JPS6375586A - Ultrasonic type object-position discrimination system - Google Patents

Abstract

(57) [Abstract] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to an ultrasonic object location identification system. , is configured as an electronic system for.

The system according to the invention can be used, for example, as an ultrasonic personnel location identification system using Prus code modulation transmission.

4' White [Prior Art and Problems to be Solved by the Invention] In large room complexes, identifying the positions of various personnel;
is often desirable. For example, in a hospital room, it is important for the head nurse and other nurses at the central station to know in which rooms various types of people, such as other nurses and assistants, are located. It happens often.

Staff location systems of the type discussed above are well known and widely used in hospitals. One such system has a switch in each room that is turned on when the nurse and/or assistant enters the room. The switch is connected to the central nursing stage block, which displays the staff's position. The problem with this type of system is that
Employees often forget to activate switches to enter and exit rooms. As a result, the information obtained by the central station is also being used. These types of systems have RF or IR receivers in each patient room. Each receiver is connected to its central station.

Portable transmitters carried by personnel periodically transmit RF or IR wound signals specific to that personnel. When they enter the room, they are detected by an RF or IR wound signal receiver. The receiver then informs the central station of its location.

The signals produced by the RF transmitters of these systems tend to be detected by receivers in adjacent rooms.

IR transmitters have the opposite problem. The signal transmitted by an IR transmitter is highly directional and may not be detected by a receiver in the room, depending on the placement of the person. Ultimately, the use of the exemplary system results in an unreliable display at the central station.

It is clear that there is a continuing need for improved personnel location identification systems. For convenience and accuracy, the system must operate without any action on the part of a human who needs to know its location. The system also
It must be able to recognize personnel regardless of their position or arrangement within the room, and must not be perceptible to personnel in adjacent rooms.

Simply put, the system must be such that the central station provides highly accurate information of reliable personnel in case of an emergency.

[Means to solve problems]

The present invention is an ultrasonic system for the complete location identification of personnel in a collection of rooms. The system has at least one
All three ultrasonic transmitters are suitable for being carried by personnel and emit one ultrasonic transmission signal that characterizes the personnel. A plurality of ultrasound receivers are placed in each room of the assembly. The receiver receives the transmitter signals and generates a received signal representative of each. 1
A central station is connected to each receiver so that the receiver signal can be used to display the room in which the transmitter is walking.

In an advanced embodiment, the transmitter periodically uses pulse code modulation (
The PCM transmits an ultrasonic transmission signal representing the digital code sequence characteristic of the transmitter rich walking staff (~. defined by a predetermined number of bit positions separated from the

The ultrasound receiver is adapted to receive the PCM transmission signal and detects bits of the code sequence only in window periods that correspond in time to expected bit positions. The detected digital code sequence is compared with a predetermined code sequence. The receiver signal is created as a function of the comparison,
sent to the central station.

The ultrasonic personnel location identification system of the present invention overcomes the related problems of the prior art. The ultrasonic signal is transmitted with enough power to cause reflections from the walls of the room, ensuring reliable reception by the receiver regardless of the placement of the transmitter (and even better reception in adjacent rooms). Since the bits of the PCM signal are separated from adjacent bits, the reflections from the previous bin are appropriately attenuated before the other code bits are transmitted.As expected. By detecting the bits of the transmitted signal received only during the window period corresponding to the bit positions, reflections and common interference from other transmissions are greatly reduced.The system is therefore very accurate and reliable. be.

〔Example〕

The ultrasonic personnel location identification system 10 of the present invention is generally illustrated in FIG. Personnel location system 10 is suitable for use in a hospital complex, such as a communal patient room 12, which includes multiple rooms 1.2A-12D. Ultrasonic receiver 14. A to 14D are the respective chambers 12A to 12D
It is located within.

The receivers 14A to 14D are connected to the central nurse station 16.
are connected to a central station via transmission lines 18A to 18Di, respectively. The ultrasonic personnel location system 10 also includes one or more ultrasonic transmitters 20.
A to 20Bffi are included, and they are portable to nurses 22A and assistants 2 who are in or move to the common hospital room 12.
Suitable to be carried individually by 2B. Transmitter 2
Desirably, 0A to 20B are small and unobtrusive devices that can be fastened to a part of clothing.

