# US 2025/0127635 A1 · Prosthesis with powered ankle and toe joints > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2025/0127635 A1 - Document ID: US20250127635A1 - Status: Published application - Kind: A1 - Application number: 18/991,192 - Filed: 2024-12-20 - Published: 2025-04-24 - Earliest claimed: 2021-03-30 - Assignees: University of Utah Research Foundation - Applicants: University of Utah Research Foundation - Inventors: Tommaso LENZI; Lukas R. GABERT; Minh TRAN - Web page: https://patentgrep.com/patent/US20250127635A1 ## CPC - A61F 2/50: Prostheses not implantable in the body {(closure means for urethra or rectum or for artificial body openings therefor A61F2/0004)} - A61F 2/6607: {Ankle joints} - A61F 2/66: Feet; Ankle joints - A61F 2/68: Operating or control means - A61F 2/70: electrical - A61F 2/76: Means for assembling, fitting or testing prostheses, e.g. for measuring or balancing - A61F 2002/5043: {with rotation-limiting stops, e.g. projections or recesses} - A61F 2002/5072: {having spring elements} - A61F 2002/6621: {Toes} - A61F 2002/6836: {Gears specially adapted therefor, e.g. reduction gears} - A61F 2002/701: {operated by electrically controlled means, e.g. solenoids or torque motors} - A61F 2002/7635: {for measuring force, pressure or mechanical tension} - A61F: FILTERS IMPLANTABLE INTO BLOOD VESSELS; PROSTHESES; DEVICES PROVIDING PATENCY TO, OR PREVENTING COLLAPSING OF, TUBULAR STRUCTURES OF THE BODY, e.g. STENTS; ORTHOPAEDIC, NURSING OR CONTRACEPTIVE DEVICES; FOMENTATION; TREATMENT OR PROTECTION OF EYES OR EARS; BANDAGES, DRESSINGS OR ABSORBENT PADS; FIRST-AID KITS (dental prosthetics A61C) ## Abstract Disclosed herein is a robotic ankle foot prosthesis that replicates the key biomechanical functions of the biological ankle and toe joints while matching the weight, size, and battery life of passive microprocessor-controlled prostheses. A single actuator powers the ankle and toe joints. The mechanism maximizes the mechanical energy regeneration during walking while imitating the physiological features of energy injection by way of the ankle joint and energy dissipation by way of the toe joint. ## Claims ### Claim 1 A powered assistive ankle and foot device, comprising: a shank assembly comprising an ankle joint and a shank pivot shaft offset from the ankle joint; a tarsal assembly comprising a proximal section and a distal section, the proximal section being connected to the shank pivot shaft; a toe assembly comprising a toe joint and a toe pivot shaft offset from the toe joint, the toe pivot shaft being connected to the distal section of the tarsal assembly; and a linear actuator associated with the tarsal assembly, the linear actuator being configured as a linear series elastic actuator, wherein the linear actuator is configured to adjust the distance between the shank pivot shaft and the toe pivot shaft to thereby provide simultaneous torque to both the ankle joint and the toe joint. ### Claim 2 (depends on 1) The device of claim 1, wherein the linear series elastic actuator comprises a screw, a nut, and a compliant element. ### Claim 3 (depends on 2) The device of claim 2, wherein the linear actuator comprises a ball screw assembly. ### Claim 4 (depends on 2) The device of claim 2, wherein the compliant element is mechanically connected to the nut and functions to move the nut toward a neutral position along the screw when the screw is not rotated. ### Claim 5 (depends on 2) The device of claim 2, wherein the compliant element is attached to and spans between a proximal anchor and a distal anchor, wherein the proximal anchor is connected to the nut and the distal anchor is connected to the toe pivot shaft. ### Claim 6 (depends on 5) The device of claim 5, wherein the proximal and distal anchors include bores sized to receive the screw. ### Claim 7 (depends on 1) The device of claim 1, wherein an offset distance between the ankle joint and the shank pivot shaft is greater than an offset distance between the toe joint and the toe pivot shaft. ### Claim 8 (depends on 1) The device of claim 1, wherein: when a distance between the shank pivot shaft and the toe pivot shaft is lessened, the ankle joint moves in plantarflexion and the toe joint moves in toe flexion; and when a distance between the shank pivot shaft and the toe pivot shaft is increased, the ankle joint moves in dorsiflexion and the toe joint moves in toe extension. ### Claim 9 (depends on 1) The device of claim 1, wherein the toe assembly includes a mechanical stop configured to prevent the toe assembly from moving past a neutral position. ### Claim 10 (depends on 1) The device of claim 1, further comprising a motor mechanically connected to the linear actuator to power the linear actuator. ### Claim 11 (depends on 10) The device of claim 10, wherein the motor is attached to or housed within the shank assembly. ### Claim 12 (depends on 11) The device of claim 11, wherein the motor does not rotate relative to a shank frame during ankle joint movement of the device. ### Claim 13 (depends on 11) The device of claim 11, wherein the motor is in direct contact with the shank frame. ### Claim 14 (depends on 10) The device of claim 10, wherein the motor is mechanically connected to the linear actuator via a power transmission assembly, wherein the power transmission assembly comprises multiple bevel gears. ### Claim 15 (depends on 14) The device of claim 14, wherein a first bevel gear is coaxial to an output gear, a second bevel gear is coaxial with the shank pivot shaft, and a third bevel gear is coaxial to an axis of rotation of screw of the ball screw assembly and functions to transfer power to the screw. ### Claim 16 (depends on 1) The device of claim 1, wherein the shank assembly comprises a pyramid adaptor, the pyramid adaptor comprising an integrated ground force sensor. ### Claim 17 (depends on 1) The device of claim 1, wherein the device is a prosthesis. ### Claim 18 A powered assistive ankle and foot device, comprising: a shank assembly comprising an ankle joint; a tarsal assembly comprising a proximal section and a distal section, the proximal section being connected to the shank assembly; a toe assembly connected to the distal section of the tarsal assembly, the toe assembly comprising a toe joint; and a linear actuator included in or associated with the tarsal assembly and configured to power movement of both the ankle joint and the toe joint, wherein the linear actuator comprises a screw, a nut, and a compliant element, wherein the compliant element is connected to the nut and functions to move the nut toward a neutral position along the screw when the screw is not rotated. ### Claim 19 (depends on 18) The device of claim 18, wherein the compliant element is attached to and spans between a proximal anchor and a distal anchor, wherein the proximal anchor is connected to the nut and the distal anchor is connected to the toe pivot shaft, and wherein proximal and distal anchors include bores sized to receive the screw. ### Claim 20 (depends on 18) The device of claim 18, wherein the device is a prosthesis.