WO1985003209A1

WO1985003209A1 - Infant hospital bed unit

Info

Publication number: WO1985003209A1
Application number: PCT/US1984/002102
Authority: WO
Inventors: Pauline V. Shakas
Original assignee: Shakas Pauline V
Priority date: 1984-01-20
Filing date: 1984-12-24
Publication date: 1985-08-01
Also published as: AU3784085A; EP0168435A1

Abstract

The infant hospital unit (10) provides a hammock sheet (22), removably supported on a frame (20) that fits within a hospital bassinet (12). The hammock sheet (22) may include a pocket (16) for receiving a sonic device that generates audible and vibrational impulses, simulating a human heartbeat. Also, preferably, the unit is received on a base (50) that permits it to be rocked back and forth. These features provide an infant with an enriched environment to stimulate the normal, full development of the infant's primary sensory system in a uniquely effective, simple fashion.

Description

INFANT HOSPITAL BED UNIT

CROSS-REFERENCE TO RELATED APPLICATION

This Application is a continuation-in-part of a copending application by Pauline Shakas, titled Infant Transitional Sensory System, filed with the United States Patent and Trademark Office on April 26, 1982, and identified as serial number 06/371,990.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention concerns an infant hospital bed unit designed to be received within the typical hospital bassinet or isolette, to assist the infant in achieving a smooth transition from the womb while reducing the trauma of the birth experience and to contribute to the infant's adaptation to a totally new environment.

2. Description of the Prior Art - in recent years various psychological studies have shown that the environment and treatment of an infant in the days and months following birth can and do have a major psychological effect in later years of life. In the womb, a fetus has an intimate symbiotic relationship with the mother; it gradually becomes increasingly aware of various sensory stimuli as it develops, but particularly of sounds, touch, movement and its enveloping space. This enriched environment in the womb provides and offers the fetus both a feeling of security and considerable tactile kinesthetic stimulation.

At birth, the rich intrauterine environment is suddenly replaced with a whole new world of sensations. The gamut of stimuli given the fetus before birth suddenly stops. Recent investigations indicate that kinesthetic stimuli such as touching, movement, sound and definition of space, stimuli provided by rocking and cuddling, result in impulses in the infant's nervous system that are directed to the cerebellum to stimulate its development, a process that goes on for at least the first two years of a child's life. Since the cerebellum appears to be the only part of the brain in which brain cell multiplication continues long after birth, this cerebular stimulation has been shown to be of profound importance in the development of the whole person. Kinesthetic stimulation of the infant therefore well may be of primary importance, yet modern baby care practices often prevent just such stimulation. Indeed, many of the products available to parents today are designated to free parents from activities which would provide kinesthetic stimulation for the infant.

The development of the human infant has been described as consisting of two distinct stages of gestation, the first being the nine month period inside the womb, called uterogestation, and the second being the first nine months outside the womb, called exterogestation. During exterogestation infants progress to the point at which they can crawl on all fours. During both stages, stimulation of the infant's primary sensory syterns appears to be of great importance; the kinesthetic stimuli provided an infant during exterogestation - the sights, sounds, smells, tastes and warm feelings that comprise the enfolding love that ought to be the birthright of every child - now appears to be of-basic importance in the development of a normal, well adjusted human being. The profound influence of the primal sound and vibration of the heartbeat has been proven to enhance the infants entire physical and emotional development. So important is rhythmic sound not only in the primitive sense but is felt to be the root cause for man's need for music as a calming influence. Tactile., stimulation appears to initiate all innate infant reflexes. Touch is the infant's number one teacher. Not only does it help the infant develop emotional security but actually it appears to also assist the body in development of the brain and nervous system. For this reason, holding the infant, massaging the infant, and providing the infant with different textures to touch are important. Tactile stimulation also seems to have a calming effect on the infant and to assist the infant in organizing its sensory systems, called sensory integration.

Adding to the proper development of the motor, joint and muscle system as well as the vestibular system is the requirement for space identification and movement. Providing the infant with an environment which resists, but yields, to its own initiated movement, allows the infant to be involved in his own muscular and skeletal system development.

