BS 8432-2005 Spinal orthoses - Guide to design《脊髓正长石 设计指南》.pdf

1、BRITISH STANDARD BS 8432:2005 Spinal orthoses Guide to design ICS 11.040.40 BS 8432:2005 This British Standard was published under the authority of the Standards Policy and Strategy Committee on 15 June 2005 BSI 15 June 2005 The following BSI references relate to the work on this British Standard: C

2、ommittee reference CH/168 Draft for comment 04/19986965DC ISBN 0 580 46050 9 Committees responsible for this British Standard The preparation of this British Standard was entrusted to Technical Committee CH/168, Prosthetics and orthotics, upon which the following bodies were represented: British Ass

3、ociation of Prosthetists and Orthotists British Healthcare Trades Association British Orthopaedic Association British Plastics Federation BSI Consumer Policy Committee Chartered Society of Physiotherapy International Society for Prosthetics and Orthotics Medicines and Healthcare Products Regulatory

4、Agency (MHRA) Orthotic and Prosthetic Training and Education Council (OPTEC) SATRA Technology Centre Scottish Office Society of Chiropodists and Podiatrists Surgical Appliance Manufacturers Association Co-opted members Amendments issued since publication Amd. No. Date CommentsBS 8432:2005 BSI 15 Jun

5、e 2005 i Contents Page Committees responsible Inside front cover Foreword ii 1S c o p e 1 2 Normative references 1 3 Terms and definitions 1 4 Categories of orthoses 2 5 Design of orthoses 2 6 Reuse, decontamination and disposal 6 Bibliography 10 Annex A (informative) Manufacture of plastics compone

6、nts 7 Annex B (informative) Marking, packaging and accompanying documentation 8BS 8432:2005 ii BSI 15 June 2005 Foreword This British Standard has been prepared by Technical Committee CH/168. It supersedes BS 5473:1977, which is withdrawn. While BS 5473:1977 specified requirements for spinal and abd

7、ominal fabric supports, this standard is limited to spinal orthoses excluding sacro-iliac orthoses and gives guidance on design and manufacture. This standard deals separately with orthoses acting on the following regions of the spine: a) lumbo-sacral; b) thoraco-lumbo-sacral; c) cervical; and d) ce

8、rvico-thoraco-lumbo-sacral. For each of the above regions of the spine, information on the primary functions of the orthoses, methods by which these functions can be achieved and the form and extent of the control exerted by orthoses acting in these regions is given. This standard is not intended to

9、 recommend particular designs of orthosis and, therefore, it only gives recommendations for particular designs if specific guidance is believed to be necessary to ensure the satisfactory functioning and quality of the design. Attention is drawn to Annex 1 of the EC Council Directive 93/42/EEC which

10、concerns medical devices as they apply to orthoses. This publication does not purport to include all the necessary provisions of a contract. Users are responsible for its correct application. Compliance with a British Standard does not of itself confer immunity from legal obligations. Summary of pag

11、es This document comprises a front cover, an inside front cover, pages i to ii, pages 1 to 10, an inside back cover and a back cover. The BSI copyright notice displayed in this document indicates when the document was last issued.BS 8432:2005 BSI 15 June 2005 1 1 Scope This British Standard gives gu

12、idance on the design of spinal orthoses. It is intended for designers of orthoses, clinicians prescribing orthoses for patients, orthotists, and manufacturers of both commercially available and custom made orthoses for individual patients. The standard is not applicable to sacro-iliac orthoses (Sb),

13、 that is, orthoses that encompass the whole or a part of the sacro-iliac region of the trunk. NOTE Guidance on the manufacture of the components of spinal orthoses is given in Annex A. Guidance on the marking, packaging and accompanying documentation for orthoses is given in Annex B. 2 Normative ref

14、erences The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. BS EN 1041:1998, Information supplied by

15、the manufacturer with medical devices. 3 Terms and definitions For the purposes of this British Standard, the following terms and definitions apply. 3.1 orthosis externally applied device used to modify the structural and functional characteristics of the neuro- muscular and skeletal systems BS 7313

16、-1.1:1990, definition 2.1.2 3.2 trunk body excluding the head, the neck and the limbs BS 7313-1.1:1990, definition 2.2.14 3.3 thoracic region that part of the trunk between the neck and the diaphragm, associated with the twelve thoracic vertebrae BS 7313-1.1:1990, definition 2.2.15 3.4 lumbar region

