RU2473324C2 - Walking stick for visually impaired person - Google Patents

Abstract

FIELD: medicine.

SUBSTANCE: claimed stick relates to medical equipment, in particular to devices for blind people orientation in surrounding space, and can be used in independent movement of a blind person. Walking stick contains stick with handle, in which placed are: receiving emitter, installed on walking stick with possibility of changing angle of inclination to stick axis in the plane of walking stick symmetry, unit of information processing, power source, signaler, transmitter with antenna, switching on button, pendulum switch, relay and receiver with antenna. Transmitter is made in form of successively connected setting high-frequency generator, phase manipulator, whose second inlet is connected with outlet of pseudorandom succession, and power amplifier, whose outlet is connected to transmitting antenna. Receiver is made in form of registration unit, signalisation unit and successively connected receiving antenna, high-frequency amplifier and delay line. In addition, receiver is provided with three adders, phase changer for 180° and two detectors of envelope.

EFFECT: application of invention makes it possible to increase noise immunity and reliability of alarm signal transmission due to increase of dynamic range of inlet signals and ratio signal/noise in reception of weak signals.

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Description

The proposed cane relates to medical equipment, in particular to devices for orienting the blind in the surrounding space, and can be used in the independent movement of a blind person in a non-deterministic environment, as well as in extreme situations when a blind person needs urgent medical attention.

Canes for the visually impaired are known (auth. Certificate of the USSR No. 957.901, 1.503.809, 1.738.283; RF patents No. 2.064.789, 2.184.518, 2.280.429, 2.352.317; US patents No. 3.646. 949, 3.881.504, 5.197.502, 5.341.829, 5.445.175; EP patents No. 0.016.606, 1.025.828; R. Kokhnyak With a white cane // Our Life, 1997, No. 1, p. 22 and others).

Of the known canes, the closest to the proposed one is the "Cane for the visually impaired" (RF patent No. 2,353.317, А61Н 3/06, 2007), which is selected as a prototype.

A well-known cane for the visually impaired contains a stick with a handle, as well as a transceiver, a processing unit, and an annunciator connected by an electric circuit. The transceiver is mounted in a cane with the possibility of changing the angle of inclination to the axis of the stick in the plane of symmetry of the cane and is equipped with operative control of the angle of inclination during the movement of the user.

At the same time, in extreme situations, an alarm is transmitted over the air to rescuers, doctors or relatives equipped with receivers. The receiver includes a phase detector, consisting of a multiplier and a low-pass filter.

A disadvantage of the known cane for the visually impaired is the presence of a multiplier having a small dynamic range of input signals, a limited bandwidth and low slope, which degrade the signal-to-noise ratio at signal levels comparable to the level of the receiver's own noise.

In addition, the presence of multiplication products (harmonics of higher orders) reduces the efficiency of the receiver and requires the installation of filters that highlight useful information.

All this ultimately leads to a decrease in noise immunity and reliability of the alarm transmission to rescuers, doctors or relatives equipped with receivers.

An object of the invention is to increase the noise immunity and reliability of the alarm transmission to rescuers, physicians or relatives by increasing the dynamic range of the input signals and the signal-to-noise ratio when receiving weak signals.

The problem is solved in that the cane for the visually impaired, containing, in accordance with the closest analogue, a stick with a handle, as well as a receiving emitter interconnected by an electric circuit mounted on a cane with the ability to change the angle of inclination to the stick axis in the plane of symmetry of the cane, information processing unit, source power supply, signaling device, transmitter with antenna, power button, pendulum switch, relay and receiver with antenna, the power button, relay and pendulum are connected in series with the power source the transmitter, as well as the transmitter through closed relay contacts, the transmitter is made in the form of series-connected master oscillator, phase manipulator, the second input of which is connected to the output of the pseudo-random sequence generator, and the power amplifier, the output of which is connected to the transmitting antenna, the receiver is made in the form of a registration unit, block signaling and series-connected receiving antenna, amplifier, high frequency and delay line, differs from the closest analogue in that the receiver is equipped with three sums by 180 ° phase shifters, two envelope detectors, and the first adder is connected in series to the output of the delay line, the second input of which is connected to the output of the high-frequency amplifier, the first envelope detector and the third adder, to the output of which a recording unit and an alarm unit are connected, to the output the delay line is connected in series with a 180 ° phase shifter, a second adder, the second input of which is connected to the output of the high-frequency amplifier, and a second envelope detector, the output of which is connected to the second input retego adder.

Figure 1 presents a General diagram of the implementation of the canes in the context. The structural diagram of a special sensor mounted in a cane is shown in Fig.2. The block diagram of the receiver is shown in Fig.3.

