SIST-TP CEN/TR 15831:2009

Method for testing compression in medical hosiery

This document applies to medical compression hosiery and thrombosis prophylaxis hosiery.
An important property of hosiery is the compression it exerts on the limb. This document is intended to provide a reference for testing the compressive properties in medical hosiery.

Verfahren zur Kompressionsprüfung von medizinischen Strümpfen

Méthode d'essai de compression des bas médicaux

Le présent document s’applique aux bas médicaux de compression et aux bas prophylaxiques anti-thromboses.
La compression qu’exercent les bas sur le membre constitue une propriété importante des bas. Le présent document est destiné à fournir une méthode de référence pour les essais des propriétés de compression des bas médicaux.

Metode preskušanja kompresij medicinskih nogavic

General Information

• Status: Published
• Public Enquiry End Date: 09-Mar-2009
• Publication Date: 31-May-2009
• ICS: 11.120.20 - Wound dressings and compresses
• Technical Committee: VAZ - Healthcare
• Current Stage: 6060 - National Implementation/Publication (Adopted Project)
• Start Date: 18-May-2009
• Due Date: 23-Jul-2009
• Completion Date: 01-Jun-2009
• Directive: 93/42/EEC - Council Directive 93/42/EEC of 14 June 1993 concerning medical devices
• Mandate: M/382 - Mandate for standardisation addressed to CEN in the field of Methods of analysis for animal Feedingstuffs
• Ref Project: CEN/TR 15831:2009 - Method for testing compression in medical hosiery

Relations

• Replaces: SIST ENV 12719:2002 - Medical thrombosis prophylaxis hosiery
• Effective Date: 01-Jul-2009
• Replaces: SIST ENV 12718:2002 - Medical compression hosiery
• Effective Date: 01-Jul-2009

Overview

CEN/TR 15831:2009 - Method for testing compression in medical hosiery is a CEN technical report that defines a reference method to measure the compressive properties of medical compression hosiery and thrombosis prophylaxis hosiery. The document sets out terminology, nominal dimensions and sizes, test apparatus, conditioning and washing requirements, measurement locations on the leg, test procedures and calculation methods (compression is derived from circumferential force using the Laplace formula). It supersedes ENV 12718:2001 and ENV 12719:2001.

Key topics and requirements

• Scope and definitions: Clear definitions for terms such as compression, pressure profile, residual pressure, stiffness, custom-made and standard-size hosiery.
• Nominal dimensions: Guidance on measuring leg lengths and girths at standard measuring points (A, B, C, D, …) used to designate sizes and types (below-knee, thigh, panty).
• Test principle: Measure circumferential force required to stretch a hosiery specimen both sideways and lengthways; convert force to pressure using the Laplace formula.
• Apparatus and fixtures:
  • Marking board and clamps for placing and marking measuring points.
  • Gripping devices (distorting parallelogram or stretcher bars) to avoid fabric necking.
  • Rods/needles system and tensile tensometer with calibrated force measurement (per EN ISO 376).
• Sample preparation:
  • Required washing and flat drying (per EN ISO 6330) before testing.
  • Conditioning for at least 12 hours in a controlled atmosphere (per EN ISO 139).
• Measurement protocol:
  • Minimum number of samples (at least two for standard sizes; one for custom-made).
  • Measuring at minimum and maximum stated girths/lengths where manufacturers declare ranges.
  • Procedures to determine stiffness by measuring pressure change per centimetre change in girth at reference points.
• Calculations and reporting: Conversion of measured force to compression (pressure), pressure profiles along the leg and residual pressure expressed relative to ankle compression.

Applications and users

This standard is practical for:

• Manufacturers of medical compression hosiery (product development, sizing, quality control).
• Testing laboratories performing performance verification and compliance testing.
• Regulatory and procurement bodies evaluating performance claims and product specifications.
• Clinical procurement teams and hospitals selecting hosiery for thrombosis prophylaxis or chronic venous disease management.
• R&D teams assessing material and construction effects on pressure profiles and stiffness.

Keywords: CEN/TR 15831:2009, method for testing compression in medical hosiery, medical compression hosiery, thrombosis prophylaxis hosiery, compression testing, Laplace formula, stiffness, circumferential force.

