WO2009070057A9

WO2009070057A9 - Neonatal bed

Info

Publication number: WO2009070057A9
Application number: PCT/RU2008/000733
Authority: WO
Inventors: Вячеслав Юрьевич ЛИСИЦЫН; Николай Александрович ЛУЧИНСКИЙ; Владимир Васильевич МИТРОФАНОВ; Олег Васильевич АНТОНОВ
Priority date: 2007-11-26
Filing date: 2008-12-01
Publication date: 2009-09-03
Also published as: WO2009070057A2; RU2007143740A; RU2365362C1; WO2009070057A3

Abstract

The invention relates to medical facilities, in particular to neonatal devices for newborn care. The aim of said invention is to improve the performance characteristics of the device, to make the production process less labour-intensive and to extend the temperature range thereof. The inventive neonatal bed is directed at providing comfort temperature conditions to a newborn. The bed is in the form of a transparent capsule mounted on a trolley. A heating module, consisting of a metal base, a soft bed and a flat heater, is arranged inside the capsule. The improved performance characteristics and the increased accuracy of temperature control while the ambient temperature is changed are achieved owing to the fact that the flat heater is disposed under the metal base, a helium mattress is mounted on the metal base, the flat heater and temperature sensors are designed in the form of three insulated electric circuits located on a flexible printed board and a temperature correlation unit based on a single-chip computer is introduced.

Description

Neonatal bed.

The invention relates to medical equipment, and in particular to devices of a neonatological profile for nursing newborns.

Known crib for a newborn child [1] with a heated mattress containing a flat heater of the mattress, a temperature control unit and an alarm. However, in this device, a flat mattress heater works directly from a 220V 50Hz network. At the same time, it should be noted that the newborn is actually in a humid, aggressive, conductive environment. In this case, despite the presence of protective grounding, there is some likelihood of electric shock to the operating personnel and the patient.

The closest technical solution is the crib [2], where a safe voltage of 12V is used in the heater of the mattress. This installation is a structurally complete device for creating a comfortable thermal environment for a newborn baby. The installation passed all the necessary medical and technical tests, has a certificate of compliance and has been repeatedly exhibited at medical exhibitions.

However, the experience of serial production and operation of such a bed revealed certain disadvantages of this device.

These include:

- the relatively high complexity of the adjustment work;

- poor interchangeability of the main element of the crib-thermostat;

- lack of operational automatic correlation of the temperature regime of the crib depending on changes in ambient temperature.

Structurally, the prototype thermal mattress consists of a flat heater, a soft bed in the form of a foam mat and a thermal insulator made of felt. On

SUBSTITUTE SHEET (RULE 26) two temperature sensors are fixed with a flat heater (MMT-1-1.5 kOhm thermistors). All these components with a zipper are enclosed in a package of baby oilcloth. The flat heater and two temperature sensors are connected to the power and control units via a detachable connection. Two temperature sensors are the main regulatory link in the system of setting and maintaining specified temperature conditions. However, modern thermistors used as temperature sensors have a significant variation in the main electrical parameter - the temperature coefficient of resistance (TKC). So for the thermistors used in the prototype, the spread of TKC is in the range (2.4 ... 5.0)% / ⁰ C. Hence, there is a need for individual adjustment of the temperature measuring path separately for each crib.

In addition, this creates certain difficulties in the operation and repair of cribs in the maternity hospital, since after the sanitary treatment of thermal mattresses, which is carried out regularly, it is necessary to ensure that each concrete mattress is backlinked specifically to its crib, i.e., to its own control unit.

Another difficulty is that the likelihood of damage to the surface of the baby oilcloth of the mattress cannot be ruled out. Which will inevitably lead to the ingress of liquid secretions of the newborn on the conductive surface of the flat heater and, accordingly, to violations in its operation.

And the last one. The instruction manual for the prototype product has one significant limitation. Namely, it is indicated that the set temperature conditions of the crib are provided and guaranteed if the ambient temperature is within (24 ± 2) ° C.

