Fixed video and audio links
The three two-way fixed video links used in the video and audio communication study (Chapter 6) formed the fixed communication links of the telehealth system. They were augmented with a small fold-back monitor on the two close-up subsystems as shown in Figure 9.2. The data-projector-based room overview displays of the laboratory studies were replaced for the hospital trial with large plasma panel displays. Figure 9.2 also shows the location of the close-up camera, suspended over the corresponding display screen, and the locations of the microphone and speaker for each close-up subsystem. A wide-angle room microphone was mounted on the ceiling of each room.
Figure 9.2: Close-up video/audio subsystem with tablet and pen display
Tablet display interface
Four tablet displays with electronic pen interaction capability were deployed in the system – two in each room – and configured so that all four showed the same display at any time. The interface for the tablet displays contained a display window showing image or video data and a control window for selecting the required image or video. Three pen interactions were supported:
• Touching a listed video or image source caused that source to be displayed on all four tablets simultaneously
• Holding the pen over the display window put a live cursor point located below the pen on all four tablets
• Touching then drawing the pen on the tablet surface drew a coloured line which appeared on all four tablets.
Each tablet was coded for a different drawing colour so that different people’s drawings could be identified with them. A fade control was provided so that the drawn gestures could either be ephemeral or could be left in place on the screen for longer time-frames of discussion.
Any image or video from any source in the system could be chosen for display, including the display from external computers. Figure 9.2 shows two people (one in each room) discussing a web page loaded in a browser on a hospital computer (the computer’s monitor can be seen on the right). The surgeons had password-protected access to the hospital system and were able to show the patient’s X-rays and other radiological data on the tablet displays. They then use the electronic pen and tablet display to annotate the X-ray with pointing and drawing gestures as they explained matters to the patient and family.
Diagnostic cameras in the patient’s room
The following diagnostic video cameras were available in the patient’s room:
• Hand-held camera for close viewing, including intra-oral and extra-oral views of the patient
• A pair of arm-mounted cameras which could be placed at any position around the patient. Simultaneous views from the two cameras could be displayed to the surgeon on a special-purpose 3D stereo display system, either as live video in 640x480 pixel resolution or as high-resolution digital photographs.
• A single camera mounted 40cm above the floor on a tripod and pointing horizontally gave the surgeon a view of young patients in standing or walking poses (the “walking camera”)
• A pole-mounted camera with pan, zoom and tilt controlled by the surgeon gave a head-and shoulders view of seated patients and the equivalent of a standing view of patients lying on the examination bed.
The camera of the examination close-up subsystem was also used to observe the patient. Its field of view included patients sitting on the examination bed and older patients sitting in a chair. A high-resolution document reader with front lighting was located on the desk in each room. These allowed both family and surgeon to show each other documents such as photographs, referral forms and health clinic charts.
Figure 9.3 shows the author sitting in the examination wing of the clinic room close to several of these cameras. The “walking camera” is off-screen to the bottom right. The examination bed is along the fourth wall of the room to the right-hand side of the photographer and can be seen in Figure 9.4. This figure also shows the correspondence between the two close-up displays and the room overview display.
Figure 9.3: Patient’s room. The pole camera is above the person sitting on the right, the arm-mounted cameras are by his head, the hand-held camera is on a flexible cable behind him and the examination close-up camera is in front of him.
Figure 9.4: Patient’s room showing the correspondence of the two close-up displays and the room overview display from the surgeon’s room. The surgeon’s room
Figure 9.4 shows the surgeon’s room. The surgeon sits inside the curve of the desk, allowing him or her to turn easily to pay attention to the examination close-up display, the room overview display or the consultation close-up display.
Figure 9.4: Surgeon’s room. From left to right: 3D display, examination close-up subsystem, document scanner (below) and patient’s room overview (above),
consultation close-up subsystem and hospital computer monitor (Photo courtesy Royal Children’s Hospital)
9.3 Summary
This telehealth system was designed to support remote outpatient consultations for paediatric surgery. The design used a whole-of-room approach with three sets of fixed video cameras linked by high-quality digital connections, and parallel audio
connections. These are supplemented by a networked electronic pen and tablet display sub-system to support interactive shared access to visual data, and by a range of video cameras to capture diagnostic views of the patient.
The design allowed the surgeon to manage the consultation. It provided:
• High-quality video and audio teleconferencing with the patient and family
• Remote guidance capability, to direct and observe the examination of the patient
• Shared access to patient data, to explain the clinical interpretation of the
examination and the proposed treatment or management plan for the subsequent time interval.
The network over which this telehealth system operated had sufficient capacity, and there was sufficiently little competing network traffic, that it behaved in the manner of a broadband network for this system’s requirements.