Claims:1. An electronic gas blending device (100) for external ventilation, said device comprising:
a first pressure regulator (106-1) adapted to regulate pressure of a first gas received from a first input port (102);
a second regulator (106-2) adapted to regulate the pressure of a second gas received from a second input port (104);
a first valve (108-1) in fluid communication with the first gas in the first pressure regulator at substantially ambient pressure;
a second valve (108-2) in fluid communication with the second gas in the second pressure regulator at substantially ambient pressure;
a potentiometer (116) operated by a knob to set an input ratio of the first gas and the second gas; and
a microcontroller (120) coupled to the first valve, second valve and the potentiometer, the microcontroller configured to:
receive, from the potentiometer, the input ratio of the first gas and the second gas; and
extract corresponding pre-set values for the input ratio, wherein based on determination of extracted pre-set values, the microcontroller configured to operate the first valve and the second valve in a time sliced manner to accurately control the blending of corresponding gases to the input ratio.
2. The device as claimed in claim 1, wherein the microcontroller (120) coupled to an input connector (122) and at least two output connectors (124-1, 124-2), wherein said input connector adapted to read the input ratio of the potentiometer and said at least two output connectors adapted to control the corresponding valves (108-1, 108-2) for the first gas and the second gas in required proportion, wherein the first gas is air and the second gas is oxygen.
3. The device as claimed in claim 1, wherein the device (100) comprises an accumulator (110) coupled to the first valve and the second valve, the accumulator stores the blended gases.
4. The device as claimed in claim 3, wherein the accumulator (110) is coupled to a pressure sensor (112) that measures the pressure inside the accumulator and acts as a feedback path to maintain the mixture at a constant pressure
5. The device as claimed in claim 4, wherein the pressure sensor (112) detects the absence of at least one gas of the corresponding gases and alerts user through an alarm.
6. The device as claimed in claim 1, wherein the microcontroller (120) operates the first valve and the second valve by receiving input of the pressure sensor and the potentiometer
7. The device as claimed in claim 1, wherein the pressure sensor data and the time slicing information is remotely monitored by using a universal asynchronous receiver-transmitter (UART) interface coupled to the microcontroller (120).
8. The device as claimed in claim 1, wherein calibration data having pre-set values are stored in a look-up table, wherein the calibration data is stored in a secured non-volatile reprogrammable memory coupled to the microcontroller.
9. The device as claimed in claim 1, wherein the device performs automatic and manual calibration mechanisms to build the look-up table for each device to account for device-to-device variation.
10. A method (300) for external ventilation using an electronic gas blending device, said method comprising:
regulating (302), by a first pressure regulator, pressure of a first gas received from a first input port;
regulating (304), by a second regulator, pressure of a second gas received from a second input port;
receiving (306), at a microcontroller, from a potentiometer, an input ratio of the first gas and the second gas, the potentiometer operated by a knob to set the input ratio of the first gas and the second gas; and
extracting (308), at the microcontroller, corresponding pre-set values for the input ratio, wherein based on determination of extracted pre-set values, the microcontroller configured to operate a first valve and a second valve in a time sliced manner to accurately control the blending of the corresponding gases to the input ratio, the first valve in fluid communication with the first gas in the first pressure regulator at substantially ambient pressure and the second valve in fluid communication with the second gas in the second pressure regulator at substantially ambient pressure.
, Description:TECHNICAL FIELD
[0001] The present disclosure relates, in general, to respiratory devices, and more specifically, relates to an electronic air oxygen blender and method for ventilation.

BACKGROUND
[0002] Mechanical blenders consist of a large number of complex parts, where the manufacturing and assembly of which is time-consuming. Conventional electronic blenders consist of expensive sensors like flow sensors, oxygen sensors etc., which make the system expensive and subject to regular maintenance. In addition, these electronic blenders use proportional control valves i.e., voltage-controlled orifices to control the flow of gases.
