Description:TECHNICAL FIELD
[1] The present disclosure generally relates to a ventilator for supplying a user with ventilating gas. In particular, the present disclosure relates to a means to regulate a gas pressure in a ventilator.

BACKGROUND
[2] Background description includes information that may be useful in understanding the present invention. It is not an admission that any of the information provided herein is prior art or relevant to the presently claimed invention, or that any publication specifically or implicitly referenced is prior art.
[3] Conventional technologies that exist for positive end expiratory pressure (PEEP) regulation in a ventilator employ control of an expiratory valve to do so. In some cases, the entire expiration phase is generally divided into two phases. During the first phase, the expiratory valve is completely open, leading to a natural expiration process. As soon as the expiratory flow (or airway pressure) reaches a set threshold flow (or pressure) value, the second phase is started. In the second phase, the expiratory valve is controlled to bring the system pressure to a set PEEP. In some other cases, the time of the first phase in which the expiratory valve is completely open is iterated. This time is increased or decreased in the next breath cycle, based on the value of flow or pressure that was achieved in the previous breath cycle at the end of this time. Convergence is achieved after a number of breath cycles. Following are the limitations of the existing technologies:
• iterative nature of PEEP regulation - convergence to the set PEEP value is obtained after a number of breaths, and not in the first breath itself, causing discomfort to the user during the iteration phase. Moreover, the convergence time might become large if the convergence algorithm is not robust;
• user is subjected to varying PEEP levels during the iteration phase, which may lead to user discomfort;
• end pressure may be very lower than PEEP during the iteration phase, which may lead to the collapse of alveoli in users, such as critical patients;
• negligence of lung parameters for PEEP regulation - different users have different lung parameters (resistance and compliance), and hence, PEEP regulation controls will need to be adaptive. Applying the same regulation controls on all lung types may not be robust and efficient; and
• negligence of dynamic system parameters for PEEP regulation – ventilator parameters (such as resistance, compliance, leakage, etc.) may change at any time during the ventilation cycle, and hence, PEEP regulation controls will need to be adaptive. Applying the same regulation controls on all system types may not be robust and efficient.
[4] There is, therefore, a requirement in the art for a means to efficiently and effectively regulate gas pressure in a ventilator so as to reduce discomfort and potential harm to a user of the ventilator.

OBJECTS OF INVENTION
[5] An object of the present invention is to provide a system and method for regulating a gas pressure in a ventilator.
[6] Another object of the present invention is to provide a system for effectively and accurately regulating a gas pressure in a ventilator.
[7] Another object of the present invention is to provide a system that is not iterative.
[8] Another object of the present invention is to provide a system that can dynamically adapt to changes in a user’s lung parameters as well as to dynamics of the ventilator.
[9] Another object of the present invention is to provide a system that limits discomfort to a user.

SUMMARY
[10] The present disclosure generally relates to a ventilator for supplying a user with ventilating gas. In particular, the present disclosure relates to a means to regulate a gas pressure in a ventilator.
[11] In a first aspect, the present disclosure provides a system for regulating gas pressure in a ventilator. The system includes an inlet module configured in the ventilator and adapted to supply a ventilating gas to a user of the ventilator. The system further includes an outlet module configured in the ventilator and adapted to receive an exhaled gas from the user and vent out at least a portion of the exhaled gas to an exterior of the ventilator. The system further includes a controller communicably coupled to the inlet module and the outlet module. The controller includes a processor and a memory communicably coupled to the processor. The memory stores instruction executable by the processor. The controller is configured to receive a range of pressures for the ventilator. The range of pressures includes first and second values. The first value corresponds to a maximum pressure of the inhaled gas at an end of inhalation phase of the user. The second value corresponds to a minimum allowable pressure of the exhaled gas at an end of exhalation phase of the user. The controller is further configured to operate the outlet module during exhalation of the user to fully open the outlet module to vent the gas from the ventilator, such that the pressure in the ventilator drops from a first value to a third value. The third value is greater than the second value. The controller is further configured to determine user and ventilator parameters during operation of the outlet module. The user and ventilator parameters are indicative of expiratory time constants of the user and the ventilator. The controller is further configured to determine, based on the user and ventilator parameters, an average expiratory time constant. The controller is further configured to determine, based on the average expiratory time constant, a remaining time for complete exhalation of the user. The controller is further configured to determine, based on the remaining time for complete exhalation of the user, a function defining a pressure in the ventilator for each instant of time of the remaining time for complete exhalation of the user. The controller is further configured to operate the outlet module until the pressure in the ventilator reaches the second value, such that the pressure in the ventilator at each instant matches with the determined function.