In operation, the personnel location identification system 10 is used to locate all personnel present in the ward 12, such as nurses 22A and assistants 22B. The transmitters 2QA-20B generate and transmit all ultrasound transmission signals characterizing the personnel carrying transmitters. In this embodiment, transmitters 20A to 20B
transmits pulse code modulated (pCM) ultrasound signals characterized by the type and job of personnel 22A-22B;
.

For example, transmitter 2OA transmits a PCM signal representing nurse 22A, while transmitter 20B transmits a PCM signal representing nurse 22B'i.
Send a CM signal. Transmitters 20A-20B can also generate unique code-full transmission signals representing the identity of nurse 22A and assistant 22B.

Whenever a nurse 22A or assistant 22B enters one of the rooms 12A-12D, the receivers 14A-1 located there
40 receives the transmitted signals sent out by transmitters 20A-20B and produces respective representative receiver signals for transmission to central station 16. In response, the central station 16 displays the room in which the personnel is located, and at the same time displays the employee's job function, identification and other characteristics.

In one embodiment, station 16 provides a visual display of this information. For the embodiment shown in FIG. 1, station 16 would indicate that assistant 22B is in room 12D and nurse 22A is in room 12A.

A typical pulse code modulated transmitter signal 30 generated and transmitted by transmitters 20A-20B is generally shown in FIG. The transmitter signals 30 are Norms code modulated (PCM) separated by a predetermined interval 35.
The ultrasonic carrier signal 32 is generated by periodically turning on and off a plurality of portions 34 .

One period of signal 30 is indicated by 36. In one embodiment described below, carrier signal 32 is 40.96 k
This is a Hz ultrasonic signal. PCM section 34 has a length of approximately 488.5 m5ec. To ensure interference-free transmission, it is desirable that transmitters 20A-20B generate transmitter signals 36 with different periods 36. In one embodiment, the transmitter 2OA transmits a transmitted signal 30 with a period of 2.5 seconds.
On the other hand, the transmission signal 30 of the transmitter 20B has a period of 2.
It is 0 seconds.

As shown in FIG. 2, PCM portion 34 is formed from a plurality of pit locations 38A-38E, each pit location representing a digital value. Bit positions 38A-38E are separated from each other by a period of 40. In one embodiment returned, bits 38A-38E have a length of 4.9 m5 ec and are separated from each other by 40 periods of 97.7 ms, e3. 3
Pit positions such as 8A, 38D and 38E represent digital t-1'2 and transmit ultrasonic carrier signal 32 to
generated by switching ``on''. Bit positions such as 38B and 38c, which represent digital ``0'', are generated when carrier signal 32 is switched or held ``off''.

In the embodiment of the invention described below, r10 of PCM portion 34
The 011J code sequence is transmitted by transmitter 20A and indicates the characteristics of the nurse. For example, the transmitter 20B transmits r 11001. which indicates the characteristics of the assistant. A transmitter signal of the PCM portion 34 representing the code sequence of J can be generated.

Preferably, the first bit position 38A of all PCM portions 34 has a value of digital "1", and the first bit position 38A of all PCM portions 34 is
14D as a start or parity bit for timing. Bit positions 1i 38B-38E thus characterize the person carrying receivers 20A-OBi.

A configuration diagram of one embodiment of the transmitter 2OA, which is a representative of the transmitters 20A to 20B, is shown in FIG. A Pierce-shaped oscillator circuit 49 is formed by inverters 50 and 64, resistors 52 and 54, capacitors 56 and 58, and a tuning fork crystal 60. In this example, the crystal 60 is 40.96
kHz frequency, causing oscillator circuit 49 to generate a 40.96 kHz signal at node 62.

