An overview from a technical perspective

	An overview from a technical perspective
	The core concept of the AMIE project is digital networked multimedia. Multimedia - the integration of images, speech, music, sounds, animation, moving video and other media as data types handled by computers - has introduced new expressive ways of presenting and delivering information. Multimedia personal computers are now commonplace, but until very recently the emphasis has mostly been on displaying contents from a frozen repository such as a CD-ROM containing an encyclopaedia. AMIE, instead, has pioneered the use of multimedia technologies in a networked environment. Live feeds from microphones and cameras let you use multimedia not merely as a presentation technology but also as a convenient and user-friendly channel for interactive communication.
	The AMIE technology of digital distributed multimedia, based on state of the art ATM networking, allows the integration of continuous media within the corporate intranet and opens the door to enhanced communications at the desktop. It is particularly well suited to contexts in which people need to communicate to each other and work collaboratively on data items richer than simple textual documents: team work, remote consultancies with human experts, telecommuting, training, presentations, access to multimedia repositories etc. It is however also applicable to other unrelated fields such as "smart" security monitoring, video on demand, home area networking with particular respect to audio-visual entertainment and so forth.
	The overall technological achievement of the project is the development of a scalable hardware and software architecture for multimedia systems based on network-oriented peripherals. Other significant achievements include the development of a new handwriting recognition system for pen computers, the development of a PCMCIA wireless network adapter, and the development of a complex multimedia application addressing the needs of a group of healthcare professionals. The trial of the system in an operational capacity within the context of a group of healthcare professionals was fundamental to the success of the project. The acquisition of valuable first-hand user feedback on the acceptance and usefulness of an integrated multimedia system within the context of a medical environment will be of paramount importance to future developments and commercial success of multimedia systems. The System
	The AMIE system is perhaps best viewed and described as a number of individual components which have been integrated into a specific instance of a system with a medical application. The following components are described in a logical progression, building to form a system.
	ATM Networking
ORL's prototype 8-port 100 Mb/s ATM switch ATM Ltd's commercial 12- to 24-port, 25 to 155 Mb/s ATM switch An ATM network switch with fibre optic links used in the AMIE pilot	The core networking technology in AMIE is firmly based on ATM (Asynchronous Transfer Mode). ATM is technically the best choice for the integration of bursty computer traffic and continuous multimedia streams. ATM uses small data cells of constant size (53 bytes) which, unlike variable-sized packets, can be cheaply and rapidly switched in hardware. ATM however combines these cells to provide virtual circuits which are like dedicated connections between end-points. This dual nature (both cell-based and connection-oriented) of ATM is what makes it ideally suited to both bursty file transfers and steady time-critical traffic. Due to the fixed size of the cells one can reserve, say, every 20th cell of a link for a given audio channel and have the guarantee that no bursty file transfer will get in with a long packet and disrupt the steady flow of continuous media. Initially prototype ATM networking hardware developed by ORL was used in AMIE. By the time the system integration took place, ORL was able to replace much of its prototype ATM networking infrastructure with production products from its spin-off company ATM Ltd.

