresponding sensor within the inner structure.

[0216] With continued reference to FIG. 16, view (b) depicts an elastomeric liner 1606 in a three-dimensional residual limb or finger-like form. Elastomeric liner 1606 is an assembled liner with a rounded distal tip that conforms to the contour of a distal residual limb or a finger. Wearable liner system 1600 demonstrates the application of the embedded sensor wearable interface fabrication methodology to residual limb and finger prostheses, where fabric backing construct 1602 with magnetically permeable or conductive target material 1604 is integrated into elastomeric liner 1606 to enable inductive distance sensing between the liner and inner structure 102. For other wearable interface applications, the liner system may be adapted to conform to the corresponding body part contour. For applications where a traditional elastomeric liner is not used, magnetically permeable or conductive target material may be integrated into a fabric layer, a padding layer, or another interface component positioned between the body part and the inner structure.

[0217] Elastomeric liner 126 includes magnetically permeable or conductive target material 128 configured to interface with the sensors of sensing system 116, as described previously with respect to FIG. 1. The target material may have tensile properties consistent with commercial elastomeric liners and high compressive stiffness so that the target material has minimal sensitivity to interface pressure and does not alter the clinical performance of the liner.

[0218] Magnetically permeable or conductive target material 1604 may be integrated into elastomeric liner 1606 in various configurations, as described previously with respect to FIG. 1. For example, magnetically permeable or conductive target material 1604 may be a full ferrous layer within elastomeric liner 1606, targeted areas of ferrous material at locations corresponding to recesses 108, ferrous material integrated within fabric backing construct 1602, ferrous sections molded within a silicone, polyurethane, or thermoplastic layer of elastomeric liner 1606, or bands of ferrous material disposed on a textile or polymer affixed to an outer surface of elastomeric liner 1606. The textile or polymer may be affixed to the outersurface of elastomeric liner 1606 using adhesive, chemical, hook-and-loop fasteners, elastic tension, or another attachment method.

[0219] Magnetically permeable target material 1604 may be formed by mixing iron powder with a designed polymer, heating while applying vacuum to make the mixture smooth and pull-out air bubbles and pouring the mixture into a mold over a thin layer of clean nonferrous polymer. Magnetically permeable target material 1604 may be formed as circles cut from a ferrous polymer sheet, placed against fabric backing construct 1602, and heated under pressure so that the polymer attaches to fabric backing construct 1602. The construct may be sewn together on the edge and then affixed to elastomeric liner 1606 with adhesive. Magnetically permeable or conductive target material 1604 may be a patch containing conductive or magnetically permeable material affixed to elastomeric liner 1606. Magnetically permeable or conductive target material 1604 may be 3D printed into the elastomer or backing of elastomeric liner 1606, such as silicone, polyurethane, or thermoplastic elastomer material. Magnetically permeable or conductive target material 1604 may have circular, stripe, or grid target shapes depending on the sensing configuration and clinical application.

[0220] Once the wearable interface with embedded sensors is fabricated and paired with the elastomeric liner, the sensing system may be calibrated. Calibration may include using a bench test setup to establish a calibration curve, lookup table or computational model relating sensor signals to distance between the sensors and the target material. The liner may be placed over an inflatable element in the shape of the body part and the assembly placed in the wearable interface. Data may be collected while the inflatable element is brought to a pressure sufficient to push the liner against the inner structure to establish an offset for the calibration curve. The calibration curve may be used to convert sensor data into distance measurements in units of length.

[0221] The internal surface of the inner structure may have a vapor-smoothed finish to control the surface roughness. Other surface treatments may also be used including media tumbling, media blasting, ironing, chemical treatment, and epoxy coating or other smooth durable material coating. Vapor smoothing may be performed by placing the inner structure in a sealed processing chamber with a vapor finishing agent that melts the surface in a controlled way to even out peaks and valleys of the surface finish. The vapor smoothing process may improve surface roughness while maintaining dimensional accuracy of the inner structure. The degree of surface smoothing may be selected based on the intended application and the desired surface characteristics. The predefined dynamic coefficient of friction achieved through vaporsmoothing may be selected based on patient preference and clinical requirements, as some users and / or prosthetists may prefer higher friction for tight coupling while others may prefer lower friction to reduce perceived weight during swing phase.