[12] In some embodiments, the controller is further configured to determine, at each instant of exhalation of the user, during a transition of pressures in the ventilator from the first value to the third value, a corresponding user and ventilator parameter indicative of the expiratory time constant. An average of the determined user and ventilator parameters is used to determine the average expiratory time constant.
[13] In some embodiments, the controller is further configured to determine the remaining time for complete exhalation of the user as a function of the determined average expiratory time constant and an instant of first operation of the outlet module.
[14] In some embodiments, the controller is further configured to determine the function based on a variable parameter. The variable parameter is determined based on a predetermined fraction of the remaining time for complete exhalation of the user.
[15] In some embodiments, the controller is further configured to facilitate the operation of the outlet module between an open position and a closed position.
[16] In a second aspect, the present disclosure provides a method for regulating gas pressure in a ventilator. The method includes receiving, by a controller, a range of pressures for the ventilator. The range of pressures includes first and second values. The first value corresponds to a maximum pressure of the inhaled gas at an end of inhalation phase of the user. The second value corresponds to a minimum allowable pressure of the exhaled gas at an end of exhalation phase of the user. The ventilator is configured with an inlet module adapted to supply a ventilating gas to the user of the ventilator. The ventilator is further configured with an outlet module adapted to receive an exhaled gas from the user and vent out at least a portion of the exhaled gas to an exterior of the ventilator. The method further includes operating, by the controller, the outlet module during exhalation of the user to fully open the outlet module to vent the gas from the ventilator, such that the pressure in the ventilator drops from a first value to a third value. The third value is greater than the second value. The method further includes determining, by the controller, user and ventilator parameters during operation of the outlet module. The user and ventilator parameters are indicative of expiration constants of the user and the ventilator. The method further includes determining, by the controller, based on the user and ventilator parameters, an average expiratory time constant. The method further includes determining, by the controller, based on the average expiratory time constant, a remaining time for complete exhalation of the user. The method further includes determining, by the controller, based on the remaining time for complete exhalation of the user, a function defining a pressure in the ventilator for each instant of time of the remaining time for complete exhalation of the user. The method further includes operating, by the controller, the outlet module until the pressure in the ventilator reaches the second value, such that the pressure in the ventilator at each instant matches with the determined function.
[17] In some embodiments, method further includes determining, by the controller, at each instant of exhalation of the user during a transition of pressures in the ventilator from the first value to the third value, a corresponding user and ventilator parameter indicative of the expiratory time constant. An average of the determined user and ventilator parameters is used to determine the average expiratory time constant.
[18] In some embodiments, the method further comprises determining, by the controller, the remaining time for complete exhalation of the user as a function of the determined average expiratory time constant and an instant of first operation of the outlet module.
[19] In some embodiments, the method further includes determining, by the controller, the function based on a variable parameter. The variable parameter is determined based on a predetermined fraction of the remaining time for complete exhalation of the user.
[20] In some embodiments, the method further comprises facilitating, by the controller, the operation of the outlet module between an open position and a closed position.
[21] 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 DRAWINGS
[22] The accompanying drawings are included to provide a further understanding of the present disclosure and are incorporated in and constitute a part of this specification. The drawings illustrate exemplary embodiments of the present disclosure and, together with the description, serve to explain the principles of the present disclosure.
[23] FIG. 1 illustrates a schematic diagram for a system for regulating gas pressure in a ventilator, according to an embodiment of the present disclosure;
[24] FIG. 2 illustrates a schematic block diagram of a controller of the system of FIG. 1, according to an embodiment of the present disclosure;
[25] FIG. 3A illustrates an exemplary plot depicting a pressure function used for determining a variable parameter;
[26] FIG. 3B illustrates another exemplary plot depicting a pressure curve;
[27] FIG. 4 illustrates a schematic flow diagram of a method for regulating gas pressure in a ventilator, according to an embodiment of the present disclosure; and
[28] FIG. 5 illustrates an exemplary schematic block diagram of a hardware platform for implementation of the controller of FIGs. 1 and 2.

DETAILED DESCRIPTION
[29] The following is a detailed description of embodiments of the disclosure depicted in the accompanying drawings. The embodiments are in such details as to clearly communicate the disclosure. However, the amount of detail offered is not intended to limit the anticipated variations of embodiments; on the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the present disclosure as defined by the appended claims.
