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Journal ArticleDOI

Lossless Compression Technique for Real-Time Photoplethysmographic Measurements

01 Apr 2015-IEEE Transactions on Instrumentation and Measurement (IEEE)-Vol. 64, Iss: 4, pp 975-983
TL;DR: A lossless, real-time compression technique based on combination of second-order delta and the Huffman encoding is proposed for the PPG signal and the low time complexity of the proposed algorithm encourages its implementation for development low-cost real- time PPG measurement application in patient monitoring.
Abstract: Photoplethysmogram (PPG) signal can provide vital diagnostic information on cardiovascular functions of the human body. In this paper, a lossless, real-time compression technique based on combination of second-order delta and the Huffman encoding is proposed for the PPG signal. The algorithm was validated with 10-bit quantized PPG data collected from multiparameter intelligent monitoring in intensive care-II database under Physionet and healthy volunteers using Biopac Systems at 125-Hz sampling frequency. Using a block size of 48 samples, the average compression ratio, percentage root-mean-squared difference (PRD), and PRD normalized achieved was 2.223, 0.127, and 0.187 respectively with 30 sets of volunteers’ data. Three prime clinical features, systolic amplitude, systolic upstroke time, and pulse width from the decompressed PPG waveform were evaluated with less than 1% distortion on the diagnostic measures. A study was also done to estimate the compression efficiency for different sample block size, wave morphology, and sampling frequency of raw data. The low time complexity of the proposed algorithm encourages its implementation for development low-cost real-time PPG measurement application in patient monitoring.
Citations
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Journal ArticleDOI
TL;DR: A look at the latest biomedical topics from the perspective of Instrumentation and Measurement (I&M) and guidelines on the I&M aspects that are useful for authors with primarily biomedical backgrounds who would like to publish in IEEE TIM are presented.
Abstract: Proper measurement is crucial in the medical, biomedical, and healthcare fields because it forms the basis of medical diagnosis, prognosis, and evaluation. In fact, it is known that "measuring is the cornerstone of medical research and clinical practice" [1]. Medical professionals such as doctors or clinical laboratory scientists must have confidence in the results reported by their instruments or their measurement methods to make the correct decision for their patient. While in many industries incorrect measurements would simply lead to customer dissatisfaction or loss of money, in the medical field incorrect measurements could be fatal and lead to loss of life. Hence, we can say that proper instrumentation and measurement is vital in the medical field. In this article, we take a look at the latest biomedical topics from the perspective of Instrumentation and Measurement (I&M), and we summarize the latest medical I&M topics published in IEEE Transactions on Instrumentation and Measurement (TIM), to familiarize medical practitioners and researchers in how to achieve a proper medical I&M paper. We also briefly introduce the IEEE Instrumentation and Measurement Society's (IMS) main medical conference, the IEEE Symposium on Medical Measurements and Applications (IEEE MeMeA), which promotes the I&M aspects of the medical field in general, and we present guidelines on the I&M aspects that are useful for authors with primarily biomedical backgrounds who would like to publish in IEEE TIM.

60 citations


Cites methods from "Lossless Compression Technique for ..."

  • ...In [16], the author presents a compression method for real-time measurement acquisition of photoplethysmogram (PPG) signals at a commercial sampling rate of 125 Hz using a 10-bit quantizer....

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Journal ArticleDOI
TL;DR: A high performing, reliable and robust Photoplethysmogram compression and encryption method is proposed for efficient, safe and secure storage and transmission which is superior to existing PPG compression methods reported to date.

29 citations

Journal ArticleDOI
TL;DR: An efficient PPG compression algorithm is presented, and is developed on the basis of five major sequential steps: noise elimination through Butterworth low-pass filter, down-sampling, inter-sample difference computation, grouping and American Standard Code for Information Interchange (ASCII) character encoding of reduced dataset.

