What feature does an external fetal monitor utilize for its function?

An external fetal monitor operates by utilizing a wireless patient probe transducer, which is designed to detect and record the fetal heart rate and uterine contractions from outside the mother's body. This transducer typically uses ultrasound technology to create a non-invasive method of monitoring the fetus during pregnancy and labor.

The transducer is placed on the mother's abdomen, allowing healthcare providers to continuously monitor the fetal heart rate and the strength and frequency of contractions without the need for invasive procedures. This feature is crucial for assessing fetal well-being and managing labor effectively.

The other options do not accurately describe the mechanism of an external fetal monitor. For instance, a probe inserted into the uterus refers to an internal fetal monitoring system, while a handheld device is not typically used for continuous monitoring in a clinical setting. Additionally, a connection to a power generator is not a feature of external fetal monitoring, as these devices usually operate using battery power or plug into standard electrical outlets without complex power sources.