JP2888890B2 - Indoor wireless communication device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an indoor radio communication apparatus for transmitting and receiving data between a fixed-position master station and a movable slave station using an electromagnetic field in a long-wave band. It is about.

2. Description of the Related Art A type of indoor wireless communication device for transmitting and receiving between a fixed-position master station and a movable slave station does not have a license stipulated by the Radio Law, so that anyone can easily handle it. In some cases, data communication can be performed using a weak output. For example, there is an ultra-high frequency band wireless communication device that exchanges data between a centralized monitor installed in a nurse center of a ward and a measuring device or a detecting device provided in a bed or a patient. However, since the ultrahigh frequency band wireless communication device is easily affected by shielding by a floor, a wall, or a living body, the communication range is narrow and data transmission / reception is often hindered.

Problems to be Solved by the Invention By the way, one end of a cable-like linear induction wire (fixed antenna) stretched indoors is connected to a master station, and a signal in a long wave band is transmitted and received through the linear induction wire. By
It is conceivable to transmit and receive data to and from a slave station. In this way, data can be transmitted and received using a long-wave charging magnetic field that is relatively unaffected by the surrounding environment, such as a nearby object, and the communication range can be expanded by extending the linear guide wire.

However, the above-mentioned indoor wireless communication apparatus has a disadvantage that if the extension distance of the linear guide line is increased in order to expand the communication range because the power is weak, the communication distance from the linear guide line becomes short. there were.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an indoor wireless communication device in which the communication distance from a linear guide wire does not decrease even if the extension distance of the linear guide wire is increased. Is to provide.

Means for Solving the Problems The gist of the present invention for achieving this object is to transmit and receive signals between a fixed station and a plurality of movable slave stations using an electromagnetic field in a long wave band. An indoor wireless communication device for: (a) a cable-like linear guide wire extending indoors and having one end connected to the master station; and (b) a predetermined position of the linear guide wire. The strength of the electromagnetic field formed by the linear induction line is increased by amplifying the signal output from the master station via the linear induction line and supplying the amplified signal to the linear induction line. On the other hand, at least one satellite station for amplifying a signal from the slave station received by the linear guide line and outputting the amplified signal to the linear guide line, (c)
Satellite control means for transmitting a signal, which is provided in the master station and permits the operation of the satellite in a time-sharing manner, via the linear guide wire.

In this manner, the satellite station inserted at a predetermined position of the linear guide line and operated in a time-division manner by the satellite control means outputs from the master station via the linear guide line. The signal to be amplified is amplified and supplied to the linear induction line, thereby increasing the electromagnetic field radiated from the linear induction line, while the signal from the slave station received by the linear induction line is amplified. Then, the signal is output to the linear guide line, so that the communication distance from the linear guide line can be suitably expanded even if the extension distance of the linear guide line becomes long.

Further, since the satellite stations are operated in a time division manner by the satellite control means, the occurrence of interference is avoided.

Embodiment Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.

In FIG. 1, a centralized blood pressure monitoring device 10 provided in a nurse room of a ward (not shown) includes a monitor body provided with an input / output device such as a keyboard and an image display device, and an arithmetic device.
12, by frequency modulation, etc. The output command data from the monitor main body 12, for example, into a signal of the carrier frequency f _L of about 30～500KHz, linear guiding line serves the signal as the fixed antenna 14 And a first transmission / reception circuit 16 for outputting the data to the first transmission / reception circuit. In this embodiment, the first transmission / reception circuit 16 functions as a master station. The above linear guide wire 14
Is a cable composed of a pair of conducting wires, and extends along a corridor near a ceiling in a ward, for example, to be movable in a sickroom on both sides of the corridor. The two-way communication can be performed between the apparatus and the centralized blood pressure monitoring device 10. Further, by supplying the signal of the frequency f _L to the linear induction wire 14,
An electromagnetic field in a long-wave band, which is relatively unaffected by walls and floors due to a long wavelength, is formed by the linear guide wire 14. One end of the linear guide wire 14 is connected to the first transmission / reception circuit 16 via a capacitor 17, and the terminal is connected to a terminator 18 via a capacitor 17. The terminator 18 is for matching, and has a predetermined impedance.

In the sickrooms located on both sides of the corridor, a second transmitting / receiving circuit 22 having a whip antenna 20 and a blood pressure measurement circuit 24 are provided.
An automatic sphygmomanometer 26 is disposed. This automatic sphygmomanometer 26 usually has its cuff attached to a patient on a bed and automatically measures the blood pressure value at a predetermined cycle or in accordance with a command from the centralized blood pressure monitoring device 10, while the measured blood pressure value is Is transmitted as a long wave via the second transmission / reception circuit 22. In the present embodiment, the second transmission / reception circuit 22 functions as a slave station.

In the present embodiment, a plurality of satellite stations 28a, 28b, 28c for extending the communication distance from the linear guide line 14 are provided on the linear guide line 14 at predetermined intervals.