The 40.96 kHz signal produced by oscillator 49 is applied to timing circuit 66 for processing. Timing circuit 66 includes flip-flops 68 and 70, Johnson counters 72, 74 and 76; binary counter 78, and and darts 80, 82 and 84. Flip-flop 68 is connected to divide the signal received from oscillator 49 and produce a 20.48 kHz signal to the clock (CL) input terminal of Johnson counter 72.

Johnson counters 72 and 74 act as frequency dividers, dividing the frequency of the applied signal by a factor of ten. 2.
Signals with frequencies of 0.48 kHz and 204.8 Hz are generated at the Qo output terminals of Johnson counters 72 and 74, respectively. Flip-flop 70 divides the frequency of the signal received from Johnson counter 74 by two, producing a 102.4 Hz signal at its output terminal Qo. The frequency of this signal is 1/10 by Johnson counter 76.
The 10.24Hz signal is sent to the output terminal Qo.
occurs in Ql. Johnson counters 72, 74 and 76 are digital "1" for one-tenth of their period.
serves to produce an asymmetric output signal having a value of . Therefore, the digital signal output terminals Qo and Ql of the counter 76 are 9.77 m5ec in the period of 97.7 m5ec.
is in a high state during .

Below, the 6-millimeter counter 78 is a 14-step binary counter, and its clock (cp) terminal is the output Q of the flip-flop 70. 102.4Hz signal from or Johnson counter 7
2 Q. Switch the 2.048kHz signal from the output to switch 8.
Receive through 6. Switch 86 is 2.048 kHz
When the z signal is selected, the frequency of this signal is divided by 4096 by counter 78, producing an output signal of 0.5 Hz at its Qll output. When switch 86 is actuated to select 102.4 Hz, the frequency of this signal is determined by counter 78 at 256 Hz.
The result is 0.4I (the z signal is Q7
Sent from the output terminal.

Transmitter 20A also includes a shift register 88 that is loaded in parallel and outputs sequentially. Input terminals P7-P3 are fixedly wired to receive a supply voltage representing the digital code sequence to be transmitted.

Other input terminals such as p, , p2 and P8 are connected to ground. In the embodiment shown, shift register 8
8 is connected to receive a signal representing the rloollJ code sequence. The input terminal of P/8 is counter 7.
The output of Q7 or Q1□ of 8 is connected through a switch 90 so as to receive either a 0.4 or 0.5 Hz signal, respectively. Shift register 88 receives 10.24 Hz from Johnson counter 76 at its CL terminal.
It is clocked by receiving the signal.

If the signal received from counter 78 switches from one to
This becomes a parallel load of P7. If this signal switches to a low level, the signal from the Q8 output terminal of the shift register 88 is output from the AND gate 82 at a clock frequency of 10.24 Hz.
The loaded bits are sequentially transferred to the input terminals of .

Johnson counter 76 Q. 10.24 from output
Hz signal, 102.4 from Flip Flora 7″70
Hz signal, the sign bit sequence shifted out from shift register 88, and the 40.96 Hz signal from oscillator 49.
The kHz signal is ANDed by a combination of AND gates 80, 82 and 84 and pulse code modulated according to a code sequence applied to a shift register 88.
．． A 96 kHz transmit signal 30 is generated. Third
The circuit shown will generate a transmit signal 30 at node 92 similar to that shown in FIG. The gap between the bits of the signal is 97.7 m5ec. The value of digital “1” is 4,8 in the 40.96 kHz signal.
It is represented by a burst of 8m5ec. 38A.

Bit positions such as 38D and 38E are digital
1'', which as described above contains approximately 122 cycles of a 40.96 kHz signal. This signal is set to 2.0 or 2.5 depending on the set of switches 86 and 90.
It will have a duration of seconds.

NoJ from node 92? The Ruth code modulated signal is transmitted through inverters 96, 98 and 100 or capacitors 102 and 1.
04 to the output stage 94.

Output stage 94 includes diodes 106 and 108, transistors 110 and 112, transformer 114, and ultrasonic transducer 116.
and capacitor 118. The ultrasound transmit signal 30 shown in FIG. 2 is transmitted by an output stage 94.