Related standards

• Superseded documents: ENV 12718:2001, ENV 12719:2001
• Referenced standards: EN ISO 6330 (washing), EN ISO 376 (force calibration), EN ISO 139 (conditioning)

Standards Content (Sample)

SLOVENSKI STANDARD
01-julij-2009
1DGRPHãþD
SIST ENV 12718:2002
SIST ENV 12719:2002
Metode preskušanja kompresij medicinskih nogavic
Method for testing compression in medical hosiery
Verfahren zur Kompressionsprüfung von medizinischen Strümpfen
Méthode d'essai de compression des bas médicaux
Ta slovenski standard je istoveten z: CEN/TR 15831:2009
ICS:
11.120.20 Sanitetni materiali, obveze in Wound dressings and
komprese compresses
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

TECHNICAL REPORT
CEN/TR 15831
RAPPORT TECHNIQUE
TECHNISCHER BERICHT
April 2009
ICS 11.120.20 Supersedes ENV 12718:2001, ENV 12719:2001
English Version
Method for testing compression in medical hosiery
Méthode d'essai de compression des bas médicaux Verfahren zur Kompressionsprüfung von medizinischen
Strümpfen
This Technical Report was approved by CEN on 12 April 2009. It has been drawn up by the Technical Committee CEN/TC 205.
CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Cyprus, Czech Republic, Denmark, Estonia, Finland,
France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal,
Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION
EUROPÄISCHES KOMITEE FÜR NORMUNG
Management Centre: Avenue Marnix 17, B-1000 Brussels
© 2009 CEN All rights of exploitation in any form and by any means reserved Ref. No. CEN/TR 15831:2009: E
worldwide for CEN national Members.

Contents Page
Foreword .3
1 Scope .4
2 Terms and definitions .4
3 Nominal dimensions and sizes .5
3.1 General .5
3.2 Measurement of length .5
3.3 Measurement of girth .5
3.4 Designation of type of hosiery .5
4 Method for testing compressive properties of medical hosiery .9
4.1 Principle .9
4.2 General conditions .9
4.3 Apparatus .9
4.4 Test procedure . 10
4.5 Calculation and expression of results . 13
Bibliography . 25

Foreword
This document (CEN/TR 15831:2009) has been prepared by Technical Committee CEN/TC 205 “Non-active
medical devices”, the secretariat of which is held by DIN.
Attention is drawn to the possibility that some of the elements of this document may be the subject of patent
rights. CEN [and/or CENELEC] shall not be held responsible for identifying any or all such patent rights.
This document supersedes ENV 12718:2001, ENV 12719:2001.
This document is based on the test methods described in ENV 12718:2001 and ENV 12719:2001 which have
been withdrawn.
1 Scope
This document applies to medical compression hosiery and thrombosis prophylaxis hosiery.
An important property of hosiery is the compression it exerts on the limb. This document is intended to provide
a reference for testing the compressive properties in medical hosiery.
2 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
2.1
compression
pressure exerted on the leg by the hosiery
2.2
custom made hosiery
hosiery manufactured individually to suit the leg dimensions of an individual patient
2.3
practical elongation
elongation of hosiery in the circumferential direction with the hosiery on the leg, expressed as a percentage of
the unloaded circumference of the hosiery
2.4
pressure profile
representation of the compression exerted by the hosiery along the leg
2.5
residual pressure
compression at a certain point expressed as a percentage of the compression at the ankle
2.6
standard size hosiery
hosiery manufactured in the types and sizes specified
2.7
medical thrombosis prophylaxis hosiery
hosiery which when worn on the leg exerts graduated compression on the leg surface and is principally
intended to reduce the incidence of venous thrombosis in non-ambulant patients
NOTE Abbreviated in this document to 'hosiery'
2.8
medical compression hosiery
hosiery for treating leg diseases by means of graduated compression exerting a definite pressure on the leg in
a specific way
NOTE Abbreviated in this document to 'hosiery'
2.9
stiffness
increase in compression per centimetre increase in the circumference of the leg, expressed in hectopascals
per centimetre and/or millimetres of mercury per centimetre
3 Nominal dimensions and sizes
3.1 General
Hosiery size can be designated by the lengths and girths on the human leg at the measuring points.
3.2 Measurement of length
If measured, length can be measured and codes allocated as described in Table 2.
3.3 Measurement of girth
If measured, girths can be measured and codes allocated as described in Table 3.
3.4 Designation of type of hosiery
Hosiery can be designated by the type code according to Table 4.

