  Needle-free injector technology (NFIT) has drawn attention due to their
advantages. By using NFIT, it can be used several time unlike a conventional
needle. Also, it makes patients free from pain. Since NFIT by jet injection is
achieved by ejecting a liquid drug through a narrow orifice at high pressure,
thereby creating a fine high-speed fluid jet that can readily penetrate skin
and tissue. Until very recently, all jet injectors utilized force-and
pressure-generating principles that progress injection in anuncontrolled
mannerwith limited ability to regulate delivery volume and injection depth. In
order to address these shortcomings, we have developed a controllable jet
injection device, based on a custom high-stroke linear Lorentz-force motor.
Using this device, we are able to monitor and modulate continuously the speed
of the drug jet, and regulate precisely the volume of drug delivered during the
injection process.