[30] In a first aspect, the present disclosure provides a system for regulating gas pressure in a ventilator. The system includes an inlet module configured in the ventilator and adapted to supply a ventilating gas to a user of the ventilator. The system further includes an outlet module configured in the ventilator and adapted to receive an exhaled gas from the user and vent out at least a portion of the exhaled gas to an exterior of the ventilator. The system further includes a controller communicably coupled to the inlet module and the outlet module. The controller includes a processor and a memory communicably coupled to the processor. The memory stores instruction executable by the processor. The controller is configured to receive a range of pressures for the ventilator. The range of pressures includes first and second values. The first value corresponds to a maximum pressure of the inhaled gas at an end of inhalation phase of the user. The second value corresponds to a minimum allowable pressure of the exhaled gas at an end of exhalation phase of the user. The controller is further configured to operate the outlet module during exhalation of the user to fully open the outlet module to vent the gas from the ventilator, such that the pressure in the ventilator drops from a first value to a third value. The third value is greater than the second value. The controller is further configured to determine user and ventilator parameters during operation of the outlet module. The user and ventilator parameters are indicative of expiratory time constants of the user and the ventilator. The controller is further configured to determine, based on the user and ventilator parameters, an average expiratory time constant. The controller is further configured to determine, based on the average expiratory time constant, a remaining time for complete exhalation of the user. The controller is further configured to determine, based on the remaining time for complete exhalation of the user, a function defining a pressure in the ventilator for each instant of time of the remaining time for complete exhalation of the user. The controller is further configured to operate the outlet module until the pressure in the ventilator reaches the second value, such that the pressure in the ventilator at each instant matches with the determined function.
[31] In some embodiments, the controller is further configured to determine, at each instant of exhalation of the user, during a transition of pressures in the ventilator from the first value to the third value, a corresponding user and ventilator parameter indicative of the expiratory time constant. An average of the determined user and ventilator parameters is used to determine the average expiratory time constant.
[32] In some embodiments, the controller is further configured to determine the remaining time for complete exhalation of the user as a function of the determined average expiratory time constant and an instant of first operation of the outlet module.
[33] In some embodiments, the controller is further configured to determine the function based on a variable parameter. The variable parameter is determined based on a predetermined fraction of the remaining time for complete exhalation of the user.
[34] In some embodiments, the controller is further configured to facilitate the operation of the outlet module between an open position and a closed position.
[35] In a second aspect, the present disclosure provides a method for regulating gas pressure in a ventilator. The method includes receiving, by a controller, a range of pressures for the ventilator. The range of pressures includes first and second values. The first value corresponds to a maximum pressure of the inhaled gas at an end of inhalation phase of the user. The second value corresponds to a minimum allowable pressure of the exhaled gas at an end of exhalation phase of the user. The ventilator is configured with an inlet module adapted to supply a ventilating gas to the user of the ventilator. The ventilator is further configured with an outlet module adapted to receive an exhaled gas from the user and vent out at least a portion of the exhaled gas to an exterior of the ventilator. The method further includes operating, by the controller, the outlet module during exhalation of the user to fully open the outlet module to vent the gas from the ventilator, such that the pressure in the ventilator drops from a first value to a third value. The third value is greater than the second value. The method further includes determining, by the controller, user and ventilator parameters during operation of the outlet module. The user and ventilator parameters are indicative of expiration constants of the user and the ventilator. The method further includes determining, by the controller, based on the user and ventilator parameters, an average expiratory time constant. The method further includes determining, by the controller, based on the average expiratory time constant, a remaining time for complete exhalation of the user. The method further includes determining, by the controller, based on the remaining time for complete exhalation of the user, a function defining a pressure in the ventilator for each instant of time of the remaining time for complete exhalation of the user. The method further includes operating, by the controller, the outlet module until the pressure in the ventilator reaches the second value, such that the pressure in the ventilator at each instant matches with the determined function.
[36] In some embodiments, method further includes determining, by the controller, at each instant of exhalation of the user during a transition of pressures in the ventilator from the first value to the third value, a corresponding user and ventilator parameter indicative of the expiratory time constant. An average of the determined user and ventilator parameters is used to determine the average expiratory time constant.
[37] In some embodiments, the method further comprises determining, by the controller, the remaining time for complete exhalation of the user as a function of the determined average expiratory time constant and an instant of first operation of the outlet module.
[38] In some embodiments, the method further includes determining, by the controller, the function based on a variable parameter. The variable parameter is determined based on a predetermined fraction of the remaining time for complete exhalation of the user.
[39] In some embodiments, the method further comprises facilitating, by the controller, the operation of the outlet module between an open position and a closed position.
