A pixel-size receiver with integrated subarray beamformer for 3-dimensional photoacoustic imaging
Abstract/Contents
- Abstract
- Photoacoustic imaging is an emerging imaging modality based on light excitation and acoustic sensing, providing valuable diagnostic information through the optical absorption contrast in the object. Due to the same receiving scheme, photoacoustic imaging is often combined with ultrasound imaging to provide both the functional information and the structural information at the same time. Therefore, current photoacoustic imaging setups often reuse the existing ultrasound imaging instruments and therefore suffer from the same limitations as those present in today's ultrasound imaging systems. The current 2-Dimensional (2D) medical ultrasound system is a mature and prevalent technology; however, the development of a 3-Dimensional (3D) system faces substantial challenges due to the large channel count. In a conventional 2D system, each element of a 1-Dimensional (1D) array is directly accessed through a coaxial cable by a main system that processes the signal; however, this approach is not feasible for a 2D array in a 3D system. To address this issue, recent work has proven the viability of flip-chip bonding or direct transducer integration. This shifts the burden to a CMOS substrate, which must be designed within the same pixel pitch and must provide dense signal conditioning and processing to ensure the compatibility of the output channel count with the current cable connections. A common approach for data reduction is to employ subarray beamforming, which applies delay-and-sum (DAS) operations within a group of pixels. Conventional digital beamforming involves high complexity analog-to-digital converter (ADC) design and is difficult to be integrated within the pixel area. Alternatively, prior works apply analog beamforming for its simplicity and, yet, suffer from a combination of issues related to limited delay, coarse delay resolution and low signal-to-noise-ratio (SNR). In this thesis work, we leverage the integration density of fine line CMOS and implement pixel-size receivers with efficient integrated ΔΣ digital subarray beamformer. To simplify the building block, design specification are appropriately tailored to the system requirements derived from imaging simulation results. In addition, we combine functional blocks and utilize inverterbased amplifiers to achieve compact layout in the pixel-size receiver. This thesis work is realized in a receiver chip fabricated in a 28nm CMOS process, demonstrating the first pitch-matched receiver electronics with in-pixel A/D conversion and subarray beamformer.
Description
| Type of resource | text |
|---|---|
| Form | electronic; electronic resource; remote |
| Extent | 1 online resource. |
| Publication date | 2016 |
| Issuance | monographic |
| Language | English |
Creators/Contributors
| Associated with | Chen, Man-Chia |
|---|---|
| Associated with | Stanford University, Department of Electrical Engineering. |
| Primary advisor | Murmann, Boris |
| Thesis advisor | Murmann, Boris |
| Thesis advisor | Khuri-Yakub, Butrus T, 1948- |
| Thesis advisor | Wooley, Bruce A, 1943- |
| Advisor | Khuri-Yakub, Butrus T, 1948- |
| Advisor | Wooley, Bruce A, 1943- |
Subjects
| Genre | Theses |
|---|
Bibliographic information
| Statement of responsibility | Man-Chia Chen. |
|---|---|
| Note | Submitted to the Department of Electrical Engineering. |
| Thesis | Thesis (Ph.D.)--Stanford University, 2016. |
| Location | electronic resource |
Access conditions
- Copyright
- © 2016 by Man-Chia Chen
- License
- This work is licensed under a Creative Commons Attribution Non Commercial 3.0 Unported license (CC BY-NC).
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