TOY FETAL LIFE SOUNDS MONITOR

The present invention, in general, is an educational toy for hearing intrauterine life sounds in pregnant women and, in particular, is a toy monitor contained in a novel housing attractive to young children and others, encouraging them to listen to the sounds made by the developing fetus.

BACKGROUND ART

Existing disclosures in this general category fall into three classes:

1. toy stethoscopes which are merely imitations of the physical structure of the real thing, which may not be intended to pick up sounds from the developing fetus, and which often fall apart after a short period of use by children;

2. toy stethoscopes which contain mechanical or electronic devices generating sounds simulating actual heart sounds; and

3. professional stethoscopes, acoustic or electronic, which pick up various body sounds needing to be interpreted by experienced listeners, and which are too expensive to be easily available to children and most non-professionals.

The first category will not be dealt with further, because it has no relevance to the present invention.

The following references, of the second and third categories, are all United States patents.

The second category, that of toy stethoscopes containing mechanical or electronic devices simulating heart sounds, will be surveyed as illustrative of the present approach to providing realistic toys in this field, although none of this category is relevant, since the present invention permits listening to actual intrauterine life sounds, not simulations thereof.

Petit 2,715,296 discloses a toy stethoscope containing a mechanical device, the noise of which simulates the human heartbeat to the untrained user.

Barnett 3,024,568 discloses a toy stethoscope with an electronic circuit contained therein which generates an audio signal simulating the sound of a human heartbeat.

Tsui 4,282,678 discloses a toy stethoscope with a pneumatic device contained therein which simulates the sound of a human heartbeat when the stethoscope head is pressed against the "patient".

Sirota 4,601,668 discloses a toy system which includes a doll, a toy stethoscope, and an electronic circuit contained therein to generate an audio signal simulating the human heartbeat. The doll contains a magnet in the region of the "heart" which activates the simulator circuit only when the stethoscope head is brought close thereto.

None of these references is germane to the present invention.

The third category of references is surveyed as illustrative of the professional medical approach to hearing intrauterine life sounds, although the present invention is not intended for such use but is a toy for use by children and other non-professionals.

Farrar et al 3,187,098 discloses a fetal heartbeat detector containing a mechanical filter tending to pass those frequencies prominent in the fetal heartbeat and suppressing those prominent in the maternal heartbeat.

Gregg 3,348,535 discloses a parturitive phone which is used to monitor the fetal heartbeat during labor and delivery.

Andries 3,790,712 discloses an electronic stethoscope system useful for medical educational purposes. The pickup head is especially shaped to pass those frequencies which have been found to contain the information most useful in medical diagnosis.

Pfeiffer 4,071,694 discloses a combination acoustic/electronic stethoscope, wherein the transition from the acoustic mode to the electronic mode can be accomplished by one hand.

Giampapa 4,048,444 discloses a conversion unit for conventional stethoscopes which can be placed between the end of the air column from the stethoscope head and the ear tip piece of the stethoscope.

Hower 4,618,986 discloses an electronic stethoscope which replaces the acoustic sound distributor of the conventional stethoscope with a case containing the electronics required to operate the device.

Furugard et al 4,821,327 discloses an electronic stethoscope which combines the functions of both electronic and acoustic stethoscopes, enabling the instrument to be used both for automatic measurement of blood pressure as well as for listening to the arterial sounds.

None of the references in the third category, taken individually or together, or in combination with the references in the second category, discloses or even suggests the present invention.

DISCLOSURE OF THE INVENTION

The present invention is a life sounds monitor packaged for use as a toy, intended to be sold in toy, baby and maternity stores to children and their parents so that the children can hear the sounds of the developing fetus in their mother's uterus. It has the unexpected result of encouraging young children to associate the imminent arrival of a new sibling or baby with the pleasant experience of holding a cuddly animal rather than the too often forbidding aura of a doctor's office.

The present invention includes a novel housing shaped to appeal to children, as an animal, toy or other attractive shape, and which in no way reminds them of medical instruments seen in a doctor's office, which may be too often associated with unpleasant or painful experiences.

The present invention includes within the novel housing an energy source means, supplying energy to a first transducer means, amplification means, and second transducer means. The housing has a form appealing to small children, and is to be applied to the abdominal area of a pregnant woman.

The circuitry may be standard electronic stethoscope circuitry, in any of several convenient forms. It need contain only those circuits necessary to amplify the frequencies in the range of 20-2,000 hertz, which are generally considered to contain the sounds of most interest, those associated with the mother falling primarily in the range below 50 hertz, and those associated with the fetus falling primarily in the range above 50 hertz. Filter circuits can be provided to limit the sounds heard to those in these two ranges, if desired.

No claim is made to the novelty of the electronic circuitry contained in the housing, only to such circuitry being included in housing shaped to be attractive to small children and young persons, that is, in the form of small cuddly animals or favorite toys.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a typical shape for the present invention, here shaped as a juvenile rabbit.

FIG. 2 is a view in cross section along the lines "2-2" in FIG. 1, disclosing one possible arrangement of components within the shaped housing.

FIG. 3 is a typical block diagram for the electronic portion of the present invention.

