Bio-Signal Group offers the Digital Telemeter (DT), a wireless, miniature, battery-operated, multi-channel, portable digital system to record wide-band bioelectric signals. The DT comes in a 2, 4, or 8 channel version (16 channels coming soon). The digitized signals are combined into a single data stream and the serialized data are then transmitted to a remote recording system.

The DT approach accomplishes buffering, amplification and digitization in one device that is carried by the subject. The DT is designed without buffering pre-amplification. It plugs directly into the electrode connector that is implanted. Wide-band signals can be recorded without the need for filtering low-frequency and high-frequency bioelectric signals into their separate components. Both action potentials and field [EEG] potentials can thus be recorded simultaneously from the same electrodes without a need to double the number of main amplifier and ADC channels. A further very important advantage of this is that the two signals have not been differently filtered, and thus temporal relationships between the two can be more precisely analyzed.

The DT offers a number of advantages to the user. Because the DT is a miniature device without wires, it gives the researcher more flexibility in designing behavioral experiments that might otherwise be impossible if a tether cable is needed. The DT is also superior to the 12- or 16-bit PC-based analog-to-digital converters of conventional recording systems. The electrode signals are digitized right at the headstage, with 24 bits of resolution, and then transmitted using digital techniques that guard against any noise pickup between the subject and recording system. The DT radio signal is digital, and we offer three receiver variants. The first version converts the signals from the digital form back into analog, so that the DT can work with virtually any existing recording system. The second version is for users with existing digital recording systems, such as dacqUSB by Axona (www.axona.com); here, the digital signals from DT are recorded directly, with no need to introduce an extra conversion to analog. Finally, if you don't have a recording system already, BSG offers a complete standalone recording system in which the DT signals are fed into any PC with a USB port.