[40] FIG. 1 illustrates a schematic diagram for a system 100 for regulating gas pressure in a ventilator 102, according to an embodiment of the present disclosure. The ventilator 102 may be any ventilator adapted to supply a ventilating gas to a user 190. The ventilator 102 includes an inlet module 104 adapted to supply the ventilating gas to the user 190 of the ventilator 102. The ventilating gas generally is a gas mixture including oxygen and air. The ventilator 102 is generally used to provide ventilating gas to users who are not able to breath without assistance. This may be due to various reasons which may cause pulmonary function to be depressed or compromised, such as disease, medical procedures, age, etc. The inlet module 104 may include various components, such as, without limitations, an oxygen source 106, a pressure regulator 107, an NC proportional valve 108, an oxygen flow sensor 109, a blower 110, a non-return valve 111, an air flow sensor 112, a mixing chamber 113, a pressure sensor 114, and a humidifier 115. In some embodiments, the blower 110 and non-return valve 111 together may be replaced with an air source, a pressure regulator, and an NC proportional valve.
[41] The ventilator 102 further includes an outlet module 120 adapted to receive exhaled gas from the user 190 and further configured to vent at least a portion of the exhaled gas to an exterior of the ventilator 102. In some embodiments, the exterior may be an ambient atmosphere. The inlet module 104 and the outlet module 120 may be coupled to the user 190 and to each other through a Y-piece 118. The outlet module 120 may include a controllable valve configured to operate between an open position and a closed position. At the open position, the valve is configured to allow venting of at least a portion of the exhaled gas, and at the closed position, the valve is configured to restrict venting of the exhaled air. In some embodiments, the valve is configured to vary a degree of its open position to allow a measured portion of the exhaled gas to be vented. In some embodiments, the outlet module 120 may include a voice-coil actuator, a pneumatic valve, etc. The valve may be controlled electronically, pneumatically, etc.
[42] The ventilator 102 is communicably coupled to a controller 200 configured to operate the inlet and outlet modules 104, 120 of the ventilator 102. The controller 200 is configured to regulate a gas pressure within the ventilator 102 while it is being used by the user 190.
[43] FIG. 2 illustrates a schematic block diagram of the controller 200 of the system 100, according to an embodiment of the present disclosure. Referring now to FIGs. 1 and 2, the controller 200 includes the processor 202 communicably coupled with the memory 204. The memory 204 stores instructions (not shown) executable by the processor 202, such that the controller 200 is configured to regulate the gas pressure in the ventilator 102.
[44] In some embodiments, the processor 202 may be implemented as one or more microprocessors, microcomputers, microcontrollers, digital signal processors, central processing units, logic circuitries, and/or any devices that process data based on operational instructions. Among other capabilities, the processor 202 may be configured to fetch and execute computer-readable instructions stored in the memory 204 for facilitating the system 100 to regulate gas pressure in the ventilator 102. Any reference to a task in the present disclosure may refer to an operation being or that may be performed on data. The memory 204 may be configured to store one or more computer-readable instructions or routines in a non-transitory computer readable storage medium for regulating the gas pressure in the ventilator 102. The memory 204 may include any non-transitory storage device including, for example, volatile memory such as RAM, or non-volatile memory such as EPROM, flash memory, and the like. In some embodiments, the controller 200 may include an interface 206. The interface 206 may include a variety of interfaces, for example, interfaces for data input and output devices, referred to as I/O devices, storage devices, and the like. The interface 206 may also provide a communication pathway for one or more components of the controller 200. Examples of such components include, but are not limited to, the processing engine 210 and a database 250.
[45] In some embodiments, the controller 200 includes the processing engine 210. The processing engine 210 may be implemented as a combination of hardware and programming (for example, programmable instructions) to implement one or more functionalities of the processing engine 210. In examples described herein, such combinations of hardware and programming may be implemented in several different ways. For example, the programming for the processing engine 210 may be processor executable instructions stored on a non-transitory machine-readable storage medium and the hardware for the processing engine 210 may include a processing resource (for example, one or more processors), to execute such instructions. In the present examples, the machine-readable storage medium may store instructions that, when executed by the processing resource, implement the processing engine 210. In such examples, the controller 200 may include the machine-readable storage medium storing the instructions and the processing resource to execute the instructions, or the machine-readable storage medium may be separate but accessible to the computing device 200 and the processing resource. In other examples, the processing engine 210 may be implemented by electronic circuitry.
[46] The processing engine 210 includes a pressure range engine 212, an outlet module operation engine 214, a user and ventilator parameters engine 216, an expiratory constant engine 218, an exhalation time engine 220, a pressure function engine 222, and other engine(s) 224. The other engine(s) 224 may include engines configured to perform one or more functions ancillary functions associated with the processing engine 210.
