Incubator with system for improving newborn acoustic comfort

Abstract

Proposed is a device formed by two parts: a heating, ventilation, and air conditioning system that does not produce noise or vibrations, based on the intake of pressurised air and the use of Peltier cells, which ensures the temperature and humidity required by this type of medical unit; and a structure that surrounds the space of the newborn with a transparent plastic double cover, the inner cover being perforated and at a set distance from the outer cover, such that the structure reduces the internal noise level. The device provides newborn incubators with an internal sound environment in which noise levels are below those recommended by the American Academy of Pediatrics, ensuring acoustic quality inside the compartment and greater comfort.

Description

[0001]INCUBATOR WITH SYSTEM FOR IMPROVING THE ACOUSTIC COMFORT OF NEONATES. TECHNICAL SECTOR According to the table of concordance with the International Patent Classification (IPC), the technical sector where the proposed system falls is found in section A, human needs, and more specifically in sub-section A61G 11 / 00 - Baby incubators. BACKGROUND OF THE INVENTION In 1929, Julius H. Hess presented one of the first proposals for incubators, which was assigned the reference US1900342A and granted a patent in 1933. This invention relates to infant incubators, and its object is to produce an incubator comprising an adapted crib and a removable canopy so that said crib can be converted into an incubator for use with premature or delicate infants. In August 1967 JR, Grosholz et al, presented the most widespread functional scheme, adopted by several manufacturers for the design of incubators.It is based on a system composed of a ventilation circuit for convective heat transfer and humidity gain through the passage of air through a container in the same ventilation flow circuit, as described in patent US3335713A. In general, thermal regulation is one of the critical factors in the survival and stability of newborns. Some of the factors that contribute to the difficulty in maintaining thermal stability are: relatively large body surface area compared to weight, limited metabolic capacity for heat production, and inadequate thermal insulation. Ideally, core and body temperatures should be maintained with minimal variation. Heating, ventilation, and respiratory assistance equipment contribute to room noise.Since the first infant incubator, patented in 1929, all improvements have focused on improving the system, which consists of a ventilation circuit for convective heat transfer and humidity gain through the passage of air through a water container in the same ventilation flow circuit. The design of these devices undoubtedly allows for improved regulation of temperature, humidity, and oxygenation of newborns. An important aspect to consider for the comfort of the newborn in the incubator is the noise level inside. While high noise levels are undesirable for anyone, the situation can be alarming for premature babies, especially considering that they are born before their auditory system has had a chance to fully mature, and it could cause sensorineural hearing loss.In this sense, premature infants have a reduced response to auditory stimulation compared to full-term infants. High noise levels not only contribute to neonatal hearing loss but also affect other physiological and psychological factors and, therefore, could have significant repercussions on newborn behavior. The damage caused by noise depends significantly on objective factors such as frequency, intensity, exposure time, and acoustic rest period, as well as subjective factors such as patient susceptibility. Susceptibility to hearing damage can be influenced by causes such as disease or hereditary factors. Thus, premature infants are more susceptible to the effects of ambient noise than full-term infants. The lower the gestational age, the greater the impairment, as brain development is incomplete, and the risk of abnormal brain maturation increases.The unique characteristics of neonatal intensive care units (NICUs), where incubators are located, must be taken into account. The NICU sound environment is noisy, containing short, disruptive noises at irregular intervals that often exceed the maximum acceptable level of 45 decibels (dB) recommended by the American Academy of Pediatrics (AAP). Hearing impairment is diagnosed in 2% to 10% of premature infants, compared to 0.1% of the general pediatric population. These types of rooms are often characterized by unpredictable noises from multiple sources and, therefore, at different frequencies, such as alarms, ventilators, telephones, and conversations between healthcare personnel and family members. Ideally, to promote healthy hearing development in newborns admitted to NICUs, noise levels in these rooms should be consistent with the intrauterine environment.Providing an adequate environment in the NICU is essential, as newborns admitted