Electro-magnetic device for measuring the integrity of long bones

Summary form only given. Monitoring the skeletal status is important for determining the effectiveness of treatment for osteoporosis. Computerized tomography, photon absorptiometry and DEXA are often used for monitoring the changes in bone mass and bone density. However, these techniques involve some radiation exposure to the patient. We have developed a non-invasive electro-magnetic device which can measure the cross-sectional geometry of long bone without using any ionizing radiation. Embalmed human long bones were subjected to an ultrasonic stress pulse. Due to the piezoelectric nature of bone, the stress pulse created an electromagnetic field which was detected by a non-contacting magnetic field detector described previously (1). Subsequently the output from this detector was compared with the actual cortical thickness at several cross-sections of the long bones. Statistically significant correlations were obtained between the actual bone thicknesses and the output of the electro-magnetic detector. This suggests that by moving the detector along the circumference and length of a long bone, it may be possible to measure the changes in bone mass of osteoporotic patients.