Phil Griffiths, PhD, presents a summary of chronic cardiovascular telemetry studies and considerations for experimental design. Ensuring you collect the best and most physiologically accurate data from your chronic telemetry experiments requires careful planning and experimental design. This webinar will give an insight into the practical aspects of designing chronic animal experiments to set you on the best path for success. The benefits of chronic studies, how to select the most appropriate sample size for your study, some basic tips and tricks for data acquisition and handling, and how to ensure high animal welfare are discussed. Key Topics Include: - What are the benefits of chronic over acute studies? - How to decide the best sample sizes and the length of experiments? - Basic tips for data acquisition and handling - How to maintain high animal welfare standards

1. Copyright 2022. All Rights Reserved. Contact Presenter for Permission
Experimental Design
Considerations to Optimize
Chronic Cardiovascular
Telemetry Studies
Phil Griffiths, PhD
Research Sales Manager - Europe
ADInstruments

2. Partners and Sponsors
At ADInstruments we create simple, flexible tools to help
scientists record and analyse data quickly and efficiently.
Powerful, flexible and accurate, our products are cited in more
than 30,000 peer-reviewed journal articles and our equipment is
the preferred choice for thousands of scientists and educators
around the world.

3. Experimental Design
for Chronic Telemetry Studies

4. A little about me...
● BSc and PhD in Neuroscience from the University of Bristol, UK
● 4.5 yrs post-doc experience using Kaha Sciences pressure telemeters
● Telemetry Applications Specialist - Europe for Kaha Sciences
● Training and Technical Support Specialist in the European Team
● Research Sales Manager - Europe

5. Overview
What are the benefits of chronic over
acute studies?
How to decide the best sample sizes
and the length of experiments?
Basic tips for data acquisition and
handling
How to maintain high animal welfare
standards

6. Data collection for in vivo studies
● Invasive recordings in anesthetized animals – one-off measurements
○ High-frequency, high fidelity sampling
○ Recording time minutes-hours, continuous
○ Difficult to account for anaesthesia, oestrous state, circadian rhythm
● Non-invasive measurements – one-off or periodically repeated
○ Time consuming
○ Recording time – minutes, non-continuous
○ Snapshots
● Tethering – repeated over days
○ Recording time – hours, days
○ Movement artefacts, noise and restricted behaviour
SNA
9
8
BP
ECG

7. Telemetry advantages
● Conscious, unrestrained
○ Fully implantable, less prone to infection
○ Minimal day-to-day maintenance
○ Multiple animals running simultaneously
● Long term recordings
○ Weeks/months
● Capture long-term variation in physiological parameters
● Reduce costs
○ Fewer animals per group (Higher statistical power)
○ Reduced staff maintenance

8. Planning chronic experiments

9. The benefits of chronic experiments
Acute, invasive experiments Battery-reliant telemetry Kaha Sciences telemetry
Benefits of chronic animal experiments
Experiments performed over an extended period of time – weeks or months
Observe experimental variables under a conscious physiological state
Can account for natural physiological variation; circadian rhythms, estrous cycles
Kaha Sciences wireless power technology allows continuous data collection for the duration of the experiment

10. How long should a chronic experiment be?
Long experiments = more expense and smaller sample size
Need to balance length with the experimental questions - ageing, pharmacology, disease progression
Do you need to record continuously for telemetry experiments?
Longer experiments
● Smaller sample
● More data to analyse
● Lifespan of the animal?
Shorter experiments
● Larger sample
● Less data to analyse
● Experimental value

11. Kaha Sciences Telemetry - the benefits
Long term experiments
● Wireless power transfer removes the reliance
and restriction of batteries
● Record for weeks or months
Continuous experiments
● Wireless power transfer supports continuous
recording
● More data collected - spontaneous activity
Quick turnaround
● Rat telemeters are reusable
● Mouse telemeters are disposable
● No costly and time-consuming refurbishment

12. Statistical Power
How likely are differences between experimental groups going to be statistically significant for a
particular statistical test?
Depends on:
1. Sample size
2. Variability of observations
3. Size of effect
4. Significance level
Power calculations – Speak to a statistician
P<0.05 P<0.05
P<0.05 ??

