Patent ID: 7896833

Claim:
An apparatus for a practitioner to administer a controlled injection of a dental anesthetic drug into intraligamentary tissue of a subject, the apparatus comprising: a drive unit for supplying the drug at least one flow rate; a handpiece for being held by the practitioner, the handpiece being connected to the drive unit by a flexible tube for receiving the drug, the handpiece carrying an injection needle to be inserted into the subject near the intraligamentary tissue of the subject, the injection needle having a tip for passing the drug to the subject at an instantaneous and at an absolute pressure that is at the tip of the injection needle, and that varies due to a placement of the needle tip in the subject, there being a minimum threshold pressure of about 200 to 500 psi and an absolute pressure which is desired for administering the drug to the intraligamentary tissue; a computer connected to the drive unit and programmed for operating the drive unit for supplying the dental anesthetic drug to the injection needle at a selected flow rate while the practitioner holds the handpiece, the tip of the needle adapted to be inserted into the subject at a location near the intraligamentary tissue of the subject for passing the drug to the subject near the intraligamentary tissue at the instantaneous and absolute pressure that is at the tip of the needle and that varies in real-time as a function of the intraligamentary tissue and a placement of the tip of the needle; a pressure sensor connected to the computer for sensing or calculating the instantaneous pressure on a real-time basis; a sound generator connected to the computer, the computer being programmed for driving the sound generator for supplying a perceptible auditory ascending signal to the practitioner that indicates when the instantaneous pressure is rising toward the minimum threshold pressure, for guiding movement of the placement of the tip of the needle by the practitioner at least until the minimum threshold pressure has been reached; the computer being programmed for driving the sound generator for supplying a perceptible auditory specific signal to the practitioner that indicates when the instantaneous pressure has reached the minimum threshold pressure which indicates that the practitioner has moved the tip of the needle into the intraligamentary tissue and so that after the perceptible auditory specific signal is supplied, the practitioner maintains the tip of the needle in the intraligamentary tissue for supplying a selected dosage of the drug to the intraligamentary tissue at the selected flow rate; and the computer also being programmed for driving the sound generator for notifying the practitioner by generating a perceptible auditory signal when the instantaneous pressure declines or fluctuates before reaching the minimum threshold pressure.