OxyFlo™

Third generation, single-channel laser-Doppler tissue blood flow monitor

Brochure PDF Sensors and Probes
 
OxyFlo™ Pro

Third-generation, two- or four-channel laser-Doppler tissue blood flow monitor with integrated touch-screen display

Brochure PDF Sensors and Probes
 

Perfusion by blood provides tissues with vital oxygen and nutrients, while removing waste products and distributing effector and signaling molecules around the organism. The measurement of microvascular blood perfusion provides researchers with critical information in a number of research applications where blood supply has been disrupted.

Oxford Optronix Ltd. remains a pioneer in the development of laser-Doppler based blood flow monitoring (LDPM) technology and continues to set unrivalled standards of reliability, robustness and sensitivity.

Applications include blood flow monitoring in peripheral vascular disorders; cerebral perfusion monitoring in models of stroke and brain injury; tumour perfusion monitoring / angiogenesis; blood flow in free flaps and pedicle flaps; wound healing; gastroenterology and more.

Please note: The OxyFlo™ and OxyFlo™ Pro monitors are intended purely for laboratory, industrial and research use and are NOT medical devices. The OxyFlo™ and OxyFlo™ Pro monitors do NOT possess regulatory approvals for use with human subjects or patients.  

Continuous tissue blood flow assessment
Our new-generation high performance laser Doppler blood flow monitors provide uncompromised reliability in continuous tissue blood flow assessment and are ideal suited to measurements of changing tissue blood flow in acute experimental models.

Versatility
A range of probe types and probe formats provide support for a host of specialist disciplines and applications requiring both invasive or non-invasive tissue blood flow assessment.

ART
OxyFlo™ monitors incorporate our proprietary artefact rejection technology, effectively filtering out the presence of motion artefacts in the blood flow signal. Substantially reduces and in most cases, completely eliminates motion artefacts or ‘spikes’ in the blood flow data arising from sensor cable movement and/or regular tissue movement (e.g. due to breathing).

Plug and play
OxyFlo™ probes require no calibration procedures or configuration following one-time probe calibration. Probes supplied at the time of monitor shipment are supplied factor pre-calibrated.

Touch-screen display and interface
OxyFlo™ Pro models feature a touch-sensitive, high-contrast, 140º viewing-angle screen, which displays real-time data in both digital and graphical (trace) formats, and provides access to instrument/user settings.

Multi-channel productivity
The OxyFlo™ Pro is available in dual or 4-channel models to suit all needs including the simultaneous monitoring of blood flow from multiple tissue sites (e.g. comparison of pathological versus control tissue sites).

Upgradeable
The OxyFlo™ Pro dual-channel model can be factory upgraded to a 4-channel device.

Multi-parameter monitoring
Our OxyFlo™ blood flow monitors are designed specifically to be used in tandem with our OxyLite™ range of oxygen monitors – providing support for simultaneous measurements of tissue oxygenation, blood flow and temperature from each combined sensor.

Analogue data outputs
Continuous data recording to PC or Mac platforms is supported via standard analogue data outputs offering compatibility with third party data recording solutions.

2-year product warranty
Our monitors are now provided with a full 2-year manufacturer’s warranty, covering defects in material or in workmanship. An optional extended warranty package, providing a total of 5 years of ‘peace of mind’ cover, including two annual maintenance services is available at the time of purchase.

OxyFlo

A model of Middle Cerebral Artery Occlusion in rat.

A dedicated needle blood flow probe, immobilized over a pre-determined region of the skull via a stereotactic apparatus was used to non-invasively measure cerebral cortex blood flow in response to temporary MCA occlusion.

“We have used OxyFlo probes for animal tumour studies and found them a great addition to the range of techniques that we use for studying the tumour microenvironment. The Oxford Optronix team is always extremely helpful, providing knowledgeable and thoughtful advice on every occasion. We will certainly carry on using them..“
Dr Gillian Tozer
School of Medicine and Biomedical Sciences, Sheffield, UK

 

Publications citing our laser Doppler blood flow monitors:

Citations List PDF

 

 

 

 

OxyFlo™  and OxyFlo™ Pro Technical Specifications

 GENERAL

 

 Dimensions

OxyFlo:            95mm (H) x 290mm (W) x 260mm (D)
OxyFlo Pro:      150mm (H) x 310mm (W) x 280mm (D)

 Weight 

OxyLite:            2kg / 4.5lbs
OxyLite Pro:      4kg / 9lbs

 Operating temperature

10 - 30°C

 Operating humidity

0 – 70% (non-condensing)

 Power requirements

OxyFlo:            VAC 100-240V, 50-60Hz, 30W max.
OxyFlo Pro:      40W max.

