A "heartbeat sensor" has been long sought by military and law enforcement, and long speculated by military fiction for over 100 years. Motion Detectors (p. 153 Panopticon) are very small, reliable systems which can detect motion via body heat and other IR radiation, and can even do so through surfaces close enough. But, this is not necessarily comprehensive, and even in active or passive modes requires targets to be moving when the sensor is pointed at them. It's ideal for security systems, but not always to carry on your person. And while they do not often make false positives, an active or passive pulse might miss a target who happens to be relatively still. To this end, the Heartbeat Sensor is an alternative.
Heartbeat Sensor: A small, handheld alternative to the Motion Detector, the Heartbeat sensor is an active sensor which uses a small array of antennas and combinations of IR and radio waves to measure back the minute responses related to respiration and pulse. The result is that it can detect a target breathing or with a beating heart even if they stand still. The accuracy enough is to measure the target's heart rate, and if maintained long enough can detect heartbeats which are faint or artificially slowed such as through drugs. It has a material penetration and range similar to Radar, though will not always be detected by the same equipment as a Radar setup. The sensor can have a flat display, or be linked to another display such as AR over mesh - and provides a rough position, range and heart rate data. [Low]
The heartbeat sensor, sometimes also called the biologic sensor, is considered an alternate for the motion detector, and neither is a replacement for the other. Motion detectors in passive mode can be defeated by thermal dampening and some chameleonic materials, but are hard to block in active mode. The Heartbeat sensor is only active, which can harm its user's stealth profiles, and can be affected by measures which inhibit both Radar and IR - but works even on targets which are still. The heartbeat sensor works perfectly on biomorphs and smart animals, and will also detect masked synthetics and Pods - but does not normally locate a Synthmorph. Depending on the user, this may be a benefit or hindrance. While small and one-handed, the Heartbeat sensor cannot be too small, as the antenna array needs to be spread a small amount to work - and takes in just less than 180 degrees in the FOV of the sensor. It is, however, small enough to mount onto a wrist or a two-handed gun if needed.