SUBSTITUTE SHEET (RULE 26) The purpose of the invention is to improve the operational characteristics of the product, reducing the complexity of its manufacture, expanding the temperature range.

This object is achieved in that the device containing the temperature setpoint adjuster, power switch, emergency switch, power supply unit, uninterruptible power supply unit, transparent capsule, with the heating module inside it, according to the invention, the claimed device further comprises a temperature correlation unit and a temperature sensor located outside the transparent capsule, a digital indicator of the temperature setting, while all the basic functions for controlling the temperature conditions of the neonatal crib performed by the temperature correlation unit, in addition, the flat heater and two temperature sensors of the heating module are made in the form of a flexible printed circuit board installed under a metal base on which a soft bed in the form of a gel mattress is located, a flexible printed circuit board contains three insulated conductive circuits, the first circuit is a flat heater, and the second and third circuits are respectively the first and second temperature sensors.

Figure l presents a General view of the thermal bed; in FIG. 2 shows a design of a heating module; in FIG. 3 shows an example of the front panel; figure 4 shows a flexible printed circuit board with a flat heater and two temperature sensors; figure 5 shows a functional diagram of the claimed device.

The neonatal bed contains:

A trolley with a rotary frame 1, a transparent capsule 2, a heating module 3. The heating module contains a flexible printed circuit board 4, consisting of a flat heater 5 with pads + 12B and -12V for connecting a low-voltage power source; the first (emergency) temperature sensor 6 with contact pads DG1 / 1 and DT1 / 2; second

SUBSTITUTE SHEET (RULE 26) (working) temperature sensor 7 with contact pads DT2 / 1 and DT2 / 2. The metal base 8 of the heating module provides heat transfer from the flexible printed circuit board to the soft bed (gel mattress) 9 and at the same time protects the heater from liquid from the child. The heat insulator 10 prevents the loss of useful heat. The heating module is enclosed in a hard casing 11.

Outside the transparent capsule there is a third temperature sensor (environmental sensor) 12. Structurally, this sensor is located inside the heating module near the inlet through which air is sucked in with a fan (not shown in FIG. 2) to cool the circuit board with electronic components.

The voltage is supplied to the flat heater from the power supply unit 13 through the power switch 14. The emergency switch 15 will turn off the heater if the temperature in the bed for some reason exceeds the permissible value. On the front panel of the device there is a digital indicator of the operating temperature 16, a digital indicator of the temperature setting 17, a temperature setting dial (temperature setting) 18, mode selection buttons and other indicators.

The temperature correlation block 19 contains a single-chip computer 20, with a reprogrammable data memory 21, program memory 22, processor 23, and trunk bus 24. The analog multiplexer 25 provides the connection to the ADC input 26 of one of the temperature sensors — working 7 or environment 12. Multi-bit keys 27, 28 of the channel selection circuit 29 separate the output information from the ADC into two channels, which makes it possible to connect one of the registers to the ADC output — the operating temperature register 30 or the ambient temperature register environment 31. The unit for fixing the temperature difference 32 shows how much the temperature recorded by the environmental sensor differs from the reference value recorded in the reference temperature register 33. The output information of the unit 32 is information about the value

SUBSTITUTE SHEET (RULE 26) numerical increment and the sign of this increment (plus or minus). The temperature correction calculation unit 34 analyzes the information received from the temperature difference fixation unit and from the register of the thermal constant 35. In the temperature setting correction module 36, the input information is processed from the temperature setting counter 37 and from the temperature correction calculation unit. The corrected digital temperature setting information is supplied to a digital comparator 38, where it is compared with a digital temperature code of the working sensor. The output bus 39 of the channel selection circuitry provides the transmission of a multi-bit digital code to the respective registers. The output bus 40 of the operating temperature register transmits a digital code to indicate the current operating temperature and at the same time this information is transmitted to the digital comparator. On the output bus 41 of the temperature setpoint setpoint, the temperature setpoint value is sequentially written to the corresponding counter.

