Orthopedic diagnostic procedures and apparatus therefor

• US 4,437,473 A
• Filed: 03/26/1982
• Issued: 03/20/1984
• Est. Priority Date: 04/03/1981
• Status: Expired due to Term

• Current Assignee: British Technology Group Ltd.
• Original Assignee: National Research Development Corporation
• Inventors: Mollan, Raymond A. B.
• Primary Examiner(s): Howell, Kyle L.
• Assistant Examiner(s): Hamley, John C.
• Application Number:
  US06/362,516
• Time in Patent Office: 725 Days
• Field of Search: 128/773, 128/715, 128/774
• US Class Current: 600/586
• CPC Class Codes: A61B 7/006 Detecting skeletal, cartilage or muscle noise A61B7/003 and A61B7/008 take precedence

Abstract

Attempts have been made to facilitate orthopedic diagnostic procedures by microphonic detection of emissions from a moving joint, with analysis of such emissions to establish correlation with pathological conditions, but these attempts have failed. Success in such a procedure is now found to require detection of emissions extending into the subsonic frequency range. Preferably a piezoelectric accelerometer detector (10) is used in direct contact with the skin. A plurality of detectors can be used around a joint with comparative analysis to localize a condition. Analysis suitably involves a frequency analyzer (14) with the possible intermediary of a multi-track tape recorder (12), the analyzer output being displayed by a printer (15) preferably of ink-jet form. One useful correlating emission characteristic is peak frequency for early diagnosis for congenital dislocation of the hip in an infant.

Claims

1. An orthopaedic diagnostic procedure comprising the steps of:

detecting vibrations emitted from a moving joint in at least the subsonic frequency range, and

analyzing the detected emissions to determine whether or not a predetermined pathological condition exists.

2. A procedure according to claim 1 where the step of detecting comprises detecting at a plurality of different positions around said joint, and comparing the emissions respectively detected from said positions to localise said condition in said joint.

3. A procedure according to claim 1 in which said joint is an infant hip joint and said condition is congenital dislocation of the hip.

4. A procedure according to claim 3 wherein said step of detecting comprises detecting emissions in at least two different positions in the areas of the sacrum, sacro-iliac, anterior superior iliac spines, and symphysis pubis.

5. A procedure according to claim 4 wherein said step of detecting comprises detecting a peak emission frequency in the region of 5 to 10 Hz.

6. A procedure according to claim 1 wherein said step of detecting comprises using a transducer is applied directly to the skin.