The second key component of TAKUMI, the magnetic probe for sentinel lymph node identification, is a Hall sensor.
Why choose a Hall sensor over other high precision magnetic flux sensors? The reason for that is the permanent magnet. The magnetic sensor has to be positioned at a specific point: on the center axis of the permanent ring magnet where the magnetic flux density is zero. But the magnetic flux field created by the permanent magnet is so strong that many high precision magnetic flux sensors break in the fabrication process. This is why Matrix Cell Research Institute Inc. opted for the more robust and reliable Hall sensor to be incorporated in TAKUMI instead.
Although Hall sensors emit more noise and have a higher temperature drift compared to other high precision magnetic flux sensors, by using a special chopping and temperature compensation technique, it was possible to minimize both of these issues and thus, TAKUMI can provide the high precision magnetic flux measurements necessary for accurate sentinel lymph node biopsies.