26 citations

Proceedings ArticleDOI
01 Feb 2015
TL;DR: A modification of delta modulation for effective compression of PPG signal for real time measurements and monitoring applications is proposed.
Abstract: Photoplethysmography (PPG) is one of the prime non-invasive vascular assessment methodology adopted in modern clinical practice. This paper proposes a modification of delta modulation for effective compression of PPG signal for real time measurements and monitoring applications. Based on the energy content and fluctuations, the PPG signal was windowed and categorized into ‘complex’ or ‘plain’ zones. The algorithm applies an adaptive hard thresholding, run length encoding and selective biasing of the first difference array based on zonal complexity. The final stage employs a selective nibble combination or offsetting rule for further compression. For performance assessment of the compression-decompression algorithms, PPG data was collected from fingers of healthy volunteers using Biopac Systems®. An average compression ratio of 3.84, percentage root mean square difference of 5.82 and percentage root mean square difference normalized of 7.57 were obtained with 20 sets of volunteers' data at 10 bit resolution and 125 Hz sampling. The decompressed data were clinically validated by Cardiologists.

21 citations

Journal ArticleDOI
TL;DR: A robust, reliable and highly efficient singular value decomposition and lossless ASCII character encoding (LL-ACE)-based quality-guaranteed PPG compression algorithm that provides a compression ratio that is much higher than that provided by other algorithms that are designed to compress the PPG signals only.
Abstract: Objective: Extraction and analysis of various clinically significant features of photoplethysmogram (PPG) signals for monitoring several physiological parameters, as well as for biometric authentication have become important areas of research in recent years. However, PPG signal compression; particularly quality-guaranteed compression, and steganography of patient's secret information is still lagging behind. Method: This paper presents a robust, reliable and highly efficient singular value decomposition and lossless ASCII character encoding (LL-ACE)-based quality-guaranteed PPG compression algorithm. This algorithm cannot only be used to compress PPG signals, but also do so for steganographed PPG signals that include the patient information. Result and conclusion: It is worth mentioning that such an algorithm is being proposed for the first time to compress steganographed PPG signals. The algorithm is tested on PPG signals collected from four different databases, and its performance is assessed using both quantitative and qualitative measures. The proposed steganographed PPG compression algorithm provides a compression ratio that is much higher than that provided by other algorithms that are designed to compress the PPG signals only. Significance: first, the clinical quality of the reconstructed PPG signal can be controlled precisely, second, the patient's personal information is restored with no errors, third, high compression ratio, and fourth, the PPG signal reconstruction error is neither dependent on the steganographic operation nor on the size of the patient information data.

16 citations


Cites background or methods or result from "Lossless Compression Technique for ..."

  • ...Even though a few attempts have been made recently to compress digitized PPG signals, [14]–[19], their performance is not satisfactory....

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  • ...in [18], whose compression performance is higher than that of the methods reported in [14] to [17]....

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  • ...The values of CC and RMSE of the methods in [14], [15], [16] and [17] are not available in the literature and hence not included in Table IV....

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  • ...[14], and therefore, PRD is used in this research as the qualitycontrolling metric of the reconstructed PPG signal....

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  • ...77 at 125 Hz sampling rate, which is higher than that of the CR values reported in [14] or [15]....

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References
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Book
01 Jan 1992
TL;DR: Basic Concepts of Medical Instrumentation (W. Olson).
Abstract: Basic Concepts of Medical Instrumentation Basic Sensors and Principles Amplifiers and Signal Processing The Origin of Biopotentials Biopotential Electrodes Biopotential Amplifiers Blood Pressure and Sound Measurement of Flow and Volume of Blood Measurements of the Respiratory System Chemical Biosensors Clinical Laboratory Instrumentation Medical Imaging Systems Therapeutic and Prosthetic Devices Electrical Safety.

1,674 citations

Journal ArticleDOI
TL;DR: The theoretical bases behind the direct ECG data compression schemes are presented and classified into three categories: tolerance-comparison compression, DPCM, and entropy coding methods and a framework for evaluation and comparison of ECG compression schemes is presented.
Abstract: Electrocardiogram (ECG) compression techniques are compared, and a unified view of these techniques is established. ECG data compression schemes are presented in two major groups: direct data compression and transformation methods. The direct data compression techniques are ECG differential pulse code modulation (DPCM) and entropy coding, AZTEC, Turning-point, CORTES, Fan and SAPA algorithms, peak-picking, and cycle-to-cycle compression methods. The transformation methods include Fourier, Walsh, and Karhunen-Loeve transforms. The theoretical bases behind the direct ECG data compression schemes are presented and classified into three categories: tolerance-comparison compression, DPCM, and entropy coding methods. A framework for evaluation and comparison of ECG compression schemes is presented. >

690 citations


"Lossless Compression Technique for ..." refers background in this paper

  • ...Although a lot of research is already available for ECG signal compression [25], [26], the area of PPG compression is largely unexplored till date by the research community....