[47] The pressure range engine 212 is configured to receive a range of pressures for the ventilator 102. The range of pressures may include first and second values. The first value may correspond to a maximum pressure of the inhaled gas in the ventilator 102 at an end of inhalation phase of the user 190. In some embodiments, the first value may be designated peak inspiratory pressure (PIP). The PIP may be a pressure required to force ventilating gas into lungs of the user 190. The second value may correspond to a minimum allowable pressure of the exhaled gas at an end of exhalation phase of the user. In some embodiments, the second value may be the PEEP. The PEEP may be a minimum pressure to be maintained in the ventilator 102 so as to prevent collapse of the lungs of the user 190.
[48] The outlet module operation engine 214 is configured to operate the outlet module 120 during exhalation of the user 190 to fully open the outlet module 120 to vent the gas from the ventilator 102, such that the pressure in the ventilator 102 drops from a first value to a third value. The third value is greater than the second value. In other words, the third value may be higher than the PEEP. The third value may be designated as “PEEP + delta”. The delta value may be any fixed value or may be a percentage or fraction above the PEEP. The outlet module 120 is completely opened to allow the user 190 to exhale naturally, until the pressure in the ventilator 102 drops to the third value.
[49] The user and ventilator parameters engine 216 is configured to determine user and ventilator parameters during operation of the outlet module 120. The user and ventilator parameters are indicative of expiratory time constants of the user and the ventilator. In some embodiments, at each time instant of natural exhalation process during a transition of pressures in the ventilator 102 from the first value to the third value, a corresponding user and ventilator parameter is determined.
[50] The expiratory constant engine 118 is configured to determine, based on the user and ventilator parameters, an average expiratory time constant. An average of the determined user and ventilator parameters is used to determine an average expiratory time constant. The determination of the expiratory time constant may be done by methods already known in the art. The determined expiratory time constant reflects a true nature of the user’s lung as well as that of the ventilator 102. Thus, the system 100 may be adaptive.
[51] In one example, at each instant of the user’s natural expiration, the resistance and compliance of the system (user 190 and the ventilator 102) is calculated based on parameters such as pressure, volume, and flow rate of the gas. The expiratory time constant may be determined as a product of the resistance and compliance values.
[52] In another example, an end inspiratory pause (EIP) is applied in volume-controlled ventilation modes during which the resistance and compliance of the system (user 190 and the ventilator 102) is calculated. The expiratory time constant may be determined as a product of the resistance and compliance values.
[53] For example, if time to natural expiration is t1, the recording pressure value at time t1 may be Pstart, which is the airway pressure at time t1. From the recorded expiratory time constants during each time instant of the natural exhalation of the user 190, an average value of the expiratory time constant is determined.
[54] The exhalation time engine 220 is configured to determine, based on the average expiratory time constant, a remaining time for complete exhalation of the user 190. For example, the remaining time for complete exhalation may be calculated as a function of three times the average expiratory time constant. A value of three times the average expiratory time constant is typically a time taken for the total lung volume of the user 190 to be exhaled. However, since only a portion of the total lung volume is exhaled until the time t1, the remaining time for complete exhalation may be calculated as,

[55] The pressure function engine 222 is configured to determine, based on the remaining time for complete exhalation of the user 190, a function defining a pressure in the ventilator 102 for each instant of time of the remaining time for complete exhalation of the user 190. The pressure function is determined from the following equation,

where,
target – target value of pressure to be achieved at any time instant during the remaining time for complete exhalation;
t – time;
a, b – constants;
c – variable parameter = about 40% of tct; and
d – fixed parameter = 2.718.

[56] The constants a, b may be calculated from,

where,
Pstart – pressure at time instant t1;
Pend – PEEP value; and
tct – remaining time for complete exhalation.
[57] Once the target value of pressure is determined, the outlet module operation engine 214 is further configured to operate the outlet module 120 to be in a position, such that the pressure in the ventilator 102 at each time instant during the remaining time for complete exhalation matches with the target values determined.
[58] If the airway pressure drops to PEEP before the end of tct, the system 100 is configured to stop the cycle in order to prevent further drop in pressure in the ventilator 102. Further, the system 100 is configured to operate the inlet and outlet modules 104, 120 together, such that airway pressure in the ventilator 102 is maintained at PEEP for the remaining duration of the exhalation phase.