13. Accurate, repeatable, and reliable data
Reduce Variability
● Millar Mikro-Tip® pressure sensor at the catheter tip on
rat BP telemeters
● No long-term signal attenuation and reduced variability
● Excellent frequency response
● Detect small changes in pressure, even at low pressure
High Sampling Rate
● Up to 2 kHz sampling rate
● High signal fidelity
Quick turnaround
● No refurbishment in studies with large sample size

14. Considerations for data acquisition

15. Choosing the right sampling rate
Sampling frequency refers to the number of data points collected per second – 2 kHz = 2000 data
points/second
In simple terms, the more data points collected, the more accurate your waveform
1kHz sampling rate

16. Choosing the right sampling rate

17. Data acquisition and handling
Long-term studies + high sampling rate = Large data files
Sampling rate = 2 kHz
Channels = 8 File size = ~2.8
GB
Recording time = 24 hrs
Use a dedicated data acquisition computer
Schedule recording to manage file size
Consider data storage carefully - back up!

18. Sampling
Think about data analysis and presentation – do you need 24 hrs of waveform data?
● Recording long-term BP from large sample size?
○ Periodic means and scheduling to only take short snippets of waveform data e.g. 10 mins
of every hour
○ Reduces file size for downstream analysis and management
● Recording EEG to identify seizures or interest in sleep/wake cycles?
○ Require all waveform data at high sampling rate
○ Regular file saving to reduce file size e.g. every 3 hrs

19. LabChart Lightning

20. LabChart Lightning

21. Data acquisition with ADInstruments
Choose your sampling rate
● Sampling rate up to 2 kHz with Kaha telemetry
● Ideal for neuroscience applications and LVP
● Option to sample at lower frequency to reduce data file size
Powerful data acquisition with LabChart Lightning
● Lightning has been built with telemetry studies in mind
● Easy management of large recordings with
multiple experimental groups
● Manage recordings within Projects
● Unlimited channels
● Cross-recording analysis

22. Maintaining animal welfare

23. Good surgical practice
Choice of anaesthesia – isoflurane or injectables
Aseptic technique for recovery surgery
Analgesia and antibiotics
Recovery – fluids, follow-up dosing, treats (?)

24. Importance of post-surgical recovery

25. Experimental timeline
Implantation Study End
Baseline Recording Experimental Phase
7-10 days
Wound healing
Prophylactics
Weight loss/gain
~5 days Days/Weeks/Months
Repeated dosing
Disease progression
Ageing
Without the limitation of battery life, experiments using Kaha Sciences telemetry are flexible and unrestricted

26. During study considerations
● Flexibility of recovery with each animal
● What can affect animals behaviour/physiology?
○ Feeding times
○ Cage changes
○ Light/dark cycles
● Use Scheduler function of LabChart to limit recordings to 22 hrs
● Reverse light/dark cycle so animals are active in the day time
● KEEP GOOD NOTES - Lab book, Comments in LabChart, Annotations in Lightning

27. Applying reduction and refinement with Kaha Sciences
More data collected from each animal
– wireless power for continuous recording
Increased accuracy and fidelity
– Millar Mikro-Tip® pressure sensor and 2kHz sampling
Improved animal welfare
– record from 2 implanted rats housed in one cage using cohousing mode
Customised experiments for unique application
– implant 2 telemeters in one rat (>350g) to record
up to 4 physiological parameters

28. Summary
● More data from each animal
● Improved data accuracy and repeatability
● Considerations for data acquisition
● The future of data acquisition for
telemetry
with LabChart Lightning
● Importance of animal welfare

29. Thank you for participating!
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