Ultrasonic receiver 14A which is representative of receivers 14A to 14D
Selected circuit embodiments are illustrated as block diagrams in Figures 4 to 4C. First, referring to FIG. 4(A), a pulse code modulated ultrasonic transmission signal 30 (FIG. 2) is received by an ultrasonic transducer 130 and transmitted to three amplification stages 132, 13.
4 and 136. Width increase stage 132-1
36 bias network includes resistors 138, 140 and 1
42, also formed by capacitors 144 and 146.

The first stage of amplifier 132 includes an operational amplifier 147 and a capacitor 14
8 and 1501 and resistors 152, 1.54 and 156
including. Amplification stage 134 includes operational amplifier 158, capacitors 160 and 162, and resistors 164, 166 and 16.
formed by 8.

The amplifier stage 136 includes an operational amplifier 170 and a capacitor 172.
, also formed by resistors 174 and 176. In one embodiment, the combined gain of amplifier stages 132, 134 and 136 is 60,000. Capacitors 146, 144,
150 and 162, and resistors 1421156 and 1
The power supply provided by 64 and associated decoupling circuitry ensure stability at this high gain.

The signal output from the amplification stage 136 is
79, a capacitor 180 and a resistor 182 to a Schmitt trigger circuit 178. Schmitt trigger circuit 178 processes the signal received from amplifier stage 136 in a well-known manner to ensure that the signal is in the form of a square wave.

Demodulator/detector 191 is illustrated in FIGS. 4B and 4C. Demodulator/detector 191 includes a Pierce-shaped oscillator 19 formed by an inverter 193, resistors 194 and 196, a tuning fork-shaped tuned crystal 198, and capacitors 200 and 202.
Contains 0. Oscillator 190 is buffered by inverter 192 to produce a 20.48 kHz signal.

The 20.48 kHz signal from buffer 192 is applied to the clock (CL) terminal of Johnson counter 204, which divides the frequency of the signal by 10 to generate a 2.048 kHz signal at its Q terminal. The 2-048 kHz signal is then converted to a Johnson counter 20
6, and 206 again divides the frequency of this signal by 10 to generate a 204.8 Hz signal at its Q output terminal. johnson counter 20
This 204.8 Hz signal generated by 6 is applied to the clock (CL) terminal of flip 70 tube 208. A 7-rig flop 208 is configured to divide the frequency of this signal by two, producing a 102.4 Hz signal at its Q output terminal.

The 102.4 Hz signal from flip-flop 208 is applied to the clock (CL) input terminal of Johnson counter 210. Johnson counter 210 Q2,
Although only the terminals Q7, Qll, and Q are shown, it is the output terminal Q. -Q.

It is a 5-stage device with Terminal Q with continuous cycles of the 102.4 Hz clock signal. ~Q, are sequentially switched to the value of digital "1", while all others remain at the value of digital "O" (at t9).

Demodulator/detector 191 also includes flip-flops 212,
Single or monostable multivibrators 214 and 21
6. Binary counter 218, or dirt 220, 222.
and 224, AND darts 226 and 228, and a shift register 230 (FIG. 4(C)). OR gate 220 is connected such that its input terminals receive the signals appearing at the Q and Q8 output terminals of Johnson counter 210, while OR gate 222 receives at its input terminals the signals appearing at the Q2 and Q7 output terminals of Johnson counter 210. connected like this. The outputs of OR gates 220 and 222 are applied as inputs to OR gate 224. The output of ORDART 224 is applied to the reset (R) terminal of counter 218. Therefore, the counter 218 is
Johnson counter 210 Q2 , Q7 , Q8 ,
or Q, which is reset when one of the outputs goes high.

The counter 218 has one clock (CL) terminal,
Schmitt trigger circuit 178 increased 1] 4 0.9
It is connected to receive a 6 kHz signal. AND-DATE 226 has an input terminal connected to receive the signals appearing at the Q3 and Q6 output terminals of counter 218. The signals appearing at the Q4 and Q6 output terminals of counter 218 are applied to the input terminals of ANDGOO 228.