[0003] An example of such blenders is recited in a patent US 2004/0163706A1, entitled “Electronic gas blender and gas flow control mechanism”. The patent describes a gas flow control mechanism for a gas blender comprising a voltage-sensitive orifice defining a passage for each gas to be controlled and having an inlet port in fluid communication with a gas source and an outlet port in fluid communication with a plenum for mixing at least two gases. Another example is recited in a patent US 2014/0254305 A1, entitled auto-controlled air-oxygen blender”. The patent describes a gas mixing device comprising an oxygen input-source, the oxygen input-source further comprising an oxygen sensor, a gas input-source, the gas input further comprises a first gas flow sensor and a combined gas output-source. The existing way of mechanical blending of air and oxygen poses challenges like complex parts, difficulty in assembly, high manufacturability cost and low accuracy at low flow rates and pressure. The modern electronic blenders make use of expensive components like proportional control valves and flow sensors, which drives up the price of the product and also increases the complexity. There are various problems associated with using the proportional control valve like accounting for hysteresis and variations in performance with temperature.
[0004] Therefore, it is desired to develop accurate blenders that function with fewer sensors and valves that are easy to control.

OBJECTS OF THE PRESENT DISCLOSURE
[0005] An object of the present disclosure relates, in general, to respiratory devices, and more specifically, relates to an electronic air oxygen blender and method for ventilation.
[0006] Another object of the present disclosure is to provide a device that replaces proportional control valves with the less expensive 2/2-way (on/off) solenoid valves.
[0007] Another object of the present disclosure is to provide a device that is easy to control the blending of gases.
[0008] Another object of the present disclosure is to provide a device that avoids accounting for hysteresis and variations in performance with temperature
[0009] Another object of the present disclosure is to provide a device that accurately mixes air and oxygen to the desired output levels with minimal use of sensors.
[0010] Yet another object of the present disclosure is to provide a device with low cost and complexity.

SUMMARY
[0011] The present disclosure relates, in general, to respiratory devices, and more specifically, relates to an electronic air oxygen blender and method for ventilation. The blending of air and oxygen in required proportion plays a paramount role in treating patients who need external ventilation for breathing. The traditional way of mechanical blending of air and oxygen poses challenges like complex parts, difficulty in assembly, high manufacturability cost and low accuracy at low flow rates and pressure. The modern electronic blenders make use of expensive components like proportional control valves and flow sensors which drives up the price of the product and also increases the complexity. The main objective of the present disclosure is to overcome the limitations of the prior art by accurately controlling the blending of the gases in the required proportion with fewer sensors and valves using the time-slicing method. The present disclosure relates to the field of respiratory care of patients that require oxygen-enriched air to maintain blood oxygen levels. An air oxygen blender is a device used to mix hospital-grade air and oxygen into a gas source consisting of 21% to 100% oxygen.
[0012] The present disclosure aims at replacing proportional control valves with less expensive 2/2-way (on/off) solenoid valves. The proposed device avoids various problems associated with using the proportional control valve like accounting for hysteresis and variations in performance with temperature. The cost of the device has also been reduced. The method and configuration adapted to achieve accurate blending with minimal use of sensors is another ingenuity of the present disclosure. The proposed device makes use of one sensor, a pressure sensor, to accurately mix air and oxygen to the desired output levels, thereby reducing the cost, and complexity of the device.
[0013] In an aspect, the present disclosure relates to an electronic gas blending device for external ventilation, the device comprising a first pressure regulator adapted to regulate the pressure of a first gas received from a first input port, a second regulator adapted to regulate the pressure of a second gas received from a second input port, a first valve in fluid communication with the first gas at substantially ambient pressure, a second valve in fluid communication with the second gas at substantially ambient pressure, a potentiometer operated by a knob to set an input ratio of the first gas and the second gas, a microcontroller coupled to the first valve, second valve and the potentiometer, the microcontroller configured to receive, from the potentiometer, the input ratio of the of the first gas and the second gas; and extract corresponding pre-set values for the input ratio, wherein based on determination of extracted pre-set values, the microcontroller configured to operate the first valve and the second valve in a time sliced manner to accurately control the blending of the gases to the input ratio.
[0014] According to an embodiment, the microcontroller coupled to an input connector and at least two output connectors, wherein the input connector adapted to read the input ratio of the potentiometer and the at least two output connectors adapted to control the corresponding valves for the first gas and the second gas in required proportion.
