Extended Data Fig. 3: Injection test mechanism setup and ex vivo injection force calculations.
(a) (Top) Computer aided design of the custom actuation mechanism used to insert a needle a controlled distance and inject an exact amount of fluid. (Bottom) Experimental setup of controlled injection studies. The texture analyzer pushes down on the plunger which causes the liquid to inject into the swine stomach tissue below. (b, c) The force required to inject a depot into ex vivo swine stomach tissue at a given needle insertion depth. (Mean ± SD; 4 mm: n=11; 4.5 mm: n=9; 5 mm: n=18). (d, e) The force required to inject a depot into ex vivo swine stomach tissue using a needle with a 10° backgrind and a backgrind of >50°. (Mean ± SD; 10°: n=20; >50°: n=5; Unpaired t test).
