Archive for the ‘MEIGaN – Medical Electrical Installation’ Category

Healthcare – Patient's calling devices

Thursday, March 18th, 2010

Patient’s calling devices

Patient-to-nurse calling devices should have a tactile feel. The push-button or pull-ring should be easily recognised by its colour (normally amber) and by a nurse symbol indelibly engraved/printed on or alongside the device. Examples of typical nurse symbols are shown in the diagram below.

Typical layout of patient handset with example of symbolsTypical layout of patient handset with example of symbols

The device should be easy to operate by the patient irrespective of whether he/she is ambulant, disabled or confined to bed.

Patient-to-nurse calling devices are normally of the push-button type; however, different designs and configurations should be available to suit individual patient condition requirements. These should be capable of utilising a common basesocket connector unit to allow flexibility in use at each call point.

For ease of location at night, the hand unit should be permanently back-lit, but not so brightly that it could be confused with the reassurance lamp.

A reassurance lamp in the form of a light-emitting diode (LED) should be positioned adjacent to, or should be integrated within, the call device.

The voltage potential difference between any two points, including earth, likely to be experienced by patients or persons associated with the call unit or its cable should not exceed that which applies to medical equipment described in the MEIGaN regulations either under normal or fault conditions. The nurse-call circuit should be automatically monitored so that a break in the cable or withdrawal of the plug will initiate a call.

Further information:

Wall- or trunking-mounted push-button

The push-button should be large enough and easily recognisable and suitable for all areas of a healthcare facility frequented by ambulant patients or where it may be intended to be used. Associated with the push-button – either integrally or alongside – a reassurance lamp should be fitted.



Hand-held nurse-call-only unit

A hand-held unit used solely for patient–nurse call purposes should consist of a push-button attached to a fixed unit by means of a suitable cable plug/ socket connector. The push-button should be large and easily recognisable, with a reassurance lamp in the form of an LED fitted either integrally or alongside.

The push-button should be permanently illuminated to a level sufficient to allow easy location in the dark, but should not be so bright as to be confused with the nurse-call reassurance lamp.

The unit should be ergonomically designed, with a flexible lightweight cable of sufficient length to enable patients to activate a call from the bed or whilst sitting in a bedside chair or nursing area etc. The means of attachment at both ends of the cable should be in the form of an effective strain-relief device in order to minimise risk of cable failure. The plug attachment to the base unit should be of a pattern that will disengage from the wall socket when strain is applied to the cable from any angle without damage to plug, socket or cable. Where the same plug and socket is used for a patient handset as an alternative to a call-only unit, the circuitry of the call-only unit should be compatible with that of the handset so that the socket can be used for either.

The control of infection should also be considered in the design and manufacture of the patient handset unit. It should be designed with an appropriate IP rating (see BS EN 60529) so that the unit can withstand submersion in various liquids.

It should also be designed to allow patients with a range of disabilities not only to operate the unit but also to understand the functions of the unit.

Some means of attaching the call-only unit securely to the bedclothes or the patient’s clothes should be available, but it should be so designed that any undue force will allow the clip to disengage without tearing the materials.

A parking clip or bracket should be provided to allow the unit to be stored on the wall or locker when not in use.


Pull-cord unit

In showers, bathrooms and toilets, the patientcalling device is normally a ceiling-mounted pullcord unit with pull rings as described in Part M of the Building Regulations – namely, coloured red, located as close to the wall as possible, and having two red 50 mm diameter bangles (or similar) set at different heights. It is important that the pull-cord is easily recognised as the calling device and cannot be confused with a light switch. The pull-cord unit should provide reassurance that the system has operated. The switch should have a momentary action to activate a call. Use of pull-cords within mental illness units needs careful consideration to avoid potential ligature points, and in any case, the cord should have a low breaking strain.


Other call units

Pneumatically-operated call units can be used for patients who are unable to use their hands. The unit comprises an air bulb and connecting tube, terminating in an air-velocity-operated switch that is integral with the wall unit.

Other forms of call unit that facilitate operation by disabled patients should be considered if these provide enhanced and more efficient use. The design and manufacture of such units should be sufficiently robust to provide a safe and reliable service, and their method of operation should be compatible with the remainder of the patient call system.