to these rooms are born prematurely, with low birth weight, and / or with serious health problems. According to the AAP, exposure to noise levels above 45 dBA can cause cochlear damage or even disrupt the normal growth and development of the newborn. Therefore, the AAP recommends that neonatal care areas should include sound-absorbing units or other means to ensure that the combination of continuous background noise and transient sound in any patient care area does not exceed a cumulative noise level (LAeq per hour) of 45 dBA, a level (L10) of 50 dBA, and a maximum level (Lmax) not to exceed 65 dBA.Noise measurement studies inside incubators show that the main sources of noise come from air circulation and / or motors, pumps, and fans that support various life support mechanisms, alarms from various monitors and maintenance devices, the newborn's crying, the opening and closing of doors, and the conversations of healthcare professionals near the incubator. Many noises are even amplified inside an incubator, such as the noise generated by CPAP (continuous positive airway pressure) due to the enclosed space. The sound inside a modern incubator, especially at low frequencies, can reach levels that are likely harmful to the developing newborn. Much of the noise is at low frequencies and is therefore difficult to reduce by conventional means. Much of the noise inside the incubator comes from sources external to the incubator.Thus, although the average noise level in the most modern NICUs is around 62 dBA, various tests conducted in these facilities show that noise outside the incubator can reach levels of 88.8 dBA, compared to 84.1 dBA inside. However, in general, most studies revealed average noise levels between 55 dBA and 67 dBA and impulse noise levels above 140 dB (banging the incubator to stimulate the apneic premature infant). On the other hand, noise generated during incubator operation ranges from 72.5 dB (placing the formula bottle on top of the incubator) to 98.4 dB (closing the side openings). While some authors recorded sound pressure levels below 60 dBA, which is within the tolerance limit specified in the IEC 60601-2-19 standard, it should be noted that these measurements were carried out during the shutdown condition.During incubator operation at a controlled temperature of 36°C with a maximum humidity setting, other authors recorded levels exceeding 60 dBA. In this regard, some authors indicate that sound levels, especially at low frequencies, inside a modern incubator can reach levels that are likely harmful to the developing newborn. However, others believe that high-frequency sound levels could be the real harm, by analogy with the sound spectra of the pregnant uterus. Therefore, although the AAMI / IEC standard for incubators sets the noise level limit inside incubators at 60 dBA, this level is far from the 45 dBA recommended by the AAP and the 30 dBA recommended by the WHO more than thirty years ago.Advances in controlling noise levels generated by the incubator itself are more recent. In 2013, Northern Illinois University filed patent US20130204617A1, which proposes an apparatus, system, and method for noise cancellation and communication for incubators and related devices. Since then, there are currently patents in this field focused on the active / passive control of noise generated inside incubators, some aimed at noise cancellation and others at generating a proactive sound environment for premature newborns, attempting to recreate the environment existing in the mother's womb. In 2014, patent WO2015029044A2 introduced a noise dampening system based on an acoustic attenuation module, which, using one or more sensors, detects the characteristics of the sound and generates destructive interference from that sound.The sound environment inside the incubator is influenced by the cover materials themselves. These are typically acrylic (methacrylates) containing a certain percentage of polypropylene and other polymers, and are approximately 6 mm thick, sufficient to isolate the external environment from the incubator's microenvironment. Their influence on the sound environment generated inside the incubator stems from the acoustic properties of these materials. They are highly reflective, and while they are responsible for isolating the baby and creating a barrier between the external environment and the microenvironment generated by the incubator, protecting it from situations such as drafts and low temperatures, they also create a reverberant environment that amplifies the already high noise levels generated by the incubator's own devices.Although multi-walled enclosures are known, most enclosures are transparent to sounds in the immediate vicinity and therefore increase the sound level present in the infant's ears. For these reasons, the infant is exposed to potentially dangerous sound pressure levels. It has been observed that the technological development of these devices has not taken into account the noise levels they generate. In the