The ORL video brick The ORL audio brick The multimedia networked endpoint as a commercial product by TSL The ORL prototype RAID storage array The ATML Virata Store commercial product RAID storage arrays deployed in the AMIE trial	ATM multimedia peripheral devices The modular hardware used in AMIE is a set of digital multimedia peripherals (camera digitiser, audio AD/DA converter, high-bandwidth RAID disc storage array) with a unique advantageous property: each unit has a dedicated direct network connection. Instead of being plugged into the workstation's bus as slaves, these peripherals are promoted to first-class network citizens. This brings the advantages of scalability (you can assign ten cameras to a computer as easily as one without running out of slots), uniform addressing (the distinction between "local" and "remote" peripherals disappears) and avoidance of bus bottlenecks (there is no reason to route digital audio on the computer's bus, slowing down everything else and being slowed down by everything else, when it can go directly over the network from the audio source peripheral to the audio sink). The audio and video units deployed in the AMIE trial system were ORL prototypes which are now being commercialised by the ORL spin-off company TSL. The disc brick RAID arrays used during the AMIE development were ORL prototypes; the Virata Store production units commercialised by the ORL spin-off ATML were used during the trial.
	Wireless radio networking
The Sixtel PCMCIA radio transceiver for wireless networking	A PCMCIA DECT wireless radio was developed by Sixtel. The DECT standard is a mixed mode voice and data telephony network. These units were used to provide a data network connection between pen-based portable computers and the rest of the AMIE system. During the project Sixtel obtained European type approval of the DECT radio. This is a significant achievement which allows the product to be sold across Europe.
The control pad application running on a pen computer with radio networking	The pen computers used as control pads were standard commercially available units from Toshiba with no custom modifications. The Sixtel PCMCIA card plugs into the portable and allows it to communicate via radio to a base station up to 100 metres away. The base station is in turn connected to a fixed PC which relays the messages to the rest of the network.
	Portable pen-based computing with handwriting recognition
Taking handwritten notes during the seminar	The handwriting recognition technology used in the project was developed by LEP-Philips. It is based on a new neural network algorithm called CTRBF (Constructive Tree Radial-Basis-Function), which was awarded a patent. The original plan was to replace the default PenWindows recognition engine with CTRBF, which offers better recognition rate and superior flexibility, but lack of cooperation from Microsoft forced the adoption of an alternative strategy. In the pilot system, the CTRBF recogniser has been implemented in C++ as a Windows 32 library which is then linked with the AMIE control pad application written by CAPTEC.

A technical overview of Medusa (PDF slide show, 17 pages, 664 KB) If you can view PowerPoint7 files, the same presentation is available with audio (8.41 MB)	Systems software At the core of the technology deployed in AMIE is a networked multimedia environment developed by ORL, called Medusa, in which many streams of continuous media can be active simultaneously. While stand-alone multimedia PCs (equipped with CD-ROMs, sound and perhaps video capture cards) are commonplace, solutions that integrate digital multimedia streams (particularly live ones) and networking like Medusa does are rather rare. The Medusa software infrastructure is entirely distributed: software objects called modules act as sources, sinks and processors of multimedia data. There are modules running inside the direct peripherals and there are modules running on the computers in the system; an application is a distributed entity which uses a collection of interconnected modules running simultaneously on various processors in the system. If found convenient, a software module can be moved from, say, a peripheral to a networked processor bank with no change in the structure of the application that uses it. This architecture is a world first. The closest competitor is a system built at the Massachusetts Institute of Technology (MIT) which exhibits similar functionality, but treats peripherals as dumb devices and keeps all the software objects on the workstation. The Medusa core is designed for portability. It was originally developed on Unix and was successfully compiled and used on several Unix platforms (including Sun, Digital and SGI), and on ATMos, the ORL-developed microkernel that runs on the networked peripherals. Within the context of the AMIE project, porting and further developments to Medusa have been completed to encompass the Microsoft Win32 platform.

Static dumps of some of the medical data types handled by Captec's AMIE application (NB: large pictures). ECG (and control pad) Invasive Blood Pressure Angiography (DCI) movie Heart diagram Echocardiography (ultrasound) movie Form with notes Nuclear medicine X-ray	Application software In order to provide a conference system which could be accepted by the clinicians, it was necessary to understand the procedures and quality requirements appropriate to their work. A major objective in the design of the application was to provide the data presentation without introducing radical change to the display formats practiced with previous methods. CAPTEC implemented a CSCW based distributed application which also took account of the workflows inherent in the current practice. This meant that several pen-computer based user interfaces were developed, each targetted at users with specific functions in the meeting. In addition, the diagnostic patient data was carefully prepared, managed and processed so that it could be presented in a convenient and familiar fashion with no loss of quality or reduction in fluidity of presentation. To enhance the readability of the medical images to be displayed, the control pad application allows the presenter to adjust brightness, contrast, zooming, edge sharpening, artificial colouring, adjust video speed and to step from frame to frame and so on. This is achieved by calling into a modular library of MAVIS image processing routines from CAPTEC.
	Field trial
Playback of an ultrasound video sequence in the main seminar room	Users of AMIE technology took advantage of a state of the art environment in which multiple high quality audio and video streams, woven together by the distributed applications, enhance communications within the organisation. Wireless pen-operated computers with handwriting recognition were integrated into the system and provided convenient control units in operating environments where users cannot be confined to one particular location.