COMPUTER CONTROLLED DRUG DELIVERY SYSTEM WITH DYNAMIC PRESSURE SENSING

• US 20080154188A1
• Filed: 12/21/2006
• Published: 06/26/2008
• Est. Priority Date: 12/21/2006
• Status: Active Grant

• Current Assignee: Milestone Scientific Incorporated
• Original Assignee: Milestone Scientific Incorporated
• Inventors: Hochman, Mark N.
• Granted Patent: US 7,618,409 B2
• Time in Patent Office: Days
• US Class Current: 604/67
• 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. An apparatus for a controlled injection of a drug into a selected tissue of a subject by a practitioner, the apparatus comprising:

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

a handpiece for being held by the practitioner, the handpiece being connected to the drive unit for receiving the drug and being adapted for holding an injection needle to be inserted into the selected tissue of the subject by the practitioner, for passing the drug to the selected tissue at an instantaneous and absolute pressure that is at a tip of the needle and that varies as a function of the type of the selected tissue and a placement of the needle in the selected tissue, there being a minimum threshold and absolute pressure which is desired for administering the drug to the selected tissue;

a pressure sensor for sensing or calculating the instantaneous pressure; and

a feedback mechanism for supplying a perceptible signal to the practitioner that indicates when the instantaneous pressure has reached the minimum threshold pressure, for guiding movement by the placement of the needle at least until the minimum threshold pressure has been reached.

2. The apparatus according to claim 1, wherein the feedback mechanism includes means for supplying an audible perceptible signal.

3. The apparatus according to claim 1, wherein the feedback mechanism includes means for supplying a visual perceptible signal.

4. The apparatus according to claim 1, wherein the feedback mechanism includes means for supplying an audible and a visual perceptible signal.

5. The apparatus according to claim 1, wherein the feedback mechanism includes means for supplying a visual perceptible signal which includes a plurality of signals that correspond to the instantaneous pressure at different values before it has reached the minimum pressure, and at least one visual signal that indicates that the instantaneous pressure has reached the minimum pressure.

6. The apparatus according to claim 1, wherein the feedback mechanism includes means for supplying a further perceptible signal when the instantaneous pressure is above a selected over-pressure value to indicate to the practitioner that an undesirable over-pressure condition has occurred.

7. The apparatus according to claim 1, wherein the drive unit includes a foot pedal that is operated by the practitioner to supply the drug at the at least one flow rate.

8. The apparatus according to claim 1, wherein the drive unit includes a housing, a hermetically sealed assembly near an upper end of the housing for receiving a drug cartridge for supplying a drug to the drive unit, and a drain hose extending from the hermetically sealed assembly to a lower drain opening of the housing for discharging any leaked liquid from inside the hermetically sealed assembly to a location below the unit.

9. The apparatus according to claim 1, wherein the drive unit includes a housing and a mounting member connected to the housing for mounting the housing to a support.

10. The apparatus according to claim 1, wherein the drive unit includes a housing with at least one wing extending outwardly of the housing and having a handpiece receiving opening in the wing for holding an end of the handpiece.

11. A method for administering a controlled injection of a drug into a selected tissue of a subject by a practitioner, the method comprising:

supplying a drug to an injection needle at a selected flow rate;

using a handpiece held by the practitioner and to which the needle is connected, for inserted the needle into the selected tissue of the subject for passing the drug to the selected tissue at an instantaneous and absolute pressure that is at a tip of the needle and that varies in real-time as a function of the type of the selected tissue and a placement of the needle in the selected tissue, there being a minimum threshold and absolute pressure which is desired for administering the drug to the selected tissue;

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

supplying a perceptible signal to the practitioner that indicates when the instantaneous pressure has reached the minimum threshold pressure, for guiding movement of the placement of the needle by the practitioner at least until the minimum threshold pressure has been reached.

12. The method according to claim 11, wherein the perceptible signal is an audible signal.

13. The method according to claim 11, wherein the perceptible signal is a visual signal.

14. The method according to claim 11, wherein the perceptible signal is an audible and a visual signal.

15. The method according to claim 11, wherein the perceptible signal is 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 pressure, and at least one visual signal that indicates that the instantaneous pressure has reached the minimum pressure.

16. The method according to claim 11 wherein the perceptible signal includes 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.

17. The method according to claim 11, wherein the selected tissue is intraligamentary tissue and the drug is a dental anesthetic.

