Mr. Che-Chou Shen Profile

Che-Chou Shen

at National Taiwan Univ of Science and Technology

SPIE Involvement:

Author

Publications (4)

Proceedings Article | 5 March 2021 Presentation

Improving axial resolution of optical resolution photoacoustic microscopy with frequency domain delay multiply and sum beamforming method

Sing-Shuo Su, Che-Chou Shen, Meng-Lin Li

Proceedings Volume 11642, 116421E (2021) https://doi.org/10.1117/12.2582989

KEYWORDS: Optical resolution, Photoacoustic microscopy, Sensors, Imaging arrays, Ultrasonography, Spatial resolution, Signal attenuation, Photoacoustic spectroscopy, Photoacoustic imaging, In vivo imaging

Read Abstract +

Proceedings Article | 6 March 2020 Presentation

Low complexity and flexible baseband delay-multiply-and-sum photoacoustic array imaging (Conference Presentation)

Meng-Lin Li, Che-Chou Shen

Proceedings Volume 11240, 112402K (2020) https://doi.org/10.1117/12.2546990

KEYWORDS: Imaging arrays, Photoacoustic spectroscopy, Photoacoustic imaging, Image quality, Multispectral imaging, Signal to noise ratio, Image resolution, Bandpass filters, Image filtering, Linear filtering

Read Abstract +

Proceedings Article | 12 March 2007 Paper

Differential maximum Doppler frequency for transverse flow estimation

Che-Chou Shen, Ching-Han Chou

Proceedings Volume 6513, 65131A (2007) https://doi.org/10.1117/12.706718

KEYWORDS: Doppler effect, Transducers, Ultrasonography, Statistical analysis, Blood circulation, Velocity measurements, Speckle, Error analysis, Optical filters, 3D image processing

Read Abstract +

Classic Doppler equation can only provide the axial velocity of blood flow. To acquire the complete flow vector, estimation of the non-axial flow velocity is essential. For Doppler-bandwidth-based transverse estimation, however, accuracy is limited because of the complex dependence of the Doppler bandwidth on the geometry and the location of the sample volume in the vessel. Specifically, the Doppler bandwidth tends to be overestimated because it is conventionally decided from the difference between maximum Doppler frequency and Doppler shift frequency. The maximum Doppler frequency only depends on the peak flow velocity within the vessel and can be used as a stable parameter in flow estimation. However, the Doppler shift frequency is susceptible to the position of the sample volume and it decreases when the sample volume is not centered within the vessel. The distance between the center of the sample volume and the central line of the vessel is referred to as the position offset of the sample volume. Based on the stable nature of maximum Doppler frequency, a novel method utilizing the differential maximum Doppler frequencies from two parallel beams with different beam widths is proposed to improve the accuracy of transverse estimation. In vitro experiments were performed to validate the proposed method and results were compared with the conventional method. In this study, a steady flow condition was considered and two 5-MHz pistons were used to generate the two beams with different widths. For the conventional method, it is demonstrated that the Doppler bandwidth is severely overestimated when the position offset is present. For the proposed method, however, the differential maximum Doppler frequency is relatively stable even in the presence of the position offset as long as the sample volume is sufficient in length. Hence, both accuracy and stability of the transverse estimation can be significantly improved by taking advantage of the differential maximum Doppler frequency.

Proceedings Article | 12 March 2007 Paper

Effect of third harmonic transmit phasing on second harmonic generation

Che-Chou Shen, Yu-Chun Wang

Proceedings Volume 6513, 65130T (2007) https://doi.org/10.1117/12.708390

KEYWORDS: Tissues, Acoustics, Harmonic generation, Wave propagation, Signal to noise ratio, Signal detection, Transducers, Ultrasonography, Nonlinear optics, Signal generators

Read Abstract +

View contact details

UPDATE YOUR PROFILE

Is this your profile? Update it now.

Sign into your SPIE.org account

Don’t have a profile and want one?

Create an account on SPIE.org

Keywords/Phrases

Search In:

Publication Years