[0222] The inner structure may be fabricated as a full structure or as a partial inner structure. In some cases, only a portion or subset of the inner structure may be fabricated and instrumented rather than a full inner structure. The portion may correspond to a specific region where sensor placement is desired, such as a distal region, an anterior region, or a posterior region. The portion of the inner structure may be supported during fabrication using a mold, first lamination layer, residual limb, liner, or other supporting material. In some cases, the portion may be supported by a residual limb for direct socket fabrication, where socket material is formed directly over the inner structure and residual limb to complete the socket. The residual limb may be covered with a protective membrane, sock, liner, pad, or flexible inner during direct socket fabrication.

[0223] The inside of the inner structure may be flexible to provide compatibility with the body part. A flexible internal surface may allow the inner structure to conform to variations in body part shape and may accommodate changes in volume during use. The inner structure may alternatively be made deformable so that after the sensing system is applied, the inner structure may be adhered to outer material for mechanical support. A deformable inner structure may be shaped to conform to a mold or body part during fabrication and then adhered to a rigid outer material to provide structural support for the completed wearable interface. The inner structure may be exposed to heat or a chemical that causes it to stiffen so that its properties are more closely matched to the outer lamination, coating or shell.

[0224] The inner structure may be fabricated from various materials depending on the type of wearable interface to be made and the outer layer application method, as described previously with respect to FIG. 4. Materials suitable for a stiff inner structure may include glass-filled polymers, carbon-filled polymers, ceramic-filled polymers, ceramic composites, thermoplastics, glass-embedded resins or engineering resins. Materials suitable for a less stiff inner structure may include acrylonitrile butadiene styrene, polyethylene terephthalate / polyethylene terephthalate glycol, nylon, thermoplastic polyurethane, acrylonitrile styrene acrylate, polycarbonate, polypropylene. In one embodiment, the inner structure may be made of a glass-filled or carbon-filled polymer such as glass-filled blended nylon 12 having a glass transition temperature, Young’s modulus, and tensile strength suitable for the outer layer application. The inner structure may be fabricated using additivemanufacturing methods as described previously with respect to FIG. 1. The inner structure materials may have variable stiffness or a gradient in stiffness from the internal surface to the external surface and may have embedded target material.

[0225] A digital workflow may integrate outcomes from sensor data into other aspects of patient care. The digital workflow may connect sensor data to tracked variables such as activity level, time conducting different activities, pylon forces / moments, step count, and walking speed, to prosthesis variables such as socket and liner stiffness, and to patient health variables such as limb volume changes, skin condition, and pain levels. Information about necessary activity or prosthesis modifications may be communicated to the user, prosthetist or other stakeholders via a wireless interface and to the patient’s medical record. The integrated digital workflow may support training, diagnostic, and prognostic applications where sensor data informs patient education, identifies causes of symptoms or predicts future outcomes.

[0226] The sensors, for example inductive sensor antennae, and lead wires may be three-dimensionally printed directly onto the inner structure, eliminating or simplifying the sensor harness by forming the sensing elements as part of the inner structure fabrication process, as described previously with respect to FIG. 2. A thin layer of support material such as a polyimide film may be three-dimensionally printed onto the inner structure before printing the sensor antennae and lead wires to provide electrical insulation and a smooth surface for conductive trace formation. Connector housing, connector, and electrical connections may also be three-dimensionally printed using conductive materials, enabling fabrication of a fully integrated sensing system where all electrical components are formed during the additive manufacturing process.

[0227] An electronic assembly that receives a cable from the connector may be placed within a closeable receptacle on an outside of the wearable interface. The closeable receptacle may be configured to protect the electronic assembly from mechanical damage and may include elements such as mounting posts or clips that mechanically support a circuit board. The closeable receptacle may be designed as part of the inner structure during additive manufacturing or may be attached to the outer layer after fabrication.

[0228] The fabrication process for the wearable interface with embedded sensors may reduce technician time compared to traditional fabrication methods. Because the inner structure replaces the inner lamination layer, the fabrication may require only a single lamination cure rather than multiple curing steps, which may enable completion in a shorter time. Thefabrication time may be further reduced through implementation of computational algorithms for automated sensor placement determination, vendor fabrication of pre-assembled sensor harnesses, and use of a sensor-check instrument for rapid functionality verification.

[0229] The dimensions and values disclosed herein are not to be understood as being strictly limited to the exact numerical values recited. Instead, unless otherwise specified, each such dimension is intended to mean both the recited value and a functionally equivalent range surrounding that value. For example, a dimension disclosed as “40 wt.%” is intended to mean “about 40 wt.%”.

[0230] A number of implementations have been described. Nevertheless, it will be understood that various modifications may be made without departing from the spirit and scope of the disclosure. Accordingly, other implementations are within the scope of the following claims.