The normal hospital bassinet or isolette provided for an infant in the days following birth offers little if any of the necessary stimulation. For example, the typical hospital bassinets is simply a basin of clear plastic holding a firm mattress pad. A newborn infant, wrapped in a blanket, is placed on that pad, the clear sides of the bassinet offering attending nurses an unobstructed view of the infant. This arrangement is obviously far different than the rich intrauterine. environment, and creates an enormous sensory deprivation for it offers little if any stimuli to the infant's primary senses.

Obviously, parents for centuries have been attempting to satisfy the needs of their children, especially in the days and weeks following birth. In animals in which the infants are born at an intermediate stage of development, such as kangaroos and opossums, the female is equipped with a pouch to provide primary sensory stimuli to the infant during the period of exterogestation. However, while human infants also go through a distinct period of exterogestation, for centuries their parents have placed them in a bassinet or crib without regard to adaptation problems and trauma as the result of cessation of pleasant and familiar sensory input of touch, movement, sound and space. Particularly in recents years parents seem to provide less and less tactile kinesthetic stimulation for the infant, a deficiency which is becoming increasingly apparent as a major contributor to serious psychological problems in later life.

3. Objectives of the Invention. The basic object, then, of the infant hospital bed unit is to provide, following the first moments of birth, an enriched environment directed to the infant's need for continuing positive input into his delicate sensory system. Particular attention is directed to the high requirement for sound vibration and space identification. ith the knowledge now in the professional community to the need for sensitive reception of the newly born in" the delivery room, this unit has been designed to take this awareness to the next step ... that of the hospital nursery and the handling therein.

Other objectives, and advantages, will be apparent from the following detailed description of. a preferred embodiment of the unit. BRIEF SUMMARY OF THE INVENTION

The infant hospital bed unit of the present invention is designed and intended to fit within the typical hospital bassinet and to rest upon the mattress pad normally found in such a bassinet. It consists of a frame structure that rests on the mattress pad, for example, and supports a hammock of sufficient size to receive and hold an infant. Preferably the hammock is formed from a sheet of flexible fabric with flexible margins to conform and deform to a variety of shapes permitting an infant held in the hammock to move, exercise and define its surrounding space, the fabric having an inner pile surface to provide tactile stimulation for the infant. Also, preferably the sheet has side portions foldable over an infant resting on the sheet. Means are provided to attached at least the corners or end areas of the hammock to the supporting frame to hold the hammock reasonably taut, the hammock and frame cooperating to cradle an infant' body and to offer some resistance to movement of- the infant.

In a preferred configuration, the flexible fabric material forming the hammock includes a deep pile inner surface (i.e. terrycloth) and an outer surface of non- stretchable netting to assist in firmly holding and supporting the infant. The side portions which are provided on the hammock sheet and are foldable over an infant include a zipper in other means to attach together the two side portions over the center area of the sheet and form a pocket for snuggly receiving the infant.

In the preferred embodiment, the means to attach the hammock to the frame consists of pockets in the en margins of the hammock, which may be slipped over and cooperate with similarly shaped wings on the end margins of the frame. Preferably interlocking velcro tabs are provided on the underside of the frame and at the corresponding area of the end margins so that the end margins of the hammock may be securred to the frame in a positive fashion.

In addition, in the preferred embodiment the hammock preferably includes a sonic device for producing audible sounds and mechanical vibrational impulses simulating a human heartbeat, and means for attaching this sonic device to the hammock sheet to transmit vibrations of the sonic device through the sheet to an infant. Also, the frame is preferably formed as a unitary piece of moulded fabric. A motorized support mechanism may be provided to receive the base of the frame and to gently rock it back and forth, thereby providing additional sensory stimulation for the infant.