A visually impaired cane, containing a stick 1 with a handle 2, in which a transceiver 3 is mounted, mounted on a cane with the ability to change the angle of inclination to the stick axis 4 in the plane of symmetry of the cane, information processing unit 5, power supply 6, signaling device 7, button 13 inclusion, the transmitter 14 with the transmitting antenna 23, a pendulum switch consisting of a pendulum 16 and a ring 17. The axis 4 is located perpendicular to the plane of symmetry of the cane. Structurally, the transceiver, information processing unit 5, relay 18, power supply 6, signaling device 7, transmitter 14 and pendulum switch (16 + 17) are located inside the handle 2 and are interconnected by electric circuit 8. The transceiver 3 is mounted with the possibility of changing the angle α of inclination of its axis 9 directivity relative to the axis of symmetry 10 of the stick 1 and handle 2, i.e. in the plane of symmetry of the cane. A control lever 11 is attached to the transceiver 3, the free end of which is brought out to the side portion 12 of the surface of the handle 2. The transceiver 3 is provided with a return spring 15, one end of which is fixed to the handle 2, and the other end is connected to the transceiver 3. The transmitter 14 is made in the form of series-connected a master oscillator 19, a phase manipulator 21, the second input of which is connected to the output of the pseudo-random sequence generator 20, power amplifier 22 and transmitting antenna 23. To the power source 6 in series the power button 13, the relay 18 and the pendulum switch 16, 17 are connected. The transmitter 14 is connected to the power supply 6 through the closed contacts 18.1 of the relay 18 and the power button 13.

The receiver 25 is made in the form of a series-connected receiving antenna 24, a high-frequency amplifier 26, a delay line 28, a first adder 31, the second input of which is connected to the output of a high-frequency amplifier 26, a first envelope detector 34, and a third adder 36, to the output of which a block 29 is connected registration and block 30 alarm. To the output of the delay line 28, a 180 ° phase shifter 32 (phase-inverter), a second adder 33, the second input of which is connected to the output of the high-frequency amplifier 26, and a second envelope detector 35, the output of which is connected to the second input of the third adder 36, are sequentially connected. Delay line 28 , adders 31, 33, and 36, phase shifter 32 through 180 °, envelope detectors 34 and 35 form a PSK signal demodulator 27.

In general, the cane operates as follows.

When the free end of the control lever 11 is located on the end part 12 of the surface of the handle 2, the direction of the directional axis 9 of the receiver 3 relative to the axis of symmetry 10 of the stick 1 can be quickly registered by the user, for example, by means of the thumb acting on the control lever 11.

In the presence of a return spring 15, which is attached at one end to the handle 2 and the other connected to the transceiver 3, the position of the directional axis 9 of the transceiver 3 relative to the axis of symmetry 10 of the stick 1 is uniquely determined, namely, in the absence of impact on the control lever 11 from the side of the transceiver 3 is in the extreme initial position, predetermined by the user.

When leaving the house, the visually impaired person presses the power button 13, which is located on the front end part 12 of the handle 2. In case of emergency, for example, if the visually impaired person faints or slipped, broke his leg, felt bad and dropped his cane, then the latter, being in a horizontal position, will autonomously contact the rescue service, the nearest medical center or relatives of a visually impaired person through a radio channel.

It is in extreme situations when the cane occupies a horizontal position, i.e. when a visually impaired person drops a cane for some good reason, the pendulum 16 is in contact with the metal ring 17 located inside the stick 1 and closes the electrical circuit of the relay 18 from the power source 6 through a closed power button 13. The relay 18 is activated, closes its contacts 18.1, through which all the elements of the transmitter circuit 14 from the power supply 6 are simultaneously supplied with power (power circuits are not shown in FIG. 2).

In this case, the master oscillator 19 generates a high-frequency oscillation

u _c (t) = U _c cos (ω _c t + φ _c ), 0≤t≤T _c ,

where U _c , ω _c , φ _c , T _c is the amplitude, carrier frequency, initial phase, and duration of the high-frequency oscillation, which is supplied to the first input of the phase manipulator 21. The second input of the latter is supplied with the modulating code M (t) from the output of the pseudo-random generator 20 sequence (PSP). Moreover, the modulating code M (t) in digital form contains all the necessary information about the visually impaired, for example, last name, first name, middle name, year of birth, home address, phone number, degree of disability, etc.

The output of the phase manipulator 21 produces a complex signal with phase shift keying (PSK)

u ₁ (t) = U _c cos [ω _c t + φ _k (t) + φ _c ], 0≤t≤T _c ,

where φ _k (t) = {0, π} - manipulated component phase mapping law phase shift keying in accordance with a modulation code M (t), wherein φ _k (t) = const at kτ _E <t <(k + 1) τ _E and can change abruptly at t = kτ _E , i.e. at the borders between elementary premises (k = 1, 2, ..., N-1);

τ _E , N is the duration and number of chips that make up a signal of duration T _c (T _c = N · τ _E ).