Measurements should preferably be taken at the patient's leg in a standing position
Figure 1 — Measuring points, lengths and girths on the human leg
Table 1 — Nominal measuring points (see Figure 1)
Measuring point Description of the measuring point
a sole of the foot at the heel
A forefoot at the implantation of the toes
B ankle at the point of its minimum girth
B1 point at which the Achilles tendon changes into the calf muscles
C calf at its maximum girth
D just below the tibial tuberosity
E centre of the patella and over the back of the knee
F between K and E
G 5 cm below K with the patient in the upright position
H greatest lateral trochanteric projections of the buttock
K centre point of the crutch
K1 level at the pubic symphysis
K2
level at the infra-gluteal fold
T natural waistline
X middle of the foot
Y instep
Z tip of toe
Table 2 — Nominal measurement of length
Length code Length of the leg
distance measured from a to B
lB
distance measured from a to B1
lB1
distance measured from a to C
lC
distance measured from a to D
lD
distance measured from a to E
lE
distance measured from a to F
lF
distance measured from a to G
lG
distance measured from a to H
lH
distance measured from a to K
lK
distance measured from a to T
lT
distance measured from the most prominent part of the heel to X
lX
distance measured from the most prominent part of the heel to A (foot length without toe)
lA
horizontal distance between the perpendiculars in contact with the end of the most prominent toe
lZ
and the most prominent part of the heel (total foot length)
1)
lGT distance measured from G to T
1)
lK1T distance measured from K1 to T
1)
lK2T distance measured from K2 to T
1)
For panty hose only, measured along the body.
Table 3 — Nominal measurement of girth
Girth code Girth of the leg
cA girth measured at A
cB girth measured at B
cB1 girth measured at B1
cC girth measured at C
cD girth measured at D
cE girth measured at E
cF girth measured at F
cG girth measured at G
cH girth measured at H
cT girth measured at T
cX girth measured at X
cY girth at Y, measured with the foot in maximum dorsal flexion

Table 4— Designation of types of hosiery
Type of hosiery Code
1)
Below-knee hosiery AD
2)
Mid-thigh hosiery AF
3)
Thigh hosiery AG
4) 5)
Single leg panty AGTL , AGTR
4)
Panty hosiery AT
1)
Upper end of hosiery corresponds to measuring position D.
An area of maximum 10 mm below can be less or non-

compressive.
2)
Compressive up to measuring position F. There can be a

less or non-compressive welt or part above.
3)
Upper end of hosiery corresponds to measuring position G.
An area of maximum 50 mm (stretched condition) below upper

end can be less or non-compressive.
4)
Compressive at least up to measuring position G.
5)
L = left leg; R = right leg
4 Method for testing compressive properties of medical hosiery
4.1 Principle
Measurement of the force exerted by hosiery across its width when it is stretched simultaneously both
sideways and lengthways according to its size designation. The measured force is transformed into pressure
using the Laplace formula.
Compressive properties can be determined by measuring the circumferential force at certain positions
necessary to stretch the hosiery specimen to the extent according to its size designation.
4.2 General conditions
4.2.1 Number of test samples
For each size and length of standard hosiery to be tested, at least two samples should be tested. For custom
made hosiery one specimen should be tested.
4.2.2 Measuring positions
The compression can be measured at the relevant measuring positions given in Figure 1.
4.2.3 Measurement of compression at minimum and maximum sizes
If the manufacturer states a range of girths and/or lengths, compression measurements should be taken at
both minimum and maximum girths for each measuring position, and/or both the minimum and maximum
lengths.
If the difference between minimum and maximum girths indicated by the manufacturer does not exceed 10 %
(based on the minimum girth) for each applicable measuring position, compression measurements should be
determined at minimum girths only.
If the difference between minimum and maximum lengths indicated by the manufacturer does not exceed
15 % (based on the minimum length), compression measurements should only be determined at the mean of
the minimum and maximum values, rounded down to whole numbers.
4.2.4 Stiffness
If stiffness is to be determined, force (pressure) measurements on the hosiery at reference point B for girths
that are 1 cm smaller and 1 cm larger than the ankle girth stated by the manufacturer should be taken. Always
the smallest girth should be measured first.
4.3 Apparatus
4.3.1 Washing machine, described in EN ISO 6330:2001
4.3.2 Device for marking of measuring positions
The device would preferably comprise a marking-board (see Figure 2), on which an adjustable clamp is
mounted that is capable of fixing the lower end of the hosiery with either one of two different systems as
follows:
a) for circular knitted specimens, a system of clamps or needles should be used (see Figure 3a);
b) for flat knitted specimens, a foot frame (see Figure 3b) made from a round metal bar of approximately 6
mm diameter should be used.
4.3.3 Metre rule, graduated in
...