Flip-flop 212 has one clock (CL) terminal connected to receive the output signal of AND gate 226. 7 Ritzo flop 212 is configured such that the signal appearing at its Q output terminal applied to the trigger (11) terminal of monostable multivibrator 214 changes state by cycles following the signal received at its clock terminal. .

The monostable multivibrator 2 ] 4 has one output (
0) It has a terminal. Complementary output (0) terminal is flip-flop 208, Johnson counter 2
06 and 210 and reset of shift register 230 (
R) is coupled to the terminal. The monostable multivibrator 214 is designed to have a time constant sufficient to demodulate the 3° PCM portion 34 (FIG. 2) of the transmitted signal received by the demodulator/detector 191 and detect the code sequence therein. is formed. In order to demodulate the ultrasonic transmission signal 30 as described above, a monostable multivibrator 214H of about 500m5e is used.
It is formed to have a time constant of c.

Multivibrator 216 has one trigonium terminal connected to accept the signal appearing at the output of AND gate 228. The output (0) terminal of multivibrator 216 is coupled to the data (D) terminal of shift register 230. The multivibrator 216 functions as a pulse expansion device and is configured to have a time constant of approximately 22 m5ec for use with the 3° transmission signal.

Shift register 230 has one clock (CL) terminal connected to receive the signal of 1 0.24 H7, at output terminal Q2 of Johnson counter 210. The data sequentially shifted into shift register 230 appears in one parallel form at its output terminals Oo-04.

The operation of the demodulator/detector 191 is shown in Figures 4) and (c).
and a timing diagram is shown in FIG. Receiver 14. Once received by A, the PCM portion 34 of the transmitter signal 3o is transmitted to the amplification stage 132.
, 134. and 136 and the Schmitt trigger 1 before being applied to the clock (CL) terminal of counter 218.
78. Following the example used above, the l''CM portion 34 illustrated in FIG. 5 has bit positions 38A-38E, which correspond to the received rloo
It represents a code series called llJ indicating the characteristics of a nurse.

As previously discussed, the first bit position 3 of portion 34 of the PCM
8A has a value of digital "1" and receiver 14A is used with the start bit. counter 218
After receiving 72 cycles of the 40.96 kHz carrier signal 32 forming the first digital ``1'' at pit location 38A, the AND GO-4226 sends a 7-lip-flop 212 clock signal, which is also monostable. Trigger the multivibrator 214. The signal at the O output of monostable multivibrator 214, illustrated as 242 in FIG. 5, is switched to a low level, causing counters 206 and 210 . Flip-flop 208 and shift register 230 are reset. The monostable multivibrator 214 described above.

The output remains low for approximately 500 m5ec, which is the time required to demodulate the 5-bit code in portion 34 of the PCM.

The counter 218 receives a 40.96 kHz carrier signal 32 representing that the pit positions 38A-38F have a value of digital "1" only when the reset signal 244 applied to the reset (R) terminal is at a low level. Count the cycles. The reset signal 244 is the OR gate 220
．． 222 and 224 is illustrated in FIG.

As shown, the reset signal 244 includes a window period W during which the signal is at a low level.

The reset signal 244 is high on both sides of the window period W. The window period W occurs at the time when a digital value in bit positions 38B through 738E can be expected with respect to the first bit position 38A. Therefore the receiver 14
A is insensitive to stray ultrasound signals that can be mistaken for digital "1n code beeps".

40,9 by the counter 18 during the window period W
When 80 cycles of the 6 kHz carrier signal 32 have been counted, that is, when a bit position representing a digital "1" has been received, the AND counter 228 triggers the multivibrator 216 to output the signal at its O output terminal. At a high level. The signal 245 at the O output terminal of multivibrator 216 is illustrated in FIG. Monostable multivibrator 216 acts as a pulse extender and generates pulses of 22m5ec, representing bit positions 38A-38E, which provide a digital "1" value to the data (D) terminal of shift register 230.

Clock signal 246 goes high at output terminal Q2 of Johnson counter 210 for 1'19.8 m5ec of each window period W of signal 244.

