Structural analyzer, in particular for medical implants

• US 5,518,008 A
• Filed: 08/25/1994
• Issued: 05/21/1996
• Est. Priority Date: 08/25/1994
• Status: Expired due to Fees

• Current Assignee: Spectral Sciences Research Corporation
• Original Assignee: Spectral Sciences Research Corporation
• Inventors: Cucchiaro, Paul J., DeLuzio, Anthony, Cucchiaro, Stephen J., Dario, Lawrence J.
• Primary Examiner(s): HINDENBURG, MAX F
• Application Number:
  US08/296,333
• Time in Patent Office: 635 Days
• Field of Search: 128/774, 128/776, 128/777, 128/781, 128/782, 128/739, 128/740, 128/744, 433/72, 433/215
• US Class Current: 600/590
• CPC Class Codes: A61B 2562/0219 Inertial sensors, e.g. accelerometers, gyroscopes, tilt switches
• CPC Class Codes: A61B 5/1111 Detecting tooth mobility
• CPC Class Codes: A61B 5/4528 Joints A61B5/4533, A61B5/4538 take precedence
• CPC Class Codes: A61B 5/4547 Evaluating teeth
• CPC Class Codes: A61B 5/682 Mouth, e.g., oral cavity; tongue; Lips; Teeth
• CPC Class Codes: A61B 5/6843 Monitoring or controlling sensor contact pressure
• CPC Class Codes: A61B 9/00 Instruments for examination by percussion; Pleximeters
• CPC Class Codes: A61C 19/04 Measuring instruments specially adapted for dentistry A61C5/44 takes precedence; testing vitality of teeth A61B5/0534; radiation diagnosis specially adapted for dentistry A61B6/51
• CPC Class Codes: A61F 2/36 Femoral heads ; Femoral endoprostheses
• CPC Class Codes: A61F 2/4657 Measuring instruments used for implanting artificial joints for surgical instruments A61B90/06
• CPC Class Codes: A61F 2/48 Operating or control means, e.g. from outside the body, control of sphincters
• CPC Class Codes: A61F 2002/3625 Necks
• CPC Class Codes: A61F 2002/4671 for measuring resonant frequency

Abstract

A dental analyzer for analyzing dental implants includes a dental probe having a probe tip for contacting a patient'"'"'s dental implant. An accelerometer is coupled to the probe tip. A hammer fired by an actuator against the accelerometer impacts the probe tip against the dental implant which vibrates the dental implant. The accelerometer measures the acceleration time history of the vibrating dental implant. A processor converts the measured acceleration time history of the dental implant into a frequency spectrum from which a diagnosis can then be made regarding the condition of the dental implant.

Claims

1. A probe comprising:

a probe tip for contacting a structure;

an accelerometer coupled to the probe tip for measuring an acceleration time history of the structure;

a hammer for impacting the probe tip against the structure, the probe tip being mechanically isolated from the hammer such that the probe tip can move independently from the hammer after the structure is impacted; and

an actuator for firing the hammer.

2. The probe of claim 1 further comprising:

a probe body comprising a hollow tube for housing the actuator; and

a membrane secured to the probe body and supporting the accelerometer for isolating motion of the accelerometer from motion of the probe body.

3. The probe of claim 1 in which the actuator comprises:

an electromagnetic coil for positioning the hammer into firing position; and

a spring positioned against the hammer for firing the hammer.

4. The probe of claim 1 further comprising a sensor for preventing the actuator from firing the hammer until the probe tip contacts the structure at a predetermined force.

5. The probe of claim 1 further comprising a processor for converting the measured acceleration time history of the structure into a frequency spectrum.

6. The probe of claim 1 in which the structure is a dental implant.

7. A probe comprising:

a probe tip for contacting a structure;

an accelerometer coupled to the probe tip for measuring an acceleration time history of the structure;

a hammer for impacting the probe tip against the structure;

an actuator for firing the hammer;

a probe body comprising a hollow tube for housing the actuator; and

a membrane secured to the probe body supporting the accelerometer for isolating motion of the accelerometer from motion of the probe body.

8. The probe of claim 7 in which the actuator comprises:

an electromagnetic coil for positioning the hammer into firing position; and

a spring positioned against the hammer for firing the hammer.

9. The probe of claim 7 further comprising a sensor for preventing the actuator from firing the hammer until the probe tip contacts the structure at a predetermined force.

10. The probe of claim 7 further comprising a processor for converting the measured acceleration time history of the structure into a frequency spectrum.

11. The probe of claim 7 in which the structure is a dental implant.

12. A method of measuring dynamic characteristics of a structure comprising the steps of:

positioning a probe tip against the structure, the probe tip being secured to an accelerometer;

impacting the probe tip against the structure with a hammer to initiate dynamic resonance of the structure, the probe tip remaining in contact with the structure during dynamic resonance of the structure; and

measuring an acceleration time history of the structure with the accelerometer.