17、 central part of the trunk between the ribs and the pelvis, associated with the five lumbar vertebrae BS 7313-1.1:1990, definition 2.2.16 3.5 sacro-iliac region that part of the trunk lying caudal to the lumbar vertebrae, associated with the fused sacral vertebrae and their articulations with the os

18、 coxae BS 7313-1.1:1990, definition 2.2.17 3.6 distraction application by an orthosis of an extending axial load 3.7 strut compressive load bearing column NOTE Struts can also transmit bending moments.BS 8432:2005 2 BSI 15 June 2005 4 Categories of orthoses A spinal orthosis is categorized according

19、 to the joint(s) or body region(s) it encompasses as follows. a) Cervical orthosis (CO) An orthosis that encompasses the whole or a part of the cervical region, including the atlanto-occipital joint. b) Cervico-thoracic orthosis (CTO) An orthosis that encompasses the whole or a part of the cervical

20、and the thoracic regions, including the atlanto-occipital joint. c) Cervico-thoraco-lumbo-sacral orthosis (CTLSO) An orthosis that encompasses the whole or a part of the cervical, the thoracic, the lumbar and the sacro- iliac regions, including the atlanto-occipital joint. d) Thoraco-lumbo-sacral or

21、thosis (TLSO) An orthosis that encompasses the whole or a part of the thoracic, the lumbar and the sacro-iliac regions of the trunk. e) Lumbo-sacral orthosis (LSO) An orthosis that encompasses the whole or a part of the lumbar and sacro-iliac regions of the trunk. Hereafter in this standard the orth

22、oses are referred to by the initials indicated. NOTE Different parts of the spine are interconnected and act as an integrated unit. As a consequence some orthoses extend beyond the region(s) that they are intended to treat. For example a CTLSO might be prescribed to treat problems in the thoracic re

23、gion only. 5 Design of orthoses 5.1 Lumbo sacral region 5.1.1 Objectives and means of achievement The types of orthoses that can be used to treat the lumbo-sacral region of the spine include TLSOs and LSOs. The primary function of an orthosis acting on the lumbo-sacral region of the spine is to prov

24、ide relief of pain. This can be achieved through improved posture, which can be invoked by restricting motion, by supporting weak muscles, by increasing local body surface temperature or by sensory feedback. Orthoses can achieve these objectives by: a) restricting motion; NOTE This will depend on th

25、e incorporation of an effective system of three point loading. None of these devices is capable of achieving immobilization and their effect is to reduce inter-regional motion thereby reducing the total range of motion. b) providing sensory feedback; c) increasing intra-abdominal pressure by support

26、ing weak muscles; d) retaining body heat; and e) creating a total contact system by means of components which maximize the areas of body contact. 5.1.2 Form and means of control The form and extent of the control exerted by the orthosis depend on one or more of the following: a) the material from wh

27、ich it is made; b) the length of the orthosis and its anterior/posterior and lateral dimensions; c) the accuracy of placement and/or shaping of the stiffeners or reinforcing components incorporated into it; d) the effectiveness of the fastenings; e) the security of the orthosis-patient interface in

28、respect of location, load transmission and comfort. Controls applied in the lumbo-sacral region have an effect on the pelvis and other areas of the spine generating increased control or limiting movement ranges within the higher regions of the body. The orthosis design should take account of these c

29、onsiderations.BS 8432:2005 BSI 15 June 2005 3 5.1.3 Loading and strength requirements Due to the large amount of surrounding tissue it is not possible to apply significant direct forces to the spine via orthotic devices. The loads have to be transmitted through the surrounding tissue. It is necessar

30、y to consider the effects of the increased pressures which are generated in order to transmit the required forces, both on the immediately surrounding tissue and that which is distant from the spinal region. If an appropriate stable location can not be provided for the orthosis, migration of the ort

31、hosis from its desired location might occur. Additional strapping arrangements might be necessary to prevent this migration from compromising the intended effect. Although cyclic loadings will be applied to these orthoses, the limited values of the dynamic loads means there is only a small likelihoo