Claims

CLAIMSWhat is claimed is:

1. A method for fabricating a wearable interface with embedded sensors, the method comprising:receiving a digital file representing a contour of a body part or a modified contour of the body part, the digital file being for fabrication of the wearable interface;executing a computational algorithm to determine locations for at least one recess and routing features based on landmark data within or calculated from the digital file;creating an inner structure based on the digital file, wherein the inner structure comprises an internal surface configured to interface with the body part and an external surface comprising the at least one recess configured to receive at least one sensor and the routing features configured to guide electrical connections;placing a sensing system onto the external surface of the inner structure, wherein the sensing system comprises at least one sensor positioned within the at least one recess and electrical connections routed through the routing features; andapplying an outer layer over the inner structure and the sensing system to encapsulate the at least one sensor and the electrical connections.

2. The method of claim 1, wherein the inner structure is fabricated using additive manufacturing comprising at least one of selective laser sintering (SLS), stereolithography (SLA), multi -jet fusion (MJF), fused deposition modeling (FDM), lubricant sublayer photocuring (LSPC), photopolymerization (DLPs, LEDs), direct energy deposition (DED), electron beam melting (EBM), carbon digital -like synthesis (DLS), or material or binder jetting.

3. The method of claim 1 or 2, wherein the inner structure is made of a glass-filled, carbon-filled or ceramic-filled polymer.

4. The method of any one of claims 1-3, wherein creating the inner structure further comprises:forming a connector enclosure within the external surface configured to receive a connector of the sensing system.

5. The method of any one of claims 1-4, further comprising:executing the computational algorithm to optimize placement of the at least one recess based on local surface contour of the inner structure, and minimizing intersecting paths of the routing features across the external surface of the inner structure.

6. The method of any one of claims 1-5, wherein placing the sensing system comprises placing a pre-assembled sensor harness, the pre-assembled sensor harness comprising the at least one sensor with electronic components encapsulated in a protective material and the electrical connections pre-installed within a single connector housing.

7. The method of any one of claims 1-6, further comprising:applying, over the at least one sensor prior to applying the outer layer, a material that is magnetically permeable and electrically resistive sufficient to limit eddy current losses when a magnetic field is applied; andweaving a ground wire from the sensing system into the outer layer to electrically isolate the at least one sensor from conductive materials in the outer layer.

8. The method of any one of claims 1-7, wherein the inner structure further comprises structural elements configured to support at least one of: adjustable socket panels; vacuum or suction mechanism; adjustable cabling mechanism; fluid-filled enclosure; air-filled enclosure; stiffness adjustment mechanism; frictional adjustment mechanism; socket length adjustment mechanism; manual mechanisms for adjustment of the wearable interface; electronic actuators for auto-adjustment of the wearable interface; a release-relock mechanism; vents; a cooling mechanism or a grip control mechanism.

9. The method of any one of claims 1-8, wherein the at least one sensor comprises at least one inductive sensor antenna or antenna array configured to sense distance to a magnetically permeable or conductive target material.

10. The method of any one of claims 1-9, wherein the method is implemented at least in part via software executed by a processor, the software being stored on a non-transitory computer-readable medium.

11. The method of any one of claims 1-10, further comprising:receiving sensor data from the sensing system indicating motion of a bony structure relative to the inner structure; anddetermining a socket fit metric from the sensor data that reflects the bony structure motion relative to the inner structure.

12. The method of claim 11, further comprising:using the sensor data with the digital file and a computational model to determine tissue stresses at a body-device interface; andcomputationally testing adjustments to at least one actuator dependent on the wearable interface based on the determined tissue stresses.

13. The method of any one of claims 1-12, wherein the sensing system is three-dimensionally printed directly onto the inner structure during fabrication of the inner structure.

14. A wearable interface with embedded sensors, the wearable interface comprising: an inner structure having an internal surface configured to interface with a body part and an external surface, wherein the external surface comprises a predefined layout including at least one recess configured to receive at least one sensor and routing features configured to guide electrical connections;a sensing system comprising at least one sensor positioned within the at least one recess, electrical connections extending from the at least one sensor through the routing features, and a connector configured to receive the electrical connections; andan outer layer disposed over the inner structure and completely encapsulating the at least one sensor and the electrical connections, wherein the at least one sensor is sub-surface embedded on the external surface of the inner structure and protected from wear by the outer layer, while on the inside surface the continuous inner structure protects the at least one sensor.

