Calibration and electrical safety status of therapeutic ultrasound used by chiropractic physicians

Ultrasound therapy is a commonly used therapeutic modality within the chiropractic profession. Previous calibration studies of ultrasound units within the physical therapy communities in Scotland and Canada have shown that approximately two thirds of units tested did not conform to minimum calibration standards. Similar failure rates may exist in the chiropractic profession and need to be addressed.

To determine whether ultrasound machines used by chiropractic physicians met established calibration and electrical safety standards, and to assess frequency of ultrasound therapy use.

This cross-sectional study tested 45 ultrasound units for ultrasonic output and electrical safety. Additionally, we asked the doctors to complete a short survey relating to education, usage, and maintenance of their ultrasound equipment.

Of the 45 machines tested, 44% failed either calibration or electrical safety inspection. Failure rate was age dependent (P < or =.05). Only 2 of the 45 machines tested had been safety checked within the last year.

A large percentage of ultrasound machines in chiropractic physicians' offices deliver too much or too little dosage to the patient. Electrical safety inspections also revealed a significant failure rate. Chiropractic physicians must become more aware of the requirement for yearly calibration and safety inspections, and understand that failure to maintain their equipment could result in loss of therapeutic effectiveness and pose a threat to the safety of their patients and staff.