BRIEF DESCRIPTION OF THE .DRAWINGS

The invention will be further described in connection with the accompanying drawings, in which:

FIGURE 1 is a perspective view of the infant hospital bed unit received within a typical hospital bassinet;

FIGURE 2 is a side view of the infant hospital bed unit;

FIGURE 3 is a top view of the hammock sheet which forms a portion of the infant hospital bed unit;

FIGURE 4 is a perspective view of a rockable base on which the infant hospital bed unit may rest;

FIGURE 5 is a vertical cross-sectional view of the rockable base; FIGURE 6 is a face view of a preferred sonic device opened to reveal its components; and

FIGURE 7 is an electrical schematic of a preferred circuit employed in the sonic device.

DETAILED DESCRIPTION

The infant hospital bed unit of the present invention is both simple and effective. It provides an enhanced environment for an infant, particularly in the days immediately following birth. As discussed in greater detail subsequently in this application, the components of the unit function together to provide the infant with stimulation for its primary senses, ^" particularly the senses of touch, sound, movement, and space. Thus, the infant receives considerable positive sensory input in the critical hours and days following birth.

As shown in FIGURE 1, the infant hospital bed unit 10 is received within the clear moulded plastic bassinet 12 typically found in most hospitals, and rests on the mattress pad 14 at the bottom of the bassinet. Of course, it may be similarly received within a typical hospital isolette unit.

Those attending to newborns in hospitals need to be able-to see the infant at all times. The transparent sides of the typical hospital bassinet permit this, and the infant hospital bed unit is therefore designed to not obstruct such visual monitoring of infants. Such hospital bed units also should be washable and sterilizable, should cuddle and envelop the infant, and preferably should be simple to use and inexpensive to manufacture. As will be apparent from the following description, the present infant hospital bed unit, in its preferred embodiment, meets all of these objectives.

The infant hospital bed unit, as shown in FIGURE 2, consists of a frame 20 and a hammock sheet 22. A top view of the hammock sheet is shown in FIGURE 3. It consists of a central portion 24 and two side portions 26 that fold over the central portion and may be attached together, as by a zipper 28 along the adjacent inner margins of the side portions to, with the central portion, form a pocket for receiving an infant.

Preferably the inner surface of the hammock sheet is formed of a fur-like dense pile material, such as terrycloth, to provide the infant with tactile stimulation. Preferably this pile material is bonded to or otherwise supported and reinforced by an outer material 28 which may, for example, be nylon netting. While the resulting sheet will give and deform somewhat to receive an infant, as well as in response to the infant's movement, it does permit the infant to be held in a reasonably snug fashion and also resists gradual relaxation of the sheet to deepen and deform the desired hammock shape. A pocket 32 is formed at each end portion or margin of the sheet, such as by sewing an appropriately shaped hem in the nylon netting. This pocket receives outwardly extending wings 34 formed as part of frame 20. Preferably pockets 32 and wings 34 include an indented center portion to permit a nurse or other attendant of the infant to pass their fingers between these indented portions and the inner sides of the bassinet to easily place the infant hospital bed unit in the bassinet and to remove the hospital bed unit from the bassinet. Frame unit 20 conveniently may be formed of moulded plastic. It includes a base 36, side margins 38 that may be lowered or recessed for the majority of their length to enhance the freedom of movement of. the infant, and end portions 40 that terminate in the outwardly extending wings 34.

If desired, pockets 32 may include tabs of velcro 41 which cooperate with velcro tabs on the underside of wings 34 to positively lock the hammock sheet to the frame. In another embodiment of the hammock sheet (not shown) the sheet may consist of end portions having velcro strips extending along outer margins, the outer margins being folded over wings 34 -and interlocking with cooperating velcro strips on the underside of the wings to hold the hammock sheet to the frame.

By either of these arrangements, the hammock sheet is suspended by frame 20 above the mattress pad 14 in bassinet 12, and may assume an arcuate position conforming to an infant. It provides flexible side areas or margins 39 that conform and deform to a variety of shapes, permitting an infant held in the hammock to move, exercise and define its surrounding space. The hammock sheet 22 is readily removable from the frame for laundering. It is constructed of materials to permit it to be sterilized.

