Note: Descriptions are shown in the official language in which they were submitted.
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Description
Technical Field
Medical and Scientific Support
Infants recognize their own mother's heartbeat. This sound
Significant body of evidence has proven the benefits of the mother's heartbeat
for a
newborn baby. According to Early Human Development, "Scores of the behavioral
response to stress also decreased significantly in neonates who were presented
with
the maternal heartbeat in comparison with those hearing no sound.
Ref. Hiroyuki Kurihara, Hiroshi Chiba, Yukiko Shimizu, Takumi Yanahihara,
Minoru Takeda, Kiyobumi Kawakami and Kiyoko Takai-Kawakami,
" Behavioral and adrenocortical responses to stress in neonates and
stabilizing
on them".
Early Human Development Volume 46, Issues 1-2, Pages 117-127 920
(20 September 1996) (Japan).
The medical and scientific research supports the basic principle behind the
Product.
It has been proven that the unique sound of a mother's heartbeat helps calm
and sooth
an infant baby.
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Background of the invention
Several devices were made to simulate the heartbeat as sleep inducing effect
to the
neonates. A more effective one has been produced, under my name, (Shawky
Sedaros) to
play the prerecorded own mother's heartbeat. (U.5. Patent Number 6,004,259).
This application is a simplified and an improved version of that Patent.
In this version, the low-pass frequency amplification stage, that was used as
a buffer
stage and a high frequency noise filter in the prior art, has been eliminated.
This was
substituted by deploying a Large Scale Integration Chip (L S I), which
integrates a
preamplifier and the AGC amplifier and an output amplifier with balanced
output.
Considerable reduction of input noise to the data storage chip was achieved
due to
this modification. Not to mention the additional white noise caused by that
stage.
A reduction between 90 and 95% of the noise generated by the LSI Chip itself
(between 10
to 15 mV P.P) was accomplished by modifying the circuit design of the audio
output stage.
A balanced line amplifier with differential inputs has replaced the bridge
amplifier with a
single unbalanced input (in the original design). This resulted into further
noise and
interference reduction.
An equalizer Bass Boost has been added in the feedback circuit of the line
amplifier, in
order that the low fundamental tones of the heartbeats become more audible.
By replacing the bridge amplifier at the output, in the prior art, by the
differential amplifier
improved considerably the S/N ratio and, feeding its output to an external
integrated
amplifier/speaker having its own power supply; the power consumption of the
unit to be
placed near the baby has been greatly reduced.
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amplifier/speaker having its own power supply; the power consumption of the
unit to be
placed near the baby has been greatly reduced.
Original power was 12 Watt (1 Amp. at 12 ~, this was reduced to 150 m. Watt
(30 m.
Amp. at 5 V). Also, the original unit required large heat sink due to its high
consumption
and represented a hazard to the newborn.
Minor modification was done in the logic section of the original design to
prevent latching
in the timing circuit.
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Summary of the invention
A Sound Activated device placed on a table near the crib, integrating a sensor
triggered by
the crying of the infant to playback his mother's heartbeat. The heartbeat
sound was
recorded earlier by the mother during pregnancy. The recording was
accomplished by
placing the diaphragm piece of a stethoscope, on the skin within the heart
area. The ear
piece removed from the acoustical tube to fit around an electret sensitive
microphone. Its
output is fed into a high fidelity amplifier followed by a feedback stage both
integrated in a
Large Scale Integration chip (LSI) then stored in its memory banks. The
maximum
recording duration is 20 seconds; 10 seconds is adequate. Certain addresses
are wired for
playback looping. This way the output will sound as a continuous heartbeat.
The playback of the heartbeat is triggered by the baby crying, by a sensor
circuit, and ends
about 3 minutes after the crying has stopped. This will reassure the newborn
by producing a
calming and soothing effect, thus inciting the baby to go back to sleep.
This invention has two important features:
1- it enables the mother to record her heartbeat in her own privacy, which is
not
provided by Hughes (US Pat. No. 5,063,912) invention that produces only a
playback of an
average womb sounds of several pregnant women recorded by inserting a
microphone into
their wombs;
2- a sensor that is activated by the crying of the newborn, or any other sound
loud
enough to awaken the baby, to playback the true mother's heartbeat thus
producing a
reassuring and calming effect thus inciting the infant to return to sleep.
Continuous
playback may be done manually by setting SW1, for other applications.
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Brief Description of the drawing
FIGURE 1 (Section A) shows a block diagram of the recording and playback of
the
mother's heartbeat.
FIGURE 2 (Section B) shows the noise detector and playback time control part
of the
device. (Prior Art)
FIGURE 3 (Sections A and B) A block diagram of the whole device.
Detailed Description of the Drawings
Figure 1 shows:
Section A: The Recording and Playback of the mother's Heartbeat Diagram.
Numerical (1) powers the unit, which is shown in the block diagram excluding
the
integrated Amp. & Speaker which operates by its own power Supply (13),
l2Vdc@lA.
A voltage regulator and filter (02) produces 5 ~ 0.1 Vdc (hum and noise better
than 70dB)
The recording section comprises the diaphragm piece with its acoustical
coupling tube (3)
The free end of this tube is fitted to a sensitive electret type microphone
numerical (4)
(prior art). The output signal is fed into a Large Scale Integration circuit
(L S I) which
comprises the following: a balanced input Mic. Preamplifier (5) followed by a
line
amplifier with an AGC loop (6), which feeds back to the first stage (5) in
order to
compensate for the various intensity levels at the Stethoscope/ Microphone (4)
For the heartbeat recording, the switch SW-1 should be on off position (in
order to
disconnect the rest of the circuit in the Data Storage, Record/Playback (7))
to achieve a
cleaner recorded signal.
The mother placing the diaphragm (3) on the skin in the vicinity of the heart
area and
holding it there while pressing the push button SW 2 and hold for few seconds
to record,
then release. The maximum recording time is 20 seconds (prior art). Very light
pressure
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should be applied on the diaphragm (3) since its membrane has to vibrate
freely with the
heartbeat sound. SW 2 replaces switch S-2 in the prior art. This replacement
minimizes the
mechanical switching noise generated by S-2).
This action resets the recording address in the Data Storage (7). Meanwhile,
as the
recording takes place, LED (9) will be energized (Red light acts as a
recording indicator).
The signal is then transmitted by means of an acoustical coupler to a
sensitive microphone
with a balanced input circuit thus reducing all interference and improves the
S/N ratio.
The output amplified through (5) and (6), the resulted amplified signal is
then digitized and
stored in the memory bank of the Data Storage unit in the LSI numeral (7).
By wiring certain buffer addresses, of the LSI, together this loops the
recorded signal. This
way, the payback will sound as a continuous regular heartbeat rhythmic sound.
On Playback mode, (with SW 1 A/B positioned on either Continuous or Auto/
Standby
mode), the signal from Data Storage, Record/Record Playback is first converted
into analog
signal and fed to the Output Amp (10) that provides a balanced output audio
signals from
the LSI, (SP+ and SP-) of the same heartbeats.
The signal is then injected inversely into theDifferential Amp/Equalizer &
Line Amplifier
(I 1) meaning the attenuated signal from SP+ is connected to the negative
input of the
amplifier and vice versa. This results into a very high Common Mode Rejection
Ratio
(CMRR) of the amplifier.
This results into improvement of the S/N ratio at the output of the high gain
differential
amplifier.
The "Bass Boost" (or Equalizer Boost) in the feedback circuit loop is added at
the output
of the amplifier 11 in order to make the low fundamental tones more audible.
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Heartbeat frequency response covers from 08-1024 Hz.
Ref. " AUSCULTATION OF THE HEART"
A Cardiophonetic Approach
By: Antony Don Michael ISBN 0-07-018005-9
Editor Mc Graw Hill, Page 5 top figure 1-4
(USA).
The low impedance output from (11) passes through a level control forwarded to
an
external speaker with Integrated Amp (12) which has its own power supply (13).
Repeating the recording procedure may be required until satisfactory result is
obtained.
Figure 2 (Prior Art) shows:
(Section B: The Baby's Sensor and timer circuit (prior art)
SW 1 A/B is a DPDT switch having three positions: 1. Auto/Standby mode,
2. Off /Recording mode,
3. Continuous Play mode.
This circuit operates only with SW 1 AB set in the Auto/Standby mode.
Upon the baby cries, sensitive Baby Sensor electrect Microphone picks up the
signal (15)
then passed into the Hi-Pass/Mic. Preamp. Stage (16).
The output is limited through a Detector (17), then shaped into a standard
single pulse by
Pulse/Timer circuit (18) that activates the play address in the Data Storage,
Record/Playback unit (7); this in turn triggers the playback of the pre-
recorded heartbeat to
be heard by the baby (prior art). In the same time, LED D2 first flashes then
stays on
(Green light also acts an indicator that the unit is energized). Placing SW 1
AlB in Cont.
Play position activates the continuous playback mode of the LSI. The green LED
(14) D2
stays lit (Play Mode).
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The width of the input pulse of the Timer circuit (18) determines the playback
time with
duration of approximately 190 seconds. If the baby is still crying at the end
of this duration,
that restores playing period to another 190 seconds.
This implies that playback will stop at 190 seconds after the absence of
crying.
In the absence of baby cries, the Hi-pass Mic. Preamp. prevents false
activation of the
playback circuit.
Figure 3
It represents the ensemble of the 2 sections and accessories (the stethoscope
diagram with
its acoustical tubing and the speaker with integrated amplifier).
