1
|
Seok C, Yamaner FY, Sahin M, Oralkan O. A Wearable Ultrasonic Neurostimulator - Part I: A 1D CMUT Phased Array System for Chronic Implantation in Small Animals. IEEE TRANSACTIONS ON BIOMEDICAL CIRCUITS AND SYSTEMS 2021; 15:692-704. [PMID: 34314360 PMCID: PMC9579984 DOI: 10.1109/tbcas.2021.3100458] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
In this work, we present a wireless ultrasonic neurostimulator, aiming at a truly wearable device for brain stimulation in small behaving animals. A 1D 5-MHz capacitive micromachined ultrasonic transducer (CMUT) array is adopted to implement a head-mounted stimulation device. A companion ASIC with integrated 16-channel high-voltage (60-V) pulsers was designed to drive the 16-element CMUT array. The ASIC can generate excitation signals with element-wise programmable phases and amplitudes: 1) programmable sixteen phase delays enable electrical beam focusing and steering, and 2) four scalable amplitude levels, implemented with a symmetric pulse-width-modulation technique, are sufficient to suppress unwanted sidelobes (apodization). The ASIC was fabricated in the TSMC 0.18- μm HV BCD process within a die size of 2.5 × 2.5 mm2. To realize a completely wearable system, the system is partitioned into two parts for weight distribution: 1) a head unit (17 mg) with the CMUT array, 2) a backpack unit (19.7 g) that includes electronics such as the ASIC, a power management unit, a wireless module, and a battery. Hydrophone-based acoustic measurements were performed to demonstrate the focusing and beam steering capability of the proposed system. Also, we achieved a peak-to-peak pressure of 2.1 MPa, which corresponds to a spatial peak pulse average intensity ( ISPPA) of 33.5 W/cm2, with a lateral full width at half maximum (FWHM) of 0.6 mm at a depth of 3.5 mm.
Collapse
|
2
|
Lee S, Jeon H, Shim S, Im M, Kim J, Kim JH, Lee BC. Preclinical study to improve microbubble-mediated drug delivery in cancer using an ultrasonic probe with an interchangeable acoustic lens. Sci Rep 2021; 11:12654. [PMID: 34135427 PMCID: PMC8209130 DOI: 10.1038/s41598-021-92097-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2021] [Accepted: 06/04/2021] [Indexed: 11/21/2022] Open
Abstract
Focused ultrasound with microbubbles (FUS-MBs) has shown that it can lead to an efficient drug delivery system (DDS) involving the oscillation and destruction of the MB but is limited in drug delivery due to its narrow pressure field. However, unfocused ultrasound with MBs (UUS-MBs) and an interchangeable acoustic lens can tune and enhance the pressure field for MB destruction to overcome the disadvantages of FUS-MB DDSs. We designed a lens suitable for an ultrasound-phased array probe and studied the optimal treatment conditions for MB destruction in vitro through an optical imaging setup. The DDS effects were evaluated in a rat hepatoma model using doxorubicin (DOX) treatment. A concave lens with a radius of curvature of 2.6 mm and a thickness of 4 mm was selected and fabricated. UUS-MBs with the acoustic lens at 60 Vpp for 32 cycles and a PRF of 1 kHz could induce MB destruction, promoting the DDS even under fluidic conditions. In the animal experiment, the UUS-MBs in the acoustic lens treatment group had a higher concentration of DOX in the tumor than the control group. Our system suggests uses an acoustic lens to increase DDS effectiveness by providing sufficient ultrasound irradiation to the MBs.
Collapse
Affiliation(s)
- Seunghyun Lee
- Department of Radiology, Seoul National University Hospital, 101 Daehak-ro, Jongno-gu, Seoul, 03080, Republic of Korea.,Department of Radiology, Seoul National University College of Medicine, Seoul, 03080, Republic of Korea.,Institute of Radiation Medicine, Seoul National University Medical Research Center, 103 Daehak-ro, Jongno-gu, Seoul, 03080, Republic of Korea
| | - Hoyoon Jeon
- Brain Science Institute, Korea Institute of Science and Technology (KIST), Seoul, 02792, Republic of Korea.,Department of Medical Biotechnology, Dongguk University, Seoul, 04620, Republic of Korea
| | - Shinyong Shim
- Brain Science Institute, Korea Institute of Science and Technology (KIST), Seoul, 02792, Republic of Korea
| | - Maesoon Im
- Brain Science Institute, Korea Institute of Science and Technology (KIST), Seoul, 02792, Republic of Korea
| | - Jinsik Kim
- Department of Medical Biotechnology, Dongguk University, Seoul, 04620, Republic of Korea
| | - Jung Hoon Kim
- Department of Radiology, Seoul National University Hospital, 101 Daehak-ro, Jongno-gu, Seoul, 03080, Republic of Korea. .,Department of Radiology, Seoul National University College of Medicine, Seoul, 03080, Republic of Korea. .,Institute of Radiation Medicine, Seoul National University Medical Research Center, 103 Daehak-ro, Jongno-gu, Seoul, 03080, Republic of Korea.
