HIGH-SPEED JET DEVICES FOR DRUG DELIVERY
A method and apparatus for performing jet injections using piezoelectric technology. A jet injector apparatus includes a reservoir having a variable capacity for holding a liquid to be delivered to a biological tissue via a jet injection. A nozzle is disposed at a first end of the reservoir with at least one opening for allowing the liquid to be expelled from the reservoir. The capacity of the reservoir may be altered by the actuation of a piezoelectric transducer located at a second end of the reservoir
1 . An apparatus, comprising:
a microliter syringe barrel having a reservoir therein for holding a liquid;
a nozzle disposed at a first end of the syringe barrel with at least one opening for allowing the liquid to be expelled from the reservoir;
a plunger received in a second end of the syringe barrel; and
a piezoelectric transducer operatively connected with said plunger for actuation of the plunger, the actuation of the plunger causing the liquid to be expelled from the reservoir in the form of a jet injection.
2 . The apparatus as recited in claim 1 , further comprising an electronic circuit for actuating the piezoelectric transducer, the electronic circuit comprising a power source in series with a solid state switch and a resistor, wherein an output of the electronic circuit is coupled to the piezoelectric transducer.
3 . The apparatus as recited in claim 1 , wherein a resistance value of the resistor is variable for controlling a velocity of the jet injection.
4 . The apparatus as recited in claim 1 , wherein a voltage level of the power source is variable for controlling a volume of the jet injection.
5 . The apparatus as recited in claim 1 , wherein a diameter of the nozzle is 100 micrometers or less.
6 . The apparatus as recited in claim 1 , wherein the jet injection is employed for providing transdermal inoculation of the liquid into a biological tissue.
7 . The apparatus as recited in claim 1 , further comprising at least one external pressurized fluid source coupled to the reservoir of the syringe barrel for providing a continuous supply of the liquid.
8 . An apparatus, comprising a hollow structure for creating jet injections, the hollow structure having a nozzle on one end and a plunger inserted in the other end; wherein the plunger is actuated by a piezoelectric transducer and the piezoelectric transducer is driven by an electronics unit comprising a voltage source, a solid state switch, and a resistor.
9 . The apparatus as recited in claim 8 , wherein a volume of the jet injection is controlled independently from a velocity of the jet injection.
10 . The apparatus as recited in claim 9 , wherein the resistor has adjustable resistance, and wherein the level of resistance controls the velocity of the jet injection.
11 . The apparatus as recited in claim 9 , wherein the voltage source is variable, and wherein the level of the voltage source controls the volume of the jet injection.
12 . A method for operating a piezoelectric jet injector, the method comprising:
loading a syringe barrel with a predetermined volume of a liquid, the syringe barrel having a nozzle on a first end for allowing the liquid to be expelled from the syringe barrel;
loading a plunger into a second end of the syringe barrel, wherein a piezoelectric transducer is positioned for actuating the plunger; and
applying a predetermined voltage to the piezoelectric transducer to actuate the plunger and expel the liquid from the nozzle in the form of a jet injection.
13 . The method as recited in claim 12 , further comprising advancing the plunger and the piezoelectric transducer until the nozzle of the syringe is filled completely with the liquid.
14 . The method as recited in claim 12 , further comprising defining jet injection parameters including a velocity of the jet injection and a volume of the jet injection.
15 . The method as recited in claim 14 , wherein the volume of the jet injection is controlled by adjusting the predetermined voltage, and wherein the velocity of the jet injection is controlled by adjusting a resistance of an electronic circuit employed for controlling the piezoelectric transducer.
16 . The method as recited in claim 12 , further comprising adjusting the positioning of the piezoelectric transducer in relation to the plunger between each successive application of the predetermined voltage to the piezoelectric transducer.