The newest device from Hitachi the – Wearable Optical Topography Series WOT-S20 – measures saliva secretions using near infrared imaging. Hitachi will begin accepting orders on November 1. The product will be marketed toward food and beverage companies and laboratories, primarily because it is classified as non-pharmaceutical and cannot be used to diagnose or treat any disease.
The technology in the new saliva sensor is based on existing optical topography technology. By shining weak near-infrared light on the scalp, it is possible to measure and graph changes in blood volume. If you have ever had a sensor put on the end of your finger to measure how much oxygen was in your blood then you have experienced this kind of optical topography. Hitachi explained that they were looking for a new application for this technology when they developed the WOT-S20.
Until now anyone wanting to know how much saliva a person was producing would have had to measure drool in a beaker, or have the subject fill his mouth with cotton, or directly insert tubes into the subject's salivary glands. Ouch! This new device consists of a headset with sensors on either side of the face, a control box for changing settings, and a handheld controller which displays readings in real time. It works by releasing pulses of near infrared light targeted at your parotid glands. Those are the largest of your salivary glands, wrapped around your jaw bone behind your teeth. The device then records how the light diffuses through the soft tissue. It measures levels of oxygenated, deoxygenated, and total hemoglobin. Because of the way it works you could even use it while the subject was having a drink.
The control box and the controller are wirelessly connected. Readings can also be taken directly from the control box attached to the headset. The whole system is expandable. One controller can be used with up to four headsets. That image of one researcher simultaneously monitoring how much four people are salivating, should be proof enough for anyone that there are always new things to be invented.