Quantifying and Reducing Posture-Dependent Distortion in Ballistocardiogram Measurements

Javaid, Abdul Q.; Wiens, Andrew D.; Fesmire, N. Forrest; Weitnauer, Mary Ann; Inan, Omer T.

doi:10.1109/jbhi.2015.2441876

Cited by 28 publications

(22 citation statements)

References 35 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The H-F vibrations show increased energy in the 6-12Hz band for the supine and seated positions. These results are consistent with our previous findings with healthy subjects that the changes in SCG morphology-specifically, increased higher frequency vibration modes in addition to the primary mode in the 1-5 Hz range-are more associated with body mechanics rather than physiologic changes [9]. The L-R axis signals, however, do not show increased energy in higher frequency bands.…”

Section: Psd Based Differencessupporting

confidence: 92%

Quantification of Posture Induced Changes in Wearable Seismocardiogram Signals for Heart Failure Patients

Javaid

Dowling

Etemadi

et al. 2016

2016 Computing in Cardiology Conference (CinC)

Self Cite

View full text Add to dashboard Cite

Our goal is to characterize the effects of posture-supine, seated, and standing-on the seismocardiogram (SCG) signal for patients with heart failure (HF). Posture can (1) distort the SCG signal, for example due to altering the body's mechanical vibration response, and (2) affect a person's cardiovascular physiology, for example due to changes in venous return. This work focuses on characterizing the former, such that in future studies we can use the SCG to assess physiological changes in patients with HF at home. Our team has developed a circular patch (7 cm in diameter) which, when placed on the sternum, simultaneously measures the electrocardiogram (ECG) along with SCG signals in the dorso-ventral and head-to-foot directions. We recruited six HF patients thus far for this ongoing study. Each subject was asked to lie down in a supine position on a patient bed for 1 minute followed by 1 minute in each of the seated and standing postures. A novel algorithm was implemented to compare distortion in the shape of the SCG signals in the supine and seated postures as compared to the standing upright posture. The frequency domain analysis of the SCG signals revealed presence of high energy in bands greater than 8 Hz for supine and seated postures. Based on the findings of this paper, features can be derived to correct for posture related changes in the measured SCG signals for accurate assessment of patients with HF at home.

show abstract

Section: Psd Based Differencessupporting

confidence: 92%

Quantification of Posture Induced Changes in Wearable Seismocardiogram Signals for Heart Failure Patients

Javaid

Dowling

Etemadi

et al. 2016

2016 Computing in Cardiology Conference (CinC)

Self Cite

View full text Add to dashboard Cite

show abstract

“…Adaptive filters can update their filter weights automatically to fit the input noise level. Several researchers have presented contributions on the analysis of ICG using signal processing techniques (Wang et al 1995 ; Muzi et al 1985 ; Ishiguro et al 2006 ; Barros et al 1995 ; Dromer et al 2009 ; Yamamoto et al 1988 ; Javaid et al 2015 ; Sebastian et al 2011 ). In these contributions, both least mean square (LMS) and recursive least square (RLS) algorithms are used.…”

Section: Introductionmentioning

confidence: 99%

Efficient reference-free adaptive artifact cancellers for impedance cardiography based remote health care monitoring systems

Mallam

Rao

2016

SpringerPlus

View full text Add to dashboard Cite

In this paper, a new model for adaptive artifact cancelation in impedance cardiography (ICG) signals is presented. It is a hybrid model based on wavelet decomposition and an adaptive filter. A novel feature of this model is the implementation of reference-free adaptive artifact cancellers (AAC). For this implementation, the reference signal is constructed using a wavelet transformation. During critical conditions the filter weights may be negative and cause an imbalance in the convergence. To overcome this problem, we introduce non-negative adaptive algorithms in the proposed artifact canceller. To accelerate the performance of the AAC, we propose exponential non-negative and normalized non-negative algorithms to update the filter coefficients. The computational complexity of the filtering section in a remote health care system is important to avoid inter-symbol interference of the incoming samples. This can be achieved by combining sign-based algorithms with the adaptive filtering section. Finally, several AACs are developed using variants of the non-negative algorithms and performance measures are computed and compared. All of the proposed AACs are tested on actual ICG signals. Among the AACs evaluated, sign regressor normalized non-negative LMS (SRN3LMS) based adaptive artifact canceller achieves highest signal to noise ratio (SNR). The SNR achieved by this algorithm in baseline wander artifact elimination is 8.5312 dBs, in electrode muscle artifact elimination is 7.5908 dBs and in impedance measurement artifact elimination is 8.4231 dBs.

show abstract

“…This is important due to the increase in BCG signal quality seen as the subject is standing upright as opposed to seating [43], which is required for reliable PTT measurements.…”

Section: Discussionmentioning

confidence: 99%

Robust Sensing of Distal Pulse Waveforms on a Modified Weighing Scale for Ubiquitous Pulse Transit Time Measurement

Carek

Inan

2017

IEEE Trans. Biomed. Circuits Syst.

Self Cite

View full text Add to dashboard Cite

The measurement of aortic pulse transit time (PTT), the time for the arterial pulse wave to travel from the carotid to the femoral artery, can provide valuable insight into cardiovascular health, specifically regarding arterial stiffness and blood pressure, BP. To measure aortic PTT, both proximal and distal arterial pulse timings are required. Recently, our group has demonstrated that the ballistocardiogram (BCG) signal measured on a modified weighing scale can provide an unobtrusive, yet accurate, means of obtaining a proximal timing reference; however, there are no convenient, reliable methods to extract the distal timing from a subject standing on the modified weighing scale. It is common to use a photoplethysmograph (PPG) attached to a toe to measure this distal pulse, but we discovered that this signal is greatly deteriorated as the subject stands on the scale. In this paper, we propose a novel method to measure the distal pulse using a custom reflective PPG array attached to the dorsum side of the foot (D-PPG). Twelve subjects of varying skin tones were recruited to assess the preliminary validation of this approach. Pulse measurements using the D-PPG were taken from seated and standing subjects, and the commercially available PPG were measured for facilitating comparison of timing measurements. We show that the D-PPG was the only sensor to retain the high detection rate of feasible timing values. To further test and optimize the system, various factors such as applied pressure, measurement location, and LED/photodiode configuration were tested.

show abstract

Quantifying and Reducing Posture-Dependent Distortion in Ballistocardiogram Measurements

Cited by 28 publications

References 35 publications

Quantification of Posture Induced Changes in Wearable Seismocardiogram Signals for Heart Failure Patients

Quantification of Posture Induced Changes in Wearable Seismocardiogram Signals for Heart Failure Patients

Efficient reference-free adaptive artifact cancellers for impedance cardiography based remote health care monitoring systems

Robust Sensing of Distal Pulse Waveforms on a Modified Weighing Scale for Ubiquitous Pulse Transit Time Measurement

Contact Info

Product

Resources

About