32、d of fatigue failure. Nevertheless, care should be taken with highly loaded components to minimize stress concentrations by ensuring they have a smooth surface finish and no abrupt changes of cross-section. 5.2 Thoraco-lumbo-sacral region 5.2.1 Objectives and means of achievement The types of orthos

33、es that can be used to treat the thoraco-lumbo-sacral region of the spine include CTLSOs, TLSOs and LSOs. The primary functions of an orthosis acting on the thoraco-lumbo-sacral region of the spine are: a) to support, control and/or correct pathological curvatures of the spine in the sagittal and/or

34、 coronal planes; b) to control instability; and c) to relieve pain. Orthoses can achieve these objectives by: 1) restricting motion; 2) applying corrective forces; 3) promoting improved alignment; 4) increasing intra-abdominal pressure; 5) providing sensory feedback; and 6) creating a total contact

35、system. 5.2.2 Form and means of control The form and extent of the control exerted by the orthosis depend on one or more of the following: a) the material from which it is made; b) the length of the orthosis and its anterior/posterior and lateral dimensions; c) the accuracy of the shaping of the ort

36、hosis; d) the security of the fastenings; e) the comfort and stability of the orthosis-patient interface. When designing these orthoses consideration should be given to the restriction of movement which is required and/or can be tolerated by the patient, the functional capability of the patient and

37、the degree of functional loss that an orthosis might cause to the patient, and the body mass and underlying pathology of the patient to be treated. The interface between the patient and orthosis should be designed to transmit the loads generated. The shape and skin condition of the trunk and the cha

38、racteristics of the underlying tissue at the patient-orthosis interface should be taken into account, with particular reference to areas of high sensitivity, as should be the integrity of the underlying structures through which loads might need to be applied. These orthoses normally achieve their ob

39、jectives by the method of loading at three or more points for each spinal curve through adjacent structures and by promoting improved alignment through muscular activity.BS 8432:2005 4 BSI 15 June 2005 The larger the angle of the spinal curves the smaller will be the moment arms through which these

40、loads can be applied, and the moments which can be generated will be constrained by the limit of patient tolerance of the contact forces. Improved alignment needs to be “self generated” by the patient because the externally applied loads necessary to achieve this are so great that they would damage

41、the delicate structures through which they would need to be applied (e.g. the chin). Mechanical structures placed adjacent to these areas are normally expected to act as “reminders” to the patient to stretch upwards to achieve improved alignment. These orthoses might also be required to control or r

42、educe rotational deformities of the spine. This requires a torque to be generated about the main axis of the spine. To be effective this demands a reactive element which is firmly located on the pelvis with de-rotational forces applied tangentially above the rotational deformity. In both regions the

43、re should be a minimum of two opposing de-rotational forces to apply torque whilst minimizing translational bending effects. None of the external mechanical corrective effects on the orthosis can be achieved through direct application to the spine of all the required forces. Care should be taken to

44、ensure that irreversible damage is not caused to the skeletal structures and other tissues through which loads are applied. Interface pressures should be minimized by spreading loads over the maximum areas available in practice. Interface materials used should allow compliance to the intricate patie

45、nt shapes through which the structures apply the loads. Metal superstructures should be shaped so that they do not apply damaging forces to tissue or otherwise impinge upon the patient during any normal functional activity of the patient. Controls applied in the thoraco-lumbo-sacral region can influ

46、ence the pelvis and the head. This effect might generate increased control or limitations of movement and the design should take account of these considerations. The effects on respiratory function should be taken into account. 5.2.3 Loading and strength requirements Plastics moulded structures prov

47、ide opportunities for applying loads over the maximum area, combining good cosmesis with acceptable structural rigidity. To achieve these objectives the positive moulds should be carefully rectified to achieve the desired effects, particularly when the pelvis is to be used as a reaction region. Whil

48、st the general pattern of moulded plastics spinal orthoses has the potential for good structural rigidity this inevitably is diminished by the need for an opening to allow putting on and taking off, which compromises the structural integrity of the essentially tubular shape. Rigid fastenings across

49、the opening should be used to counteract this effect and prevent the two adjacent edges of the moulding sliding relative to each other as bending and torsion are applied to the structure. Close fitting moulded structures can generate excessive perspiration in the patient, and ventilation should be provided to counteract this. Considerable forces can be applied to the structures of these orthoses and the possibility of overload should be borne in mind. The use of brittle material