 Fuse rating

OxyFlo:            2 x T1.6A
OxyFlo Pro:      Not applicable (external PSU)

 Number of sensors supported /
 Number of channels 

OxyFlo:            1
OxyFlo Pro:      2 or 4

 Display

OxyFlo:            32 character alphanumeric VFD
OxyFlo Pro:      High contrast 800 x 480 LCD touch-screen

 Instrument configuration

OxyFlo:            Via function button at rear
OxyFlo Pro:      Via touch-screen display

 Analogue voltage outputs

OxyFlo:            2 x male BNC connectors, 2 outputs
OxyFlo Pro:      2 x 15-pin D-type, 4 or 8 (Pro XL) outputs 

 Laser type

Temperature-stabilized semi-conductor laser diode

 Laser wavelength

830 ±10nm

 Laser classification

Class 1 (EN 60825-1:1994, 21 CFR 1040.10 and 1040.11)

 Laser power

 <0.5mW from probe tip

   

 PERFORMANCE

 

 Mode of operation

Laser Doppler flowmetry

 Measurement units (displayed)

0 – 9999 BPU (blood perfusion units)

 Stability of reading

± 5%

 Sampling rate

200Hz

 Measurement averaging

200ms (Flow); 5ms (Raw); 5s (ART); 200ms (Backscatter), rolling

 Display update interval (numerical)

2s (5s rolling averaged)

 Probe identification

Automatic; monitor stores one-time calibration

 Probe calibration

Factory or user-calibrated using Oxford Optronix motility standard

 Probe shelf-life

Unlimited

 Zeroing

Automatic, controlled

 Default analogue data output range

0 - 5V (= 0 - 5000 BPU or 0 - 100% Backscatter) 

 Analogue data output rate

65Hz

 

What physiological parameters does OxyFlo™ measure?
Our range of laser Doppler blood flow monitors are intended for the investigation of blood flow (also knows as blood perfusion or microvascular blood flow) in the microcirculation. The laser Doppler technique is well-established as the most convenient method for assessing tissue blood flow non-invasively and continuously. The technique allows continuous assessment of flow at one or more tissue sites via fibre-optic probes in contact with the tissue. The measurement of microvascular blood flow provides researchers with critical information in a number of research applications where blood supply has been disrupted (ischaemia). The technique is not intended for the measurement of blood flow rates in isolated blood vessels.

What makes the OxyFlo™ unique?
While substantially equivalent to other laser Doppler monitors on the market, our OxyFlo™ monitors offer a number of distinguishing key features. Most notable of these is their ability to operate in conjunction with our counterpart oxygen monitors for combined tissue oxygen, blood perfusion and temperature monitoring from a single sensor and therefore the same tissue micro-region. Furthermore, our multi-channel OxyFlo™ Pro models offer an industry-first touch-screen display and user interface as well as an advanced, intelligent signal noise suppression output (ART™).

What are the typical applications for your instruments?
Our instruments have proved popular in applications covering such disciplines as peripheral vascular disease, cerebral perfusion monitoring in models of stroke and brain injury, tumour perfusion monitoring / angiogenesis, blood flow in free flaps and pedicle flaps, wound healing, gastroenterology and more.

How do your blood perfusion instruments work?
Our blood perfusion monitors utilise the well-established method of laser-Doppler Flowmetry (LDF) to provide a continuous measure of tissue blood blow. LDF works by illuminating a small region of tissue under observation with low power laser light from a sensor containing optical fibre light guides. Laser light from one fibre is directed towards the tissue and is scattered within the tissue. Some of the scattered laser light is incident upon moving red blood cells within the tissue and this light becomes Doppler-frequency shifted as a result. A second optical fibre collects this backscattered, Doppler-shifted light from the tissue and returns it to the detector within the monitor. The photo-detected signal comprises a broad spectrum of Doppler frequency shifted signals generated as a result of the movement of red blood cells within the tissue. Microvascular blood flow is electronically calculated as the product of mean red blood cell velocity and mean red blood cell concentration in the volume of tissue under illumination from the sensor.

What are your blood flow probes made of and how large are they?
All our blood flow probes are constructed internally from glass or specialist plastic optical fibre light guides, terminating in needle, surface or other, specialist conformations designed to support the measurement of blood flow from almost any tissue. Probes are typically supplied in 3 m lengths and composed of specialist surgical steel, medical grade plastic and silicone materials. See here for a full list of available blood flow probe types.

Do your blood flow monitors support the use of multiple probes at the same time?
Yes, the OxyFlo™ Pro is a two-channel monitor, while the OxyFlo™ Pro XL is a four-channel monitor capable of simultaneously driving and reading from up to 4 blood flow probes simultaneously. This allows the simultaneous collection of physiological blood flow data from up to four separate tissue sites at the same time, which may for example be useful when comparing pathological versus control tissue sites (e.g. contralateral cerebral perfusion). The ability to monitor from more than one tissue site can also be useful in mitigating for natural site to site blood flow variability by allowing multi-site signal averaging.