The hospital bed unit may simply be placed in the normal full terry hospital bassinet, as shown in FIGURE 1, and provide an infant with considerable sensory stimulation as a result of its vibrational heart beat, pile material, its flexibility and its resistance to movement of the infant. In the case of the pre-term or premature infants, the shortened gestation period results in deprivation of sensory input in critical degrees. The absence of movement, sound, vibration and space identification required in the womb for proper development has been eliminated, and enormous developmental trauma takes place. Intensive care hospitals report that they have sought for years a means to provide these isolated and emotionally deprived babies with positive and ongoing sensory diet. One of the greater needs aside from the requirement for rhythmic sound vibration is the infant's high requirement for movement. The normal baby has been rocked by this mother's movements until full term development. The premature infant has been robbed of this developmental influence with profound implications. Lack of movement results in a severe lack of development in the vestibular and gravity sensory systems. For this reason, this unit has been provided with a rocking base in the correct head to foot movement direction which will impart a timed rocking as shown in Figure 4. This rockable base consists of a top portion 50 and a bottom portion 52, the top portion being received on and supported by the bottom portion. The top portion includes a depressed area 54 shaped to receive the base 36 of frame 20.

The preferred construction of the rockable base is best shown in FIGURE 5, which is generally a vertical section through the base. The longitudinal side edges of the bottom portion 52 each include two arcuate portions 54 as well as a centrally located arcuate slot 56. Rollers 58 are appropriately supported on shafts 62 attached to the sides of to portion 50. Also, a pin 64 attached to the side of top portion 50 extends through slot 56 and prevents the top portion from being lifted from bottom portion 52, yet permits movement of top portion 50 back and forth relative to portion 52, rollers 58 rolling on arcuate edges 54 while the pin 64 moves in arcuate slot 56.

Preferably, the arcuate edges 54 are shaped to centrally locate portion 50 relative to portion 52 when at rest, yet to permit easy movement of the two portions relative to one another for some distance, then increasing resistance to further movement. This is achieved by providing each arcuate edge 54 with a central area that is slightly curved, the lowest portion of the curve being positioned to locate the top and base portions in the relationship illustrated in the Figure 5 for example. This slight curve to each arcuate edge gradually turns upward at an increasing rate to provide increasing resistance to further rocking of the top portion relative to the base beyond a given range of movement. A driving mechanism 70 may be provided, such as about the central side edge of base 52, to, for example, drive a magnet on a rod 72 received within the drive system 70, this magnet being linearly dri-ven by the drive system, first in one direction then the other direction. Such drive systems are in common use, for example, in window display. They are simple in construction, inexpensive, and will operate for long periods without attention.) The drive system may be powered by an appropriate source of electrical power (not shown) applied to the drive system through an electrical connection (not shown) . Preferably, the hammock sheet includes a

^' pocket 76 that receives .a heart-shaped sonic device or generator 78 (see FIGURE 6) which generates both audible and vibratory impulses, simulating a human heartbeat, thereby duplicating to a significant extent the dominant, normal and soothing sound patterns received by an infant during its period of uterogestation. Such simulation has been shown to exert a calming influence and to promote a sound, deep state of sleep in the infant. The electrical components of the sonic device are contained within a heart-shaped housing. In FIGURE 6, the upper shell of the housing has been removed to reveal the lower shell and the various components it holds. These components include a battery 80, a circuit board 82 bearing the major electrical components of the generator, including a switch 84, and a solenoid vibration generator 86 that is attached to the side of the case or shell as by screws or adhesive, to transmit vibrations to the housing. The preferred electrical system is schematically illustrated in FIGURE 7. It is a simple, syncopated circuit. Its operation likely will be readily understood by those skilled in this art from an examination of the schematic. Nevertheless, it functions as follows: the positive potential of battery 80 is applied to bias one of the two inputs to each of exclusive or gates 90 and 91. Since the other input of gate 90 is at a quiescent or lower voltage condition, gate 90 will produce a positive output. This output is applied to the other input of gate 91 causing it to produce a zero or grounded output. It is also applied to the series connected resistors 92 and

