ES3007459B2 - INCUBATOR WITH SYSTEM FOR IMPROVING THE ACOUSTIC COMFORT OF THE NEONATE - Google Patents

Description

DESCRIPTION

INCUBATOR WITH SYSTEM FOR IMPROVING THE ACOUSTIC COMFORT OF THE NEONATE

TECHNICAL SECTOR

According to the table of concordance with the International Patent Classification (IPC), the sector of the Technique where the proposed system is classified 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 widely used functional scheme, adopted by several manufacturers for incubator design. 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, 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 include: a relatively large body surface area relative to body 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 support equipment contribute to room noise.

Since the first infant incubator, patented in 1929, to the present day, all the improvements implemented have focused on improving the system composed of a ventilation circuit for heat transfer by convection and humidity gain by 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 a newborn's comfort in the incubator is the noise level inside. While high noise levels are undesirable for everyone, the situation can be alarming for premature babies, especially considering that they are born before their auditory system has had the opportunity to fully mature, and it could cause sensorineural hearing loss. In this sense, premature babies have a reduced response to auditory stimulation compared to full-term babies. 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 the newborn's 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 newborns are more susceptible to the effects of ambient noise than those born at term. The lower the gestational age, the greater the impairment, as brain development is not complete, 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 power 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 this noise is at low frequencies and is therefore difficult to reduce by conventional means. Much of the noise inside the incubator comes from sources outside 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, overall, most studies revealed average noise levels between 55 dBA and 67 dBA and impulse noises above 140 dB (incubator knocks to stimulate the apneic premature infant). On the other hand, the noise generated during handling of the incubators 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 operation of the incubator at a controlled temperature of 36°C with a maximum humidity setting, other authors recorded levels above 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 dB, 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 child's ears. For these reasons, the child is exposed to potentially dangerous sound pressure levels. It has been found 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 (Lmin) and 84.2 dBA (Lmax), with a LAeq<(24>h) of 50.4 dBA. Studies have been found with LCpeak peaks close to 108.3 dBC. The highest levels are found at low frequencies, remaining below 45 dBA from 250 Hz.

Currently, the noise level limit inside the incubator is set by UNE-EN 60601-2-19 (Medical electrical equipment. Part 2-19: Particular requirements for the basic safety and essential performance of infant incubators), which indicates that under normal operating conditions (control temperature of 36°C and maximum humidity), the sound level inside the infant compartment should not exceed a sound pressure level of 60 dBA and when any incubator alarm is sounding, the sound level in the neonate compartment should 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 above 50 dB(A), and therefore, 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 legislation that may be applicable to the noise dose to which newborn patients could be exposed, the calculation described in NTP 270 will be taken into account, without forgetting the recommendation of the AAP, remembering that it is not prudent to keep premature newborns in ambient noise environments greater than 45 dB(A).

EXPLANATION OF THE INVENTION

The object of the invention is 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 drives and regulates the air to the required pressure and flow rate, eliminating all sources of noise and vibrations from within.

b) 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 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 achieved by the solution adopted in improving 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 the fan 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 entry of pressurized air from the outside. Once introduced, the air 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 newborn's space is composed of a double layer of transparent plastic, separated by a certain distance. The inner layer is microperforated, a feature that, combined with the distance separating it from the outer layer, reduces the noise level inside the incubator. To achieve separation between the two layers, the structure is completed with a series of profiles that hold the inner and outer plastic panels in place. This structure includes 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, thus limiting the entry of untreated air into the incubator.

Eliminating the source of current interior noise levels, combined with the neonatal space's enclosure structure, which reduces outside noise, ensures high-quality acoustics inside the compartment and a higher level of comfort.

As a result of this new design, there is an improvement in maintaining the air/oxygen flow for convective heat transfer and humidity gain through the passage of air through a water container located in the same ventilation flow circuit of the compartment itself where the baby is located. Such that by incorporating an insulating closure system, it is possible to achieve a certain degree of pressurization of the compartment space, ensuring its ventilation and an atmosphere with a controllable oxygen level. These parameters would be completely adjustable by medical personnel, along with the already traditional parameters of temperature, humidity, and 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 contains the newborn.

- Upper level (2) of the lower drawer with system to maintain temperature and humidity.

- Touch screen (3) to display system information and configure it.

- Electronic power and control systems (4).

- Lower level (5) of the lower drawer intended to contain the electronic power and control systems, which has slots for ventilation of the electronic systems.