NICU environment, sound pressure levels inside incubators have been observed to fluctuate between 44.2 dBA (L. min ) and 84.2 dBA (L max ) being L Aeq(24 h) of 50.4 dBA. Work has been found at peak L Cpeakclose to 108.3 dBC. The highest levels are found in low frequencies, remaining below 45 dBA from 250 Hz onwards. Currently, the noise level limit inside the incubator is set by UNE-EN 60601-2-19 (Electrical equipment. Part 2-19: Particular requirements for the basic safety and essential operation of baby incubators), which indicates that under normal operating conditions (control temperature of 36ºC and maximum humidity), the sound level inside the baby's compartment must not exceed a sound pressure level of 60 dBA and when any incubator alarm is sounding, the sound level in the newborn's compartment must not exceed 80 dBA.Although the same standard refers to what is indicated by the AAP, it indicates that it is not prudent to keep premature neonates in ambient noise environments greater than 50 dB (A), so, as a recommendation, it emphasizes to manufacturers the need to ensure that the sound levels in the incubator compartment are compatible with those indicated by the AAP. Within the scope of the legislation that may be applicable to the noise dose to which neonatal patients may be subjected, the calculation described in NTP 270 will be taken into account, without forgetting the AAP recommendation, remembering that it is not prudent to keep premature neonates in ambient noise environments greater than 45 dB (A). EXPLANATION OF THE INVENTION The object of the invention consists of a new incubator whose operating sound levels guarantee the recommendations provided by international organizations such as the AAP and the WHO, among others.The technical problem to be solved is to have an incubator containing air at the necessary pressure and flow rate, and with the temperature and humidity conditions required by this type of medical unit, without the introduction of air and its conditioning generating noise or vibrations inside, while providing a compartment to contain the newborn, effectively reducing outside noise. The solution adopted is based on: a) Air is introduced into the incubator using an external element, separate from the incubator, which propels and regulates the air at the required pressure and flow rate, eliminating all sources of noise and vibrations inside. b) The air temperature and humidity required inside the incubator are controlled in a lower drawer consisting of two levels.An upper level that has a circuit through which the air passes, composed of three zones intended for preheating and humidification, for heating through the use of Peltier cells and a third zone through which the air is introduced into the interior of the dome and a lower level intended to contain the electronic power and control systems (4) that has slots for ventilation of the electronic systems. c) The design of a structure with a double envelope that forms the compartment intended to contain the newborn, built of transparent material, formed by an outer cover and an inner one whose panels are microperforated, these being able to be of equal or different thicknesses, separated from each other by a distance determined by the profiles that serve as a union. The technical effects obtained by the solution adopted in the improvement of the acoustic comfort inside the enclosure are listed below.The elimination of the air and oxygen supply device as an internal component of the incubator prevents noise and structural vibrations transmitted by the fan motor and guarantees a constant and adjustable level of pressurization inside the chamber. The external air inlet is regulated by pressure and flow rate and can be combined with the introduction of oxygen. The external pressurized air inlet replaces the fan built into existing incubators. Since there is no motor, the noise and vibrations generated by it are eliminated. The device that guarantees the temperature and humidity conditions inside the incubator dome is based on an air circulation system driven by the inlet of pressurized air from the outside.Once the air is introduced, it performs a preheating and humidification circuit through channels located in the lower drawer. It then circulates through heat sinks connected to a series of Peltier cells. The air is heated and sent, through a series of slots in the top cover of the lower drawer, to the incubator dome. The use of Peltier cells allows for distributed heat generation with more precise control. This ensures that the temperature and humidity levels required by this type of medical unit are reached inside the incubator.The implementation of an external device separate from the incubator, replacing current ventilation devices and thermal control using Peltier cells, provides a sound environment inside neonatal incubators, whose noise levels measured in dBA are below the recommendations provided by the AAP. Additionally, the structure surrounding the neonatal space is