[59] FIG. 3A illustrates an exemplary plot 300 depicting a pressure function used for determining the variable parameter c. The plot illustrates a pressure curve 302, and a line 304 joining the Pstart and Pend points with a straight line. The pressure curve 302 has a Pstart at about 100 cm H2O, a Pend of about 20 cm H2O, and a tct of about 150 ms. The curvature of the pressure curve 302 may be varied by changing the Pstart, Pend or tct values. smax denotes a maximum perpendicular distance between the line 304 and the pressure curve 302, and tmax is a time at which smax is achieved. The value of tmax may be given by,

where,
p = –(slope of the line 304).
[60] In order to maintain a smooth curve of the pressure curve 302, the value of c should be such that the tmax is about 40% of tct.
[61] FIG. 3B illustrates another exemplary plot 350 depicting a pressure curve 352. The pressure curve 352 is substantially similar to the pressure curve 302 shown in FIG. 3A. However, the pressure curve 352 has a tct of about 10 ms, as compared to the pressure curve 302, which has a tct of about 150 ms. As a result, the value c is calculated to be about 0.25, such that tmax = 4 ms (about 40% of tct = 10 ms).
[62] FIG. 4 illustrates a schematic flow diagram of a method 400 for regulating gas pressure in a ventilator 102, according to an embodiment of the present disclosure. At step 402, the method 400 includes receiving, by the controller 200, a range of pressures for the ventilator 102. At step 404, the method 400 further includes operating, by the controller 200, the outlet module 120 during exhalation of the user 190 to fully open the outlet module 120 to vent the gas from the ventilator 102, such that the pressure in the ventilator 102 drops from a first value to a third value. At step 406, the method 400 further includes determining, by the controller 200, user and ventilator parameters during operation of the outlet module 120. At step 408, the method 400 further includes determining, by the controller 200, based on the user and ventilator parameters, an average expiratory time constant. At step 410, the method 400 further includes determining, by the controller 200, based on the average expiratory time constant, a remaining time for complete exhalation of the user 190. At step 412, the method 400 further includes determining, by the controller 200, based on the remaining time for complete exhalation of the user 190, a function defining a pressure in the ventilator 102 for each instant of time of the remaining time for complete exhalation of the user 190. At step 414, the method 400 further includes operating, by the controller 200, the outlet module 120 until the pressure in the ventilator 102 reaches the second value, such that the pressure in the ventilator 102 at each instant matches with the determined function.
[63] In some embodiments, the method 400 further includes determining, by the controller 200, at each instant of exhalation of the user 190 during a transition of pressures in the ventilator 102 from the first value to the third value, a corresponding user and ventilator parameter indicative of the expiratory time constant. An average of the determined user and ventilator parameters is used to determine the average expiratory time constant.
[64] In some embodiments, the method 400 further includes determining, by the controller 200, the remaining time for complete exhalation of the user 190 as a function of the determined average expiratory time constant and an instant of first operation of the outlet module 120.
[65] In some embodiments, the method 400 further includes determining, by the controller 200, the function based on a variable parameter. The variable parameter is determined based on a predetermined fraction of the remaining time for complete exhalation of the user 190.
[66] In some embodiments, the method 400 further includes facilitating, by the controller 200, the operation of the outlet module 120 between an open position and a closed position.
[67] FIG. 5 illustrates an exemplary schematic block diagram of a hardware platform for implementation of the controller 200. As shown in FIG. 5, a computer system 500 can include an external storage device 510, a bus 520, a main memory 530, a read only memory 540, a mass storage device 550, communication port 560, and a processor 570. A person skilled in the art will appreciate that the computer system may include more than one processor and communication ports. Examples of processor 570 include, but are not limited to, an Intel® Itanium® or Itanium 2 processor(s), or AMD® Opteron® or Athlon MP® processor(s), Motorola® lines of processors, FortiSOC™ system on chip processors or other future processors. Processor 570 may include various modules associated with embodiments of the present invention. Communication port 560 can be any of an RS-232 port for use with a modem-based dialup connection, a 10/100 Ethernet port, a Gigabit or 10 Gigabit port using copper or fibre, a serial port, a parallel port, or other existing or future ports. Communication port 560 may be chosen depending on a network, such a Local Area Network (LAN), Wide Area Network (WAN), or any network to which computer system connects. Memory 530 can be Random Access Memory (RAM), or any other dynamic storage device commonly known in the art. Read-only memory 540 can be any static storage device(s) e.g., but not limited to, a Programmable Read Only Memory (PROM) chips for storing static information e.g., start-up or BIOS instructions for processor 570. Mass storage 550 may be any current or future mass storage solution, which can be used to store information and/or instructions. Exemplary mass storage solutions include, but are not limited to, Parallel Advanced Technology Attachment (PATA) or Serial Advanced Technology Attachment (SATA) hard disk drives or solid-state drives (internal or external, e.g., having Universal Serial Bus (USB) and/or Firewire interfaces), e.g. those available from Seagate (e.g., the Seagate Barracuda 7102 family) or Hitachi (e.g., the Hitachi Deskstar 7K1000), one or more optical discs, Redundant Array of Independent Disks (RAID) storage, e.g. an array of disks (e.g., SATA arrays), available from various vendors including Dot Hill Systems Corp., LaCie, Nexsan Technologies, Inc. and Enhance Technology, Inc.
