Related Experiment Video
Updated: Jan 30, 2026
14:21
Optical Frequency Domain Imaging of Ex vivo Pulmonary Resection Specimens: Obtaining One to One Image to Histopathology Correlation
Published on: January 22, 2013
14.6K
Next-generation frequency domain diffuse optical imaging systems using silicon photomultipliers.
Optics Letters
|February 1, 2019
Summary
This study introduces a new silicon photomultiplier (SiPM) detector for frequency domain diffuse optical spectroscopy (FD-DOS). The SiPM enhances signal-to-noise ratio, enabling deeper tissue imaging for applications like optical mammography.
Area of Science:
- Biomedical Optics
- Photonics
- Medical Imaging
Background:
- Diffuse optical imaging measures functional tissue properties using intrinsic contrast.
- Frequency domain diffuse optical spectroscopy (FD-DOS) is used in mammography and brain imaging.
- Photodetector sensitivity limits FD-DOS depth and dynamic range.
Purpose of the Study:
- To present FD-DOS utilizing a silicon photomultiplier (SiPM) detector.
- To demonstrate improved signal-to-noise ratio (SNR) and depth penetration compared to avalanche photodiodes (APDs).
Main Methods:
- Implemented FD-DOS with a SiPM detector.
- Compared SiPM performance to APDs in terms of SNR and light detection sensitivity.
- Validated optical property recovery in tissue-simulating phantoms.
Main Results:
- SiPM offered 10-30 dB greater SNR than APDs.
- SiPM detected 1.5-2 orders of magnitude lower light levels.
- SiPM enabled accurate optical property recovery at extended source-detector separations (up to 48 mm).
Conclusions:
- SiPM-based FD-DOS enhances SNR and depth penetration.
- This technology improves capabilities for diffuse optical spectroscopy in biomedical applications.
- SiPMs represent a significant advancement for diffuse optical imaging.
Related Concept Videos
01:26Linear Approximation in Frequency Domain
375
Linear systems are characterized by two main properties: superposition and homogeneity. Superposition allows the response to multiple inputs to be the sum of the responses to each individual input. Homogeneity ensures that scaling an input by a scalar results in the response being scaled by the same scalar.
In contrast, nonlinear systems do not inherently possess these properties. However, for small deviations around an operating point, a nonlinear system can often be approximated as linear....
In contrast, nonlinear systems do not inherently possess these properties. However, for small deviations around an operating point, a nonlinear system can often be approximated as linear....
375
01:24Frequency-Domain Interpretation of PD Control
367
Proportional-Derivative (PD) controllers are widely used in fan control systems to improve stability and performance. A fan control system can be effectively represented using a Bode plot to illustrate the impact of a PD controller through its transfer function. The Bode plot visually conveys how PD control modifies the fan's response across various frequencies, providing a frequency domain interpretation of the controller's behavior.
The proportional control gain, combined with the...
The proportional control gain, combined with the...
367
01:27Time and frequency -Domain Interpretation of PI Control
411
Proportional-Integral (PI) controllers are essential in many control systems to improve stability and performance. They are commonly used in everyday devices like thermostats to enhance system damping and reduce steady-state error. When the zero in the controller's transfer function is optimally placed, the system benefits significantly in terms of stability and accuracy.
Acting as a low-pass filter, the PI controller slows the system's response and extends settling times. This requires...
Acting as a low-pass filter, the PI controller slows the system's response and extends settling times. This requires...
411
01:24Time and frequency -Domain Interpretation of Phase-lead Control
451
Phase-lead controllers are commonly used in various control systems to enhance response speed and stability. Adjusting the brightness on a television screen offers a practical example of phase-lead control. When contrast is enhanced, a phase-lead controller is employed. Mathematically, phase-lead control is identified when the first parameter is smaller than the second.
The design of phase-lead control involves the strategic placement of poles and zeros to balance steady-state error and system...
The design of phase-lead control involves the strategic placement of poles and zeros to balance steady-state error and system...
451
01:21Time and frequency -Domain Interpretation of Phase-lag Control
415
Phase-lag controllers are widely used in control systems to improve stability and reduce steady-state errors. A dimmer switch controlling the brightness of a light bulb serves as a practical example of phase-lag control, gradually adjusting the bulb's brightness. Mathematically, phase-lag control or low-pass filtering is represented when the factor 'a' is less than 1.
Phase-lag controllers do not place a pole at zero, but instead influence the steady-state error by amplifying any...
Phase-lag controllers do not place a pole at zero, but instead influence the steady-state error by amplifying any...
415
01:12Diffusion
218.0K
Diffusion is the passive movement of substances down their concentration gradients—requiring no expenditure of cellular energy. Substances, such as molecules or ions, diffuse from an area of high concentration to an area of low concentration in the cytosol or across membranes. Eventually, the concentration will even out, with the substance moving randomly but causing no net change in concentration. Such a state is called dynamic equilibrium, which is essential for maintaining overall...
218.0K