[0015] According to an embodiment, the device comprises an accumulator coupled to the first valve and the second valve, the accumulator stores the blended gases.
[0016] According to an embodiment, the accumulator is coupled to a pressure sensor that measures the pressure inside the accumulator and acts as a feedback path to maintain the mixture at a constant pressure.
[0017] According to an embodiment, the pressure sensor detects the absence of at least one gas of the corresponding gases and alerts user through an alarm.
[0018] According to an embodiment, the microcontroller operates the corresponding valves by receiving input of the pressure sensor and the potentiometer.
[0019] According to an embodiment, the pressure sensor data and the time slicing information is remotely monitored by using a universal asynchronous receiver-transmitter (UART) interface coupled to the microcontroller.
[0020] According to an embodiment, the calibration data can include pre-set values that are stored in a look-up table, wherein calibration data is stored in a secured non-volatile reprogrammable memory coupled to the microcontroller.
[0021] According to an embodiment, the device performs automatic and manual calibration mechanisms to build the look-up table for each device to account for device-to-device variation.
[0022] In an aspect, the present disclosure relates to a method for external ventilation using an electronic gas blending device, the method includes regulating, by a first pressure regulator, pressure of a first gas received from a first input port, regulating, by a second regulator, pressure of a second gas received from a second input port, receiving, at a microcontroller, from a potentiometer, an input ratio of the first gas and the second gas, the potentiometer operated by a knob to set the input ratio of the first gas and the second gas and extracting corresponding pre-set values for the input ratio, wherein based on determination of extracted pre-set values, the microcontroller configured to operate a first valve and a second valve in a time sliced manner to accurately control the blending of the gases to the desired input value, the first valve in fluid communication with the first gas at substantially ambient pressure and the second valve in fluid communication with the second gas at substantially ambient pressure.
[0023] Various objects, features, aspects, and advantages of the inventive subject matter will become more apparent from the following detailed description of preferred embodiments, along with the accompanying drawing figures in which like numerals represent like components.

BRIEF DESCRIPTION OF THE DRAWINGS
[0024] The following drawings form part of the present specification and are included to further illustrate aspects of the present disclosure. The disclosure may be better understood by reference to the drawings in combination with the detailed description of the specific embodiments presented herein.
[0025] FIG. 1A illustrates an exemplary pneumatic circuit of electronic blender, in accordance with an embodiment of the present disclosure.
[0026] FIG. 1B illustrates an exemplary functional component of motherboard, in accordance with an embodiment of the present disclosure.
[0027] FIG. 1C illustrates an exemplary view of potentiometer knob, in accordance with an embodiment of the present disclosure.
[0028] FIG. 2A illustrates an isometric view of the device, in accordance with an embodiment of the present disclosure.
[0029] FIG. 2B illustrates a front view of the device, in accordance with an embodiment of the present disclosure.
[0030] FIG. 2C illustrates a side view of the device, in accordance with an embodiment of the present disclosure.
[0031] FIG. 2D illustrates a top view of the device, in accordance with an embodiment of the present disclosure.
[0032] FIG. 3 illustrates a flow chart of a method for external ventilation using an electronic gas blending device, in accordance with an embodiment of the present disclosure.
DETAILED DESCRIPTION
[0033] The following is a detailed description of embodiments of the disclosure depicted in the accompanying drawings. The embodiments are in such detail as to clearly communicate the disclosure. If the specification states a component or feature “may”, “can”, “could”, or “might” be included or have a characteristic, that particular component or feature is not required to be included or have the characteristic.
[0034] As used in the description herein and throughout the claims that follow, the meaning of “a,” “an,” and “the” includes plural reference unless the context clearly dictates otherwise. Also, as used in the description herein, the meaning of “in” includes “in” and “on” unless the context clearly dictates otherwise.
[0035] The present disclosure relates, in general, to respiratory devices, and more specifically, relates to an electronic air oxygen blender and method for ventilation. The device of the present disclosure enables to overcome the limitations of the prior art by accurately controlling the blending of the gases in the required proportion using the time-slicing method.
[0036] The term “time slicing” used herein refers to a scheduling mechanism/way used in time sharing systems. It is a timeframe for which process is allotted to run in a multitasking manner.