15. The wearable interface of claim 14, wherein the inner structure is fabricated using additive manufacturing comprising at least one of selective laser sintering (SLS), stereolithography (SLA), multi -jet fusion (MJF), fused deposition modeling (FDM), lubricant sublayer photo-curing (LSPC), photopolymerization (DLPs, LEDs), direct energy deposition (DED), electron beam melting (EBM), carbon digital-like synthesis (DLS), or material or binder jetting.

16. The wearable interface of claim 14 or 15, wherein the inner structure is made of a glass-filled, carbon-filled or ceramic-filled polymer.

17. The wearable interface of any one of claims 14-16, wherein the inner structure further comprises structural elements configured to support at least one of: adjustable socket panels; vacuum or suction mechanism; adjustable cabling mechanism; fluid-filled enclosure; air-filled enclosure; stiffness adjustment mechanism; frictional adjustment mechanism; socketlength adjustment mechanism; manual mechanisms for adjustment of the wearable interface; electronic actuators for auto-adjustment of the wearable interface; a release-relock mechanism; vents; a cooling mechanism or a grip control mechanism.

18. The wearable interface of any one of claims 14-17, further comprising an elastomeric liner configured to be worn between the body part and the internal surface of the inner structure, wherein the elastomeric liner includes a magnetically permeable or conductive target material configured to interface with the at least one sensor.

19. The wearable interface of claim 18, wherein the magnetically permeable or conductive target material comprises at least one of:a full magnetically permeable or conductive layer within the elastomeric liner; targeted areas of magnetically permeable or conductive material positioned at locations corresponding to the at least one recess;magnetically permeable or conductive material integrated within a fabric backing of the elastomeric liner;magnetically permeable or conductive sections molded within an elastomer layer of the elastomeric liner; ordisks or bands of magnetically permeable or conductive material disposed on a textile or polymer affixed to an outer surface of the elastomeric liner.

20. The wearable interface of any one of claims 14-19, wherein the at least one sensor comprises inductive distance sensors arranged as a single sensor, in a sensor array of more than one sensor or a fusion of multiple sensors configured to determine at least one position of a target relative to the inner structure, and wherein the sensing system further includes a capacitor configured to tune a resonant frequency of the at least one inductive sensor antenna and a thermistor configured to measure temperature at a location of the at least one inductive sensor antenna.

21. The wearable interface of claim 20, further comprising a processor configured to receive data from the single sensor, sensor array or fusion of multiple sensors and to determine a socket fit metric and from that determine a device adjustment, and wherein the inner structure further comprises mounting features for at least one actuator configured to adjust a dimension of the wearable interface or a dependent feature based on a command from the processor.

22. The wearable interface of any one of claims 14-21, wherein the external surface further comprises a connector enclosure configured to receive the connector.

23. The wearable interface of any one of claims 14-22, wherein the outer layer comprises a vacuum-assisted carbon-fiber lamination, and wherein a material that is magnetically permeable and electrically resistive sufficient to limit eddy current losses when a magnetic field is applied is disposed over the at least one sensor between the at least one sensor and the outer layer, and a ground wire from the sensing system is woven into the outer layer to electrically isolate the at least one sensor from conductive materials in the outer layer.

24. The wearable interface of any one of claims 14-23, wherein the sensing system is a pre-assembled sensor harness that is a standalone subassembly physically separable from the inner structure prior to integration.

25. The wearable interface of claim 21, wherein the processor is further configured to: receive sensor data from the sensing system indicating motion of a bony structure relative to the inner structure;determine a socket fit metric from the sensor data that reflects the bony structure motion relative to the inner structure.

26. The wearable interface of claim 25, wherein the processor is further configured to: use the sensor data with a digital file representing a contour of the body part and a computational model to determine tissue stresses at a body-device interface, wherein the computational model is a finite element model; andcomputationally test adjustments to at least one actuator dependent on the wearable interface based on the determined tissue stresses.

27. The wearable interface of claim 21, wherein the processor is further configured to use activity data to calculate the socket fit metric.

28. The wearable interface of claim 21, wherein the processor is further configured to use sensor data history to calculate the socket fit metric; anduse patient characteristics, prosthesis characteristics, and patient medical history and imaging data in determining the device adjustment.

