DST milli-HRT ACT

Small and long battery life

The DST milli-HRT ACT is a fairly small heart rate, activity and temperature logger that weighs 12g in air, with a diameter of 13 mm and length of 39.5 mm. Long-term heart rate and activity studies are simple to set up. You can expect battery life lasting several months, typically between 1-7.5 months*, depending on sampling frequency and measurement interval.

*sampling frequency every 2-20 minutes

Published data from several fish species

Star-Oddi loggers, available in four sizes, have been used successfully in several publications in various salmonid and other fish species. Fish weighing from approximately 120g up to several kg.

The DST milli-HRT ACT is ideal for use in physiological and behavioral research on aquatic animals over 470g. Published studies include thermal tolerance and swim speed tests.

Small, minimally invasive

The heart rate and activity logger DST milli-HRT ACT simultaneously measures long-term heart rate, activity, and body temperature. The logger has no external wires, which makes it especially simple to implant. The logger is hermetically sealed for biocompatibility.

For advice on implantation, please contact us.

Application

This bio-logging tag is ideal for a variety of studies including those looking at welfare, behaviour, stress response, swimming physiology and physiological response to environmental variations, including temperature and hypoxia. It is suitable for use in fish and other aquatic animals.

Correlation between heart rate and activity

Fish and aquatic animal scientists can identify correlation between heart rate and activity in the animal, for example when measuring stress response or swimming behaviour. The logger comes with the option of programming either two or three parameters: activity and temperature, heart rate and temperature or activity, heart rate and temperature.

Leadless ECG derived heart rate as low as 5 bpm

Heart rate is derived from a leadless single channel ECG. As the electrodes are part of the housing the logger is especially easy to implant. The logger takes a measurement of ECG (e.g., 15 second long) at a set time interval and calculates the mean heart rate for each recording. The logger can measure heart rates ranging from 5-1022 bpm. For validation purposes, individual ECG measurements can be saved. In addition, each measurement is graded with a quality index (QI).

Statistical activity parameters and raw accelerometer data

Each activity measurement is recorded over a one-minute period with a 3-axis accelerometer, using a user programmable sampling frequency of 0.03Hz-10Hz. The on-board algorithm of the logger provides six statistical parameters for each one-minute measurement including: minimum, maximum and average EA* values, variance of EA, skewness and kurtosis. Raw accelerometer data can be stored for additional calculations such as tailbeat frequency (TBF) and tailbeat amplitude (TBA).

*EA stands for “external acceleration”, an individually calibrated and normalized variable comparable to the vectoral sum of the dynamic body acceleration (VeDBA).

Stress-Free Long-Term Studies

The logger has a typical battery life of over 8 months, when sampling activity, heart rate, and temperature every 30 minutes in the individual fish or aquatic animal, e.g., Atlantic Salmon. The logger can measure individual physiological response to stressful events or environmental challenges in commercial aquaculture net pens, without the interference of humans.

Optimize battery life and memory with multiple intervals

Optionally, the loggers can be programmed with multiple different intervals within a study. This can, for example, be useful when different intervals are preferred during the day or night and can optimize battery life and save memory at the same time.

Guaranteed accuracy and performance

Every logger is individually calibrated and comes with a calibration certificate. We guarantee the loggers’ accuracy and performance for one year after production.