composed of a double transparent plastic shell, separated by a certain distance. The inner shell is microperforated, a feature that, combined with the distance separating it from the outer shell, reduces the noise level inside the incubator. To achieve separation between the two shells, the structure is completed with a series of profiles that hold the inner and outer plastic panels in place.This structure incorporates a door for access to the interior, also equipped with a double panel with a microperforated interior, and a series of openings and portholes for access to the interior of the incubator, limiting the entry of untreated air into the incubator. The elimination of the source that generates the current interior noise levels, combined with the enclosing structure of the neonatal space, capable of reducing external noise, guarantees acoustic quality inside the compartment and a greater level of comfort.As a result of this new design, an improvement is obtained in the maintenance of the air / oxygen flow for heat transfer by convection and the gain of humidity by the passage of air through a water container located in the same ventilation flow circuit of the compartment itself in which the baby is located, such that by incorporating an insulating closure system it is possible to obtain a certain degree of pressurization of the compartment space that guarantees its ventilation and an atmosphere with a controllable oxygen level. These parameters would be completely adjustable by medical personnel together with the already traditional ones of temperature, humidity, weight control. BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 shows a general view of the incubator with the system object of the invention. Figure 2 shows a general view of the incubator with the system object of the invention showing its interior.Figure 3 shows an overview of the incubator showing the main parts of which it is composed: - Dome (1) with double envelope that compartment intended to contain the newborn. - Upper level (2) of the lower drawer with a system to maintain temperature and humidity. - Touch screen (3) to display the system information and configure it. - Electronic feeding and control systems (4). - Lower level (5) of the lower drawer intended to contain the electronic feeding and control systems, which has slots for ventilation of the electronic systems. Figure 4 shows an overview of the dome (1) surrounding the newborn. In this view the following elements can be distinguished: - The incubator door (1.2). - The transparent plastic outer panels (1.3). - The transparent microperforated plastic inner panels (1.4). It can be seen that the thickness is different from that of the outer panels (1.3).- The profiles of the surrounding structure (1.5), which serve to establish a separation between the inner and outer panels of the surrounding structure panels. - The profiles of the door frame (1.6), which serve to establish a separation between the inner and outer panels of the door. - Recess (1.7) and porthole (1.8) for access to the newborn so as to limit the entry of cold air into the incubator. - The enclosure profiles (1.9) which serve to complete the enclosure of both the inner and outer envelope of the structure. Figure 5 shows a partial view of the dome (1) enclosing the newborn and the lid of the lower drawer. In this view the following elements can be distinguished: - The outer panels (1.3) made of transparent plastic. - The inner panels (1.4) made of transparent microperforated plastic. It can be seen that the thickness is different from that of the outer panels (1.3). - The profiles (1.5) of the surrounding structure, which serve to establish a separation between the inner and outer panels of the panels of the surrounding structure. - Recess (1.7) for access to the newborn so as to limit the introduction of cold air into the incubator. - The top cover (2.4) of the lower drawer. - The slots (2.5) for air outlet to the interior of the surrounding structure of the upper part of the drawer. Figure 6 shows an isometric view of the lower drawer of the incubator. In this view the following elements can be distinguished: - The air inlet hole (2.1). - The channels (2.2) for air circulation in the lower drawer. - The Peltier cell heatsinks (2.3). - The top cover (2.4) of the lower drawer. - The slots (2.5) for air outlet to the interior of the dome (1)) - The Peltier cells (2.6) - Touch screen (3) to display system information and configure it. - Electronic power and control systems (4).