92', and through them charges capacitors 93 and 93' connected in series. The increasing charge on this chain of capacitors eventually will apply sufficient positive voltage to the input of gate 90 connected thereto through resistor 94 to cause gate 90 to produce a zero or grounded output. The positive output of gate 91 is applied through resistor 95 to charge capacitor 96, and is also applied to one input of exclusive or gate 97. As the output of gate 91 charges capacitor 96, eventually the input of exclusive OR gate 97 connected to the junction of resistor 95 and capacitor 96 will receive a sufficient positive voltage to produce a positive output (the other input to gate 97 is grounded and therefore will always be at a zero state) . When the output of gate 97 goes positive, gate 98 will cease producing a positive output since both of its inputs now will be positive.

The output of OR gate 98 is applied through resistor 99 to transistor 101 causing it to conduct current from the battery through the coil of solenoid 86 and to ground. A short time later (on the order of 2-3 milliseconds) , when the output of gate 98 drops to zero, transistor 101 will cease conduction. The resulting electromotive force in the coil of solenoid 86 due to collapse of its magnetic field generates a current that is shunted around the coil by diode 102, to prevent a detrimental back bias condition from being applied to transistor 101. Since logic elements can be harmed quite easily by improper application of current, preferably the circuit includes a diode 103 in series with the battery and the various logic elements to prevent this. The purpose of the circuit is to, in cooperation with the solenoid vibration generator, produce a thump-thump that closely simulates the audible and vibratory impulses of the human heart. The sound is characterized by two pulses in rapid succession, then a long pause, followed again by the two pulses in rapid succession. Each thump is produced by a conduction cycle of transistor 101. To illustrate, a first thump is initiated by conduction of gate 91 causing gate 98 to conduct. A short time later gate 97 conducts. Its output with the output of gate 91, causes gate 98 to terminate conduction. A short time later, gate 90 conducts, and conduction of gate 91 terminates, again causing gate 98 to conduct. Conduction of gate 98 terminates when capacitor 96 is discharged through resistor 95 to the grounded output of gate 91 sufficiently to remove the positive bias to the input of gate 97, causing its output to match the grounded output of gate 97. The interval between these two conduction cycles is generally determined by the discharge rate of capacitors 93 and 93' through diode 104 and resistor 92' to the grounded output of gate 90. Preferably there is a 0.4 to 0.7 second delay between the resulting two conduction sequences of transistor 101 that have just been described.

At this point, both inputs to gate 91 are positive, and the outputs of gates 91, 97 and 98 are all at a zero or grounded state. The positive output of gate 90 resumes charging capacitors 93 and 93' through resistor chain 92 and 92'. Preferably the value of these resistors, and particularly resistor 92, is chosen to result in approximately a 1.0 - 1.2 second delay between the termination of the last described cycle of conduction of transistor 101 and the moment when the positive potential on capacitor 93 reaches a state sufficient, when applied to the other input of gate 90, to cease conduction. This re-initiates the conduction cycle just described.

The conduction sequence of the four gates during each stage of the process just described, termed for convenience stage A, B, C and D, can be diagrammatically represented as follows:

GATE A B c D

90 inputs + + + + o + + o

90 outputs + o o

91 inputs + + + +

+ o o +

91 outputs o + +

97 inputs o o o + o o + +

97 outputs

98 inputs o . o + + o + + +

98 outputs o + o +

The preferred solenoid device 86 includes a coil 110 wrapped about a magnetizable armature or core, and a magnetizable plate 112 that is attached to a resilient mounting consisting of a spring-like arm or panel 114 attached to a base on which the coil and core are supported, this mounting holding plate 112 spaced somewhat from the face of the core. A weight or inertial element may be attached, as by adhesive or any other convenient means, to the outer surface of plate 112.

