Subclause 6.3.2 – Visual ALARM SIGNALS

ü Visual ALARM SIGNALS should indicate to the OPERATOR the presence and level of urgency of any ALARM CONDITION, help the OPERATOR to locate the specific PATIENT or equipment where an OPERATOR response or awareness is required, and identify to the OPERATOR the specific ALARM CONDITION.

ü There are two requirements for visual ALARM SIGNALS:

ü a “distant” requirement that the presence of an ALARM CONDITION and its priority are correctly perceived from a distance of 4 m (far away); and

ü an “OPERATOR'S POSITION” requirement that the visual ALARM SIGNAL indicating the specific ALARM CONDITION and its priority are legible from at least 1 m or from the OPERATOR’S POSITION.

ü It is possible to comply with the requirements of this collateral standard using either a single visual ALARM SIGNAL or with separate “distant” and “OPERATOR’S POSITION” visual ALARM SIGNALS.

ü The “distant” requirements are only required when they are necessary to allow the OPERATOR to locate the part of the ALARM SYSTEM that is generating ALARM SIGNALS. The ability to identify the priority of visual ALARM SIGNALS from a distance of 4 m allows the OPERATOR to decide which equipment to respond to first when simultaneous ALARM SIGNALS occur in a multiequipment environment without having first to go to the OPERATOR’S POSITION.

ü The ability to discriminate between specific ALARM CONDITIONS and their priorities from a distance of 1 m or the OPERATOR'S POSITION aids the OPERATOR in deciding what actions need to be taken. MANUFACTURERS can choose to also make this “OPERATOR'S POSITION” visual ALARM SIGNAL legible from a distance of 4 m.

ü The committee considered the use of the standard general alarm symbol and urgent alarm symbol (triangle with 1 or 2 and extended to 3 curved lines) to represent LOW, MEDIUM or HIGH PRIORITY ALARM CONDITIONS. Concern was raised that they are too similar and would be impossible to distinguish on many displays at a viewing distance of 1 m to 4 m.

? The committee recognized this limitation, and decided that adding optional elements could be used to indicate the priority. (זה צריך להיות מוגדר בתקן, לא באופציה)

? MANUFACTURERS are free to enhance legibility by any of several means. For instance, the symbols could be coloured red or yellow, or placed on a red or yellow background. Additional symbols, letters, or words could be added to these symbols to enhance distinctiveness.

ü One suggestion was to use three identical symbols to indicate HIGH PRIORITY, two identical symbols for MEDIUM PRIORITY and a single symbol for LOW PRIORITY (זה יכול להיות מוגדר בתקן ).