Patents by Inventor Changkuan Yu

Changkuan Yu 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: 11154444
    Abstract: A medical bed for automatically rolling a patient from back to either side to help avoid the pressure points causing decubitus ulcers. A footboard is provided with a pair of driving mechanisms to independently move a first carriage and a second carriage. The driving mechanisms each translate force to a corresponding unpowered third carriage and fourth carriage on the headboard. The first and third carriages are connected by a first roller shaft. The second and fourth carriages are also connected by a second roller shaft. The first roller shaft and second roller shaft are connected to opposing parallel edges of a sheet. The first and second roller shaft each independently spool the edges of the sheet. As the first roller shaft spools the sheet and the first and third carriages move carrying the first roller shaft, the patient is rolled in a first direction.
    Type: Grant
    Filed: May 21, 2021
    Date of Patent: October 26, 2021
    Inventor: Changkuan Yu
  • Patent number: 9284825
    Abstract: A valve actuator, valve, and method of actuation of a valve are disclosed. The valve actuator includes a shape memory alloy element attachable to a valve body, capable of use with a valve to cause movement of the valve between first and second positions. The valve actuator also includes a sensor located within a well and capable of detecting the presence of a fluid based on a fluid property of the fluid. The valve actuator includes a power supply electrically connected to the sensor and the shape memory alloy element, capable of applying an electric current to the shape memory alloy element in response to the sensor detecting the presence of the fluid. The electric current causes a temperature of the shape memory alloy element to increase beyond a threshold temperature at which the shape memory alloy element actuates.
    Type: Grant
    Filed: November 30, 2012
    Date of Patent: March 15, 2016
    Assignees: Massachusetts Institute of Technology, Chevron U.S.A. Inc.
    Inventors: Changkuan Yu, Eric Wright Gilbertson, Franz Hover, Dennis Harris, Jose Arellano
  • Patent number: 9145974
    Abstract: A valve actuator, valve, and method of actuation of a valve are disclosed. The valve actuator includes a shape memory alloy element attachable to a valve body, capable of use with a valve to cause movement of the valve between first and second positions at a predetermined temperature and responsive to at least a threshold amount of temperature change of the shape memory alloy element. The valve actuator further includes an expansion element attached to the shape memory alloy element, the expansion element responsive to temperature changes at a rate lower than a rate of change of temperature indicative of a valve leak, the expansion element adjusting tension on the shape memory alloy element, thereby changing the predetermined temperature.
    Type: Grant
    Filed: November 30, 2012
    Date of Patent: September 29, 2015
    Assignees: Massachusetts Institute of Technology, Chevron U.S.A. Inc.
    Inventors: Eric Wright Gilbertson, Changkuan Yu, Franz Hover, Dennis Harris, Jose Arellano
  • Publication number: 20140150869
    Abstract: A valve actuator, valve, and method of actuation of a valve are disclosed. The valve actuator includes a shape memory alloy element attachable to a valve body, capable of use with a valve to cause movement of the valve between first and second positions. The valve actuator also includes a sensor located within a well and capable of detecting the presence of a fluid based on a fluid property of the fluid. The valve actuator includes a power supply electrically connected to the sensor and the shape memory alloy element, capable of applying an electric current to the shape memory alloy element in response to the sensor detecting the presence of the fluid. The electric current causes a temperature of the shape memory alloy element to increase beyond a threshold temperature at which the shape memory alloy element actuates.
    Type: Application
    Filed: November 30, 2012
    Publication date: June 5, 2014
    Applicants: MASSACHUSETTS INSTITUTE OF TECHNOLOGY, CHEVRON U.S.A. INC.
    Inventors: Changkuan Yu, Eric Wright Gilbertson, Franz Hover, Dennis Harris, Jose Arellano
  • Publication number: 20140150879
    Abstract: A valve actuator, valve, and method of actuation of a valve are disclosed. The valve actuator includes a shape memory alloy element attachable to a valve body, capable of use with a valve to cause movement of the valve between first and second positions at a predetermined temperature and responsive to at least a threshold amount of temperature change of the shape memory alloy element. The valve actuator further includes an expansion element attached to the shape memory alloy element, the expansion element responsive to temperature changes at a rate lower than a rate of change of temperature indicative of a valve leak, the expansion element adjusting tension on the shape memory alloy element, thereby changing the predetermined temperature.
    Type: Application
    Filed: November 30, 2012
    Publication date: June 5, 2014
    Applicants: Massachusetts Institute of Technology, Chevron U.S.A. Inc.
    Inventors: Eric Wright Gilbertson, Changkuan Yu, Franz Hover, Dennis Harris, Jose Arellano