The uninterruptible power supply 42 signals the loss of mains voltage and transfers the temperature control circuitry to battery power.

All the main functions for controlling the temperature conditions of the neonatal crib are performed by the temperature correlation unit 19, the basis of which can be a high-resolution SIGMA DELTA ADC with the integrated microprocessor module ADu824 MK 8051 made by ANALOG DEVICES, made in the microcircuit design. A feature of this chip is the presence of two ADCs for 16- and 24-bit, built-in peripherals in the form of an internal temperature sensor, a 12-bit DAC, an excitation current source, a time interval counter, a serial port, and other circuits.

The main information input channels for block 19 are two temperature sensors 7, 12 and a temperature setpoint setter 18.

SUBSTITUTE SHEET (RULE 26) The first and second temperature sensors 6.7 are an integral part of the heating module 3 and are located on a flexible printed circuit board 4.

The first (emergency) temperature sensor 6, together with the emergency switch circuit 15, performs the function of protecting the crib in the event of a failure of the temperature control system. Functionally, the node 15 can be performed similarly to the prototype and contains a threshold circuit, the end stage of which is a relay that breaks the input circuit of the power switch 14, turning off the flat heater 5.

All of the following operations performed using a single-chip computer 20 are aimed at removing restrictions on the ambient temperature at which the specified temperature conditions are guaranteed.

Two temperature sensors 7, 12 together with block 19 actually perform the function of automatically controlling the temperature of the neonatal crib. The analog multiplexer 25 on command from the computer 20 connects to the input of the ADC 26 temperature sensor 7 (working). The ADC has a high-precision reference voltage source Uoporn. In the ADC, analog information about the current temperature of the heater 5 is compared with the reference voltage and converted to digital form. The same command applies for multi-bit keys 27, 28 in the channel selection circuit 29 and digital information about the current temperature in the heating module via bus 39 is entered into the operating temperature register 30 and stored there.

The next command from the computer 20 to the output of the multiplexer receives analog information from another sensor - the ambient temperature sensor 12, it is also converted to digital form and through multi-digit keys 27.28 and bus 39 is now stored in the register of ambient temperature 31.

In the same block 19, a register of reference temperature 33 is organized by software and hardware. A temperature, for example, 24 ° C, at which it normally works, can be taken as a reference temperature

SUBSTITUTE SHEET (RULE 26) prototype bed. The digital code of the reference temperature is stored in the memory of the computer 20 and by the appropriate command is copied to the register of the reference temperature 33.

After that, in the fixation unit of the temperature difference 32, again, by hardware and software, it is recorded how much at the current time the ambient temperature differs from the reference, i.e. the digital value of the increment of the ambient temperature is formed. It is clear that this increment can be both positive and negative depending on which direction the ambient temperature has changed.

Then the temperature correction value is determined. This operation is performed in the node for calculating the temperature correction 34, where the temperature correction coefficient is generated by software taking into account another value, called HEAT CONSTANT. This parameter reflects the design features of a particular heating module. The fact is that when measuring the temperature of the surface of the mattress, it is impossible for structural reasons to install a temperature sensor directly on the mattress, i.e., under the newborn. Therefore, the heater is controlled by a temperature sensor 7 (working sensor), which is located on a flexible printed circuit board 4 inside the heating module 3. In this case, there is inevitably a temperature difference on the surface of the mattress and inside the heating module 3. Depending on the design features of the mattress, its thickness, the heat-conducting properties of the gel filler, etc. this temperature difference can reach 8 ⁰ C. That is, if the surface of the mattress is heated, for example, to a temperature of 35 ° C, then the temperature of the flat heater at this point may already be 43 ⁰ C. This temperature difference is the thermal constant of the mattress. Thus, this parameter takes into account the structural and heat-conducting features of specific gel mattresses. The specific value of this constant is determined by adjusting the crib and

SUBSTITUTE SHEET (RULE 26) stored in the computer memory 20 and by another command through the main bus 24 is written to the register of thermal constant 35. Thus, in the node for calculating the temperature correction, the digital code of the temperature difference stored in the node 32 and the code of the thermal constant (register 35) are added taking into account the sign of the temperature difference generated in node 32.