18. The method according to claim 11, wherein the selected tissue is intraligamentary tissue, the drug is a dental anesthetic, and the minimum pressure is in the range of about 200 to 500 psi.

19. The method according to claim 11, wherein the selected tissue is intraligamentary tissue, the drug is a dental anesthetic, the minimum pressure is in the range of about 200 to 500 psi and the selected flow rate is at least about 0.002 ml/sec.

20. The method according to claim 11, wherein the drug is supplied by the practitioner operating a foot pedal to supply the drug at the selected flow rate.

21. An apparatus for a controlled injection of a dental anesthetic into intraligamentary tissue of a subject by a practitioner, the apparatus comprising:

a drive unit for supplying a dental anesthetic at at least one flow rate;

a handpiece for being held by the practitioner, the handpiece being connected to the drive unit for receiving the anesthetic and being adapted for holding an injection needle to be inserted into the intraligamentary tissue of the subject by the practitioner, for passing the anesthetic to the tissue at an instantaneous and absolute pressure that is at a tip of the needle and that is a function of the intraligamentary tissue and a placement of the needle in the intraligamentary tissue, there being a minimum threshold and absolute pressure which is desired for administering the anesthetic to the intraligamentary tissue;

a pressure sensor for sensing or calculating the instantaneous pressure; and

a feedback mechanism for supplying a perceptible signal to the practitioner that indicates when the instantaneous pressure has reached the minimum threshold pressure, for guiding movement by the placement of the needle at least until the minimum threshold pressure has been reached.

22. The apparatus according to claim 21, wherein the feedback mechanism includes means for supplying an audible perceptible signal.

23. The apparatus according to claim 21, wherein the feedback mechanism includes means for supplying a visual perceptible signal.

24. The apparatus according to claim 21, wherein the feedback mechanism includes means for supplying an audible and a visual perceptible signal.

25. A method for administering a controlled injection of a dental anesthetic drug into intraligamentary tissue of a subject by a practitioner, the method comprising:

supplying a dental anesthetic drug to an injection needle at a selected flow rate;

using a handpiece held by the practitioner and to which the needle is connected, for inserted the needle into the intraligamentary tissue of the subject for passing the drug to the intraligamentary tissue at an instantaneous and absolute pressure that is at a tip of the needle and that varies in real-time as a function of the intraligamentary tissue and a placement of the needle in the tissue, there being a minimum threshold and absolute pressure which is desired for administering the drug to the intraligamentary tissue;

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

supplying a perceptible signal to the practitioner that indicates when the instantaneous pressure has reached the minimum threshold pressure, for guiding movement of the placement of the needle by the practitioner at least until the minimum threshold pressure has been reached.

26. The method according to claim 25, wherein the perceptible signal is an audible signal.

27. The method according to claim 25, wherein the perceptible signal is a visual signal.

28. The method according to claim 25, wherein the perceptible signal is an audible and a visual signal.

29. The method according to claim 25, wherein the perceptible signal is 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 pressure, and at least one visual signal that indicates that the instantaneous pressure has reached the minimum pressure.

30. The method according to claim 25, wherein the perceptible signal includes 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.

31. The method according to claim 25, wherein the minimum threshold pressure is in the range of about 200 to 500 psi.

32. The method according to claim 25, 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.

33. An apparatus for a controlled injection of a drug into a selected tissue of a subject by a practitioner, the apparatus comprising:

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

a handpiece for being held by the practitioner, the handpiece being connected to the drive unit for receiving the drug and being adapted for holding an injection needle to be inserted into the selected tissue of the subject by the practitioner, for passing the drug to the selected tissue at an instantaneous and absolute pressure at a tip of the needle that varies as a function of the compliance of the selected tissue and a placement of the needle in the selected tissue, there being a minimum absolute pressure which is desired for administering the drug to the selected tissue;

a pressure sensor for sensing or calculating the instantaneous pressure; and

a feedback mechanism for supplying a perceptible signal to the practitioner that indicates when the instantaneous pressure has reached the threshold minimum pressure, for guiding movement by the placement of the needle at least until the minimum pressure has been reached;

the pressure sensor for sensing the instantaneous pressure comprising means for determining change in pressure (P²−

P¹=Δ

P) over a defined time period, a means for determining a change in volume (V²−

V¹=Δ

V) over a defined time period, and a means for determining the compliance of the tissue based on a change in volume to over a change in pressure, the calculated compliance being compared to a defined compliance for a given anatomic location or structure and the practitioner being guided to a specific target tissue based on identification of specific compliance.