| 摘要 |
PROBLEM TO BE SOLVED: To provide a metal detection device capable of reliably distinguishing between action of a sparking electrical instrument on metal and action thereof on biological tissues.SOLUTION: A metal detection device includes a metal detector that determines whether a spark (18) generated by an instrument touched a biological tissue (11) or metal part (19) based on current (and the voltage) delivered to the instrument. This is preferably implemented by determining a component of the current that is inconsistent with a linear equivalent circuit. Elements of the linear equivalent circuit are determined prior to or during regression calculation. As a first determination criterion, a spark characteristic variable (F) is determined from the current. As a second determination criterion, a resistance characteristic variable (R) is determined. Both characteristic variables are compared with threshold values. If the resistance characteristic variable falls below a resistance threshold value and if the spark characteristic variable exceeds a spark size threshold value, a signal indicating that the spark (18) has acted on the metal part (19) is generated.SELECTED DRAWING: Figure 1 |