[68] Bus 520 communicatively couples processor(s) 570 with the other memory, storage, and communication blocks. Bus 520 can be, e.g., a Peripheral Component Interconnect (PCI) / PCI Extended (PCI-X) bus, Small Computer System Interface (SCSI), USB or the like, for connecting expansion cards, drives and other subsystems as well as other buses, such a front side bus (FSB), which connects processor 570 to software system.
[69] Optionally, operator and administrative interfaces, e.g., a display, keyboard, and a cursor control device, may also be coupled to bus 520 to support direct operator interaction with a computer system. Other operator and administrative interfaces can be provided through network connections connected through communication port 560. The external storage device 510 can be any kind of external hard-drives, floppy drives, IOMEGA® Zip Drives, Compact Disc - Read Only Memory (CD-ROM), Compact Disc-Re-Writable (CD-RW), Digital Video Disk-Read Only Memory (DVD-ROM). Components described above are meant only to exemplify various possibilities. In no way should the aforementioned exemplary computer system limit the scope of the present disclosure.
[70] It should be apparent to those skilled in the art that many more modifications besides those already described are possible without departing from the inventive concepts herein. The inventive subject matter, therefore, is not to be restricted except in the spirit of the appended claims. Moreover, in interpreting both the specification and the claims, all terms should be interpreted in the broadest possible manner consistent with the context. In particular, the terms “comprises” and “comprising” should be interpreted as referring to elements, components, or steps in a non-exclusive manner, indicating that the referenced elements, components, or steps may be present, or utilized, or combined with other elements, components, or steps that are not expressly referenced. Where the specification claims refer to at least one of something selected from the group consisting of A, B, C ….and N, the text should be interpreted as requiring only one element from the group, not A plus N, or B plus N, etc. The foregoing description of the specific embodiments will so fully reveal the general nature of the embodiments herein that others can, by applying current knowledge, readily modify and/or adapt for various applications such specific embodiments without departing from the generic concept, and, therefore, such adaptations and modifications should and are intended to be comprehended within the meaning and range of equivalents of the disclosed embodiments. It is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation. Therefore, while the embodiments herein have been described in terms of preferred embodiments, those skilled in the art will recognize that the embodiments herein can be practiced with modification within the spirit and scope of the appended claims.
[71] While the foregoing describes various embodiments of the invention, other and further embodiments of the invention may be devised without departing from the basic scope thereof. The scope of the invention is determined by the claims that follow. The invention is not limited to the described embodiments, versions, or examples, which are included to enable a person having ordinary skill in the art to make and use the invention when combined with information and knowledge available to the person having ordinary skill in the art.

ADVANTAGES OF INVENTION
[72] The present invention provides a system and method for regulating a gas pressure in a ventilator.
[73] The present invention provides a system for effectively and accurately regulating a gas pressure in a ventilator.
[74] The present invention provides a system that is not iterative.
[75] The present invention provides a system that can dynamically adapt to changes in a user’s lung parameters as well as to dynamics of the ventilator.
[76] The present invention provides a system that limits discomfort to a user.