- Lower level (5) with slots for ventilation of the electronic systems. Figure 7 shows an isometric view of the lower drawer. In this view the following elements can be distinguished: - The air inlet hole (2.1). - The channels (2.2) for air circulation in the lower drawer. - The Peltier cell heatsinks (2.3). - The upper cover (2.4) of the lower drawer. - The slots (2.5) for air outlet to the interior of the enclosing structure of the upper part of the drawer. Figure 8 shows an isometric view of the lower drawer with an indication of the air path. In this view the following elements can be distinguished: - Air inlet hole (2.1). - The air preheating path (6). - The air heating path (7) through the Peltier cell heatsinks. - The air outlet path from the lower drawer to the interior of the dome (8).Figure 9 shows a sectional view of the lower part of the incubator. In this view the following elements can be distinguished: - The air circulation channels (2.2) in the lower drawer. - The Peltier cell heatsinks (2.3). - The upper cover (2.4) of the lower drawer. - The slots (2.5) for air outlet to the interior of the surrounding structure of the upper part of the drawer. - The Peltier cells (2.6). - Touch screen (3) to display system information and configure it. - Electronic power and control systems (4). - Lower level (5) with slots for ventilation of the electronic systems. Figure 10 shows the lower drawer. In this view the following elements can be distinguished: - The air inlet hole (2.1). - The air circulation channels (2.2) in the lower drawer. - The Peltier cell heatsinks (2.3). - The upper cover (2.4) of the lower drawer. - The slots (2.5) for air outlet to the interior of the enclosing structure of the upper part of the drawer. Figure 11 shows a view of the lower drawer with an indication of the air path. In this view the following elements can be distinguished: - The air inlet hole (2.1). - The air preheating path (6). - The air heating path (7) through the Peltier cell heatsinks. - The air outlet path from the lower drawer to the interior of the enclosing structure (8). PREFERRED EMBODIMENT OF THE INVENTION As previously indicated, the present invention presents a neonatal incubator model that basically has two main elements, an air conditioning system that eliminates the structure-borne noises generated by the fans incorporated in the incubator, and a structure surrounding the neonate space that reduces noises inside.This reduces the impact of noise and vibration on a premature newborn in a neonatal nursery, as a result of the acoustic and vibration conditions of the incubator and the neonatal nursery itself. This improves the habitability of the facility and reduces the potential harmful effects on the newborn's health from prolonged exposure to noise and vibration. Figures 1 and 2 show the complete incubator, a simplified view in Figure 1, and a view of the interior elements in Figure 2.Figure 3 shows the parts of the incubator, the structure surrounding the newborn (1), the upper level of the lower drawer (2) with a system to maintain temperature and humidity, the touch screen (3) to display the system information and configure it, and the electronic power and control systems (4) and the lower level of the lower drawer (5) which consists of a base designed to contain the electronic power and control systems (4) that has slots for ventilation of the electronic systems. Figures 4 and 5 show, in perspective, details of the surrounding structure that make up the dome (1). The outer panels (1.3) and inner microperforated panels (1.4) can be distinguished, both made of transparent plastic, with different thicknesses, and separated from each other by a distance determined by the shape of the profiles (1.5) that form the frame of the surrounding structure. The door of the incubator (1.2) is made up of specific profiles (1.6) and two panels as described in the structure. There are also a series of openings (1.7) and portholes (1.8) that give access to the interior of the structure, limiting the entry of cold air, as they are large enough to allow the hands of personnel to enter, but much smaller than that of the door. The portholes are also fitted with double plastic, like the rest of the structure. There are also enclosure profiles (1.9), whose function is to maintain the continuity of the enclosure in each of the surrounding structures, both interior and exterior.The configuration of the surrounding structure is capable of attenuating sound, so that in the perception area of ​​a 24-week-old fetus, the levels generated by the prototype, even under the influence of the usual alarms in neonatal intensive care units, are below the hearing threshold. Figure 6 shows an exploded view of the device that guarantees the temperature and humidity conditions in the incubator. A device based on the use of Peltier cells (2.6) is proposed, which guarantees the necessary temperature gradient inside the incubator housing (<1,200gr 34ºC / 35.4ºC) and, combined with the humidifier, the humidity percentage (85 / 50% depending on the gestational age) required by this type of medical units. Air is introduced under pressure through an orifice (2.1), circulates through a series of channels (2.2) carried out in the lower drawer, where it is humidified by the presence of water in the channels and preheated; the preheated and humidified air then passes through the heatsinks (2.3) of the Peltier cells to heat up and pass through a series of slots (2.5) made in the