The clock signal 246 is the clock of the shift register 230 (C
L) applied to the terminal. As a result, a digital code sequence representing the digital state of signal 245 during window period W, and thus representing the code sequence of PCM portion 34 of transmitted signal 30, enters shift register 230 as a clock signal. Output terminals oo, o, , o, , o8 . and 04 are therefore digital states representative of the 5-bit code of the PCM portion 34 of the received transmission signal 30.

Receiver 14A also includes comparators 250 and 252 that compare the detected code sequence appearing at output terminals 0O-08 of shift register 230 by a predetermined code. Terminal B of comparator 250.

-B3 is the most 4 bits of the code sequence transmitted by the transmitter 2OA, and is a rool indicating the characteristics of the nurse.
It is connected to receive a supply voltage representing a code sequence of lJ. Comparator 252 has an input terminal Bo-B fixedly wired to receive a supply potential representing the fl-most 4 bits of the other expected code sequence. In the embodiment shown, terminal B. -B3 is connected to receive a supply potential representative of the 1001 code sequence transmitted by transmitter 20B and representative of the assistant's characteristics.

When shift register 230 receives the fifth clock signal after being reset, a digital "1" in starting bit position 38A is clocked into the 04 output. Comparator 25
At this time, input terminals 0 and 252 (Che9=3) become high level. As a result, comparators 250 and 252 have input terminals B0
The code series fixedly wired to ~B3 and the code series appearing at the output terminal 0°-03 of the shift register 230 are compared. As a result of a favorable comparison in comparator 250 or 252, its output terminal 0A=B
The signal at the signal goes high, generating a pulse indicating that a transmitted signal with a special code sequence has been received.

Receiver 1.4. A also includes counter/timer circuits 360 and 362 connected to receive signals from comparators 250 and 252, respectively. Circuits 360 and 362 generate a receive signal only if a predetermined number characterizing special people, such as an assistant or a nurse, is received within a predetermined time. The received signals produced by detectors 360 and 362 are continuously communicated to central station 16 (FIG. 1) through driver circuitry (not shown) throughout the time the presence of the persons is detected.

The counter/timer circuit 360 includes monostable multi-pie breaks 364 and 366, and flip flora fs 368 and 3.
70. Counter/timer circuit 3
62 includes monostable vibrators 372 and 374 and Frino flops 376 and 378. circuit 36
The operation of counter/timer circuit 360, which is also representative of the operation of No. 2, is as follows.

The pulse produced at terminal 0A=H of comparator 250 is applied to the trigger input terminals of monostable multivibrators 364 and 366 and to the clock (CL) input terminals of flip-flops f 368 and 370. Comparator 250
By receiving the first i9 pulse from the flip-flop 368 and 370, a clock signal is given to the clear die reflex (CD) terminal of the flip-flop 368 and 370 by the signal from the 0 terminal of the multivibrator 364,
The states of 70 and multivibrator 366 are cleared. By receiving three more subsequent pulses during the time constant of the multivibrator 364 of the previous pulse, the signal at the output terminal 0 of the multivibrator 366 goes to level 7, indicating the transmitted signal characteristic of the nurse. 3
A received signal is generated indicative of a zero detection. In other words,
4 subsequent PCs with code sequences representing nurse characteristics
M portions 34 and those within 6 seconds of the previous one must be identified by comparator 250 before counter/timer circuit 360 produces a received signal. A received signal is continuously produced by circuit 360 until six seconds have elapsed without receiving a reply from comparator 250.

One embodiment of the central station 16 is illustrated in FIG. Central station 16 is connected to receive received signals from receivers 14A-14D. In the embodiment shown in FIG. 6, the central station 16 receives on a separate transmission line the received signals representing the receiver 14A and the assistants and nurses generated as described above. Connected. Each room 12A in section 12 of the hospital
For 12D, the central station 16 includes a room reference designation, such as the word rRoom 12A J. It also has devices such as 380 LEDs that provide a visual indication of the presence of nurses and assistants. In response to a received signal from one of the receivers 14A-14D representing either a nurse or an assistant, an LED indicating the same.
380 emits light. In the example shown in FIG. 6, the central station 16 indicates that the nurse is in room 12A and the assistant is in room 12D, as shown in FIG.

