
EMC modifications to bone densitometers aim to protect weak measurement signals. The power supply for the detector preamplifier should use a linear regulator instead of a switching power supply. If a switching power supply must be used, its output must be carefully filtered using a π-type filter (inductor + capacitor). All cables leading to the detector and the position encoder of the motor should be shielded, and the shielding layer should be properly grounded at the equipment end. The low-voltage control and status feedback terminals of the X-ray high-voltage generator can be isolated by connecting ferrite beads in series and using optocouplers or digital isolators. The I/O lines of the equipment's human-machine interface touchscreen or buttons must be equipped with ESD protection devices (e.g., ESD5V0D9B) to prevent electrostatic discharge from causing malfunctions or system crashes.