, Claims:1. A system (100) for regulating gas pressure in a ventilator (102), the system (100) comprising:
an inlet module (104) configured in the ventilator (102), and adapted to supply a ventilating gas to a user (190) of the ventilator (102);
an outlet module (120) configured in the ventilator (102), and adapted to receive an exhaled gas from the user (190) and vent out at least a portion of the exhaled gas to an exterior of the ventilator (102); and
a controller (200) communicably coupled to the inlet module (104) and the outlet module (120), the controller (200) comprising a processor (202) and a memory (204) communicably coupled to the processor (202), the memory (204) storing instruction executable by the processor (202), the controller (200) configured to:
receive a range of pressures for the ventilator (102), the range of pressures comprising first and second values, wherein the first value corresponds to a maximum pressure of the inhaled gas at an end of inhalation phase of the user (190), and the second value corresponds to a minimum allowable pressure of the exhaled gas at an end of exhalation phase of the user (190);
operate the outlet module (120) during exhalation of the user (190) to fully open the outlet module (120) to vent the gas from the ventilator (102), such that the pressure in the ventilator (102) drops from a first value to a third value, wherein the third value is greater than the second value;
determine user and ventilator parameters during operation of the outlet module (120), wherein the user and ventilator parameters are indicative of expiratory time constants of the user (190) and the ventilator (102);
determine, based on the user and ventilator parameters, an average expiratory time constant;
determine, based on the average expiratory time constant, a remaining time for complete exhalation of the user (190);
determine, based on the remaining time for complete exhalation of the user (190), a function defining a pressure in the ventilator for each instant of time of the remaining time for complete exhalation of the user (190); and
operate the outlet module (120) until the pressure in the ventilator (102) reaches the second value, such that the pressure in the ventilator (102) at each instant matches with the determined function.
2. The system (100) as claimed in claim 1, wherein the controller (200) is further configured to determine, at each instant of exhalation of the user (190) during a transition of pressures in the ventilator (102) from the first value to the third value, a corresponding user and ventilator parameter indicative of the expiratory time constant, wherein an average of the determined user and ventilator parameters is used to determine the average expiratory time constant.
3. The system (100) as claimed in claim 1, wherein the controller (200) is further configured to determine the remaining time for complete exhalation of the user (190) as a function of the determined average expiratory time constant and an instant of first operation of the outlet module (120).
4. The system (100) as claimed in claim 1, wherein the controller (200) is further configured to determine the function based on a variable parameter, and wherein the variable parameter is determined based on a predetermined fraction of the remaining time for complete exhalation of the user (190).
5. The system (100) as claimed in claim 1, wherein the controller (200) is further configured to facilitate the operation of the outlet module (120) between an open position and a closed position.
6. A method (400) for regulating gas pressure in a ventilator (102), the method (400) comprising:
receiving (402), by a controller (200), a range of pressures for the ventilator (102), the range of pressures comprising first and second values, wherein the first value corresponds to a maximum pressure of the inhaled gas at an end of inhalation phase of a user (190), and the second value corresponds to a minimum allowable pressure of the exhaled gas at an end of exhalation phase of the user (190), wherein the ventilator (102) is configured with:
an inlet module (104) adapted to supply a ventilating gas to the user (190) of the ventilator (102); and
an outlet module (120) adapted to receive an exhaled gas from the user (190) and vent out at least a portion of the exhaled gas to an exterior of the ventilator (102);
operating (404), by the controller (200), the outlet module (120) during exhalation of the user (190) to fully open the outlet module (120) to vent the gas from the ventilator (102), such that the pressure in the ventilator (102) drops from a first value to a third value, wherein the third value is greater than the second value;
determining (406), by the controller (200), user and ventilator parameters during operation of the outlet module (120), wherein the user and ventilator parameters are indicative of expiration constants of the user (190) and the ventilator (102);
determining (408), by the controller (200), based on the user and ventilator parameters, an average expiratory time constant;
determining (410), by the controller (200), based on the average expiratory time constant, a remaining time for complete exhalation of the user (190);
determining (412), by the controller (200), based on the remaining time for complete exhalation of the user (190), a function defining a pressure in the ventilator for each instant of time of the remaining time for complete exhalation of the user (190); and
operating (414), by the controller (200), the outlet module (120) until the pressure in the ventilator (102) reaches the second value, such that the pressure in the ventilator (102) at each instant matches with the determined function.
7. The method (400) as claimed in claim 6, wherein the method (400) further comprises determining, by the controller (200), at each instant of exhalation of the user (190) during a transition of pressures in the ventilator (102) from the first value to the third value, a corresponding user and ventilator parameter indicative of the expiratory time constant, wherein an average of the determined user and ventilator parameters is used to determine the average expiratory time constant.
8. The method (400) as claimed in claim 6, wherein the method (400) further comprises determining, by the controller (200), the remaining time for complete exhalation of the user (190) as a function of the determined average expiratory time constant and an instant of first operation of the outlet module (120).
9. The method (400) as claimed in claim 6, wherein the method (400) further comprises determining, by the controller (200), the function based on a variable parameter, and wherein the variable parameter is determined based on a predetermined fraction of the remaining time for complete exhalation of the user (190).
10. The method (400) as claimed in claim 6, wherein the method (400) further comprises facilitating, by the controller (200), the operation of the outlet module (120) between an open position and a closed position.