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Broadband Diffuse Optical Spectroscopy and Imaging (DOSI)

DOSI uses a model-based approach for quantitative subsurface tissue spectroscopy and imaging based on swept multi-frequency frequency-domain photon migration (FDPM). We have several different DOSI systems that are designed for clinical-use and laboratory research. All of these systems separate the effects of absorption and scattering at the discrete FDPM wavelengths. Most of these systems employ an integrated broadband steady-state spectrometer system to recover the absorption and scattering spectra of thick tissues from 600 to 1000 nm. Within the 600-1000 nm spectral range, the DOSI separates optical absorption from scattering in thick tissues and provides the concentrations of oxygenated (ctO2Hb) and reduced hemoglobins (ctHHb), water (ctH2O), and lipids. Other hemoglobin states, such as met-hemoglobin, can also be measured in tissues, as well as alterations in lipid and water biochemistry and cytochrome oxygenation state. Different tissue structures can be targeted such as deep tissue structures (brain, breast tumors) and superficial structures (skin) through the use of interchangeable handheld probes.

Clinical Broadband DOSI (5 systems)

The Laser Breast Scanner (LBS) is a bedside-capable clinical instrument with a handheld probe that can be moved easily to any location on the breast (or other tissues as well). There are currently 5 LBS systems in clinical use at The University of Pennsylvania, Massachusetts General Hospital (MGH), Dartmouth, UCSF and UCI.

System Specifications:
  • Network Analyzer-based system allowing modulation frequencies up to 3GHz (50-500MHz is commonly used in breast studies)
  • 6 discrete FDPM wavelengths - 660, 690, 780, 810, 830, and 850 nm
  • Broadband source and spectrometer with wavelength range of 650-1000 nm
  • Software designed for clinical data collection
  • TEC controlled lasers and avalanche photodiode detector (APD) module

Research Broadband DOSI (2 systems)

We have 2 LBS systems with similar specifications to the clinical systems that are used solely for research and technology development. One of these systems is has a 1 x8 fiber optic switch for multiplexing applications. The other is dedicated for animal models.

System Specifications:
  • Network Analyzer-based system allowing modulation frequencies up to 3GHz (50-500MHz is commonly used in breast studies)
  • 6 discrete FDPM wavelengths - 660, 690, 780, 810, 830, and 850 nm
  • Broadband source and spectrometer with wavelength range of 650-1000 nm
  • Software designed for clinical data collection
  • TEC controlled lasers and avalanche photodiode detector (APD) module

Miniature Broadband DOSI (2 systems)

These systems are portable embodiments of the clinical/research LBS instruments. The enabling feature is a board-level FDPM unit that replaces the network analyzer.

System Specifications:
  • Board-based system allowing modulation frequencies up to 1GHz (50-300MHz is commonly used in breast studies)
  • 4 discrete FDPM wavelengths - 660, 690, 785 and 830 nm
  • Broadband source and spectrometer with wavelength range of 590-1100 nm
  • FDPM detector with 3mm active area, fiber coupled and direct contact
  • Real-time continuous acquisition (~ 3-5s, full broadband)

Miniature Broadband Multichannel DOSI (1 system)

This system is an integration of 2 miniature broadband DOSI systems, allowing up to 4 broadband views of tissues in 15s. These views allow for tomographic/layered reconstructions of tissue optical properties.

System Specifications:
  • Board-based system allowing modulation frequencies up to 1GHz (50-300MHz is commonly used in breast studies)
  • 4 discrete FDPM wavelengths - 660, 690, 785 and 830 nm
  • Broadband source and spectrometer with wavelength range of 590-1100 nm
  • FDPM detector with 3mm active area, fiber coupled and direct contact
  • Serial acquisition of 4 independent views, each one fully broadband.

Miniature FDPM-only Systems (7 systems)

Board-level engine that drives the miniature DOSI instruments. This unit is available as a stand-alone system or can be integrated with a spectrometer to achieve broadband spectral coverage.

System Specifications:
  • Size : 125mm(width) * 165mm(length) * 55mm(height)
  • Frequency modulation up to 1GHz
  • 4 discrete FDPM wavelengths - 660, 690, 785 and 830 nm
  • Built-in 3mm APD detector for only fiber coupling measurement
  • Fast measurement with two lasers (300ms per measurement)

Supercontinuum-Based DOSI System (1 system)

A Fianium SC-450 laser is the engine for a full broadband system.

System Specifications:
  • 450-1700nm coverage (2W over entire band) through a single optical fiber
  • 6ps master pulse, ~ 3GHz bandwidth
  • Spectrometer detectors (400-1100 nm)
  • PMT detector (400-850 nm)
  • APD detector (600-1000 nm)

Probes

We have a variety of handheld optical probes that can be used on any of the above systems. These include:
  1. Handheld breast probe with TEC controlled and 1mm APD detector on the probe (in contact with patient skin)
  2. Low profile bent fiber probe customized to measure muscle tissue
  3. Prototype handheld ergonomic breast probe with 3mm APD
  4. Multi-channel probe with two FD and broadband sources and two FD and broadband detectors, providing four views at each measurement point. All sources, as well as broadband detectors and one
  5. FD detector are fiber coupled, but the second FD detector is in direct contact with patient's skin. FD detectors are APDs with 3mm active area
  6. Laboratory fiber probe with motorized source-detector adjustment in steps of 1mm
  7. Superficial tissue sample probe (~ 1-2 mm)

[Return to list of shared instrumentation]

Research

Contact Us

  • Hanna Kim
    Resource Coordinator
    Phone:949.824.2251
    Email: hhkim3@uci.edu

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P41EB015890