[0037] The gas blending device can include two pressure regulators, an accumulator, a motherboard, inlet ports for two gas sources, an outlet port and two solenoid valves controlled by a microcontroller that defines the time duration of flow opening or closing for the gases to be channelled. The microcontroller receives input from a potentiometer operated by an input knob that is used to set the ratio of the two gases in the output mixture. Based on the input from the potentiometer and the stored pre-set values, the microcontroller uses time slicing method to control the solenoid valves and accurately blend the gases to the set ratio. The blended gas is stored in the accumulator and is connected to a pressure sensor, which ensures that the blended gases are maintained at a constant pressure.
[0038] The advantages achieved by the device of the present disclosure can be clear from the embodiments provided herein. The present disclosure aims at replacing proportional control valves with less expensive 2/2-way (on/off) solenoid valves. The various problems associated with using the proportional control valve like accounting for hysteresis and variations in performance with temperature can be avoided. The cost of the device has also been reduced. The method and configuration adapted to achieve accurate blending with minimal use of sensors is another ingenuity of the present disclosure. The proposed device makes use of one sensor, a pressure sensor, to accurately mix air and oxygen to the desired output levels, thereby reducing the cost, and complexity of the device. The present disclosure can be described in enabling detail in the following examples, which may represent more than one embodiment of the present disclosure. The description of terms and features related to the present disclosure shall be clear from the embodiments that are illustrated and described; however, the invention is not limited to these embodiments only. Numerous modifications, changes, variations, substitutions, and equivalents of the embodiments are possible within the scope of the present disclosure. Additionally, the invention can include other embodiments that are within the scope of the claims but are not described in detail with respect to the following description.
[0039] FIG. 1A illustrates an exemplary pneumatic circuit of electronic blender, in accordance with an embodiment of the present disclosure.
[0040] Referring to FIG. 1A, electronic gas blending device 100 (also referred to as a device 100, herein) is a microcontroller based low-cost system for electronic gas blending. The device 100 can include one or more input ports (102, 104), one or more pressure regulators (106-1, 106-2), one or more valves (108-1, 108-2), accumulator 110, pressure sensor 112, motherboard 114, potentiometer 116 and oxygen sensor 118.
[0041] In an embodiment, the one or more input ports (102, 104) can include a first input port as air source 102 that can include pressurized air (also referred to as first gas) and a second input port as oxygen source 104 that can include pressurized oxygen (also referred to as second gas). The first gas as presented in the example is air and the second gas is oxygen. As can be appreciated, the present disclosure is not limited to blending air and oxygen as described but may be extended to other gases. The first pressure regulator 106-1 coupled to the air source 102 on an inlet path to receive pressurized air and adapted to regulate the pressure of the first gas. The second pressure regulator 106-2 coupled to the oxygen source 104 on an inlet path to receive pressurized oxygen and adapted to regulate the pressure of the second gas.
[0042] The first pressure regulator 106-1 coupled to the first valve 108-1 and the second pressure regulator 106-2 coupled to the second valve 108-2. In an exemplary embodiment, one or more valves (108-1, 108-2) can be normally closed (NC) 2/2 solenoid valves. The opening and closing of these one or more valves (108-1, 108-2) are controlled by a microcontroller 120 configured in the motherboard 114 shown in FIG 1B.
[0043] FIG. 1B illustrates an exemplary functional component of motherboard, in accordance with an embodiment of the present disclosure. The motherboard 114 can include microcontroller 120 as a programmable logic device with two UART interface, on-board voltage regulators and buzzer 126. The input connector 122 adapted to read set value (also referred to as input ratio) of the potentiometer 116, the at least two output connectors (124-1, 124-2) control the one or more solenoid valves (108-1, 108-2) and pressure sensor 112. Based on the position of the mechanical knob connected to the potentiometer 116, the one or more solenoid valves (108-1, 108-2) are opened to meet the exact proportion of gases.