upper part of the drawer (2.4) to the interior of the surrounding structure. You can also see the location of the touch screen (3) that shows the system information and where it can be controlled, the electronic power and control systems (4), and the base with slots (5) for ventilation of the electronic systems. Figures 7 and 8 show the different parts of the lower drawer, as well as the air flow path indicated by arrows. The hole for the air inlet (2.1), the channels (2.2) for the air circulation that make up the preheating path 6), the heatsinks of the Peltier cells (2.3), through which the air heating path (7) is located, the upper cover of the drawer (2.4), where the upper structure rests, and in which the slots (2.5) are located for the outlet of the treated air (8) to the inside of the enclosure. Figure 9 shows a section of the lower drawer, in which the position of the Peltier cells (2.6), the heatsinks (2.3) located above and below the cells, as well as the channels for air circulation (2.2), the upper cover of the drawer (2.4) where the slots (2.5) are located for the outlet of the air to the inside of the enclosing structure, in addition to the position in that section of the electronic power and control systems (4), the base with slots for ventilation of the electronic systems (5), as well as the touch screen (3).This lower drawer produces the conditioning of the temperature and humidity of the air that is introduced into the interior of the enveloping structure that forms the dome, without using any motor, and therefore avoiding the production of vibrations and noise. The path of the air, shown in figures 10 and 11, begins at the air inlet hole (2.1), through which the air or the combination of air and oxygen enters at the pressure required, travels through (6) the different preheating channels (2.2) of the lower drawer, passes through (7) the heat sinks (2.3) of the Peltier cells to heat up, and through the grids (2.5) of the lid (2.4) of the lower drawer passes (8) to the interior of the structure.

Claims

CLAIMS 1. Incubator with a system for improving the acoustic comfort of the newborn, characterized in that a) the introduction of air into its interior is carried out by means of an external element, separate from the incubator, which drives and regulates the air at the required pressure and flow rate, eliminating all sources of noise and vibrations from its interior, b) the effective reduction of outside noise is carried out by means of a structure composed of a dome (1) with a double envelope that forms the compartment intended to contain the newborn, constructed of transparent material, formed by an outer cover (1.3) and another inner cover (1.4) whose panels are microperforated, these being able to be of equal or different thicknesses, separated from each other by a distance determined by the profiles that serve as a connection.c) the conditioning of the temperature and humidity of the air required inside the incubator is carried out in a lower drawer composed of two levels: - An upper level (2) that forms a circuit for the circulation of air that has an opening (2.1) for the introduction of air into its interior and that comprises: - a first preheating zone composed of a series of channels (2.2) through which the air circulates, preheating it and humidifying it due to the presence of water in the channels (6). A second heating zone that incorporates a set of heat sinks (2.3) connected to Peltier cells (2.6), through which the air passes (7). - A series of slots (2.5) made in the lid (2.4) through which the treated air (8) accesses the interior space of the dome.- A lower level (5) consisting of a base designed to contain the electronic power and control systems (4) that has slots for ventilation of the electronic systems, d) has a series of electronic elements among which is a touch screen (3) to display the necessary information, and to adjust its operation.

2. Incubator with a system for improving the acoustic comfort of the newborn, according to claim 1, characterized in that the dome (1) with a double envelope that forms the compartment intended to contain the newborn has a door (1.2) and a series of openings (1.7) and portholes (1.8) on its sides, which preserve the double-covered structure of the dome panels with their micro-perforated inner cover, which serve to access the newborn without needing to open the door (1.2), limiting the introduction of cold air into the incubator.

3. Incubator with a system for improving the acoustic comfort of the newborn, according to claims 1 and 2, characterized in that the double-enveloped structure of the dome (1) is formed by using: a. A series of profiles (1.5) that serve to establish the separation between the outer (1.3) and inner micro-perforated panels (1.4), b. A series of profiles (1.6) that form the outline of the door frame (1.2), c.A series of profiles (1.9) that ensure the enclosure of both the interior and exterior structure.

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