Figure 4 shows a general view of the dome (1) surrounding the newborn. The following elements can be distinguished in this view:

- The incubator door (1.2).

- The transparent plastic outer panels (1.3).

- The inner panels are made of transparent micro-perforated plastic (1.4). It can be seen that the thickness is different from that of the outer panels (1.3).

- The profiles of the enclosing structure (1.5), which serve to establish a separation between the inner and outer panels of the enclosing structure panels.

- The door frame profiles (1.6), which serve to establish a separation between the inner and outer panels of the door.

- Hole (1.7) and porthole (1.8) for access to the newborn so that the introduction of cold air into the incubator is limited.

- The enclosure profiles (1.9) that serve to complete the enclosure of both the interior and exterior envelope of the structure.

Figure 5 shows a partial view of the neonatal dome (1) and the lower drawer lid. The following elements can be distinguished in this view:

- The outer panels (1.3) made of transparent plastic.

- The inner panels (1.4) are made of transparent micro-perforated plastic. It can be seen that the thickness is different from that of the outer panels (1.3).

- The profiles (1.5) of the enclosing structure, which serve to establish a separation between the inner and outer panels of the enclosing structure panels.

- Hole (1.7) for access to the newborn so that the introduction of cold air into the incubator is limited.

- 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 incubator's lower drawer. The following elements can be distinguished in this view:

- The air inlet hole (2.1).

- The channels (2.2) for air circulation in the lower drawer.

- 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))

- 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 electronic systems.

Figure 7 shows an isometric view of the lower drawer. The following elements can be distinguished in this view:

- The air inlet hole (2.1).

- The channels (2.2) for air circulation in the lower drawer.

- 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 surrounding structure of the upper part of the drawer.

Figure 8 shows an isometric view of the lower box, indicating the air path. The following elements can be distinguished in this view:

- 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 box to the interior of the dome (8).

Figure 9 shows a sectional view of the lower part of the incubator. The following elements can be distinguished in this view:

- The channels for air circulation (2.2) in the lower drawer.

- 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 surrounding structure of the upper part of the drawer.

- 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 electronic systems.

Figure 10 shows the lower drawer. The following elements can be distinguished in this view:

- The air inlet hole (2.1).

- The channels (2.2) for air circulation in the lower drawer.

- 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 surrounding structure of the upper part of the drawer.

Figure 11 shows a view of the lower box with the air path indicated. The following elements can be distinguished in this view:

- 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 surrounding 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 structure-borne noise generated by the fans incorporated into the incubator, and a structure surrounding the newborn's space that reduces noise inside. This reduces the impact of noise and vibrations on a premature newborn in a neonatal room, as a result of the acoustic and vibration conditions of the incubator and the neonatal room itself. This improves the habitability of the room and reduces the potential harmful effects on the newborn's health due to prolonged exposure to noise and vibrations.

Figures 1 and 2 show the complete incubator, in a simplified form in Figure 1, and with 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 enclosing structure that makes 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 enclosing structure. The incubator door (1.2) is formed by specific profiles (1.6), in addition to 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 part of the structure, limiting the entry of cold air, as they are large enough for the hands of the staff 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 some 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 with 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 34°C /35.4°C) and combined with the humidifier the percentage of humidity (85/50% depending on the gestational age) required by this type of medical units. The air is introduced under pressure through an orifice (2.1), circulates through a series of channels (2.2) made in the lower drawer, where it is humidified by the presence of water in the channels, and preheats; then, the preheated and humidified air passes through the heat sinks (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 inside 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 box, as well as the air flow path indicated by arrows. The hole for air inlet (2.1), the channels (2.2) for air circulation that make up the preheating path 6), the Peltier cell heatsinks (2.3), through which the air heating path (7) is located, the upper cover of the box (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) can be identified, 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 air outlet to the interior of the surrounding 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 controls the temperature and humidity of the air 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 required pressure, 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 it passes (8) to the interior of the structure.

Claims (3)

1. Incubator with a system to improve the acoustic comfort of the newborn, characterized by a) the introduction of air into the 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 the interior, b) the effective reduction of noise from the outside 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, built 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 thickness, 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 consisting of two levels: - An upper level (2) that forms a circuit for air circulation 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 (7) passes. - A series of slots (2.5) made in the cover (2.4) through which the treated air (8) enters the interior space of the dome. - A lower level (5) consisting of a base intended to contain the electronic power and control systems (4) that has slots for ventilation of the electronic systems, d) It has a series of electronic elements, including 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 having 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 envelope 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 panels (1.3) and the microperforated inner 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.