[0044] The microcontroller 120 coupled to the first valve 108-1, second valve 108-2 and the potentiometer 116, the microcontroller 120 configured to receive the input ratio of the first gas and the second gas from the potentiometer 116 and extract corresponding pre-set values for the input ratio. The calibration data can include pre-set values that are stored in a look-up table, where the calibration data is stored in a secured non-volatile reprogrammable memory coupled to the microcontroller 120. The microcontroller 120 configured to operate the first valve 108-1 and the second valve 108-2 in a time-sliced manner to accurately control the blending of the gases to the input ratio based on the determination of extracted pre-set values.
[0045] For example, the algorithm running inside the microcontroller 120 uses the time-slicing concept to achieve this blending of air and oxygen. A period of 200 milliseconds is taken as one cycle and is split into Ta and To, where To + Ta =200. Ta is the time duration in milliseconds for which the first solenoid valve 108-1 for air is opened and To is the time duration in milliseconds for which the second solenoid valve 108-2 for O2 is opened. This ratio of Ta and To determines the relative concentration of the gases in the output mixture.
[0046] The microcontroller 120 coupled to the input connector 122 and at least two output connectors (124-1, 124-2), where the input connector 122 adapted to read the input ratio of the potentiometer 116 and at least two output connectors (124-1, 124-2) adapted to control the corresponding valves (108-1, 108-2) for the first gas and the second gas in required proportion.
[0047] The output from the solenoid valves (108-1, 108-2) is connected to the accumulator 110, where the blended gases are stored. The pressure sensor 112 measures the pressure inside the accumulator 110 and acts as a feedback path to maintain the mixture at constant pressure (Pac). Pac is maintained lower than the regulated pressures of both the gases. This pressure difference ensures controlled flow into the accumulator 110 when the solenoid valves (108-1, 108-2) are opened.
[0048] The proposed device 100 gives an option to calibrate the electronic blender before use to enable accurate blending of gases by accounting for device-to-device variations. The device 100 can be calibrated automatically or even manually. Calibrated results can be stored in a secured non-volatile reprogrammable memory for future use.
[0049] The electronic blender operates in two different modes:
• Calibration mode
• Operating mode
[0050] Calibration Mode:
[0051] A 9-point automatic calibration is done at different values of Ta and To, and the oxygen percentage at each point is recorded. A sample look up table is depicted in Table 1. It is known that when To = 0 and when To = 100 the O2% is 21 and 100 respectively. This look-up table is saved in the flash memory of the microcontroller 120 and used during the operation cycle to set the To and Ta values. The oxygen sensor 118 is used only for calibration and not during operation. Each device needs to be calibrated once at the time of installation.
[0052] Manual calibration can also be done by recording the O2% reading on the sensor against manually set values of Ta and To. Similar to automatic calibration, this look-up table is saved in the flash memory of the microcontroller 120 and used during the operation cycle to set the To and Ta values.
Sl. No To Ta O2%
1 20 180 29
2 40 160 67
3 60 140 45
4 80 120 53
5 100 100 60
6 120 80 68
7 140 60 76
8 160 40 84
9 180 20 92
Table 1: Sample calibration table
[0053] However, these are just exemplary values, and that the actual values can be a wide range, and the values included here are just for illustrative purposes other values and integer multiples are possible as well.
[0054] Operating Mode:
[0055] The user sets the required O2% using the knob of the potentiometer 116. A pointer attached to the potentiometer 116 knob points to the O2% scale as shown in FIG. 1C. Logic is incorporated in the microcontroller 120 to convert the angle of the pointer θ (where θ1 ≤ θ ≤ 180-θ2) to required O2%. The two stoppers present restricts the pointer to O2% values between 21 and 100.
[0056] Based on the required O2%, values, Ta and To are interpolated from the look-up table. The first 2/2 solenoid valve 108-1 for air and the second 2/2 solenoid valve 108-2 for O2 are operated based on these calculated Ta and To values. For example, initially, the first solenoid valve 108-1 for air is opened for time Ta. After time Ta, the first solenoid valve 108-1 for air is closed and the second solenoid valve 108-2 is opened for time To. After time To, the second solenoid valve 108-2 for O2 is closed. This represents one cycle of 200 ms and the cycle is repeated until the pressure in the accumulator reaches Pac. The blended gas is stored in the accumulator 110 for further usage. As the mixed gas is drawn from the accumulator 110 during usage, the pressure in the accumulator 110 drops which are sensed by the pressure sensor 112. This signals the microcontroller 120 to start operating the valves (108-1, 108-2) again to bring up the pressure in the accumulator 110 to Pac.