The final operation of block 19 is the correction operation of the set temperature setpoint (set temperature), performed according to the results of the analysis of the changing ambient temperature and taking into account the heat-conducting features of a particular gel mattress. Such correction is performed by software in the temperature setpoint correction module (set temperature correction module) 36. The essence of the operation is that this module automatically adjusts the set temperature set point, i.e. set point (set temperature), which is displayed unchanged on the digital indicator 17. This current temperature set is set by the temperature setpoint setpoint (temperature setpoint) 18 and via bus 41 (which connects the first and second outputs (outputs to increase and decrease the set temperature) of the setpoint temperature the settings with the third and fourth inputs of the temperature correlation block, respectively) is recorded and stored in the counter of the temperature setpoint (counter of the set temperature) 37.

Thus, to correct the temperature setpoint, all the initial data are available, namely: the set temperature setpoint (from counter 37) and a digital temperature correction code (from the node for calculating the temperature correction 34).

The digital code of the adjusted digital temperature setpoint is, on command from the computer 20, fed to the second input of the digital comparator 38, where it is compared with the digital code of the current temperature of the mattress received via bus 40 from register 30 (operating temperature register) to the first input of the comparator. Digital comparator 38 will provide an input enable signal

SUBSTITUTE SHEET (RULE 26) power key 14, i.e. to turn on the heater for as long as the operating temperature of the mattress is less than the adjusted temperature setting (meaning of course that the emergency switch 15 circuit is closed in this case).

The exchange of information between nodes in the temperature correlation unit 19 is carried out on the bus 24.

As already noted, the temperature correlation block can be made on the basis of the MK ADuC 824 microcontroller. The chip is available in a 52-pin package and has an extensive debugging and programming system compatible with the WINDOWS-98 operating system.

According to the technical requirements for such products, they must be functional even with a short-term loss of mains voltage. A mandatory attribute of such a scheme is the battery and charger. In the prototype there is such a circuit, but it performs there only the function of signaling the disappearance of the mains voltage. Uninterruptible power supply 42 can be performed, for example, according to the scheme given in the journal RADIO (J. RADIO, 2001. JVb 7, p. 44). As noted in this article, "if the mains fails, the device simply continues to work on battery power, as soon as the mains voltage is restored, the battery will begin to recharge." Block 42 allows you to save on the digital display all current information about the operating temperature and temperature setting even with a short-term loss of mains voltage. This unit, of course, is intended only for supplying control and indication circuits, but by no means for power circuits.

The power circuits include, first of all, a flat heater 5, which can consume a current of at least 10A at a voltage of 12V. The current source for the flat heater is the power supply unit 13. As it can be used, the MPS-200-12 unit from MEAN WELL is designed for a current of 16A with an output voltage of 12V. But its main feature is that this development has a special

SUBSTITUTE SHEET (RULE 26) medical series and has increased electric strength, its breakdown voltage is not less than 4000V.

A distinctive feature of the claimed technical solution is that it was possible to physically separate the soft bed (gel mattress) 9 from the flexible printed circuit board 4 with a heater (Fig. 2), placing a metal base between them 8. This metal base has three functions - it forms a hard horizontal surface for the mattress, transfers heat from the flat heater to the mattress and protects the flexible circuit board 4 from the liquid secretions of the newborn.

Now about the design of a flat heater.

