US 12,004,996 B2
Miniature fixed and adjustable flow restrictor for the body
Yu-Chong Tai, Pasadena, CA (US); Aubrey M. Shapero, Pasadena, CA (US); Nicholas E. Scianmarello, Pasadena, CA (US); and Mark S. Humayun, Glendale, CA (US)
Assigned to California Institute of Technology, Pasadena, CA (US); and University of Southern California, Los Angeles, CA (US)
Filed by California Institute of Technology, Pasadena, CA (US); and University of Southern California, Los Angeles, CA (US)
Filed on Nov. 9, 2022, as Appl. No. 17/984,046.
Application 17/984,046 is a division of application No. 16/418,899, filed on May 21, 2019, granted, now 11,523,939.
Claims priority of provisional application 62/674,737, filed on May 22, 2018.
Prior Publication US 2023/0069775 A1, Mar. 2, 2023
Int. Cl. A61F 9/00 (2006.01); A61K 9/00 (2006.01); A61M 31/00 (2006.01); G02C 7/04 (2006.01)
CPC A61F 9/0017 (2013.01) [A61K 9/0051 (2013.01); A61M 31/002 (2013.01); A61F 2250/0068 (2013.01); B01L 2400/082 (2013.01); G02C 7/049 (2013.01)] 16 Claims
OG exemplary drawing
 
1. A method of adjusting a microfluidic flow restrictor, the method comprising:
a fluid flow rate through a microfluidic flow restrictor having a bead trap with a fill port;
piercing the fill port with a first injection needle;
piercing a downstream port of the microfluidic flow restrictor with a second injection needle;
injecting chemically inert spherical beads into, or aspirating chemically inert spherical beads out of, the bead trap in the microfluidic flow restrictor using the first injection needle, the chemically inert spherical beads having a diameter between 10 μm and 100 μm, thereby adjusting a fluidic resistance of the microfluidic flow restrictor;
pulling or pushing fluid with the second injection needle contemporaneously with the injecting or aspirating of the first injection needle in order to assist movement of the spherical beads; and
re-measuring the fluid flow rate after the injecting.
 
2. The method of claim 1 further comprising:
vibrating, using an ultrasound transducer, a wall of the microfluidic flow restrictor in order to dislodge spherical beads.