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Rapid communication: cleaning up a Hartley oscillator.
1MRC Neurological Prosthesis Unit, London, UK.
Journal of Medical Engineering & Technology
|March 1, 1991
Summary
A simple Hartley oscillator unexpectedly produced numerous radiofrequency harmonics up to 1 GHz. While easily removed, standard engineering instruments might miss these significant harmonic emissions from neurological prostheses.
Area of Science:
- Biomedical Engineering
- Electromagnetics
- Neurotechnology
Background:
- Neurological prostheses can generate radiofrequency interference (RFI).
- Understanding and controlling RFI is crucial for device safety and efficacy.
- Harmonic oscillators are fundamental electronic components.
Purpose of the Study:
- To investigate RFI generated by a Hartley oscillator in the context of neurological prostheses.
- To characterize the harmonic content of the oscillator's output.
- To highlight potential detection challenges with common engineering tools.
Main Methods:
- Utilized a Hartley oscillator as a model system.
- Analyzed the radiofrequency spectrum of the oscillator's output.
- Evaluated the detectability of harmonics using typical development engineer instrumentation.
Main Results:
- Observed a significant 'forest' of harmonics extending up to 1 GHz.
- These harmonics were found to be relatively simple to eliminate.
- Standard instrumentation may fail to detect these pervasive harmonics.
Conclusions:
- A basic Hartley oscillator can be a source of extensive RFI.
- The detection of such harmonics may be overlooked with conventional equipment.
- Awareness and appropriate measurement techniques are necessary for controlling RFI in neuroprosthetic development.
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