# US 10,369,023 B2 · Impedance parameter power control for lower limb assistive device > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,369,023 B2 - Document ID: US10369023B2 - Status: Granted - Kind: B2 - Application number: 14/070,150 - Filed: 2013-11-01 - Published: 2015-05-07 - Granted: 2019-08-06 - Earliest claimed: 2013-11-01 - Assignees: Rehabilitation Institute of Chicago - Applicants: Rehabilitation Institute of Chicago - Inventors: Ann M. Simon; Nicholas P. Fey - Web page: https://patentgrep.com/patent/US10369023B2 ## CPC - A61F 2/72: Bioelectric control, e.g. myoelectric - A61F 2/60: Artificial legs or feet or parts thereof - A61F 2/64: Knee joints - A61F 2/6607: {Ankle joints} - A61F 2002/503: {for adjusting elasticity, flexibility, spring rate or mechanical tension} - A61F 2002/5033: {for adjusting damping} - A61F 2002/607: {Lower legs} - A61F 2002/701: {operated by electrically controlled means, e.g. solenoids or torque motors} - A61F 2002/704: {computer-controlled, e.g. robotic control} - A61F 2002/7625: {for measuring angular position} - 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 Systems and methods are described that relate to the control of a powered lower limb assistive device with one or more joints, where a controller of the assistive device is configured to receive one or more user-generated signals, determine control information using information in the one or more user-generated signals, select one or more joint impedance parameters of the assistive device for adjustment, and, for a mode and state of the assistive device, adjust the selected joint impedance parameters as a function of the control information. Additionally, systems and methods are described that relate to the control of such an assistive device, where a controller of the assistive device is configured to receive one or more user-generated signals containing information about the ankle angle of the assistive device, and adjust the stiffness of the ankle joint of the assistive device as a function of the ankle angle. ## Claims ### Claim 1 A system comprising a controller for a powered lower limb assistive device, the system comprising a motorized joint of the assistive device, the controller comprising a microprocessor and being configured to: a. receive one or more user-generated signals while the assistive device is operating in a mode and a state, wherein the mode represents a particular type of activity of the assistive device and the state represents a particular period of operation of the assistive device during a mode; b. determine an amount of load on the assistive device using information in the one or more user-generated signals; c. select one or more joint impedance parameters of the assistive device for adjustment, selected from the group consisting of a stiffness parameter, a damping parameter, and an equilibrium angle parameter, wherein the one or more selected joint impedance parameters are selected depending upon the mode and the state in which the device is operating; and d. within the mode and state in which the device is operating, continuously adjusting the one or more selected joint impedance parameters as a function of the amount of load on the assistive device, and e. initiate a signal that controls the motorized joint using the one or more adjusted joint impedance parameters. ### Claim 2 (depends on 1) The system of claim 1, where the controller is configured to adjust the selected joint impedance parameters as a function of the amount of load on the assistive device for at least the modes of ramp ascent and ramp descent. ### Claim 3 (depends on 1) The system of claim 1, where the mode of the assistive device is sit-to-stand. ### Claim 4 (depends on 1) The system of claim 1, further comprising the assistive device. ### Claim 5 (depends on 1) The system of claim 1, where the controller is for a powered lower limb assistive device having a knee joint and an ankle joint. ### Claim 6 (depends on 1) The system of claim 1, where the load is an axial load. ### Claim 7 (depends on 1) The system of claim 1, where the load is a torque or a moment. ### Claim 8 (depends on 1) The system of claim 1, the controller being further configured to: a. receive one or more user-generated signals containing information about the ankle angle of the assistive device; and b. adjust the stiffness of the ankle joint of the assistive device as a function of the ankle angle when the assistive device is in an ambulation mode. ### Claim 9 (depends on 8) The system of claim 8, further comprising the assistive device. ### Claim 10 (depends on 1) The system of claim 1, wherein the selected joint impedance parameters comprise a stiffness parameter. ### Claim 11 (depends on 1) The system of claim 1, wherein the selected joint impedance parameters comprise a damping parameter. ### Claim 12 (depends on 1) The system of claim 1, wherein the selected joint impedance parameters comprise a knee stiffness parameter when the assistive device is in a walking mode and a stance state, a ramp ascent mode and a stance state, and a ramp descent mode and a stance state. ### Claim 13 (depends on 1) The system of claim 1, wherein the selected joint impedance parameters comprise an ankle equilibrium angle parameter when the assistive device is in a walking mode and a stance state, a ramp ascent mode and a stance state, and a ramp descent mode and a stance state. ### Claim 14 (depends on 1) The system of claim 1, wherein the selected joint impedance parameters comprise a knee equilibrium angle parameter when the assistive device is in a walking mode and a stance state, a ramp descent mode and a stance state, and a ramp descent mode and a stance state. ### Claim 15 (depends on 1) The system of claim 1, wherein the selected joint impedance parameters comprise knee stiffness, ankle equilibrium angle, and knee equilibrium angle parameters when the assistive device is in a walking mode and a stance state, a ramp ascent mode and a stance state, and a ramp descent mode and a stance state. ### Claim 16 (depends on 1) The system of claim 1, wherein the selected joint impedance parameters comprise a knee stiffness parameter when the assistive device is in a ramp ascent mode and a stance state and in a ramp descent mode and a stance state. ### Claim 17 (depends on 1) The system of claim 1, wherein the selected joint impedance parameters comprise an ankle equilibrium angle parameter when the assistive device is in a ramp ascent mode and a stance state and in a ramp descent mode and a stance state. ### Claim 18 (depends on 1) The system of claim 1, wherein the selected joint impedance parameters comprise a knee equilibrium angle parameter when the assistive device is in a ramp ascent mode and a stance state and in a ramp descent mode and a stance state. ### Claim 19 (depends on 1) The system of claim 1, wherein the selected joint impedance parameters comprise knee stiffness, ankle equilibrium angle, and knee equilibrium angle parameters when the assistive device is in a ramp ascent mode and a stance state and in a ramp descent mode and a stance state. ### Claim 20 (depends on 1) The system of claim 1, wherein when the assistive device is in a stair ascent mode and in a stance state, the selected joint impedance parameters comprise an ankle equilibrium angle parameter. ### Claim 21 (depends on 1) The system of claim 1, wherein when the assistive device is in a stair descent mode and in a stance state, the selected joint impedance parameters comprise an ankle equilibrium angle parameter. ### Claim 22 (depends on 1) The system of claim 1, wherein when the assistive device is in a sit-to-stand mode and a sit-to-stand state, the selected joint impedance parameters comprise knee equilibrium angle and ankle equilibrium angle parameters.