Are your blood flow probes supplied sterile?
No. While we manufacture blood flow probes in a clean room environment, they are not supplied sterile. Our blood flow probes can however be disinfected using 70% IMS or ethanol, and can be sterilized using industry-standard liquid sterilizers (e.g. Cidex®) or the low-temperature ethylene oxide gas method. Note that neither our blood flow probes, nor our blood flow monitors possess CE or FDA regulatory approval for use in human subjects.

What is the sampling volume of your blood flow probes?
For most tissues the mean sampling depth is in the region of 0.5 - 1.0 mm with a typical sampling volume in the region of 0.5 mm3. These values could be higher in regions where reduced photon absorption would be expected due to depleted erythrocyte concentration. These values have been obtained heuristically through many years of experience and are based on both in vitro observations and mathematical modelling of photon diffusion through ‘imaginary tissues’ using Monte-Carlo techniques.

What are the units of blood flow measurement?
The laser-Doppler technique for tissue blood flow measurement provides arbitrary, non-absolute, units for blood perfusion since the actual sampling volume/depth can only be determined by identifying which erythrocytes have interacted with the light remitted from the tissue, which in turn, is principally dependant on two parameters; namely the optical scattering and the optical absorption coefficients of the tissue under observation. Since both of these coefficients are entirely dependent on the site of observation and perfusion of the microvasculature at the time of measurement, it is impossible to determine the actual sampling volume at any tissue site and thus to express the measured component in absolute terms. The strengths of the laser-Doppler technique lie in observing continuous and quantifiable changes relative to baseline (control) measurements.

Do your tissue blood flow monitors possess regulatory approval for clinical use?
No. At this time our blood flow monitors and probes do NOT possess CE or FDA regulatory approvals for use on human subjects.

Do you offer on-site demonstrations of your instruments?
Yes, depending on geographical location we will try to arrange for an on-site demonstration of our products by an experienced product specialist. Ideally this will involve a full simulation of your application in order to maximise the benefit of the demonstration. On-site demonstrations are usually free of charge and can typically be arranged at 2 - 8 weeks notice. Alternatively we can also arrange for a limited free trial of our monitors and sensors.


PowerLab™
Third party analogue data acquisition and analysis solution

Our OxyFlo™ and OxyFlo™ Pro monitors feature standard analogue data outputs for continuous recording to PC or Mac platforms.

A popular choice is the PowerLab™ range of data recording and analysis systems by ADInstruments, which are supplied with advanced and user-friendly LabChart software.

PowerLab™ data acquisition systems (comprising hardware and software) offer versatile data acquisition and analysis solutions for life science research and education applications. The systems are used with Windows or Macintosh computers to record and analyze physiological signals from human and animal subjects. In one compact unit, PowerLab™ systems perform the functions of chart recorders, XYT plotters, digital voltmeters and storage oscilloscopes.

PowerLab™ systems can be supplied by ourselves to complement our monitors at the time of purchase, or can be sourced directly from your local AD Instruments supplier/distributor.
  

 


Single fibre adapter
Our specialist single fibre implantable blood flow probe type requires the connecting 'MSFD NX' adapter depicted.
 

 


Calibration kit for blood flow probes

A Motility Standard comprising a solution of micro-spheres at a precisely controlled concentration and a probe positioning device together ensure highly reproducible blood flow probe calibration. Only required with stand-alone probe orders, where probes cannot be supplied pre-calibrated. Probes that accompany a blood flow monitor will be supplied factory pre-calibrated.
 

 


Adhesive rings
Double-sided adhesive rings used to secure surface blood flow probes to the skin. Sold in lots of 200.
 

 


Miniature needle probe holders
Miniature holders for use specifically with the MNP100NX-3/10 needle probe type probe. These are designed primarily for MCAO applications in rodents and can be attached directly to exposed skull using rapid-setting adhesive in order to firmly, yet reversibly secure the MNP100NX-3/10 probe type. Available in 5 mm or in 10 mm diameters and sold in packs of 5.
 

 


Interlock adapter
LDF interlock adapter for OxyFlo™ Pro. Since the internal laser source in our multi-channel OxyFlo™ Pro monitors is shared between PAIRS of channels, the interlock adapter can be used to occupy the vacant connector when a single probe is used (in the case of OxyFlo™ Pro), or when three probes are used (in the case of OxyFlo™ Pro XL).
 

 


BNC data cables
1 m BNC data cables for single channel OxyLite™ and OxyFlo™ monitors.
For data connection to third-party data recorder (e.g. PowerLab™).
 

 


BNC adapter cable for Pro models
1 m high density 15-pin D-connector to 4 BNC data adapter cable for OxyLite™ Pro and OxyFlo™ Pro monitors. For data connection to third-party data recorder (e.g. PowerLab™).