The personnel location system 10 described above provides several advantages over conventional techniques. The ultrasound signals generated by the aforementioned transmitters do not have sufficient power to penetrate the walls separating the rooms of the assembly. As a result, these transmitters will not overwhelm receivers in adjacent rooms and give false indications to the central station. Directionality problems often associated with infrared systems are also overcome by the present invention. Since the detectors of receivers 14A-14D are timed to "listen" for bits of the transmitted signal code sequence for an expected amount of time, i.e., window period W, the output power of the transmitted signal is It can take relatively large amount of power. At these high power levels, the transmitted power is reflected from the walls of the room with sufficient strength to be detected by the receiver regardless of the location of the transmitter. These reflections will not interfere with detection of the original bits. The reason is that they are always shielded from the receiver except during window periods.

The spacing between the bits of each PCM section will also allow reflections to weaken. Interference-free transmission is further ensured by varying the periods of the signals transmitted by the transmitters used by different types of people.

Although the invention has been described above with reference to preferred embodiments, those skilled in the art will recognize that changes may be made in form or detail without departing from the spirit or scope of the invention.

[Brief explanation of the drawing]

Fig. 1 is a block diagram showing the ultrasonic staff location identification system according to the present invention, and Fig. 2 shows some details of the ultrasonic transmission signal transmitted from the ultrasonic transmitter shown in Fig. 1. FIG. 3 is a schematic diagram showing a preferred specific example of the ultrasonic transmitter shown in FIG. A schematic diagram showing a preferred embodiment of a sonic receiver; FIG. 5 is a diagram showing the timing of signals in the portion of the circuit shown in FIGS. 4(4) to C); FIG. FIG. 3 is a diagram showing a specific example of a central station. 10...Ultrasonic employee location identification system, 12...
Common patient rooms, 12A-12D...rooms, 14A-14D...
...Ultrasonic receiver, 16...Central nurse station, 18A-18D...Transmission line, 20A-20B...
Ultrasonic transmitter, 22A...Nurse, 22B...Assistant.

Claims (1)

