Systems and methods for detecting tissue contact and needle penetration depth

• US 20050004513A1
• Filed: 06/10/2002
• Published: 01/06/2005
• Est. Priority Date: 06/10/2002
• Status: Active Grant

• Current Assignee: Advanced Cardiovascular Systems Incorporated (Abbott Laboratories)
• Original Assignee: Advanced Cardiovascular Systems Incorporated (Abbott Laboratories)
• Inventors: Beyerlein, Dagmar
• Granted Patent: US 7,364,567 B2
• Time in Patent Office: Days
• US Class Current: 604/66
• CPC Class Codes: A61B 2017/00247 Making holes in the wall of the heart, e.g. laser Myocardial revascularization
• CPC Class Codes: A61B 2018/00392 Transmyocardial revascularisation
• CPC Class Codes: A61B 2090/062 penetration depth
• CPC Class Codes: A61B 2090/064 for measuring force, pressure or mechanical tension
• CPC Class Codes: A61B 5/0215 by means inserted into the body catheters A61M25/00
• CPC Class Codes: A61B 5/03 Detecting, measuring or recording fluid pressure within the body other than blood pressure, e.g. cerebral pressure; Measuring pressure in body tissues or organs A61B5/205 takes precedence
• CPC Class Codes: A61B 5/15003 for venous or arterial blood
• CPC Class Codes: A61B 5/150389 Hollow piercing elements, e.g. canulas, needles, for piercing the skin
• CPC Class Codes: A61B 5/150503 Single-ended needles hollow piercing element tip design A61B5/150396, needle sets for catheters A61M25/06, needles for bringing media into the body A61M5/32
• CPC Class Codes: A61B 5/150954 Means for the detection of operative contact with patient, e.g. by temperature sensitive sensor
• CPC Class Codes: A61B 5/153 Devices specially adapted for taking samples of venous or arterial blood, e.g. with syringes
• CPC Class Codes: A61B 5/4839 combined with drug delivery
• CPC Class Codes: A61B 5/489 Blood vessels
• CPC Class Codes: A61B 5/4896 Epidural space
• CPC Class Codes: A61B 5/6885 Monitoring or controlling sensor contact pressure
• CPC Class Codes: A61M 2025/009 the needle having a bent tip, i.e. the needle distal tip is angled in relation to the longitudinal axis of the catheter
• CPC Class Codes: A61M 2025/0096 being laterally outward extensions or tools, e.g. hooks or fibres

Abstract

Systems and methods for determining tissue contact and penetration depth are provided. In one aspect, the system includes a needle and a pressure measurement assembly. The needle, in one exemplary embodiment, includes a first end and a second end with at least one aperture located a predetermined distance from the first end. The pressure measurement assembly is connected with a portion of the needle to measure pressure of fluid flowing through the needle. The pressure measurement assembly measures a first pressure when the needle contacts tissue and a second difference in pressure when the needle penetrates the tissue and the aperture becomes occluded. In an alternative aspect, the system includes a needle and a sensor. The sensor, in another exemplary embodiment, is coupled with a portion of the needle to detect tissue contact pressure on the sensor as the needle penetrates tissue and makes contact with the sensor. The sensor is located a predetermined distance from the first end of the needle.

Claims

1. A system for detecting tissue contact and penetration depth comprising:

a needle with a first end and a second end, the needle having at least one aperture located a predetermined distance from the first end;

a pressure measurement assembly coupled with a portion of the needle to measure pressure of a fluid flowing through the needle, the pressure measurement assembly measuring a first pressure before the aperture becomes occluded and a second pressure as the needle penetrates tissue and the aperture becomes occluded.

2. The system of claim 1 wherein the pressure measurement assembly comprises:

a pump to dispsense fluid through the needle at a constant rate; and

a pressure sensor.

3. The system of claim 1 wherein said pressure of fluid includes a pressure of a therapeutic agent to be injected into the tissue.

4. The system of claim 1 wherein the aperture has an area in the range between about 0.003 and 10 mm².

5. The system of claim 1 wherein the predetermined distance is a desired penetration depth of the needle into the tissue.

6. The system of claim 5 wherein the predetermined distance from the first end is about 0.5 to 10 millimeters.

7. The system of claim 1 wherein the first end of the needle has at least one of a tapered and untapered portion.

8. The system of claim 1 wherein the needle has an outer diameter in the range between about 0.008 and 0.26 inches.

9. The system of claim 1 wherein the needle has an inner diameter in the range between about 0.004 and 0.22 inches.

10. A system for detecting needle penetration depth comprising:

a needle with a first end and a second end; and

a sensor coupled with a portion of the needle to detect a contact pressure of tissue on the sensor as the needle penetrates tissue, the sensor located a predetermined distance from the first end of the needle.

11. The system of claim 10 wherein the sensor comprises a strain gauge located a predetermined distance from the first end of the needle.

12. The system of claim 11 further comprising an encapsulant coupled with the strain gauge and needle.

13. The system of claim 10 wherein the sensor comprises a piezoelectric transducer located a predetermined distance from the first end of the needle.

14. The system of claim 13 wherein the piezoelectric transducer has a ring shape with an inner diameter larger than an outer diameter of the needle.

15. The system of claim 10 wherein the predetermined distance is approximately equal to a desired penetration depth of the needle into the tissue.

16. The system of claim 15 wherein the predetermined distance from the first end is about 0.5 to 10 millimeters.

17. The system of claim 10 wherein the first end of the needle has at least one of a tapered and untapered portion.

18. The system of claim 10 wherein the needle has an outer diameter in the range between about 0.008 and 0.26 inches.

19. The system of claim 10 wherein the needle has an inner diameter in the range between about 0.004 and 0.22 inches.

20. The system of claim 11 wherein the strain gauge has a width in the range between about 0.006 and 0.20 inches.

21. The system of claim 13 wherein the piezoelectric transducer has an inner diameter in the range between about 0.008 and 0.26 inches.

22. A method of detecting tissue contact and a needle penetration depth of a needle used internally to deliver a therapeutic agent to a patient comprising:

dispensing a measured amount of therapeutic agent from a second end of a needle to a first end of a needle;

measuring a pressure of the therapeutic agent in the needle;

measuring a first change in pressure when the first end of the needle contacts tissue; and

measuring a second change in pressure when the needle penetrates the tissue and occludes an aperture located a predetermined distance from the first end of the needle.

23. The method of claim 22 wherein dispensing a measured amount of therapeutic agent includes dispensing the therapeutic agent using a pump coupled to the second end of the needle.

24. The method of claim 22 wherein measuring pressure of the therapeutic agent in the needle includes measuring pressure of the therapeutic agent using a pressure measurement assembly.

25. The method of claim 22 wherein the therapeutic agent is one of a drug, growth factor, and gene therapy.

26. The method of claim 22 wherein the predetermined depth ranges between 0.5 and 10 millimeters.

27. A method to determine penetration depth of a needle used internally to deliver a therapeutic agent to a patient comprising:

inserting the needle into tissue until the tissue contacts a sensor located a predetermined distance from a first end of the needle; and

sensing a contact pressure of the tissue on the sensor to determine penetration depth of the needle.

28. The method of claim 27 wherein the predetermined distance is approximately equal to a desired penetration depth of the needle into the tissue.

29. The method of claim 28 wherein the predetermined distance from the first end is about 0.5 to 10 millimeters.

30. The method of claim 27 wherein the sensor comprises a strain gauge.

31. The method of claim 27 wherein the sensor comprises a piezoelectric transducer.