Computer controlled drug delivery system with dynamic pressure sensing

• US 7,618,409 B2
• Filed: 12/21/2006
• Issued: 11/17/2009
• Est. Priority Date: 12/21/2006
• Status: Active Grant

• Current Assignee: Milestone Scientific Incorporated
• Original Assignee: Milestone Scientific Incorporated
• Inventors: Hochman, Mark N.
• Primary Examiner(s): Lucchesi; Nicholas D
• Assistant Examiner(s): Stigell; Theodore J
• Application Number:
  US11/614,471
• Publication Number:
  US 20080154188A1
• Time in Patent Office: 1,062 Days
• Field of Search: 604 65- 67, 604/131, 604/151, 604/500, 604/503, 604/505, 604/506, 604/890.1
• US Class Current: 604/506
• CPC Class Codes: A61C 1/0015 Electrical systems
• CPC Class Codes: A61C 19/08 combined with anaesthetising implements dental hypodermic syringes A61M5/00
• CPC Class Codes: A61M 2005/2407 from the rear
• CPC Class Codes: A61M 2005/2488 via rotation, e.g. threads or bayonet
• CPC Class Codes: A61M 2205/3344 Measuring or controlling pressure at the body treatment site
• CPC Class Codes: A61M 2205/581 by audible feedback
• CPC Class Codes: A61M 2205/582 by tactile feedback
• CPC Class Codes: A61M 5/24 Ampoule syringes, i.e. syringes with needle for use in combination with replaceable ampoules or carpules, e.g. automatic ampoules or carpules A61J1/06
• CPC Class Codes: A61M 5/46 having means for controlling depth of insertion
• CPC Class Codes: A61M 5/48 having means for varying, regulating, indicating or limiting injection pressure A61M5/142 takes precedence ; monitoring pressure in infusion systems A61M5/16854

Abstract

An apparatus and method for a controlled injection of a drug into a selected tissue of a subject by a practitioner, uses a drive unit for supplying the drug and a handpiece to be held and guided by the practitioner, connected to the drive unit for receiving the drug. The handpiece holds an injection needle to be inserted into the selected tissue by the practitioner for passing the drug to the selected tissue at an instantaneous and absolute pressure that varies as a function of the type of tissue and the placement of the needle. A pressure sensor senses this instantaneous pressure and a feedback mechanism supplies a perceptible audible, visual or other signal to the practitioner that indicates when the instantaneous pressure has reached a minimum desired pressure, the practitioner thus being informed that the correct placement and dosage has been attained.

Claims

1. A method for a practitioner to administer a controlled injection of a dental anesthetic drug into intraligamentary tissue of a subject, the method comprising:

providing a drive unit for supplying the drug at at least one flow rate;

providing 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;

operating the drive unit for supplying the dental anesthetic drug to the injection needle at a selected flow rate;

having the practitioner hold the handpiece;

having the practitioner move the handpiece without moving the drive unit, to insert the tip of the needle 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, the practitioner continuing to move the tip of the needle in the subject to seek the intraligamentary tissue;

sensing or calculating the instantaneous pressure on a real-time basis;

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;

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;

after the perceptible auditory specific signal is supplied, having the practitioner maintain 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

notifying the practitioner by a perceptible auditory signal when the instantaneous pressure declines or fluctuates before reaching the minimum threshold pressure.

2. The method according to claim 1, including supplying to the practitioner a visual signal which includes a plurality of signals that correspond to different real-time values for the instantaneous pressure before it has reached the minimum threshold pressure, and at least one visual signal that indicates that the instantaneous pressure has reached the minimum threshold pressure.

3. The method according to claim 1, including supplying to the practitioner a further perceptible signal when the instantaneous pressure is above a selected over-pressure to indicate to the practitioner that an undesirable over-pressure condition has occurred.

4. The method according to claim 1, wherein the minimum threshold pressure is in the range of about 200 to 500 psi and the selected flow rate is at least about 0.002 ml/sec.