MEIGaN – Medical Electrical Installation Guidance

Thursday, March 18th, 2010

MEIGaN – Medical Electrical Installation Guidance is intended to be used by healthcare organisations and medical devices suppliers responsible for permanent electrical installation of medical devices and associated equipment in diagnostic imaging (including dental X-ray units) and radiotherapy rooms/suites. Its requirements are intended for application by staff with electrical knowledge.

Where complied with a complete set of paper commissioning records, sufficient to show compliance with the EIGaN guidance shall be made available to the owner at handover.

This document may also be of use to persons installing permanently installed medical evices in other clinical areas, but has not yet been agreed by interested parties oncerned with installations other than for imaging and radiotherapy.

Covering the electrical wiring and installation up to the terminals of ermanently installed medical devices and to the supply outlets for other medical sevices, and is intended to improve the reliability and resilience of the power supplies sed in diagnostic imaging and radiotherapy rooms/suites as well as their electrical safety.

Healthcare organisations should include as a condition of contract that ‘the electrical installation shall meet the requirements of BS 7671 IEE Wiring Regulations, MEIGaN, HTM 2007 and BS EN 60601-1-1:2001.’

The guidance document supplements the following, all relevant requirements of which apply:

• BS 7671:2001 Requirements for electrical installations. IEE Wiring Regulations. Sixteenth edition, including amendment No. 1 2002 and No. 2 2004
• NHS Estates HTM 06-01 Electrical services, supply and distribution
• BS EN60601-1-1:2006 Medical electrical equipment. General requirements for safety. Collateral standard. Safety requirements for medical electrical systems.
Annex 1 of the document is based on IEC 60364-7-710 [4] and IEE Guidance Note 7 and will be incorporated in a subsequent revision of HTM 06-01.

The document document has been produced by the MHRA and representatives from the Department of Health’s Estates and Facilities Division, the Scottish, Welsh and Northern Ireland administrations, NHS electrical experts, medical device suppliers and pre-installation companies.

It is intended for new buildings, refurbished rooms and transportable diagnostic or treatment rooms and is not retrospective.

1 BS 7671:2001 Requirements for electrical installations. IEE Wiring Regulations.

2 Department of Health: Estates and Facilities Division. HTM 06-01 Electrical ervices supply and distribution.

3 BS EN 60601-1:2006 Medical electrical equipment. General requirements for basic safety and essential performance. BSI, 2006.

4 IEC 60364-7-710:2002 Electrical installations of buildings – Part 7-710: requirements for special installations or locations – medical locations.
Note: the MHRA and DH Estates and Facilities Division recommend that MEIGaN is used.

5 The Institution of Engineering and Technology IEE Guidance Note 7: Special locations, 2nd Edition. IEE Publications, 2004.

6 Statutory Instrument 1999 No. 3232 The Ionising Radiation Regulations 1999. MSO 1999.

7 BS 6231:2006 Electric cables. Single core PVC insulated flexible cables of rated voltage 600/1000 V for switchgear and controlgear wiring. BSI, 2006.

8 Canadian Standards Association. C22.2.127-99 Equipment and lead wires. CSA, 1999.

9 Underwriters Laboratories Inc. UL 758 Appliance wiring material, 2nd edition.

10 BS EN 60309-2:1999, IEC 60309-2:1999 Plugs, socket-outlets and couplers for industrial purposes. Dimensional interchangeability requirements for pin and contact-tube accessories. BSI, 1999.

11 Medical Devices Directives. Council of the European Communities. Council Directive 93/42/EEC of 14 June 1993 concerning medical devices. OJ L169: 1-43. 1993.

12 BS EN 60601-1-4:1997, BS 5724-1.4:1997, IEC 60601-1-4:1996 Medical electrical equipment. General requirements for safety. Collateral standard. General requirements for programmable electrical medical systems. BSI, 1997.

13 IEC 61557-8 Electrical safety in low voltage distribution systems up to 1000 V a.c. and 1 500 V d.c. – Equipment for testing, measuring or monitoring of protective measures – Part 8: Insulation monitoring devices for IT systems.