Hohenstein takes compression measurements of medical aids
12 Dec '08
2 min read
The Hohenstein Institute recently began aiding manufacturers in the development of compression products of all types by providing inexpensive, speedy tests in conjunction with DIN 58133. In a specially adapted testing process, the HOSY measuring device is being used to assess the effective pressure of medical compression hosiery, sleeves, travel and sport socks and bandages, etc.
The results provide important indicators for the optimization of compression items. During product development, they are a rational precursor to tests in accordance with RAL-GZ 387/1 or /2 because assessment is quick and inexpensive. RAL-GZ 387/1 or /2 is a prerequisite for obtaining a medical aid classification number in Germany, and stipulates further testing in addition to the compression measurements taken using HOSY. Among these are assessments of elasticity using a tensile tester. There is, however, no rapid version of this test.
HOSY Measuring Device (HOhenstein-SYstem):
The device is used to evaluate compression products. These must continually decrease in the direction of the body's centre in order to support the flow of blood back to the heart. The items to be measured are fastened to 20 opposing, paired clamps. The items are then stretched and the energy required for each test clamp pair is measured.
-For dynamic measurements, the influence of stretching on pressure is recorded
-Hysteresis (lag in return to initial position in the absence of tensile force) is recorded
-Suitable for all shapes, sizes and lengths of stocking
-Does not destroy the item
Tensile tester:
The tensile tester is used to determine elastic stretchability. Compression items must have sufficiently high elasticity to enable them to be put on and taken off easily. Strips of the item to be tested are stretched in the tensile tester and a determinate amount of force is applied, during which the amount of stretching is recorded.