[0057] In case of absence of one or both of the gas inputs due to failure of the gas sources, the pressure in the accumulator 110 does not reach Pac. The pressure sensor 112 senses this and buzzer 126 is activated to alert the user. Additionally, the pressure sensor data and the time slicing information can be remotely monitored by using the UART port/ interface in the microcontroller 120.
[0058] The embodiments of the present disclosure described above provide several advantages. The device 100 replaces proportional control valves with the less expensive 2/2-way (on/off) solenoid valves. The device is easy to control the blending of gases, avoids accounting for hysteresis and variations in performance with temperature. The device accurately mixes air and oxygen to the desired output levels with minimal use of sensors. Further, the cost and complexity of the device can be reduced.
[0059] FIG. 2A to FIG. 2D illustrate different views of the device, in accordance with an embodiment of the present disclosure. FIG. 2A depicts isometric view of the device, FIG. 2B illustrates a front view of the device, FIG. 2C illustrates a side view of the device and FIG. 2D illustrates a top view of the device.
[0060] FIG. 3 illustrates a flow chart of a method for external ventilation using an electronic gas blending device, in accordance with an embodiment of the present disclosure.
[0061] Referring to FIG. 3, the method 300 includes a block 302 the first pressure regulator adapted to regulate pressure of the first gas received from the first input port. At block 304, the second regulator adapted to regulate pressure of the second gas received from the second input port. The first gas is air and the second gas is oxygen.
[0062] At block 306, the microcontroller can receive from the potentiometer, the input ratio of the first gas and the second gas, where the potentiometer operated by the knob to set the input ratio of the first gas and the second gas.
[0063] At block 308, the microcontroller can extract corresponding pre-set values for the input ratio, wherein based on determination of extracted pre-set values, the microcontroller configured to operate a first valve and a second valve in a time sliced manner to accurately control the blending of the gases to the input ratio. The first valve in fluid communication with the first gas at substantially ambient pressure and the second valve in fluid communication with the second gas at substantially ambient pressure.
[0064] The microcontroller 120 that can be in communication with each of a memory, and input/output units. The microcontroller 120 may include a microprocessor or other devices capable of being programmed or configured to perform computations and instruction processing in accordance with the disclosure. Such other devices may include microcontrollers, digital signal processors (DSP), complex programmable logic device (CPLD), field programmable gate arrays (FPGA), application-specific assimilated circuits (ASIC), discrete gate logic, and/or other assimilated circuits, hardware or firmware in lieu of or in addition to a microprocessor.
[0065] The memory can include programmable software instructions that are executed by the microcontroller 120. The microcontroller 120 may be embodied as a single processor or a number of microcontroller 120. The microcontroller 120 and a memory may each be, for example located entirely within a single computer or other computing device. The memory, which enables storage of data and programs, may include random-access memory (RAM), read-only memory (ROM), flash memory and any other form of readable and writable storage medium.
[0066] It will be apparent to those skilled in the art that the device 100 of the disclosure may be provided using some or all of the mentioned features and components without departing from the scope of the present disclosure. While various embodiments of the present disclosure have been illustrated and described herein, it will be clear that the disclosure is not limited to these embodiments only. Numerous modifications, changes, variations, substitutions, and equivalents will be apparent to those skilled in the art, without departing from the spirit and scope of the disclosure, as described in the claims.

ADVANTAGES OF THE PRESENT DISCLOSURE
[0067] The present disclosure provides a device that replaces proportional control valves with the less expensive 2/2-way (on/off) solenoid valves.
[0068] The present disclosure provides a device that is easy to control the blending of gases.
[0069] The present disclosure provides a device that avoids accounting for hysteresis and variations in performance with temperature
[0070] The present disclosure provides a device that accurately mixes air and oxygen to the desired output levels with minimal use of sensors.
[0071] The present disclosure provides a device with low cost and complexity.