13. The method of claim 12 further comprising the step of firing the hammer with an actuator.

14. The method of claim 13 further comprising the step of preventing the actuator from firing the hammer until the probe tip contacts the structure at a predetermined force.

15. The method of claim 13 further comprising the steps of:

housing the actuator within a hollow probe body; and

supporting the accelerometer on a membrane secured to the probe body for isolating motion of the accelerometer from motion of the probe body.

16. The method of claim 12 in which firing the hammer with the actuator comprises the steps of:

positioning the hammer into firing position with an electromagnetic coil; and

firing the hammer with a spring positioned against the hammer.

17. The method of claim 12 further comprising the step of converting the measured acceleration time history of the structure into a frequency spectrum.

18. The method of claim 12 in which the structure is a dental implant.

19. The method of claim 17 further comprising the step of comparing characteristics of the frequency spectrum with a database of frequency spectrums.

20. The method of claim 12 further comprising the step of adhering the probe tip to the structure.

21. The method of claim 12 further comprising the step of mechanically isolating the probe tip from the hammer such that the probe tip can move independently from the hammer after the structure is impacted.

22. A method of measuring dynamic characteristics of a structure comprising the steps of:

positioning a probe tip against the structure, the probe tip being secured to an accelerometer;

firing a hammer with an actuator, the actuator being housed within a hollow probe body;

impacting the probe tip against the structure with the hammer; and

measuring an acceleration time history of the structure with the accelerometer, the accelerometer being supported on a membrane secured to the probe body for isolating motion of the accelerometer from motion of the probe body.

23. The method of claim 22 further comprising the step of preventing the actuator from firing the hammer until the probe tip contacts the structure at a predetermined force.

24. The method of claim 22 in which firing the hammer with the actuator comprises the steps of:

positioning the hammer into firing position with an electromagnetic coil; and

firing the hammer with a spring positioned against the hammer.

25. The method of claim 22 further comprising the step of converting the measured acceleration time history of the structure into a frequency spectrum.

26. The method of claim 22 in which the structure is a dental implant.

27. The method of claim 25 further comprising the step of comparing the frequency spectrum with a database of frequency spectrums.

28. A method of measuring dynamic characteristics of a structure comprising the steps of:

positioning a probe tip against the structure, the probe tip being secured to an accelerometer;

impacting the probe tip against the structure to initiate dynamic resonance of the structure, the probe tip remaining in contact with the structure during dynamic resonance of the structure;

measuring an acceleration time history of the structure with the accelerometer; and

converting the measured acceleration time history of the structure into a frequency spectrum.

29. A method of determining dynamic characteristics of a medical implant comprising the steps of:

impacting the medical implant with a probe tip to initiate dynamic resonance of the structure, the probe tip remaining in contact with the structure during dynamic resonance of the structure;

measuring the acceleration time history of the medical implant with an accelerometer coupled to the probe tip; and

converting the measured acceleration time history into a frequency spectrum.

30. The method of claim 29 further comprising the step of comparing characteristics of the frequency spectrum with a data base of frequency spectrums.

31. A probe comprising:

a probe tip for contacting a structure;

a sensor coupled to the probe tip for measuring motion characteristics of the structure;

a hammer for impacting the probe tip against the structure;

an actuator for firing the hammer;

a probe body comprising a hollow tube for housing the actuator; and

a membrane secured to the probe body supporting the sensor for isolating motion of the sensor from motion of the probe body.

32. A system for measuring dynamic characteristics of a structure comprising:

a hand-held probe having a probe body and a probe tip, the probe tip for impacting the structure, the probe tip being substantially mechanically isolated from the probe body such that the probe tip can move independently from the probe body, an accelerometer coupled to the probe tip measuring the acceleration time history of the structure; and

a processor for converting the measured acceleration time history of the structure into a frequency spectrum.

33. The system of claim 32 in which the frequency spectrum has a spectral signature.

34. A method of measuring dynamic characteristics of a structure comprising the steps of:

positioning a probe tip against the structure, the probe tip being secured to an accelerometer;

impacting the probe tip against the structure with a hammer;

mechanically isolating the probe tip from the hammer such that the probe tip can move independently from the hammer after the structure is impacting; and

measuring an acceleration time history of the structure

with the accelerometer.

35. A probe comprising:

a probe tip for contacting a structure;

a sensor coupled to the probe tip for measuring motion characteristics of the structure;

a hammer for impacting the probe tip against the structure, the probe tip being mechanically isolated from the hammer such that the probe tip can move independently from the hammer after the structure is impacted;

an actuator for firing the hammer; and

a probe body comprising a hollow tube for housing the actuator.