Compatibility with Stellar Telemetry for cardiovascular studies
2 Sep 2013

The Stellar Telemetry system

Stellar Telemetry is a system that collects physiological data in freely moving animals. Its main features are described below1:

  • Two biopotentials (ECG, EEG), blood pressure and temperature are collected by each implant.
  • The implants are suitable for small animals like rodents as well as large animals.
  • Large groups of animals can be housed in the same cage.
  • Multiple transmitters can be placed in a single animal, e.g. for multi-pressure measurements.
  • The data can be logged in the implant while the animal is moved out of transmission range of receiver.
  • The battery life depends on the parameters of the collection schedule.

Stellar Telemetry components links to NOTOCORD-hem™

 

The NOTOCORD-hem™ link

Our forthcoming acquisition server STE30a allows direct acquisition of signals from Stellar Telemetry implants in NOTOCORD-hem™.

All the calibration data for the implants are loaded in a few clicks from the corresponding Stellar setting files and saved in the configuration of NOTOCORD-hem™.
The server allows verifying the implants presence and the barometric pressure reading before starting the data acquisition.

For each implant the following outputs are created in the acquisition module:

  • A continuous output (“red” type) is configured for each signal (Pressure, ECG, Temperature and Battery level) selected in the Implants interface.
  • A time-value output (“blue” type) is configured for each calculated mean (Temperature and Battery level). The mean value is output at the beginning of each measurement session.
  • A trigger output (“green” type) appears for the beginning (end) of the measurement session.

The barometric pressure, used as reference for all pressure measurements, is optionally output as a mean value calculated for each measurement session.
An event channel displays the implants states and messages coming from the hardware.

STE30a acquisition module and NOTOCORD-hem™ display of signals, mean values and triggers.

 

A special output allows online signalling of the events sent by the hardware during acquisition, like a delayed data transfer to NOTOCORD-hem™ due to implant absence (animal moved out of transmission range of receiver).

The parameters of the collection schedule are:

  • Measurement duration: duration of the measurement session.
  • Measurement interval: time between the beginnings of two successive measurement sessions.
  • Upload interval: time between successive transmissions of data from the implant to the receiver. An upload can be done after each measurement session, or only once for more measurement sessions. At the end of each upload, NOTOCORD-hem™ displays the received data.
  • Schedule duration is the time interval in which the first three parameters above do not change. One or more schedules can be defined (e.g. a day schedule and a different night schedule) and the scheduler will cycle through the list.

The schedule interface allows producing the most usual timing schedules and also specific timing.

An example of scheduled acquisition with Measurement duration = 10 s and Measurement interval = 5 min.

 

The signal preprocessing framework of our acquisition servers is also present is STE30a (resampling, high-pass, low-pass, notch 50/60 Hz filtering, invert, offset) and allows to record the unprocessed data, preprocessed data or both.
The data is further processed with NOTOCORD® processors and specific analyzers.

References
1 Download Stellar Telemetry brochure