A technical solution is known for designing a flat heater in the form of a printed circuit board (see, for example, patent RU 2126605). However, unlike this patent, in the claimed technical solution, not only a flat heater, but also two temperature sensors were made on a single printed circuit board in a single technological process. This allowed to significantly reduce the complexity of installation and adjustment work. In fact, installation and fastening operations with threads and glue on a flat heater of thermistors, which act as temperature sensors, are now excluded. In addition, the calibration of the temperature range of cribs is greatly simplified due to the high repeatability of temperature sensors and the high stability of their main parameter, the temperature coefficient of resistance.

Another important advantage of the claimed technical solution is that routine and repair work are greatly simplified. Regular sanitization is now not carried out on the thermo mattress with the heater and sensors, but only on the gel mattress of the child, while the flexible printed circuit board 4 with heater 5 and temperature sensors 6.7 are protected by a metal base 8 from the detergent entering the heater. In this case, the likelihood of a break in the flat heater and temperature sensors is sharply reduced.

SUBSTITUTE SHEET (RULE 26) In addition, the introduction of temperature correlation block 19 into the device reduces the requirements for ensuring stable temperature during adjustment and operation of the neonatal crib.

The claimed technical solution takes into account the experience of manufacturing and operating a large batch of thermal beds DETKA-12-01 and DETKA-12-01M at the enterprise. At the same time, it is supposed to use a new modern elemental base, as well as new technical solutions in the design.

Thus, the claimed neonatal bed contains a temperature setpoint switch, a power switch, an emergency switch, a power supply unit, an uninterruptible power supply unit, a transparent capsule, with a heating module in it, consisting of a metal base, a soft bed, a flat heater connected to the power output key, the first and second temperature sensors, and the output of the first temperature sensor is connected to the first control input of the emergency switch, the output of which is connected to the control input the power key, the power input of which is connected to the output of the power supply unit, and the output of the uninterruptible power supply unit is connected to the input of the power supply unit. A distinctive feature of the claimed invention is that the neonatal bed further comprises a temperature correlation unit, a third temperature sensor located outside the transparent capsule, a digital temperature setting indicator, a digital operating temperature indicator and a digital comparator, while the first, second, third and fourth inputs the temperature correlation unit respectively connected to the outputs of the second and third temperature sensors, with the first and second outputs of the setpoint temperature settings ; a temperature correlation unit with a first output connected to an input of a digital operating temperature indicator and a first input of a digital comparator, second and third outputs connected to a second input of a digital comparator and an input of a digital temperature setting indicator; trunk output

SUBSTITUTE SHEET (RULE 26) tires of the temperature correlation unit are connected to an uninterruptible power supply unit and to a power supply unit; the output of the digital comparator is connected to the second input of the emergency switch, in addition, the flat heater and two temperature sensors of the heating module are made in the form of a flexible printed circuit board installed under a metal base on which a soft bed in the form of a gel mattress is located, a flexible printed circuit board contains three insulated conductive circuit, and the first circuit is a flat heater, and the second and third circuits are respectively the first and second temperature sensors.

In addition, the temperature correlation unit includes the following elements: an analog multiplexer, an analog-to-digital converter, a channel selection circuit, an operating temperature register, an ambient temperature register, a reference temperature register, a thermal constant register, a temperature set point counter, a temperature difference fixation unit, a node calculation of the temperature correction, the temperature setting correction module, as well as the bus and computer in the standard configuration, which is connected to the above elements, the first and second inputs of the analog multiplexer are respectively the first and second inputs of the temperature correlation unit, the output of the analog multiplexer is connected to the analog input of the analog-to-digital converter, the output of which is connected to the information input of the channel selection circuit, the output bus of which is connected to the information inputs of the register operating temperature and ambient temperature register, the output bus of the operating temperature register forms the first output of the unit eraturnoy correlation environment register output connected to a first input of summation node fixation temperature difference, subtracting the second input coupled to an output register reference temperature, the first and second outputs of the temperature difference fixing node are connected respectively to first and second inputs of the temperature calculating unit

SUBSTITUTE SHEET (RULE 26) correction, the third input of which is connected to the output of the thermal constant register, the output of the temperature correction calculation unit is connected to the first input of the temperature setting correction module, the second input of which is connected to the output of the temperature setting counter, the first and second inputs of which form the third and fourth inputs of the temperature correlation block, respectively , the output of the temperature setpoint correction module forms the second output of the temperature correlation block, the output of the temperature setpoint counter forms the third output of the block and temperature correlation.

