64×64 pixel smart sensor array for laser Doppler blood flow imaging

He, Dahai; Nguyen, Hoang; Hayes-Gill, Barrie; Zhu, Yiqun; Crowe, John A.; Clough, Geraldine F.; Gill, C. A.; Morgan, Stephen P.

doi:10.1364/ol.37.003060

Cited by 12 publications

(8 citation statements)

References 17 publications

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“…Consequently, aliasing occurs when the detected signals has frequencies higher than 5.8 kHz, which affects the linearity of LDI. This could partially be overcome by calibration or alternatively through the use of CMOS sensors with on-chip processing [27], [28]. For LSCI, the summation of multiple short exposures produces a similar signal level to long single exposure but the noise is proportional to sum of the square roots of each exposure time.…”

Section: Discussionmentioning

confidence: 99%

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Comparison of laser Doppler and laser speckle contrast imaging using a concurrent processing system

Sun

Hayes‐Gill

et al. 2016

Optics and Lasers in Engineering

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Section: Discussionmentioning

confidence: 99%

“…The temporal resolution of LDI has been improved by the introduction of full-field LDI [23]- [28] which is based on highspeed CMOS photodiode arrays [23]- [26] or custom made CMOS photodiode arrays with on-chip signal processing [27], [28]. These high frame rate cameras allow direct detection of the laser Doppler frequency spectrum.…”

Section: Introductionmentioning

confidence: 99%

Comparison of laser Doppler and laser speckle contrast imaging using a concurrent processing system

Sun

Hayes‐Gill

et al. 2016

Optics and Lasers in Engineering

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“…The acquisition is therefore low, and rapid physiological phenomena may be missed with such imagers. Full-field laser Doppler imagers have been proposed in the last years but necessitate high-speed cameras ( [17], [18], [19], [20], [21], [22], [23], [24]). Very recently, laser speckle contrast imagers have been commercialized and have the advantage of being full-field and based on low cost devices, compared to other techniques ( [25], [26]).…”

mentioning

confidence: 99%

Analysis of Laser Speckle Contrast Images Variability Using a Novel Empirical Mode Decomposition: Comparison of Results With Laser Doppler Flowmetry Signals Variability

Humeau-Heurtier

Ábrahám

2015

IEEE Trans. Med. Imaging

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noise (CEEMDAN). CEEMDAN is suitable for non linear and non stationary data and leads to intrinsic mode functions (IMFs). It is based on the ensemble empirical mode decomposition (EEMD) which relies on empirical mode decomposition (EMD). In our work the average frequencies of LSCI IMFsgiven by CEEMDAN are compared with the ones given by EMD and EEMD. Moreover, LDF signals acquired simultaneously to LSCI data are also processed with CEEMDAN, EMD and EEMD. We show that the average frequencies of IMFs given by CEEMDAN depend on the signal to noise ratio (SNR) used in the computation but, for a given SNR, the average frequencies found for LSCI are close to the ones obtained for LDF. By opposition, EEMD leads to IMFs with frequencies that do not vary much when the SNR level is higher than a threshold. The new CEEMDAN algorithm has the advantage of achieving a complete decomposition with no error in the reconstruction but our study suggests that further work is needed to gain knowledge in the adjustment of the added noise level. CEEMDAN, EMD and EEMD are data-driven methods that can provide a better knowledge of LSCI.Index Terms-Laser speckle contrast imaging, Empirical mode decomposition, Biomedical image processing, Laser Doppler flowmetry, Microvascular blood flow.

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“…( a ) Block diagram of the sensor (MUX for multiplexer, ADC for analog to digital converter); ( b ) Sensor layout (reproduced from [35] with permission).…”

Section: Figurementioning

confidence: 99%

Laser Doppler Blood Flow Imaging Using a CMOS Imaging Sensor with On-Chip Signal Processing

Nguyen

Hayes-Gill

et al. 2013

Sensors

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The first fully integrated 2D CMOS imaging sensor with on-chip signal processing for applications in laser Doppler blood flow (LDBF) imaging has been designed and tested. To obtain a space efficient design over 64 × 64 pixels means that standard processing electronics used off-chip cannot be implemented. Therefore the analog signal processing at each pixel is a tailored design for LDBF signals with balanced optimization for signal-to-noise ratio and silicon area. This custom made sensor offers key advantages over conventional sensors, viz. the analog signal processing at the pixel level carries out signal normalization; the AC amplification in combination with an anti-aliasing filter allows analog-to-digital conversion with a low number of bits; low resource implementation of the digital processor enables on-chip processing and the data bottleneck that exists between the detector and processing electronics has been overcome. The sensor demonstrates good agreement with simulation at each design stage. The measured optical performance of the sensor is demonstrated using modulated light signals and in vivo blood flow experiments. Images showing blood flow changes with arterial occlusion and an inflammatory response to a histamine skin-prick demonstrate that the sensor array is capable of detecting blood flow signals from tissue.

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64×64 pixel smart sensor array for laser Doppler blood flow imaging

Cited by 12 publications

References 17 publications

Comparison of laser Doppler and laser speckle contrast imaging using a concurrent processing system

Comparison of laser Doppler and laser speckle contrast imaging using a concurrent processing system

Analysis of Laser Speckle Contrast Images Variability Using a Novel Empirical Mode Decomposition: Comparison of Results With Laser Doppler Flowmetry Signals Variability

Laser Doppler Blood Flow Imaging Using a CMOS Imaging Sensor with On-Chip Signal Processing

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