Isochronal map of chest wall vibration with cardiokymography

Okada, Masahiko; Nakajima, Taku; Eizuka, Noriyuki; Saitoh, Yoshiaki; Yakata, M

doi:10.1016/0169-2607(88)90033-8

Cited by 6 publications

(2 citation statements)

References 21 publications

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“…The MUSIC algorithm was applied by choosing the number of sources as K = 2 . A source plane was defined on a 40x40 grid (with 2.5 mm x 2.5 mm grid size) at 5 cm distal to the array plane, using the parameter r in (9). The distance between the source plane and the array plane is the actual distance in the measurement setup.…”

Section: Experimental Study and Resultsmentioning

confidence: 99%

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Time-frequency cardiac passive acoustic localization

Bahadirlar

Gülçür²

2001 Conference Proceedings of the 23rd Annual International Conference of the IEEE Engineering in Medicine and Biology Society

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Abstract-In a previous work, the authors have used a novel, radically different approach based on concurrent multi-sensor array measurements and "super-resolution" array processing scheme for phonocardiographic signals. Using a specially designed passive acoustic array, acoustic "images" corresponding to the various distinct phases of the heartbeat were obtained. In this paper, this approach is extended using a novel framework, called TimeFrequency Cardiac Passive Acoustic Localization (TF-CARDIOPAL). The Choi-Williams distribution is utilized to calculate a spatial time-frequency matrix to characterize the spatial time-frequency distribution for the nonstationary array signals. Distinctive components of this matrix on the time-frequency plane yield important clues on possible source locations in the heart. This finding has been used in extracting localization information from the first heart sound signals from a healthy human subject. Meaningful source localization results that are well correlated with the mechanical activation of the heart are obtained.

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Section: Experimental Study and Resultsmentioning

confidence: 99%

“…Monitoring the entire region of the heart may require many sensors. Vermarien et al [8] and Okada et al [9] successfully obtained low-frequency vibratory maps on the chest wall with contact type transducers. Ramachandran et al [10] used a capacitance type distance meter to reconstruct 2-D patterns of the cardiac activity.…”

Section: Introductionmentioning

confidence: 99%

Time-frequency cardiac passive acoustic localization

Bahadirlar

Gülçür²

2001 Conference Proceedings of the 23rd Annual International Conference of the IEEE Engineering in Medicine and Biology Society

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Cardiokymograph system with a capacitance transducer and its preliminary application in the measurement of heart wall movement

Luo

Jin

et al. 1998

Med. Biol. Eng. Comput.

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A novel cardiokymograph system is introduced. The new system features a capacitance transducer with increased sensitivity and can be used in multichannel measurements. The novelty of this technique is the injection of a current into the patient coupled with the use of a capacitive displacement transducer and the possibility of multichannel monitoring. It provides for the possibility of removing breath noise when some signal processing technique, such as adaptive filtering, is used. Further investigation is needed to demonstrate clinical significance and pathologies.

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