[Claims] 1. An ultrasonic location identification system for identifying the location of personnel within a collection of rooms, the system comprising: an ultrasound transmitter for transmitting an ultrasound transmission signal characterizing the personnel; a plurality of ultrasound receivers, each transmitting an ultrasound transmission signal characterizing the personnel;
a central station adapted to be located in a room and receiving the signal of the transmitter and generating a receive signal as a function of the transmit signal; an ultrasonic location identification system comprising: receiving a transmitter and generating an indication of the room in which the personnel transporting the transmitter is located; 2. The ultrasonic position identification system according to claim 1, wherein each of the ultrasonic transmitters periodically sends out a transmission signal at a predetermined rate. 3. The ultrasonic location identification system includes a plurality of ultrasonic transmitters, some of the ultrasonic transmitters emitting transmit signals at different predetermined rates. The ultrasonic position identification system according to item 2. 4. The ultrasonic location identification system includes a plurality of ultrasonic transmitters, some of the ultrasonic transmitters emitting transmitted signals indicative of the employee's job function. The ultrasonic position identification system according to item 1. 5. The ultrasound transmitter periodically sends out transmission signals at a predetermined rate, and the transmission signals representing characteristics of different job functions are sent out at different predetermined rates. The ultrasonic position identification system according to scope 4. 6. The ultrasound transmitter emits a pulse code modulated (PCM) ultrasound transmission signal that is characteristic of a digital code sequence of the personnel carrying the transmitter. Ultrasonic location identification system. 7. The ultrasonic position identification system of claim 6, wherein the ultrasonic transmitter sends out a PCM transmission signal with a predetermined number of bit positions representing the digital code sequence. 8. Each bit position of the PCM transmission signal is separated from neighboring bit positions by a predetermined time interval;
An ultrasonic position identification system according to claim 7. 9. Each ultrasound receiver is a receiver suitable for receiving a pulse code modulation (PCM) transmission signal representing a digital code sequence, and includes a detector for detecting the code sequence. The ultrasonic position identification system according to item 1. 10. the ultrasonic receiver is adapted to receive an ultrasonic PCM transmission signal in which a predetermined number of bit positions are separated from adjacent bit positions by a predetermined time interval; 10. The ultrasonic position identification system of claim 9, wherein the bits of the code sequence of the PCM transmission signal are detected during a window period only according to expected bit positions. 11. The ultrasonic receiver includes comparison means, and at least one
10. Ultrasonic position identification system according to claim 9, comprising detection means for comparing the detected code sequence with a predetermined code sequence, and providing a receiver signal as a function of the comparison. 12. The ultrasound receiver includes counter/timer means, the means generating a receive signal only if a predetermined number of PCM transmit signals are received during a predetermined time period; An ultrasonic position identification system according to claim 11. 13. An ultrasonic location identification system for identifying the location of personnel in a collection of rooms, the system comprising a plurality of ultrasonic transmitters suitable to be carried by the personnel; , transmitting a pulse code modulated (PCM) ultrasound transmission signal representing a digital code sequence representative of the characteristics of the personnel; a plurality of ultrasound receivers each receiving the ultrasound transmission signal and each receiving the ultrasound transmission signal; a central station adapted to be located within a chamber of the body and comprising detection means for detecting a digital code sequence and generating a received signal as a function of the detector; and a central station coupled to the receiver; , receiving the received signal and generating an indication of a room in which the personnel carrying the transmitter is present. 14. The ultrasonic system according to claim 13, wherein each ultrasonic transmitter periodically transmits its transmission signal at a predetermined rate. 15. The ultrasonic location identification system of claim 13, wherein the ultrasonic transmitter emits a transmitted signal indicative of the employee's job function. 16. Claim 15, wherein the ultrasound transmitter periodically sends out transmission signals at a predetermined rate, and the transmission signals indicative of different job functions are transmitted at different predetermined rates. The ultrasonic position identification system described in Section 1. 17. The ultrasonic position identification system of claim 13, wherein the ultrasonic transmitter transmits a signal having a predetermined number of bit positions representing a code sequence. 18. The ultrasonic position identification system of claim 17, wherein the bit positions of the transmitted signal are separated from adjacent bits by a predetermined time interval. 19. Ultrasonic position identification according to claim 18, wherein the detector means of the receiver detect bit groups of the code sequence of the transmitted signal only during a window period depending on the expected bit position. system. 20, wherein the ultrasound receiver includes comparison means responsive to a signal from the detection means for comparing the detected code sequence with a plurality of predetermined code sequences representing different job functions. The ultrasonic position identification system according to claim 19. 21. The ultrasonic receiver according to claim 20, wherein the ultrasonic receiver includes means for generating a received signal only when a predetermined number of transmitted signals are received during a predetermined period. Sonic location identification system. 22. An ultrasonic receiver suitable for use in an ultrasonic location identification system, the receiver being one of a plurality of receivers each located in one of the gathering rooms, the transmitter A pulse code modulation (PCM) transmission characterized by a code sequence of the person transmitting and carrying the transmitter and formed by a predetermined number of bit positions separated from adjacent bit positions by a predetermined period of time. interfaced with a central station adapted to receive signals and providing an indication of the room in which the personnel carrying the transmitter is located; an ultrasonic receiver comprising window detection means for detecting bits of the code sequence only during a window period. 23. An ultrasonic transmitter suitable for use in an ultrasonic personnel location identification system, wherein each transmitter is carried by one personnel and transmits ultrasonic waves characteristic of that personnel. one of a plurality of transmitters suitable for transmitting the transmitted signal and adapted to operate with a plurality of ultrasound receivers located in the assembly chamber for receiving the transmitted signal; The ultrasonic transmitter provides a received signal to a central station that provides an indication of the room in which the person carrying the person is located, and the ultrasonic transmitter provides a pulse code modulated (PCM) transmitted signal characteristic of the person's code sequence. an ultrasonic transmitter formed by a predetermined number of bit positions that transmit and are separated from adjacent bit positions by a predetermined period of time;