Patent GB-1488509-A (GB)
Title: Patient monitoring and data processing system
IPC: G08C15/12
Filed: 1974-10-23
Abstract: 1488509 Patient monitoring and data processing system GENERAL ELECTRIC CO 23 Oct 1974 [25 Oct 1973] 45839/74 Heading G1N(E) [Also in Division G4] In a system for acquiring, processing, storing, transmitting and displaying data of the physiological condition of one or more patients P in a hospital, comprising a bed side unit 10 for each patient, a central unit 11 and a central processing unit 12. Patient information such as dynamic waveforms or physiological parameters are converted into digital signals. These signals are directed under the control of their corresponding interfaces 48 or 49, or 54, or 18 to 21, or 26 to 29 or 32, 37 and data buses 13, 17, 31 to their corresponding receiving units (display devices or computers) during a corresponding repetitively occurring time slot assigned to the equipment of the bed side unit 10. That is, the data buses 13, 17, 31 are operated in a sychronous mode and the data words appear on the buses in a predetermined unique "time slot" relationship for each sensor relative to repetitive synchronizing pulses derived Figs. 2 and 3 (not shown), from a clock pulse generator 61 supplying each interface. Thus both the transmitter interface (54, say), which can generate a given data word on a given data bus (13, say), and all the intended receivers (43, say), can receive that given data word simultaneously. That is, provided the transmitting and receiving interfaces have counted the same number of intervals from the synchronizing pulse to the predetermined time slot. The analogue output of a sensor 50 associated with the patient P is passed via a signal conditioning module 51 (amplifiers and filters &c.) to an A/D converter 52 supplying a digital store 53 comprising two four bit latches (see Fig. 11 (not shown) for greater detail). Each interface may include a parity bit generator and checker to determine errors in transmission. Each bedside station also has a keyboard 46 for dictating commands to the system such as selecting certain data for display and communication with the central station 11 or for testing the various physiological data processors of the system. Part of a receiver interface is shown in Fig. 8. It comprises a "clock synchronous decoder" 110, Figs. 2 and 3 (not shown) that receives the clock signals and that provides the synchronizing pulse 112 and the clock pulses 113 which are received by a binary counter 114 that starts counting the clock pulses after a synchronizing pulse has occurred. A word and block timing decoder 115 detects when a particular number corresponding to the "time slot" of the receiver has been reached and then actuates "strobe input buffers and latches" 117 to receive incoming data on the data bus 116 and pass it on to the data processing and/or data display devices 118 and 119. A logic circuit for units 114 117 is described, Fig. 10 (not shown). A similar circuit, Fig. 9 (not shown) of the transmitting interfaces is disclosed. These circuits enable the transmission and reception of data by transmitting and receiving interfaces having the same "time slot". The data bus driver circuit which is part of the transmitting interface circuit is described, Fig. 12 (not shown). The data bus driver circuit is used for transferring generated data from its source to a data bus. The description deals with a format in which the information can appear on the data bus, Fig. 5 (not shown), and explains the assignment of the bits in the various data words, Fig. 7 (not shown).