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Journal ArticleDOI
TL;DR: Although some differences in the time-varying spectral indices extracted from HRV and PRV exist, mainly in the HF band associated with respiration, PRV could be used as a surrogate of HRV during non-stationary conditions, at least during the tilt table test.
Abstract: In this paper we assessed the possibility of using the pulse rate variability (PRV) extracted from the photoplethysmography signal as an alternative measurement of the HRV signal in non-stationary conditions. The study is based on analysis of the changes observed during a tilt table test in the heart rate modulation of 17 young subjects. First, the classical indices of HRV analysis were compared to the indices from PRV in intervals where stationarity was assumed. Second, the time-varying spectral properties of both signals were compared by time-frequency (TF) and TF coherence analysis. Third, the effect of replacing PRV with HRV in the assessment of the changes of the autonomic modulation of the heart rate was considered. Time-invariant HRV and PRV indices showed no statistically significant differences (p > 0.05) and high correlation (>0.97). Time-frequency analysis revealed that the TF spectra of both signals were highly correlated (0.99 +/- 0.01); the difference between the instantaneous power, in the LF and HF bands, obtained from HRV and PRV was small (<10(-3) s(-2)) and their temporal patterns were highly correlated (0.98 +/- 0.04 and 0.95 +/- 0.06 in the LF and HF bands, respectively) and TF coherence in the LF and HF bands was high (0.97 +/- 0.04 and 0.89 +/- 0.08, respectively). Finally, the instantaneous power in the LF band was observed to significantly increase during head-up tilt by both HRV and PRV analysis. These results suggest that although some differences in the time-varying spectral indices extracted from HRV and PRV exist, mainly in the HF band associated with respiration, PRV could be used as a surrogate of HRV during non-stationary conditions, at least during the tilt table test.

410 citations


"Lossless Compression Technique for ..." refers background or methods in this paper

  • ...The distance of the consecutive systolic peaks has been used as an alternative measure for rhythm analysis and measurement heart rate variability [7]–[9]....

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  • ...In [7] and [9], an investigation was done to compare the reliability of heart rate measurement against the same measured from electrocardiogram (ECG) signal, taken as gold standard....

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Journal ArticleDOI
TL;DR: The results from a series of in vivo studies to evaluate a prototype skin-reflectance pulse oximeter in humans are presented, showing locally heating the skin is shown to increase the pulsatile component of the reflected photoplethysmograms.
Abstract: The major concern in developing a sensor for reflectance pulse oximetry is the ability to measure large and stable photoplethysmograms from light which is backscattered from the skin. Utilizing a prototype optical reflectance sensor, locally heating the skin is shown to increase the pulsatile component of the reflected photoplethysmograms. Additional improvements to signal-to-noise ratio were achieved by increasing the active area of the photodetector and optimizing the separation distance between the light source and photodetector. The results from a series of in vivo studies to evaluate a prototype skin-reflectance pulse oximeter in humans are presented. >

314 citations


"Lossless Compression Technique for ..." refers background in this paper

  • ...of light absorbance at the wavelengths 660 and 940 nm (generated by alternate excitation of two photodiodes) by HbO2 and Hb at the arterial blood to measure SpO2 [10], [11]....

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Journal ArticleDOI
TL;DR: An effective system for estimate of blood glucose and blood pressure from a photoplethysmograph and machine learning techniques that complies with the grade B protocol of the British Hypertension society for the blood pressure and only in 1.9% of the cases did not detect hypoglycemia or hyperglycemia.

239 citations


"Lossless Compression Technique for ..." refers background in this paper

  • ...For the last few decades, information and communication technology, backed by the development of low-power and high-speed processors have revolutionized health monitoring of patients with disorders like arrhythmia, high blood pressure, and diabetes in clinical or home environment [21], [22]....

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