19/03/2010 by David Slade.

The use of data cable and infrastructures within healthcare premises to carry information to and from the bedhead opens up the possibility of using the data cable for other facilities.Where data cables (for example Cat 5e, fibre-optic) are used to carry communication and control information to and from the bedhead, or other nursing position, in support of IP (Internet protocol)-based nurse call, patient/nurse speech, telephony, Internet and entertainment services etc, these should be capable of fully supporting the required computer network technologies as directed by the healthcare facility’s IT manager. Examples of computer network technologies include 10Base-T, 100Base-T, 1000Base-T (Gigabit) Ethernet, and Token Ring.

Utilising a common data highway may, however, impact upon business and clinical risk. Therefore, careful consideration should be given to the extent to which provisions are incorporated into the system to ensure adequate reliability and resilience of the various services so as to minimise such risks.

Data cables used for bedhead services will normally be independent of the main healthcare facility’s primary IT network (unless otherwise directed by the healthcare facility’s IT manager), but they will interface with the network at appropriate strategic points.

Relevant protocols and test procedures to achieve the required functional transparency and resilience should be agreed between the bedhead services’ equipment supplier(s) and healthcare facility’s IT manager before the interface(s) is/are installed.

Entertainment (radio and TV) and communication (telephony and Internet access) services may be provided through a low-energy digital device at each bedhead. Such devices should not be used as the primary control for any patient and staff calls, but should be capable of being used for patient health education and for menu-ordering in addition to other services as described in the list at the bottom of this page. When required, the device should also be capable of being interfaced with the hospital information systems and IT network for use by hospital staff and to reduce installation and maintenance costs.

Prior to installation, all facilities that utilise common data infrastructure systems should be adequately assessed with regard to their potential effect on other hospital systems, particularly in respect of any capacity, security and safety implications. Suitable provisions should be incorporated to ensure that such systems operate safely and reliably, with no unwanted interference being incurred sufficient to cause operational difficulties between systems.

Appropriate input and output interfaces should be provided as necessary to ensure a fully operational system in compliance with manufacturers’ requirements and with functionality as specified elsewhere in the project specification.

Once installed, the capacity of a data cable is potentially considerable, so expansion of facilities in the ward or nursing area becomes possible with the appropriate input and output interfaces.

Some features that may be developed are:

• Bed status: to indicate whether the bed is occupied, vacant, in the course of preparation or out of commission.
• Patient monitoring: to allow the output signals from medical apparatus to be multiplexed onto the data line. This may take the form of a simple on/off medical alarm or a constant reporting of varying analogue signals to indicate a changing medical condition.
• Menu selection: to enable the patient to view and select their choice of meal.
• Patient details: to enable the entry of a patient’s name, address and all relevant personal information at the bedside.
• Medication requirements: to display all medical details to the nurse or doctor at the bedhead.
• Patient entertainment: Internet etc.
• Communication: Voice over Internet Protocol (VoIP) telephony.
• Patient administration systems: to provide full clinical access to the healthcare facility’s clinical data IT network at the bedside.
• Door access and security: to allow the nurse-call system to be integrated with CCTV and door-access systems.
• Clinical report displays: to enable laboratory results, X-rays and computed tomography (CT) scans to be displayed to clinical staff at the bedside.
• Administration of drugs: to facilitate the accurate discharging and recording of drugs administered at the bedside.

Posted in Patient details, Medication requirements, Meal selection, Patient monitoring, electronic patient record (EPR), Bed status, Patient entertainment, door-access systems, 10BASE-T, 1000 BASE-T, nurse-call, bedhead services, Administration of drugs, Clinical report displays, VoIP | 1 Comment »

14/11/2009 by David Slade.

Power over Ethernet (PoE).

Powering remote Ethernet devices can be a problem when you need to find an AC power outlet to plug a bulky transformer into. But with Power over Ethernet (PoE) you don’t need a power outlet because your Ethernet device draws power from the same Ethernet UTP cable that connects it to the network. You simplify installation by getting power where you need it with PoE.

What is PoE?
The seemingly universal network connection, CAT5 cable, has another role to play: to provide electrical power as well as data. Power over Ethernet (PoE) was ratified by the Institute of Electrical and Electronic Engineers (IEEE) in June 2000 as the 802.3af-2003 standard. It defines the specifications for the transmission of electrical power over CAT5 data cable.

This standard promotes the delivery of low levels of power—just 13 watts or less—over data lines to PoE devices such as IP telephones, wireless access points, Web cameras, and audio speakers. PoE is also ideal for applications such as video surveillance, building management, retail video kiosks, smart signs, vending machines, and retail point of information systems.

By eliminating the need to install separate outlets for data and power, users can save up to 50% in installation costs.

How does PoE work?
Very simply, CAT5 Ethernet cable consists of four twisted pairs of cable. Only two pairs are used for 10BASE-T and 100BASE-TX Ethernet data transmission; the remaining pairs are available for power. The PoE standard offers two options for using the twisted pairs for power. The first option sends the electrical power through the spare pair. The second option uses the data pairs for both power and data.

The data and power transmissions don’t interfere with each other either. Electricity has a low frequency of 50 - 60 Hz or less, and data transmissions have frequencies that can range from 10 million to 100 million Hz. Because data and electricity are at opposite ends of the frequency spectrum, they can travel over the same cable.

PoE devices
To install Power over Ethernet, you need to add a PoE injector (also known as Power Sourcing Equipment or PSE), to insert DC voltage onto the CAT5 cable. The injector is usually installed near the Ethernet switch and may be a single-port model that inserts power onto only one cable or may be a PoE hub, which inserts power onto multiple cables.

At the other end of the powered CAT5 Ethernet cable, you need a way to get the power from the Ethernet cable and back into a device. Many network devices are now made as PoE-compatible devices that can take power directly from the CAT5 cable. These devices are sometimes also described as active Ethernet compatible.

Additionally, you can power some network devices that aren’t PoE compatible by using a device called a picker or a tap. It “picks” the DC voltage from the CAT5 cable and routes it to the device.

PoE applications and benefits:

• Use one set of twisted-pair wires for both data and low-wattage appliances.
• Save money by eliminating the need to run electrical wiring.
• Easily move an appliance with minimal disruption.
• If your LAN is protected from power failure by a UPS, the PoE devices connected to your LAN are also protected from power failure.
• Supports the addition of end-span, standalone, and mid-span devices.
• As PoE becomes more common, the 8-pin modular connector will become the industry-standard power jack.

Posted in Cat5E, 10BASE-T, 802.3af-2003, Power over Ethernet (PoE), 100BASE-TX | No Comments »