US 12,239,824 B2
Needle-free injector with gas bubble detection
Tyler F. Barkin, Cambridge, MA (US); and Marc Pelletier, Cambridge, MA (US)
Assigned to Portal Instruments, Inc., Cambridge, MA (US)
Filed by PORTAL INSTRUMENTS, INC., Cambridge, MA (US)
Filed on Sep. 4, 2020, as Appl. No. 17/013,105.
Claims priority of provisional application 62/896,395, filed on Sep. 5, 2019.
Prior Publication US 2021/0146050 A1, May 20, 2021
Int. Cl. A61M 5/30 (2006.01)
CPC A61M 5/30 (2013.01) [A61M 2205/52 (2013.01); A61M 2205/8206 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A needle-free injector, comprising:
a plunger positioned to pressurize a fluid and a gas in a cartridge having an exit port;
a motor operatively coupled to the plunger, the motor operable to actuate the plunger in a linear motion along an axis of the cartridge to direct the fluid from the cartridge; and
a controller operatively coupled to the motor, the controller operable to, responsive to an injection initiation signal, operate the plunger according to a first delivery profile to compress the gas within the cartridge and operate the plunger according to a second delivery profile responsive to detecting a compression of the gas in the cartridge above a predetermined threshold, wherein detecting the compression of the gas in the cartridge comprises detecting a concurrent decrease in velocity of the plunger and increase in drive current to the motor.