In operation, sequences of pulses generated by the logic system are applied to the solenoid coil 110 to magnetize its core and attract plate 112, and then to release the place. The mass or inertia of the plate and any attached weight impedes the attraction of the plate to the core, and causes the plate 112 to resonate with spring arm 114 somewhat, the impedance and resonation being controlled both by the strength and duration of the pulses applied to the coil and by the mechanical charcteristics of the plate, weight and spring panel, amog other things. More particularly, the solenoid when made has certain inherent characteristics, among which are the spring constant of its arm 114 and the spacing between the facing surface of plate 112 and the solenoid core. The electrical circuit is designed to produce a series of pulses, as has been described. To achieve a series of distinct thumps, as is desired, the characteristic of the solenoid and circuit must be appropriately inter¬ related to achieve substantial movement of the plate yet. to avoid causing it to impact upon the solenoid core. Should this occur, the resulting sound tends to be simply a click. The inertia provided by the^' plate and any attached weight assists in achieving this objective. Such characteristics conveniently may be adjusted by, for example, slightly bending the base or other parts of the solenoid to adjust the spacing between plate 112 and the core. By appropriately adjusting these characteristics, vibrations can be induced in the housing of case 78 that closely simulate the thump-thump vibrations of human heart beats. In the preferred circuit, since by and large mainly logic elements are employed, the current drain of the battery 80 is for the most part the current through the coil of solenoid 86 which occurs during conduction of transistor 101. Preferably, each interval of conduction is on the order of 2-3 milliseconds. At a rate of 68 pulses a minute, a typical nine volt battery will provide on the order of 800 hours of continuous operation, which is somewhat more than one month.

As has been stated, the sonic device 78 preferably is received in a pocket 76 provided in sheet 22. The resulting vibrations of the sonic device are transmitted through the sheet to the infant supported thereby, and cooperate with the characteristic of the sheet to provide an excellent transistional environment for the infant. The sheet cuddles the infant, yet permits the infant to rock, kick and stretch; the sonic generator provides a rhythmic heartbeat simulating probably the most important sound in the womb, to both calm and reassure the infant.

Thus, the infant hospital bed unit of the present invention promotes and encourages the body, brain and psychological development of the infant during the days immediately following birth by stimulating the body's primary sensory systems, including at least the following basic senses:

(1) Sensing sounds, especially familiar, reassuring sounds, has been shown to be extremely important to the infant. The infant has come from the womb and an environment in which the constant, rhythmic beat and vibration of the mother's heart has given a continual, calming assurance. The sonic device offers both audible and vibrational impulses to the infant, when cuddled in the sheet-formed hammock, that well simulates this rhythmic beat. Studies have shown a dramatic decrease in crying by the infant and a significant weight gain in response to such sounds or impulses.

(2) The sense of touch - this sense initiates all innate infant reflexes. Touch not only develops emotional security but actually enhances growth of the infant's brain and nervous system. Textures are therefore of basic importance. The deep pile sheet directly and continuously stimulates the tactile senses of the infant. - (3) The sense of movement is another of the infant's primary teachers. - It also is important in developing the infant's brain and nervous system. The rocking motion provided by the base, when supporting the frame, stimulates the infant's sense of movement. Such vestibular stimulation, in cooperation with the sonic generator, has been shown to dramatically reduce, and in some cases instantly cure, chronic crying conditions of newborns.

(4) Sensing the surrounding, enveloping space is another of the infant's primary teachers. The newborn infant while in the womb has been in a comfortable, conformable and a confining space; the infant after birth naturally is secure when so held, and even seems to require a continuation of this definition of space during extrogestation. The hammock sheet of the system with its enveloping side portions, allows the infant to press and stretch against its sides, to aid in identifying the enveloping space as well as to promote, stabilize and integrate the infant's relationship with and to that space. Further, this pocket shape seems to reduce flailing by the infant (sometimes referred to as a "startle" reflex) which appears to be akin to the sensation of falling, thought to be a source of tension and tension-induced colic in many infants.