BEST MODE FOR CARRYING OUT THE INVENTION

FIG. 1 discloses a typical shape 12 for the novel housing of the present invention 10, in this case a juvenile rabbit.

FIG. 2 discloses a typical arrangement of components as arranged within shaped housing 12 of present invention 10. Energy source means 14 is interconnected in typical circuitry with first transducer means 16, amplifier means 18, and second transducer means 20. Acoustic energy, obtained when housing 12 is placed against the abdominal wall of the mother, is gathered from the large area covered by acoustic coupler 22, which gathers or focuses the acoustic energy from this area toward first transducer means 16.

Energy source means 14 is preferably a dry cell battery of appropriate size.

First transducer means 16 is a microphone of appropriate ruggedness, sensitivity, frequency and cost, to convert the variations in acoustic energy to analogous variations in electrical energy. Because of the limited but low frequency response required (20-2,000 hertz), it must be of appropriate structure to detect the desired frequencies within this range. If the mother's life sounds are not desired, the frequencies to be detected will fall off below 50 hertz. First transducer means can include more than one microphone.

Amplifier means 18 may be constructed of any of the several technologies appropriate. The preferred structure will be a standard IC microchip for ease of plug-in replacement, ruggedness, reliability, small size, low energy requirement and low cost. However, the use of other technologies would not avoid the spirit and intent of the invention.

Second transducer means 20 will preferably be one or more earphones. The earphones will preferably be of the type which converts the electrical energy into acoustic energy at the ear itself. Of course, they can be the type which is simply a vibrating column of air in a flexible tube, such as are used in the passenger sections of most commercial aircraft, but this may not be desirable because of the possibility of acoustic feedback through the structure of novel housing 12, and its potentially adverse effect upon the unborn fetus. For the same reasons, while a small speaker of appropriate size and frequency response can be mounted directly in the top surface of novel housing 12, this will carry with it the same feedback potential.

Acoustic coupler 22 gathers the sound emanating from a large area of the mother's abdominal wall, and gathers or focuses it into the smaller area of the

microphone entrance, giving a substantial gain in audibility over most existing stethoscopes. Coupler 22 is preferably molded into lower surface 24 of shaped housing 12, and its effectiveness may be enhanced by the addition of soft rubber or plastic skirt 26 (disclosed in dashed outline) , inserted into groove 28 also molded into lower surface 24 of housing 12. Skirt 26 is especially helpful in maintaining contact between acoustic coupler 22 and the surface of the mother's abdominal wall, during the later stages of pregnancy when the mother's abdominal wall may not present the smooth regular surface characteristic earlier, and when the fetus is much more active, especially during periods of listening, and the surface curvature may change. By maintaining contact therewith, skirt 26 prevents the introduction of extraneous noise into first transducer 16 and its subsequent amplification by amplifier 18, confusing the listeners.

Skirt 26 also provides acoustic isolation of housing 12 from the abdominal wall of the mother in those cases where no earphones are used and second transducer means 20 is mounted within housing 12. Skirt 26 also performs the same function where earphones of the same type as are used in commercial passenger aircraft, which simply couple an air column from second transducer means 20, mounted within housing 12, to the ears of the listeners.

Other features of interest can be included in the present invention. For example, a limiting circuit can be employed to limit the amount of energy delivered to second transducer means 20, when the housing is inadvertently moved while it is on. Such a circuit can be included within amplifier means 18 or external thereto. A pressure sensitive switch can be inserted to render the circuit inoperative or to reduce its gain, when the housing is

lifted from the mother's abdominal wall, to avoid extraneous noise from distorting the life sounds. Acoustic insulation can be placed about the various components, especially first and second transducers, and housing 12 can be fabricated of special low-acoustic-transmissibility material to minimize transmission of sound from the user's hand.

Second transducer means 20 can include one or more external speakers, a home speaker system, or even an external amplifier system with its own speakers.

On-off and bandpass switches, and other controls are associated with the simulated nose, feet, tail, ears, eyes or other features of the animal. The surface thereof could be rigid plastic or, preferably, soft plastic or furry fabrics to resemble the feel of a small animal.

Once again, the novelty of the present invention lies primarily in the provision of a novel housing of a shape inherently attractive to most young children, that is, a juvenile animal or toy shapes. This housing contains the circuits and components of an electronic stethoscope, so that listening to the life sounds of an unborn child in its mother's womb will be associated with the pleasant associations of home and small cuddly animals, rather than the sterile world of medical offices and instruments.

The types of animals which would be appropriate for this purpose are any of them whose juvenile shapes are attractive to small children. In addition to the bunny shape disclosed with this application, puppies, kittens, bears, ducklings, chicks, lions, tigers, and many others would be appropriate, and the omission of names from this list does not mean that their shape is not to be covered by the spirit and intent of this invention, or that animal shapes would be the only shapes attractive to young children.

The terms and expressions which have been employed in the foregoing specification are used therein as terms of description and not of limitation, and there is no intention, in the use of such terms and expressions, of excluding equivalents of the features shown and described, or portions thereof, it being recognized that the scope of the invention is defined and limited only by the claims which follow.

What we claim as our invention is: