1568 Chapter 43
she can transmit a special signal on the conversation
channel which tells them there is an important message
to be received.
Last Number Redial. Last number redial, as on tele-
phone systems, allows the caller to redial his last called
number again and again and again.
Microphone Cutout. Microphone cutout is used to
disconnect the microphone during a conversation so that
the receiver cannot hear communications between the
talker and another person in the same room.
Paging. Master stations can page to other master
stations, substations, and to remote loudspeakers
through an external amplifier.
PBX Station Intercommunications. Many intercoms
can be connected to the PBX or an outside C/O line for
communications to the outside world.
Pocket Page Access. Any master station can place calls
to the desired pocket pager receiver, up to 10,000 units.
Priority. If a priority station dials a number while the
conversation channel is busy, she has the option to over-
ride the busy link and be connected directly through to
the called party. This is normally used for emergency
systems.
Privacy. Privacy is initiated by a person so that a caller,
when calling that person, hears a signal which tells him
the receiving person does not want to be disturbed.
Program Distribution Channels. Music or special
messages can be setup to be used as background music.
Scan Monitoring. Scan monitoring allows a control
station to arbitrarily scan a group of slaves or substa-
tions for auditory monitoring. Scanning can be
performed either manually or automatically.
Time/Date. Some intercoms have the capability of
displaying the time and the date.
Nurse Call Systems. Nurse call systems must be fast,
reliable, and most of all easy to use. Patients must not
have to figure out how to use a system to call for help.
The system must not interfere with the complicated
patient monitoring systems and must not produce
ground loops between it and other equipment.
The simplest and probably best method for a patient
to call a nurse is with a pull chain. This chain, actually
cord, electrically isolates the system from the patient
and only requires a gentle pull by the patient to operate.
The cord can be draped on the rail of the bed for easy
access by the patient. A monitoring system is located at
the nurse’s station with lights corresponding to room
numbers or it could be a CRT with various messages.
An indicator light outside the patient’s room is also
energized, allowing a nurse in the hallway to answer a
call without going back to the nurse’s station. The call
remains energized until the nurse turns it off from the
patient’s station. Because the nurse call systems only
tell the nurse which room is calling, dual-bed rooms
have one call station with two call cords.
Nurse call systems can also include master/slave
two-way communications, eliminating a nurse’s extra
steps. It also allows a nurse station to monitor a room.
Some areas require an emergency button. This could be
a pull chain, a large red mushroom button, or in the case
of a psychiatric station, it could be key operated.Equipment Locator. An equipment tracer system such
as the Rauland Borg Tracer system saves hospitals time,
money, and frustration by locating their key people and
equipment quickly and quietly.
Using a Responder III Plus Nurse Console, staff can
instantly locate and communicate with key staff or
locate equipment. Equipment and staff locations can be
displayed in real time on networked PCs throughout the
facility.
Tracer works in the following manner. Three elements
comprise the system: tracer tags, in-ceiling network, and
software elements. The Windows-based software gives a
graphic, easy-to-understand location depiction or a
synthetic voice can give location over any telephone.
Special light-weight transmitter tags can be attached
to a facility’s important equipment (IV pumps, wheel-
chairs, carts) and worn by key personnel. These tags
continuously relay their position to room and hallway
sensors, Fig. 43-9.
The tag is microprocessor based and emits an
880 nm infrared hemisphere of one of 30,000 unique ID
digitally encoded packets for a broadcast range of about
20 ft.
Ceiling or wall-mounted sensors receive the packets
and convert them tzo electrical signals. The packets are
relayed to the collector box, which has star inputs for
twenty four sensors.
The collector assembles the sensor packets into
larger packets and prepares them to be sent to the
concentrator.
Each senso, or combination of sensors, is defined as
a zone. Offices, hallways, or areas can be declared as
zones.
Data from the network (tag, location) is combined
with the time of day and written to binary history files,
called Logger. The database and history files can be