Patents by Inventor Sunil Agrawal

Sunil Agrawal has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 7601104
    Abstract: A passive gravity balancing assist device for human sit-to-stand motion is provided. The design combines the use of auxiliary parallelograms with springs to produce an orthotic device wherein the total potential energy of the system is constant during standing and sitting motion.
    Type: Grant
    Filed: April 21, 2006
    Date of Patent: October 13, 2009
    Assignee: University of Delaware
    Inventors: Sunil Agrawal, Abbas Fattah, Glenn Catlin, John Hamnett
  • Publication number: 20080255488
    Abstract: A powered orthosis, adapted to be secured to a corresponding body portion of the user for guiding motion of a user, the orthosis comprising a plurality of structural members and one or more joints adjoining adjacent structural members, each joint having one or more degrees of freedom and a range of joint angles. One or more of the joints each comprise at least one back-drivable actuator governed by a controller for controlling the joint angle. The plurality of joint controllers are synchronized to cause the corresponding actuators to generate forces for assisting the user to move the orthosis at least in part under the user's power along a desired trajectory within an allowed tolerance. One embodiment comprises force-field controllers that define a virtual tunnel for movement of the orthosis, in which the forces applied to the orthosis for assisting the user may be proportional to deviation from the desired trajectory.
    Type: Application
    Filed: April 4, 2008
    Publication date: October 16, 2008
    Applicant: University of Delaware
    Inventors: Sunil Agrawal, Sai Banala
  • Publication number: 20080249438
    Abstract: Gait training apparatus and method for use thereof for providing leg swing assistance to a patient. The apparatus comprises a support structure and one or more leg orthoses attached to the support structure, each leg orthosis comprising a thigh member attached to the support structure at a hip joint, and a shank member attached to the thigh member at a knee joint. Both members have respective connectors for securing them to the corresponding body parts of the patient. The hip joint and knee joint are each biased by biasing members. The support structure may comprise a frame defining a patient activity region, including a base, a back support, a pair of support handles, and a weight support member mounted above the activity region. A method of using the device comprises selecting parameters for the biasing members using information about the patient.
    Type: Application
    Filed: April 4, 2008
    Publication date: October 9, 2008
    Applicant: University of Delaware
    Inventors: Sunil Agrawal, Kalyan K. Mankala, Sai Banala
  • Publication number: 20080104406
    Abstract: Methods and apparatus, including computer program products, implementing and using techniques for establishing trust in an electronic document. An electronic document is received. State dependent content in the electronic document is identified. The state dependent content is content that is renderable to have a several appearances. The electronic document is presented to a user, which includes disclosing the presence of any identified state dependent content in the electronic document.
    Type: Application
    Filed: December 28, 2007
    Publication date: May 1, 2008
    Inventors: James Pravetz, Krish Chaudhury, Sunil Agrawal
  • Publication number: 20080086635
    Abstract: Method and apparatus are described wherein, in one example embodiment, a public key certificate issued by a certificate authority includes at least one characteristic that does not conform to at least one rule established for the operation of a public key infrastructure. An attribute certificate is issued to be used to modify the public key certificate in accordance with information contained in the attribute certificate to create a modified public key certificate wherein the at least one characteristic is modified so as conform to the at least one rule. According to one example embodiment, the attribute certificates may be distributed by a certificate authority, or embedded in an application that includes an engine that is used to modify the non-conforming public key certificate.
    Type: Application
    Filed: October 10, 2006
    Publication date: April 10, 2008
    Inventors: Sunil Agrawal, Andrei Sheretov
  • Publication number: 20070262194
    Abstract: A vehicle with wings and a mechanism for causing a flapping motion in wings. Each wing structure comprises a wing and a wing spar coupled to a follower via a resilient member. Each wing carrier is pivotally connected to the body and is configured to restrain lateral movement and permit rotation of the wing spar about a feathering axis. A biasing member provides torsional bias to each wing spar. A linkage, driven by an actuator, transmits cyclic motion that rotates the wing carrier about a flapping axis, which moves the follower along a follower path. A guide attached to the vehicle body lies in the path of each follower, and the follower and guide are shaped such that each wing spar has a first rotational position about its axis along a first portion of the follower path and a second rotational position along a second portion of the follower path.
    Type: Application
    Filed: November 7, 2006
    Publication date: November 15, 2007
    Inventors: Sunil Agrawal, Sean McIntosh, Zaeem Kahn
  • Publication number: 20070049858
    Abstract: An ankle-foot orthosis comprising a leg member 12; a foot member 14; a frame 16 connecting the leg member to the foot member, wherein the frame comprises a first revolute joint 18 that rotates about a first axis 20 and a second revolute joint 22 that rotates about a second axis 24, wherein the first and second axes are non-parallel. The frame can further comprise a foot member segment 30 secured to the foot member 14 and extending to the second revolute joint 22. The orthosis can comprise a first force-torque sensor 36 located on the leg member, a second force-torque sensor 38 located on the foot member, and an encoder positioned on one of the revolute joints. The invention includes a method of measuring ankle-foot-related forces comprising positioning a subject's leg and foot in an ankle-foot orthosis; collecting data from the first and second force-torque sensors; and analyzing the collected data to determine the motion of the subject's ankle.
    Type: Application
    Filed: June 15, 2006
    Publication date: March 1, 2007
    Inventors: Sunil Agrawal, Abhishek Agrawal, Sai Banala, Stuart Binder-MacLeod
  • Publication number: 20060260621
    Abstract: A passive gravity balancing assist device for human sit-to-stand motion is provided. The design combines the use of auxiliary parallelograms with springs to produce an orthotic device wherein the total potential energy of the system is constant during standing and sitting motion.
    Type: Application
    Filed: April 21, 2006
    Publication date: November 23, 2006
    Inventors: Sunil Agrawal, Abbas Fattah, Glenn Catlin, John Hamnett
  • Publication number: 20060241539
    Abstract: Passive gravity balancing orthosis apparatus for assisting and training patients suffering from muscle weakness by relieving the patients afflicted member of its weight using a plurality of articulated supporting members. Relief is obtained by identifying and fixing the center of mass of the combined articulated equipment members and supported weight of the patient's member in space using a defined parallelogram mechanism and once so identified making the total potential energy for any configuration of the articulated members of the system constant. At least one zero free length spring is used to connect the center of mass to a support outside the articulated members. Additional springs connect the center of mass to the articulated members.
    Type: Application
    Filed: April 25, 2005
    Publication date: October 26, 2006
    Inventors: Sunil Agrawal, Abbas Fattah, Sal Banala