As shown in FIG. 2, in the first transmitting / receiving circuit 16,
When the transmission data such as a command signal is output from the monitor main body 12, the transmission data is supplied via the control circuit 30 to the long-wave band modulator circuit 32, where it is and the power amplifier is frequency-modulated by the carrier frequency f _L. This long wave band modulation circuit 32
Are connected to the terminals a of the pair of transmission / reception changeover switches 34 and 36, respectively, so that the modulated signal representing the transmission data is transmitted according to the control signal from the control circuit 30. 36 is the transmitting side (a
Side), and is sent to the linear guide wire 14 switched to the side, from which a long-wave electromagnetic field representing the transmission data is formed. While the transmission data is being output from the monitor body 12, the control circuit 30 controls the transmission / reception changeover switches 34 and 36.
Is output to the master station transmission side (a side). In other cases, the pair of transmission / reception changeover switches 34 and 36 are switched to the master station reception side (b side) to thereby obtain a linear guiding line. The received data supplied from 14 to the long-wave band demodulation circuit 38 and obtained by demodulating the signal of the long-wave band frequency f _L therefrom is supplied to the monitor body 12.

Further, the first transmitting / receiving circuit 16 includes a DC stabilized power supply 4 for generating a DC voltage (for example, 15 V DC) from the power supply line 40.
Two are provided. This DC stabilized power supply 42 is supplied through a low-pass filter 44 to supply power to the satellite stations 28a, 28b, 28c via the linear induction wire 14.
And outputs a DC voltage between the two conductors.

Satellite station via the linear guide wire 14 as described above
The DC voltage sent to 28a, 28b, 28c is supplied via a low-pass film 48 to a satellite stabilized power supply 46 provided in each of the satellite stations 28a, 28b, 28c,
The output voltage (12 V) of the satellite stabilizing power supply 46 is supplied as power to the components of each satellite station 28a, 28b, 28c. Thereby, each satellite station 28a, 28b, 28
In c, independent power supply from the power supply line is unnecessary.

Next, the configuration of the satellite stations 28a, 28b, and 28c will be described. Since they have the same configuration, only the satellite station 28a will be described. As shown in FIG.
The satellite station 28a is interposed between two conductors constituting the linear guide wire 14. In the satellite station 28a, is switched to the illustrated position the pair of the changeover switch 50 and 52 at all times, the signal transmission frequency f _L through the linear guide line 14, after being demodulated in the demodulation circuit 54, an amplifier The power is amplified by 56 and supplied to the control circuit 58. The control circuit 58 is constituted by a so-called microcomputer,
It is determined whether or not the above-mentioned signal output from the control circuit 30 of the first transmitting / receiving circuit 16 includes the operation command signal of the satellite station 28a. In this regard, the control circuit 30 also functions as satellite control means for controlling the operation of the satellite stations 28a, 28b, 28c in a time-sharing manner. A signal output from the control circuit 30 includes, as in a so-called polling system, an operation command signal for alternately specifying each of the satellite stations 28a, 28b, 28c to sequentially operate the satellite stations 28a, 28b, 28c. It is included. Therefore, when the control circuit 58 detects an operation command signal for commanding the operation of the satellite station 28a, it operates according to a predetermined procedure. For example, in order to transmit the signal supplied to the respective automatic sphygmomanometer 26, the control circuit 58, after being frequency modulated at the carrier frequency f _L in the modulation circuit 60 the signal, it amplifies the power in the amplifier 62 lines To the shape-guiding wire 14. As a result, the above-described signal formed by the linear guide wire 14 is transmitted using the electromagnetic field in the long wave band. After that, the control circuit 58 switches the changeover switches 50 and 52 to the side indicated by the arrow in the drawing in a predetermined reception time zone. Thus, the signal of the carrier frequency f _L generated by the signal transmitted from the automatic sphygmomanometer 26 is received in the linear guide line 14, the demodulation circuit 54
After being demodulated at and amplified by the amplifier 56, it is supplied to the modulation circuit 60 through the control circuit 58.
After the signal is again modulated into a signal of the carrier frequency f _L in the modulation circuit 60 and power-amplified in the amplifier 62, the signal is supplied to the linear induction wire 14 through the changeover switches 50 and 52. The master station side and the terminal side of the linear guide wire 14 connected to both ends of the satellite station 28a are connected by a bypass circuit 14a.

The second transmission / reception circuit 22 of the automatic sphygmomanometer 26 is configured as shown in detail in FIG. The control circuit 70 is a blood pressure measurement circuit
While the transmission data indicating the blood pressure value or the like is being output from 24, the changeover switch 72 is switched to the slave station transmission side (b side), but when the transmission data is not being output, the changeover switch 72 is set to the slave station reception side. Side (a side). Therefore, the signal of the frequency f _L in the long wave band received by the whip antenna 20 as described above in a state where the transmission data is not output from the blood pressure measurement circuit 24 is demodulated by the long wave band demodulation circuit 74, The carrier wave having the frequency f _{L in} the long wave band is removed, and the transmission data output from the monitor main body 12 is taken out, and this data is transmitted through the control circuit 70 to the blood pressure measurement circuit 24.
Supplied to As a result, a start signal is supplied to the blood pressure measurement circuit 24, and a lamp indicating predetermined information provided in the automatic blood pressure monitor 26 is turned on.

On the other hand, transmission data such as measured blood pressure values by the blood pressure measuring circuit 24 is supplied to the long-wave band modulation circuit 76 through the control circuit 70, where it is frequency-modulated on a signal carrier frequency f _L is and the power amplifier. The signal of the frequency f _L thus modulated is supplied to the whip antenna 20 through the changeover switch 72 which is switched to the slave station transmission side (b), and the long wave and ultrashort wave radio waves are transmitted from the whip antenna 20. Radiated.

According to the indoor wireless communication apparatus of the present embodiment configured as described above, a plurality of satellite stations 28a, 28b, 28c inserted at predetermined positions of the linear guide line 14 The signal output from the first transmission / reception circuit 16 is amplified and supplied to the linear induction wire 14 so that the electromagnetic field formed by the linear induction wire 14 is strengthened. Since the received signal is amplified and output to the linear guide wire 14, the linear guide wire is independent of the length of the linear guide wire 14.
The communication distance from 14 is suitably expanded.

Further, according to the present embodiment, the satellite stations 28a, 28b, 28
Since c is operated in a time-division manner by the control circuit 30 functioning as satellite control means, the occurrence of interference is preferably avoided.

Further, according to the present embodiment, the power of the satellite stations 28a, 28b, 28c provided on the linear guide line 14 is
, The satellite stations 28a, 28
There is an advantage that the power supply work for b and 28c is not required and the work is simplified.

Further, according to the present embodiment, bidirectional communication is performed between the centralized blood pressure monitoring device 10 and the automatic sphygmomanometer 26 using an electromagnetic field in the long wave band, so that the effects of shielding the wall, floor, and living body are compared. There is an advantage that communication can be stably obtained even with an electromagnetic field of small power and low power.

As mentioned above, although one Example of this invention was described based on drawing, this invention is applied also in another aspect.

For example, in the embodiment of FIG. 3, even if the changeover switches 50, 52 or the bypass circuit 14a are removed, the operation of the satellite station 28a is not affected.

Further, although the power is supplied to the satellite stations 28a, 28b, 28c of the above-described embodiment through the linear induction wire 14, the power supply voltage transmitted through the linear induction wire 14, for example, 14 V, 16
V, 18V three kinds of predetermined voltage, the control circuit
A power supply device for sequentially outputting in a time-sharing manner in accordance with a command from 30 is provided in the first transmission / reception circuit 16, while each satellite station 28
Each of a, 28b, and 28c is provided with voltage detecting means for detecting a predetermined one of the three types of voltages, and is provided while a specific voltage is detected by the voltage detecting means. The operation of the satellite station in question may be configured to be permitted by the control circuit 58.

Further, although the power is supplied to the satellite stations 28a, 28b, 28c in the above-described embodiment through the linear induction wires 14, an independent power source for taking in power from the power supply line may be provided in the satellite stations.

The above is merely an example of the present invention, and the present invention can be variously modified without departing from the gist thereof.

[Brief description of the drawings]

FIG. 1 is a diagram for explaining an arrangement of a blood pressure monitoring system to which an embodiment of the present invention is applied. FIG. 2 is a block diagram showing a configuration of a first transmitting / receiving circuit of FIG. FIG. 3 is a block diagram illustrating the configuration of the satellite station shown in FIG. FIG. 4 is a block diagram illustrating a configuration of a second transmitting / receiving circuit in FIG. 14: linear guide line 16: first transmitting / receiving circuit (master station) 22: second transmitting / receiving circuit (slave station) 28a, 28b, 28c: satellite station 30: control circuit (satellite control means)

────────────────────────────────────────────────── ─── Continuation of front page (56) References JP-A-63-250224 (JP, A) JP-A-56-27540 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) H04B 5/00 H04B 7/26 H04Q 7/00-7/38

Claims (1)

(57) [Claims] 1. An indoor wireless communication device for transmitting and receiving between a fixed-position master station and a plurality of movable slave stations using an electromagnetic field in a long-wave band. And a cable-like linear guide wire connected to the master station, inserted at a predetermined position of the linear guide wire, and amplifies a signal output and supplied from the master station via the linear guide wire. The linear guide wire is supplied to the wire to increase the intensity of the electromagnetic field formed by the linear guide wire, while amplifying the signal received from the slave station received by the linear guide wire to increase the linear shape. At least one satellite station for outputting to a guide line, and satellite control means provided at the master station and transmitting a signal that allows the operation of the satellite in a time-sharing manner via the linear guide line. An indoor wireless communication device characterized by the above-mentioned.