Thus, the infant hospital bed unit of the present invention provides an enriched environment that continues all the major stimulants during uterogestation, and offers the infant a basic, necessary stimulation during the first vital days of life in the world. It promotes exercise of the 5 infant's joint and muscle systems as well as the infant's brain and nervous systems. It assists in the integration of the infant's senses, and the infant's relationship to gravity as well. It is a valuable and unique aid, both in the physical development of the

10 infant and in the prevention of a number of psychological disorders that appear to be directly related to the lack of sensory stimulation and integration of the infant. It is designed to assist in the imprinting of the sensitive newborn that he has

-_j_5 entered a friendly and unthreatened environment. The flailing reflex as a result of the "fear of falling" syndrome is drastically reduced, making gravity a friend instead of a threat. In total, the unit offers a reception to the new infant far superior to the 0 traditionally accepted sterile hospital environment.

While a preferred embodiment of the infant hospital bed unit has been described, it will be apparent to those skilled in this field that numerous variations in the features of the system may be 5 employed. Thus, the invention is defined, not by the disclosed embodiment, but by the following claims.

Claims

WE CLAIM:

1. An infant hospital bed unit including: a frame of a size and shape for fit within a hospital bassinet, a fabric hammock having a pile inner surface and side portions which may be folded over the center portion to provide a pocket for receiving an. infant, and means for attaching the fabric hammock to the frame so that the hammock is suspended and may assume and maintain an arcuate position the hammock when so suspended having flexible margins to conform and deform to a variety of shapes, permitting an infant held in the hammock to move, exercise and define its surrounding space.

2. An infant hospital bed unit, as set forth in Claim 1 in which the means to attach the hammock to the frame holds the hammock reasonably taut, the hammock and frame cooperating to define an arcuate shape to cradle an infant's body and to offer some resistance to movement of the infant.

3. An infant hospital bed unit as set forth in Claim 1, including a sonic device for generating audible sounds and mechanical vibrational impulses simulating a human heartbeat, and means to attach the sonic device to the hammock sheet to cause said audible sounds and mechanical vibrations to be transmitted through the sheet.

4. A infant hospital bed unit as set forth in Claim 1, in which the side portions include adjustable means to, when the side portions are folded over the center portion, attach their adjacent surfaces together, and to, with the central portion, define a pocket for receiving an infant.

5. An infant hospital bed unit as set forth in Claim 4 in which the hammock sheet includes an inner pile surface and an outer reinforcing fabric.

6. An infant hospital bed unit as set forth in^'Claim 5 in which the frame includes end portions with outwardly extending edges, and in which the hammock sheet includes end portions folded over to define pockets for receiving the end portions of the frame whereby the hammock sheet is held to the frame by the interlocking engagement of the pockets on the sheet with the outwardly extending end portions of the frame.

7. An infant hospital bed unit as set forth in Claim 6, in which the end portions of the frame, and corresponding portions of the hammock sheet, are indented to provide a space between the frame and a hospital bassinet to permit an attendant's fingers to pass there through for placing the hospital bed unit in the bassinet, or removing the hospital bed unit from the bassinet.

8. An infant hospital bed unit as set forth in Claim 7, in which the means to attach the hammock to the frame holds the hammock reasonably taut, the hammock and frame cooperating to define an arcuate shape to cradle an infant's body and to offer some resistance to movement of the infant, and including a sonic device for generating audible sounds and mechanical vibrational impulses simulating a human heartbeat, and means to attach the sonic device to the hammock sheet to cause said audible sounds and mechanical vibrations to be transmitted through the sheet,. and in which the inner pile surface of the hammock sheet is terrycloth.

9. An infant hospital bed unit as set forth in Claim 1 including means to permit the frame and hammock to be rocked back and forth relative to a supporting surface.

10. An infant hospital bed unit as set forth in Claim 9 in which the rocking means includes a base portion and a top portion, the top portion receiving and supporting the frame, the base portion having side edges, the top portion including rollers mounted to the top portion and resting on the side edges of the base portion to permit the top portion to roll back and forth relative to the base portion.

11. An infant hospital bed unit as set forth in Claim 10 in which the side edges of the base portion on which said rollers rest are arcuate in shape, and means to attach the top portion and the base portion together yet to permit the top portion to rock back and forth relative to the base portion.

12. An infant hospital bed unit as set forth in Claim 10 including means to drive the top portion back and forth relative to the base portion.