An Optically Linked Telemetry System for Use with Electromagnetic-Field Measurement Probes

Bassen, H.; Hoss, Robert J.

doi:10.1109/temc.1978.303627

Cited by 13 publications

(3 citation statements)

References 3 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The three-axis probe was attached to a fiber-optic telemetry system [13]. Voltage information from the probe, along with rotational information from the pedestal, is fed into a chart recorder.…”

Section: Resultsmentioning

confidence: 99%

Design of a three-axis microwave E-field probe having submillimeter dimensions

Howerton

Batchman

1987

IEEE Trans. Instrum. Meas.

View full text Add to dashboard Cite

show abstract

Section: Resultsmentioning

confidence: 99%

Design of a three-axis microwave E-field probe having submillimeter dimensions

Howerton

Batchman

1987

IEEE Trans. Instrum. Meas.

View full text Add to dashboard Cite

show abstract

“…Apnea monitors have breath and ECG analog voltage "re corder" outputs which were observed using a fiber optic data link so that no metal wiring would be present during the EMI testing [3]. Each apnea monitor has an apnea alarm circuit with a voltage detection level which, when received either from an infant or from an electronic infant simulator, causes the monitor's indicator lights to blink, indicating normal operation.…”

Section: Methodsmentioning

confidence: 99%

Automated radiofrequency electromagnetic interference testing of apnea monitors using an open area test site

Ruggera

O'Bryan

Casamento

1992

Proceedings of the Annual International Conference of the IEEE Engineering in Medicine and Biology Society

View full text Add to dashboard Cite

Medical devices that electronically sense physiological functions may be affected by external radiofrequency (RF) radia tion from sources such as television and radio stations .. When RF disrnpts normal device function, it is referred to as electromagnetic interference (EMI). The Center for Devices and Radiological Health (CDRH) has been testing infant apnea. monitors for suscep tibility to EMI. Laboratory testing and user site surveys were conducted that confirmed susceptibility to JEMI in illl fant apnea monitors. The field strength value above which device perfor mance was compromised will be referred to as the device's threshold. An automated procedure has now been developed which enables us to obtain threshold EMI field-strength versus frequency plots and identify EMI regions by frequency band In addition, precise measurements at an outdoor open area test site have found that the ...J OO-cm (-10-ft) pati.�nt leads, when fully extended, act as significant receivers of RF signals below 50 MHz. Thresholds, averaged over the 10-54 MHz firequency range, were 0.22 Vim with minimums reaching 0.05 Vim for four of the nine monitors tested when 100% amplitude modulation at 0.5 Hz was imposed on the RF carrier. In the FM band (88-10�: MHz) the thresholds averaged 0.88 V 1m, with one model reachIng a mini mum of 0.08 Vim. These results were similar to our earlier laboratory data which were taken with the patient and power supply leads not fully extended in the RF exposure fi eldl, indicating that testing with full lead length exposures may not be necessary at higher frequencies.

show abstract

“…Moreover, long conductive cables are susceptible to electromagnetic interference, which hinders the accuracy of the measurement and might cause additional RF heating. To mitigate electromagnetic (EM) interference and additional field distortions from electric connections, dipole antenna-based sensors often use an electro-optic (EO) modulator next to the short dipole antenna for optical read-out 27 , 28 . However, the sensitivity and the spatial resolution are still determined by the dimensions of the dipole antenna; dipole length is usually limited to ∼5 mm and sensitivity suffers when operating frequencies are below 100 MHz.…”

Section: Introductionmentioning

confidence: 99%

Acousto-optic-based time domain electric field sensor for magnetic resonance imaging applications

Yaras,

Bradley,

Yildirim

et al. 2024

Opt. Eng.

View full text Add to dashboard Cite

An acousto-optic (AO)-based electric field sensor is presented for time domain measurement under magnetic resonance imaging (MRI). A fully MR-compatible sensor is designed and fabricated using a phase-shifted fiber Bragg grating mechanically coupled to a piezoelectric transducer. Mechanical resonance of the piezoelectric transducer is matched to the operating frequencies of commonly used MRI systems to increase the sensitivity of the sensor. Sensitivity of the sensor is measured as 1.27 mV∕V∕m, with a minimum detectable electric field of 4.4 mV∕m∕ p Hz.Directivity of the sensor is measured with a 18 dB orthogonal component rejection. The dynamic range of the sensor is calculated as 117 dB∕Hz, which allows the measurement of electric fields up to 3.2 kV∕m. In MRI studies, the AO sensor was able detect local hot spots around a reference implant accurately with high signal-tonoise ratio. AO sensor exhibited similar or better performance when compared with commercially available MRI compatible electric field sensors. Furthermore, the small size of the sensor with the flexible fiber optic link could allow in situ measurements of electric fields during critical interventional procedures such as pacemaker lead or deep brain stimulator placement as an MRI dosimeter during diagnostic scans.

show abstract

An Optically Linked Telemetry System for Use with Electromagnetic-Field Measurement Probes

Cited by 13 publications

References 3 publications

Design of a three-axis microwave E-field probe having submillimeter dimensions

Design of a three-axis microwave E-field probe having submillimeter dimensions

Automated radiofrequency electromagnetic interference testing of apnea monitors using an open area test site

Acousto-optic-based time domain electric field sensor for magnetic resonance imaging applications

Contact Info

Product

Resources

About