This signal, after gaining in power in the power amplifier 22, is transmitted by the transmitting antenna 23 to the ether, captured by the receiving antenna 24 of the receiver 25 and simultaneously fed through the high-frequency amplifier 26 to the input of the delay line 28 and to the first input of the first 31 and second 33 adders, to the second inputs which served the same PSK signal u ₁ (t) output from the delay line 28, delayed for a time equal to the duration _of τ _e τ chip (τ _s = τ _E). Moreover, the second input of the second adder 33 complex QPSK signal u ₁ (t) is shifted in phase by 180 ° relative to the first adder 31.

Consequently, the first 31 and second 33 adders receive unstoppable and delayed for a duration τ _{E of} elementary packages PSK signals. In these adders, the sum of the delayed and delayed PSK signals is in phase and out of phase, i.e. On one of the adders, the PSK signals are added, and on the other, they are subtracted. If the amplitudes of the delayed and uncontrolled QPSK signals are equal, the output of the first 31 and second 33 voltage combiners either doubles or becomes equal to zero, i.e. the phase relations between the symbols of the modulating code M (t) are replaced by amplitude ones. From the outputs of the first 31 and second 33 adders voltage are supplied to the inputs of the detectors 34 and 35 of the envelope of opposite polarity, respectively. The detected signals are fed to two inputs of the third adder 36.

Due to the fact that the signals are separated in time and have different polarities, a differential video signal is generated at the output of the third adder 36. A positive video signal corresponds to the phase difference of the delayed and uncontrolled chips, are equal to zero, and a negative signal corresponds to a phase difference of 180 °.

The circuit, consisting of envelope detectors 34, 35 and the third adder 36, operates as a maximum selection circuit. This does not degrade the signal-to-noise ratio at the output of the third adder 36, since one of the envelope detectors, for example 34, turns out to be a “locked” signal from the other envelope detector 35.

Video signal

u _n (t) = U _n cosφ _k (t), 0≤t≤T _c ,

proportional to the modulating code M (t), from the output of the third adder 36 is fixed by the registration unit 29 and turns on the alarm 30, which emits an alarm (audible or visual).

Rescue services, medical centers and relatives of the visually impaired may be equipped with receivers 25.

The complex FMN alarm signal emitted by the cane for the visually impaired can also be received by mobile phones, which are equipped with interested persons.

Upon returning home, the visually impaired person repeatedly presses the power button 13 and disconnects the transmitter 14 from the power supply 6 in order to avoid a false alarm when the cane can occupy a horizontal position for some reason.

The power button 13 is structurally designed in such a way that with each odd pressing it closes the contacts, and with each even - opens.

The proposed cane for the visually impaired provides a radio channel for transmitting an alarm to rescuers, doctors or relatives in case of emergency.

In this case, a complex FMN signal is used as an alarm signal, which contains the necessary information about the visually impaired, for example, last name, first name, middle name, year of birth, home address, phone number, degree of disability, etc.

Complex QPSK signals open up wide possibilities in the technique of transmitting alarm messages. They allow you to apply a new type of selection - structural selection. This means that it is possible to separate the signals. Operating in the same frequency band and at the same time intervals.

Thus, the proposed cane for the visually impaired, in comparison with the prototype and other technical solutions of a similar purpose, provides increased noise immunity and reliability of the alarm transmission to rescuers, doctors or relatives. This is achieved by increasing the dynamic range of the input signals and the signal-to-noise ratio when receiving weak signals.

To extract the analog-modulated code from the received QPSK signal, a demodulator is used, free from the phenomenon of “reverse operation”.

Adders made, for example, on resistors, are practically inertialess, the time constant of the envelope detectors can be made very small. In addition, the lack of combinational components of higher orders that arise during multiplication, can improve the technical characteristics of the proposed canes for the visually impaired.

Claims (1)

A cane for the visually impaired, containing a stick with a handle, in which a transceiver is mounted, mounted on a cane with the ability to change the angle of inclination to the axis of the stick in the plane of symmetry of the cane, information processing unit, power supply, signaling device, transmitter with antenna, power button, pendulum switch , a relay and a receiver with an antenna, a power button, a relay and a pendulum switch, as well as a transmitter through closed relay contacts are connected to the power source, the transmitter is made in the form of a serial When the master high-frequency oscillator, phase manipulator, the second input of which is connected to the output of the pseudo-random sequence generator, and the power amplifier, the output of which is connected to the transmitting antenna, are connected to the receiver, the receiver is made in the form of a recording unit, an alarm unit, and a receiving antenna, a high-frequency amplifier, and a line delay, characterized in that the receiver is equipped with three adders, a 180 ° phase shifter, two envelope detectors, and to the output of the delay line the first adder is connected, the second input of which is connected to the output of the high-frequency amplifier, the first envelope detector and the third adder, to the output of which the registration unit and the alarm unit are connected, the phase shifter 180 ° is connected to the output of the delay line, the second adder, the second input of which is connected with the output of the high-frequency amplifier, and a second envelope detector, the output of which is connected to the second input of the third adder.

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