Optimal filter design for shielded and unshielded ambient noise reduction in fetal magnetocardiography.

Comani, S; Mantini, D; Alleva, G; Di Luzio, S; Romani, G

Journal article

Optimal filter design for shielded and unshielded ambient noise reduction in fetal magnetocardiography.

Abstract:: The greatest impediment to extracting high-quality fetal signals from fetal magnetocardiography (fMCG) is environmental magnetic noise, which may have peak-to-peak intensity comparable to fetal QRS amplitude. Being an unstructured Gaussian signal with large disturbances at specific frequencies, ambient field noise can be reduced with hardware-based approaches and/or with software algorithms that digitally filter magnetocardiographic recordings. At present, no systematic evaluation of filters' performances on shielded and unshielded fMCG is available. We designed high-pass and low-pass Chebychev II-type filters with zero-phase and stable impulse response; the most commonly used band-pass filters were implemented combining high-pass and low-pass filters. The achieved ambient noise reduction in shielded and unshielded recordings was quantified, and the corresponding signal-to-noise ratio (SNR) and signal-to-distortion ratio (SDR) of the retrieved fetal signals was evaluated. The study regarded 66 fMCG datasets at different gestational ages (22-37 weeks). Since the spectral structures of shielded and unshielded magnetic noise were very similar, we concluded that the same filter setting might be applied to both conditions. Band-pass filters (1.0-100 Hz) and (2.0-100 Hz) provided the best combinations of fetal signal detection rates, SNR and SDR; however, the former should be preferred in the case of arrhythmic fetuses, which might present spectral components below 2 Hz.

Actions

Email

Email this record

Send the bibliographic details of this record to your email address.

Your Email
Please enter the email address that the record information will be sent to.

-
Your message (optional)
Please add any additional information to be included within the email.
Cite

Cite this record

APA Style

Comani, S., Mantini, D., Alleva, G., Di Luzio, S., & Romani, G. (2005). Optimal filter design for shielded and unshielded ambient noise reduction in fetal magnetocardiography. Physics in Medicine and Biology, 50(23), 5509–5521.

MLA Style

Comani, S., et al. “Optimal Filter Design for Shielded and Unshielded Ambient Noise Reduction in Fetal Magnetocardiography.” Physics in Medicine and Biology, vol. 50, no. 23, 2005, pp. 5509–21.

Chicago Style

Comani, S, D Mantini, G Alleva, S Di Luzio, and G Romani. 2005. “Optimal Filter Design for Shielded and Unshielded Ambient Noise Reduction in Fetal Magnetocardiography.” Physics in Medicine and Biology 50 (23): 5509–21.
Share
Print