Moor Instruments manufacture a wide range of probes designed to help you assess flow from almost any tissue. We are more than happy to advise on your particular application but hope too that the following general notes are useful.

Skin probes are available with two main fibre configurations, twin or multi-fibre designs. Multi-fibre designs usually contain a ring of up to eight collecting fibres around a central delivery fibre. This provides an averaged signal for a larger tissue area than would otherwise be provided by the conventional twin fibre model.

Skin probes are usually fixed to the skin with a probe holder and double sided adhesive discs, although they can be used in other applications (e.g. visceral measurements) and with other equipment (e.g. Iontophoresis). Please refer to the Accessories and Iontophoresis catalogues. moorLAB-LDF users can specify combined laser Doppler and temperature probes.

The standard length for all probes is 2 metres. Longer lengths can be supplied on request (code PXL). The range of probe holders for these (and other) probes is described in the accessories page.

Needle probes are amongst the most versatile designs. They can be used for surface measurements, inserted into tissue or used for single vessel measurements. The compact design also lends itself to measurements in tissues with restricted access, e.g. teeth, conjunctiva and where micromanipulation is required.

Probes can be fixed in position over tissue with a normal laboratory manipulator by clamping onto the black acetal shank.

Deeper measurements are possible by inserting the probe tip into tissue bulk, for which finer needles are suitable (VP4 and VP4s). The finest needles can be inserted directly into some tissues with the application of gentle pressure: for larger needles it may be necessary to puncture the tissue first with a hypodermic needle.

The use of specific probe holders can extend the application range of needle probes further still. Wet stick probe tips can be used to aid adhesion to moist/ mucosal surfaces. Dental putty can be used to create an individual probe holder for tooth measurement. Angled needle probes can be used to access hind teeth.

Although laser Doppler is not usually advocated for assessment of flow in single vessels, there is a role for the technique in the assessment of flow changes in small individual vessels. Moor manufactures a range of probe holders to aid this measurement.

Low profile designs are either used when access is difficult (e.g. oral flaps) or to reduce application pressure when the probe is covered by bandages. Various designs are available, including the titanium disc probe and the near flat silicon probe.

VP10M100ST & VP10M200ST Master/ single fibre probe system. Single fibre probes offer the smallest diameter probe packages of all the probes in our range. Intended for animal use only, they are most commonly used for the MCAO stroke model (ask for our application note!). The single fibre, in contact with the tissue, both sends and receives laser light to and from the tissue. Because the moorLAB-LDF monitor has two separate optical ports to transmit and receive light, a VP10M Master probes is used to act as a link between the monitor and the single fibre probe. The Master probe connects to the single fibre probe via an optical in-line connector (order code PCP).

This system offers a number of advantages over more conventional probe designs. The benefits include;

1. Very fine diameter probes (down to 250micron) for minimally invasive measurements (non-human applications only).
2. Wide choice of single fibre probes tips for a range of experimental tissues. Some probes (P10d for example) use a detachable connector (PCN) to link the single fibre probe to the Master, others have a permanent connection.
3. Single fibre tips can be trimmed off after each measurement so a fresh tip is available for the next measurement. Once you have used the entire single fibre (typically 1 metre long), bare optical fibre (e.g. POF500) is available in 10 metre lengths as a very economical option (re-use the PCN detachable connector supplied originally). Plastic fibre tips are easily prepared with a sharp scalpel. Stripping and cleaving tools (PST, PCT) are available for glass fibres.
4. For longer-term measurements the Master can be disconnected to leave the single fibre in position between measurement periods.