Information sources.

1. Amiterm heating bed from AMEDA switzеrlapd. Prospectus of the company. 1990

2. Neonatal thermal bed DETKA-12-01 Operation manual, (prototype) 1996

SUBSTITUTE SHEET (RULE 26)

Claims

Claim

1. A neonatal bed containing a temperature setpoint adjuster, a power switch, an emergency switch, a power supply unit, an uninterruptible power supply unit, a transparent capsule, with a heating module inside it, consisting of a metal base, a soft bed, a flat heater connected to the power key output , the first and second temperature sensors, and the output of the first temperature sensor is connected to the first control input of the emergency switch, the output of which is connected to the control input of the power switch, the silt input of which is connected to the output of the power supply unit, and the output of the uninterruptible power supply unit is connected to the input of the power supply unit, characterized in that the bed further comprises a temperature correlation unit, a third temperature sensor located outside the transparent capsule, a digital temperature setting indicator, a digital operating indicator temperature and a digital comparator, while the first, second, third and fourth inputs of the temperature correlation block are respectively connected to the outputs of the second and third sensors temperature peaks, with the first and second outputs of the temperature setpoint setter; a temperature correlation unit with a first output connected to an input of a digital operating temperature indicator and a first input of a digital comparator, second and third outputs connected to a second input of a digital comparator and an input of a digital temperature setting indicator; the output of the trunk bus of the temperature correlation unit is connected to the uninterruptible power supply unit and to the power supply unit; the output of the digital comparator is connected to the second input of the emergency switch, in addition, a flat heater, two temperature sensors of the heating module are made in the form of a flexible printed circuit board installed under a metal base, on which is located a soft bed in the form of a gel mattress, a flexible printed circuit

SUBSTITUTE SHEET (RULE 26) the board contains three insulated conductive circuits, the first circuit being a flat heater, and the second and third circuits being the first and second temperature sensors, respectively.

2. The device according to claim 1, characterized in that the temperature correlation unit includes: an analog multiplexer, an analog-to-digital converter, a channel selection circuit, an operating temperature register, an ambient temperature register, a reference temperature register, a thermal constant register, a temperature counter the settings, the node for fixing the temperature difference, the node for calculating the temperature correction, the module for the correction of the temperature setting, as well as the main bus and computer, which is connected via the main bus to the above as shown, the first and second inputs of the analog multiplexer are respectively the first and second inputs of the temperature correlation unit, the output of the analog multiplexer is connected to the analog input of the analog-to-digital converter, the output of which is connected to the information input of the channel selection circuit, the output bus of which is connected to the information inputs of the register operating temperature and ambient temperature register, the output bus of the operating temperature register forms the first output of the temperature unit correlation, the output of the environmental register is connected to the first input of the addition of the temperature difference fixation unit, the second subtraction input of which is connected to the output of the reference temperature register, the first and second outputs of the temperature difference fixation unit are connected respectively to the first and second inputs of the temperature correction calculation unit, the third input which is connected to the output of the thermal constant register, the output of the temperature correction calculation unit is connected to the first input of the temperature setting correction module, W The second input of which is connected to the output of the temperature setting counter, the first and second inputs of which form the third and fourth inputs of the temperature block, respectively

SUBSTITUTE SHEET (RULE 26) correlation, the output of the temperature setting correction module forms the second output of the temperature correlation unit, the output of the temperature setting counter forms the third output of the temperature correlation unit.

SUBSTITUTE SHEET (RULE 26)