Medical alarm

A medical alarm is an alarm system designed to signal the presence of a hazard requiring urgent attention and to summon emergency medical personnel. Another term for a medical alarm is PERS or Personal Emergency Response System.

Typical systems have a wireless pendant or transmitter that can be activated in an emergency. When the medical alarm is activated, the signal is transmitted to an alarm monitoring company's central station, other emergency agency or other programmed phone numbers. Medical personnel are then dispatched to the site where the alarm was activated.

Elderly people and disabled people who live alone commonly use/require medical alarms.

Origin
Home alert systems were conceived and developed in Germany in the early 1970s by Wilhelm Hormann with the aim of developing new comprehensive structures for ambulatory and non-ambulatory care for the sick, the elderly, those who live alone, and disabled persons.

Hormann's concept of "home alert" (Hausnotruf) is thus to be seen as fairly broad, including the communication of biomedical data and social communication, and not limited to use as an "elder alarm". This has been set forth extensively in the research literature on PERS.

The technical implementation succeeded with the help of AEG-Telefunken Backnang GmbH and was presented to the international public early in 1980. In 1982 the Hausnotruf PERS system was distinguished with the Frankfurt Innovation Prize of the German Economy by the Wirtschaftsclub Rhein Main e.V. (Rhein-Main Economic Club) in Frankfurt-am-Main.

Functionality
A medical alarm system consists of
 * an emergency transmitter, which is worn like a wristwatch or a pendant
 * a base station, which is connected to the telephone and contains a very sensitive microphone/speaker unit.

In addition there are various other types of accessories (fall sensors, smoke detectors, motion detectors). A plethora of devices is available that can be connected over analog or digital ISDN connections. These devices make possible a high degree of safety, since in event of a power outage they operate on batteries.

In case of emergency, for example, after a fall or a suddenly appearing ailment, the user can set off a call for help by a simple press of the alert button on his wrist, without needing to reach the telephone. The devices are configured so that any calls or connections in progress are terminated and a call for help can be initiated over the telephone.

An alert arrives in the offices of the alert system operator (which may be a public rescue service or a private security company) and the data of the affected person (address, medical condition, family contacts) are displayed.

Through the microphone/speaker unit in the base station the employee of the alert system operator can speak with the user in order to clarify the type and severity of the emergency and discuss further measures.

Depending on the organization of the service and the type of emergency help required, relatives or neighbors can be informed. If necessary, health care services or personal physicians can be notified or emergency medical services can be alarmed. Some monitoring services also provide the client with a USB medical alert device so that arriving emergency personnel can have immediate access to vital medical information.

Some units can call user selected numbers, so relatives or neighbors can be called directly, avoiding the expense of a monitoring service.

With some systems, it is common practice for the user to leave a house key with a neighbor or at the system office so that emergency personnel can enter the house even if the resident cannot open the door. Keys are kept in a safe and marked only with numbers so that improper use is precluded.

In addition to this "active alarm" there is also the option of a "passive alarm" (sometimes called a "safety clock"), on the principle of a so-called dead man's switch. On the base station is a button that the user is to activate several times a day; this confirms that the user is well. If this confirmation goes lacking for a longer period (usually around 12 hours), a telephone call is placed or someone is sent to check whether everything is in order at the residence.

Depending on the company offering it, the system is not only intended for emergency use, but is also used to conveniently call for help with shopping or cleaning.