29. The wearable interface of claim 21, wherein the processor is further configured to receive data from at least one additional sensor comprising at least one of a pressure sensor, acapacitive sensor, a strain-gage sensor, a piezoelectric sensor, a textile-based sensor, a MEMS sensor, a vacuum sensor, a proximity sensor, an ultrasound sensor, a laser sensor, an optical sensor, a radar infrared sensor, or a tactile feedback sensor, and to use data from the at least one additional sensor in calculating the socket fit metric.

30. The wearable interface of any one of claims 14-29, wherein the inner structure has a variable stiffness or gradient in stiffness from the internal surface to the external surface.

31. The wearable interface of any one of claims 14-30, wherein a digital file representing a contour of the body part is used to determine an active region and sensitivity distribution of the at least one sensor based on the known position and orientation of the at least one sensor within the inner structure.

32. A sensor harness for integration with a wearable interface inner structure, the sensor harness comprising:at least one sensor element, the at least one sensor element having associated electronic components;a single connector housing;lead wires pre-installed within the single connector housing and extending to the at least one sensor element; anda protective encapsulation disposed over the electronic components of the at least one sensor element, wherein the sensor harness is dimensioned and configured for physical placement within predefined recesses on an external surface of a wearable interface inner structure prior to application of an outer structural layer.

33. The sensor harness of claim 32, wherein the lead wires are arranged in a zigzag or serpentine configuration with an elastic element in parallel to accommodate varying distances between the at least one sensor element and the single connector housing.

34. The sensor harness of claim 32 or 33, wherein when the sensor harness comprises a plurality of sensor elements, adjacent sensor elements are connected through a flexible joint formed in a flexible circuit backing material to maintain sensor organization during placement while allowing the sensor elements to conform to curved surfaces of the wearable interface inner structure.

35. The sensor harness of any one of claims 32-34, wherein the at least one sensor element comprises at least one inductive sensor antenna or antenna array, and wherein theassociated electronic components include a capacitor and a thermistor for the at least one inductive sensor antenna or antenna array.

36. The sensor harness of any one of claims 32-35, wherein the protective encapsulation comprises at least one of: hot melt glue; epoxy; polyurethane; acrylic; dielectric adhesive; rubber adhesive; silicone potting compound; UV-curable resin or a conformal coating with high dielectric strength.

37. The sensor harness of any one of claims 32-36, wherein the lead wires have lengths calculated from a digital model of the wearable interface inner structure.

38. A wearable interface system comprising the sensor harness of any one of claims 32-37 integrated with the wearable interface of any one of claims 14-31, wherein the at least one sensor element of the sensor harness is positioned within the at least one recess on the external surface of the inner structure of the wearable interface, and the lead wires are routed through the routing features on the external surface of the inner structure.

39. A wearable interface with embedded sensors made by the method of any one of claims 1-13.

40. A non-transitory computer-readable medium storing instructions that, when executed by one or more processors, cause the one or more processors to perform the method of any one of claims 1-13.

41. A system for fabricating a wearable interface with embedded sensors, the system comprising: a processor; and memory coupled to the processor and storing instructions that, when executed by the processor, cause the processor to execute the computational algorithm and perform the method of any one of claims 1-13.

42. The method of claim 1, wherein the at least one sensor is selected from the group consisting of an inductive sensor, a pressure sensor, a capacitive sensor, a strain-gage sensor, a piezoelectric sensor, a textile-based sensor, a MEMS sensor, a vacuum sensor, a proximity sensor, an ultrasound sensor, a laser sensor, an optical sensor, a radar infrared sensor, and a tactile feedback sensor.

43. The method of claim 1, wherein the wearable interface comprises at least one of a prosthetic socket for a transtibial, transfemoral, or upper-limb amputation, an orthotic device, a helmet, a brace, an exoskeleton interface, a seating surface, a shoe, a cast, a finger prosthesis, an upper limb prosthesis, or a veterinary prosthetic or orthotic device for an animal.

44. The method of claim 1, wherein the outer layer is selected from the group consisting of a structural lamination, a coating, a three-dimensionally printed shell, a vacuum-assisted carbon-fiber lamination, and a non-conductive polymer layer.

45. The wearable interface of claim 14, wherein the at least one sensor is three-dimensionally printed directly onto the external surface of the inner structure.

46. The sensor harness of claim 32, wherein the at least one sensor element comprises sensor elements of different types configured to monitor different variables selected from distance, force, pressure, shear stress, temperature, humidity, oxygen concentration, sweat, hydration, muscle function, energy levels, skin health, blood flow, vessel density, collagen density, heart rate, heart rate variability, blood pressure, respiration, electrolyte concentration, metabolite concentration, and analyte concentration.

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