PeriCam PSI System is a blood perfusion imager based on the laser speckle contrast analysis (LASCA) technology [link: Microcirculation – Theory and technologies – Laser Speckle Contrast Analysis], also known as laser speckle contrast imaging (LSCI). It is a method that visualizes tissue blood perfusion in real time. LASCA provides new means to study the microcirculation in ways that were not possible in the past. PeriCam PSI System combines dynamic response and high spatial resolution in one instrument, providing both real-time graphs and video recordings of the tissue being studied. To further enhance its usability, dedicated application software, PIMSoft, has been developed.
PeriCam PSI System is available in two versions:
- PeriCam PSI NR (Normal Resolution)
- PeriCam PSI HR (High Resolution)
Easy to get started, flexible to use
PeriCam PSI is easy to set up, get started and operate. It is flexible to adjust and position at any measurement angle. A color camera for documentation, an indicator laser and automated working distance calculation enhances simplicity.
Regions of interest (ROIs) can be defined and updated before, during and after the recording, which enables real-time data analysis while recording and instant updates of data, graphs and images.
Automated background compensation, even while recording, allows for stable and accurate measurements under varying lighting conditions.
PeriCam PSI System uses an invisible near infra-red (NIR) laser (785 nm) for blood perfusion measurements. The beam is spread over the measurement area by a diffuser, creating a speckle pattern. The size of the illuminated area depends on the distance between the laser aperture in the head and the measurement object.
The speckle pattern in the illuminated area is monitored using a 1388 x 1038-pixel CCD camera that can take images at a speed of up to 100 frames per second. Blood perfusion is calculated by analyzing the variations in the speckle pattern. For more information about the measurement technique, see the page about LASCA.
To facilitate the positioning of the imager relative to the subject, a visible red laser (650 nm) is used to indicate the maximum measurement area at a certain measurement distance. To avoid interference with measurements the indicator laser is switched off during recording. Both the measurement laser and the indicator laser are safe to use without eye protection.
A separate color camera is used for documentation. The capture rate can be set at different speeds during a recording, up to one photo per second. The color photos provide an extra help when analyzing the perfusion data, assuring that the subject has not moved during the recording and for understanding the obtained blood perfusion images.
Dedicated software: all-in-one data analysis
The instrument comes with a dedicated software package, PIMSoft. A complete, all-in-one solution for setup, acquisition, analysis and reporting.
Blood perfusion is presented both as color-coded images and in graphic form, enhancing the possibilities for understanding and analyzing the microcirculatory data. Specific ROIs can be defined before, during or after recording. In addition, ROIs may be implemented during sections of a run. Time periods of interest (TOIs) allow for evaluation of blood perfusion during specific time periods. Event markers with comments may be added at any time.
Automatically calculated values include mean, percentage change, number of measurement points, standard deviation and more. Selected data is conveniently exported as PDF reports or in XML format for further processing.
PeriCam PSI Normal Resolution
PeriCam PSI NR is the instrument of choice for most applications. A flexible working distance of between 10 to 40 cm allows measurement areas of up to 24 x 24 cm. Tissue blood perfusion is visualized in real time with a resolution of up to 100 µm/pixel.
PeriCam PSI NR is a valuable and objective tool for assessment of skin microvascular function for clinical diagnosis. One of the common applications in the clinic is burn depth estimation. The imager can be mounted on a cart fitted with a flexible arm that makes it easy to position and reach a patient lying on a bed.
Common applications include the study of endothelial function by combining imaging with iontophoresis or post-occlusive reactive hyperemia PORH, scleroderma and Raynaud’s phenomenon as well as the study/assessment of burns and other wounds. The instrument can also be very useful for pharmaceutical research, dermatology and even perfusion measurements in the mouth.
PeriCam PSI High Resolution
PeriCam PSI HR is used in animal research applications where high resolution in a small measurement area is desired. High magnification optics visualize details of 20 µm/pixel in areas up to 20 x 27 mm.
Note that the fact that it has a higher resolution does not necessarily mean it is better for your application. Compare with a normal camera or a microscope. Just because the microscope has the highest resolution, does not mean it is a good tool for your landscape photography, or even suitable at all for this application.
The imager is mounted on a microscope stand for precise positional adjustment at a fixed working distance of 10 cm.
PeriCam PSI HR is an excellent tool for imaging of the cerebral blood flow (CBF) in mice and rats, e.g., for stroke models (MCAO) and cortical spreading depolarization (CSD). Other common applications are angiogenesis models such as the hindlimb ischemia (HLI) model.