On the design and assessment of a 2.45 GHz radio telecommand system for remote patient monitoring

✍ Scribed by G.C. Crumley; N.E Evans; J.B. Burns; T.G. Trouton

• Publisher: Elsevier Science
• Year: 1999
• Tongue: English
• Weight: 290 KB
• Volume: 20
• Category: Article
• ISSN: 1350-4533
• DOI: 10.1016/s1350-4533(98)00083-6

✦ Synopsis

This paper discusses the design and operational assessment of a minimum-power, 2.45 GHz portable pulse receiver and associated base transmitter comprising the interrogation link in a duplex, cross-band RF transponder designed for short-range, remote patient monitoring. A tangential receiver sensitivity of Ϫ 53 dBm was achieved using a 50 ⍀ microstrip stub-matched zero-bias diode detector and a CMOS baseband amplifier consuming 20 A from ϩ 3 V. The base transmitter generated an on-off keyed peak output of 0.5 W into 50 ⍀. Both linear and right-hand circularly-polarised antennas were employed in system evaluations carried out within an operational Coronary Care Unit ward. For transmitting antenna heights of between 0.3 and 2.2 m above floor level, transponder interrogations were 95% reliable within the 82 m 2 area of the ward, falling to an average of 46% in the surrounding rooms and corridors. Separating the polarisation modes, using the circular antenna set gave the higher overall reliability.