| | - Byung Chul Lee
- Brain Science Institute, Korea Institute of Science and Technology (KIST), Seoul, 02792, Republic of Korea.
| |
Collapse
|
3
|
Cummins G, Cox BF, Ciuti G, Anbarasan T, Desmulliez MPY, Cochran S, Steele R, Plevris JN, Koulaouzidis A. Gastrointestinal diagnosis using non-white light imaging capsule endoscopy. Nat Rev Gastroenterol Hepatol 2019; 16:429-447. [PMID: 30988520 DOI: 10.1038/s41575-019-0140-z] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Capsule endoscopy (CE) has proved to be a powerful tool in the diagnosis and management of small bowel disorders since its introduction in 2001. However, white light imaging (WLI) is the principal technology used in clinical CE at present, and therefore, CE is limited to mucosal inspection, with diagnosis remaining reliant on visible manifestations of disease. The introduction of WLI CE has motivated a wide range of research to improve its diagnostic capabilities through integration with other sensing modalities. These developments have the potential to overcome the limitations of WLI through enhanced detection of subtle mucosal microlesions and submucosal and/or transmural pathology, providing novel diagnostic avenues. Other research aims to utilize a range of sensors to measure physiological parameters or to discover new biomarkers to improve the sensitivity, specificity and thus the clinical utility of CE. This multidisciplinary Review summarizes research into non-WLI CE devices by organizing them into a taxonomic structure on the basis of their sensing modality. The potential of these capsules to realize clinically useful virtual biopsy and computer-aided diagnosis (CADx) is also reported.
Collapse
Affiliation(s)
- Gerard Cummins
- School of Engineering and Physical Sciences, Heriot-Watt University, Edinburgh, UK.
| | | | - Gastone Ciuti
- The BioRobotics Institute, Scuola Superiore Sant'Anna, Pisa, Italy
| | | | - Marc P Y Desmulliez
- School of Engineering and Physical Sciences, Heriot-Watt University, Edinburgh, UK
| | - Sandy Cochran
- School of Engineering, University of Glasgow, Glasgow, UK
| | - Robert Steele
- School of Medicine, University of Dundee, Dundee, UK
| | - John N Plevris
- Centre for Liver and Digestive Disorders, The Royal Infirmary of Edinburgh, Edinburgh, UK
| | | |
Collapse
|
4
|
Zhang J, Pun SH, Yu Y, Gao D, Wang J, Mak PU, Lei KF, Cheng CH, Yuan Z. Development of a multi-band photoacoustic tomography imaging system based on a capacitive micromachined ultrasonic transducer array. APPLIED OPTICS 2017; 56:4012-4018. [PMID: 29047533 DOI: 10.1364/ao.56.004012] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Photoacoustic tomography (PAT) as a hybrid technology combines the high optical contrast and high acoustic resolution in a single imaging modality. However, most of the available PAT systems cannot comprehensively or accurately characterize biological systems at multiple length scales due to the use of narrow bandwidth commercial ultrasonic transducers. In this study, we fabricated a novel multi-band capacitive micromachined ultrasonic transducer (CMUT) array, and first developed a CMUT-based multi-band photoacoustic tomography (MBPAT) imaging system. The MBPAT imaging system was examined by the phantom experiment, and then was successfully applied to image the zebrafish in vivo. The imaging results indicated that CMUT-array-based MBPAT can provide a more comprehensive and accurate characterization of biological tissues, which exhibit the potential of MBPAT/CMUT in various areas of biomedical imaging.
Collapse
|
5
|
Underwater Imaging Using a 1 × 16 CMUT Linear Array. SENSORS 2016; 16:312. [PMID: 26938536 PMCID: PMC4813887 DOI: 10.3390/s16030312] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/25/2016] [Revised: 02/20/2016] [Accepted: 02/25/2016] [Indexed: 11/16/2022]
Abstract
A 1 × 16 capacitive micro-machined ultrasonic transducer linear array was designed, fabricated, and tested for underwater imaging in the low frequency range. The linear array was fabricated using Si-SOI bonding techniques. Underwater transmission performance was tested in a water tank, and the array has a resonant frequency of 700 kHz, with pressure amplitude 182 dB (μPa·m/V) at 1 m. The -3 dB main beam width of the designed dense linear array is approximately 5 degrees. Synthetic aperture focusing technique was applied to improve the resolution of reconstructed images, with promising results. Thus, the proposed array was shown to be suitable for underwater imaging applications.
Collapse
|