Gallium Indium or Mercury - Strain gauges or photocells are used as transducers in the Plethysmograph DIGITMATIC DM2000 to see the effect of cuff inflation and deflation
GaIn gauges can be cleaned as Mercury strain gauges using alcohol or corsoline. The Warranty Period is one year from delivery, but the duration of functionality is longer. Unlike mercury, which is dangerous if inhaled, organ damaging and has a toxicity of reproduction, is GaIn corrosive/burning and classified as far less dangerous.
A strain gauges mounted distally to an occlusion cuff measures the max systolic pressure under the cuff - This pressure is decisive for the healing ability of ulcers
In contrast to a Doppler recording or to regular AC-recordings, it is possible with a DC transducer recording mounted distal to an occlusion cuff to avoid false negative test results completely.
When measuring distal blood pressure using Doppler probe versus using volume/blushing transducer, results can differ completely.
The information obtained using distal blood pressure measurement and knowledge of the patients age allow the prognosis of the risk for the development of an artherosclerotic disease
It is possible to detect even minor obliterativ stenoses/occlusions located proximally, using distal systolic pressure measurement following a simple working test that provides locally reactive hyperemia. The increased flow due to hyperemia leads to an increased pressure drop over the stenosis which results in reduced distal pressure.
A significantly reduced distal pressure in a sub acute occlusion case might lead to necrosis. The increased pressure gradient can slowly decrease in case of a conservative treatment as function of the collateral development
The max pressure at the measuring level can be traced by a “Healing evaluating detector” which provides skin perfusion pressures and gives an evaluations of the development for ulcer healing on tibia, heel and forefoot
The skin perfusion pressure must be at least 30 mmHg prior to a major or minor amputation to insure wound healing and it is essential that this pressure can be measured precisely without rim artefacts
White fingers/Raynauds syndrome can be diagnosed objectively and in some cases are regarded as a work related injury for which the patients can be entitled to receive compensation.
The DM2000-PC plethysmography provides distal pressures at different selected segments using a variety of transducers and instantly makes all results available in a patient record
A 40% too narrow cuff width gives a 50 % (1.5 versus 2.5 cm cuff width) over estimated systolic digital pressure. However, it is still better to measure imprecisely than not to measure at all