A time domain mean frequency estimation algorithm of two-dimensional real-time Doppler imaging system

1995 ◽  
Vol 19 (5) ◽  
pp. 405-411
Author(s):  
Nihal F. Güler
Keyword(s):  
Real Time ◽  
Time Domain ◽  
Imaging System ◽  
Frequency Estimation ◽  
Estimation Algorithm ◽  
Doppler Imaging ◽  
Two Dimensional ◽  
Mean Frequency

Real time Doppler imaging system using forced vibration of the object

1977 ◽  
Vol 16 (5) ◽  
pp. 1263 ◽  
Author(s):  
Takuso Sato ◽  
Yutaka Nakatani ◽  
Mitsuhiro Ueda
Keyword(s):  
Real Time ◽  
Forced Vibration ◽  
Imaging System ◽  
Doppler Imaging

Progress in Two-Dimensional Arrays for Real-Time Volumetric Imaging

1998 ◽  
Vol 20 (1) ◽  
pp. 1-15 ◽  
Author(s):  
E. D. Light ◽  
R. E. Davidsen ◽  
J.O. Fiering ◽  
T. A. Hruschka ◽  
S. W. Smith
Keyword(s):  
Real Time ◽  
Insertion Loss ◽  
Imaging System ◽  
Two Dimensional ◽  
Volumetric Imaging ◽  
Dimensional Array ◽  
Transducer Arrays ◽  
Volumetric Images ◽  
Duke University

The design, fabrication, and evaluation of two dimensional array transducers for real-time volumetric imaging are described. The transducers we have previously described operated at frequencies below 3 MHz and were unwieldy to the operator because of the interconnect schemes used in connecting to the transducer handle. Several new transducers have been developed using new connection technology. A 40 × 40 = 1,600 element, 3.5 MHz array was fabricated with 256 transmit and 256 receive elements. A 60 × 60 = 3,600 element 5.0 MHz array was constructed with 248 transmit and 256 receive elements. An 80 × 80 = 6,400 element, 2.5 MHz array was fabricated with 256 transmit and 208 receive elements. 2-D transducer arrays were also developed for volumetric scanning in an intracardiac catheter, a 10 × 10 = 100 element 5.0 MHz forward-looking array and an 11 × 13 = 143 element 5.0 MHz side-scanning array. The −6 dB fractional bandwidths for the different arrays varied from 50% to 63%, and the 50 Ω insertion loss for all the transducers was about −64 dB. The transducers were used to generate real-time volumetric images in phantoms and in vivo using the Duke University real time volumetric imaging system, which is capable of generating multiple planes at any desired angle and depth within the pyramidal volume.

Clinical applications of a new type of real-time two-dimensional doppler flow imaging system

1984 ◽  
Vol 54 (7) ◽  
pp. 857-868 ◽  
Author(s):  
Kunio Miyatake ◽  
Mitsunori Okamoto ◽  
Naokazu Kinoshita ◽  
Shiro Izumi ◽  
Mafumi Owa ◽  
...  
Keyword(s):  
Real Time ◽  
Imaging System ◽  
Clinical Applications ◽  
Flow Imaging ◽  
Two Dimensional ◽  
Doppler Flow ◽  
New Type

Development of Adaptive Feed-Forward Cancellation With Frequency Estimation Algorithm for Compensation of Periodic Disturbance at Arbitrary Frequency

2019 ◽  
Vol 141 (12) ◽  
Author(s):  
Shota Yabui ◽  
Tsuyoshi Inoue
Keyword(s):  
Real Time ◽  
Frequency Estimation ◽  
Estimation Algorithm ◽  
Open Loop ◽  
Fixed Frequency ◽  
Nyquist Diagram ◽  
Feed Forward ◽  
Periodic Disturbance ◽  
Arbitrary Frequency ◽  
The Stability

Abstract In this study, an adaptive feed-forward cancellation (AFC) with frequency estimation algorithm has been developed to compensate for periodic disturbance at an arbitrary frequency. Conventional AFC was developed to compensate for periodic disturbance at a fixed frequency and cannot compensate for the disturbance in which the frequency varies in real-time. The proposed method can estimate the frequency of the disturbance in real-time by using the input and output signals of the AFC. It can compensate for the periodic disturbance at an arbitrary frequency. In addition, the stability of the feedback control system with the proposed AFC can be optimized at any frequency based on the vector locus of the open-loop characteristic on the Nyquist diagram. The effectiveness of the proposed AFC was confirmed in experiments compensating for whirling vibration, whose frequency varies in real-time in rotating machinery. The proposed AFC can estimate the frequency of the disturbance automatically and compensate for this adequately.

Real-time measurements of spatial velocity distribution with a laser Doppler imaging system

1983 ◽  
Vol 22 (16) ◽  
pp. 2448 ◽  
Author(s):  
Takeaki Yoshimura ◽  
Hirohiko Sakashita ◽  
Nobuo Wakabayashi
Keyword(s):  
Velocity Distribution ◽  
Real Time ◽  
Imaging System ◽  
Laser Doppler ◽  
Doppler Imaging ◽  
Laser Doppler Imaging ◽  
Spatial Velocity

scholarly journals Real-Time Analysis of Oxygen Gradient in Oocyte Respiration Using a High-Density Microelectrode Array

Biosensors ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 256
Author(s):  
William Tedjo ◽  
Yusra Obeidat ◽  
Giovana Catandi ◽  
Elaine Carnevale ◽  
Tomas Chen
Keyword(s):  
Real Time ◽  
Oxygen Concentration ◽  
Microelectrode Array ◽  
Temporal Dynamics ◽  
Imaging System ◽  
High Density ◽  
Oxide Semiconductor ◽  
Two Dimensional ◽  
Imaging Results

Physiological events related to oxygen concentration gradients provide valuable information to determine the state of metabolizing biological cells. The existing oxygen sensing methods (i.e., optical photoluminescence, magnetic resonance, and scanning electrochemical) are well-established and optimized for existing in vitro analyses. However, such methods also present various limitations in resolution, real-time sensing performance, complexity, and costs. An electrochemical imaging system with an integrated microelectrode array (MEA) would offer attractive means of measuring oxygen consumption rate (OCR) based on the cell’s two-dimensional (2D) oxygen concentration gradient. This paper presents an application of an electrochemical sensor platform with a custom-designed complementary-metal-oxide-semiconductor (CMOS)-based microchip and its Pt-coated surface MEA. The high-density MEA provides 16,064 individual electrochemical pixels that cover a 3.6 mm × 3.6 mm area. Utilizing the three-electrode configuration, the system is capable of imaging low oxygen concentration (18.3 µM, 0.58 mg/L, or 13.8 mmHg) at 27.5 µm spatial resolution and up to 4 Hz temporal resolution. In vitro oxygen imaging experiments were performed to analyze bovine cumulus-oocytes-complexes cells OCR and oxygen flux density. The integration of a microfluidic system allows proper bio-sample handling and delivery to the MEA surface for imaging. Finally, the imaging results are processed and presented as two-dimensional (2D) heatmaps, representing the dissolved oxygen concentration in the immediate proximity of the MEA. This paper provides the results of real-time 2D imaging of OCR of live cells/tissues to gain spatial and temporal dynamics of target cell metabolism.

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