TECHNICAL FIELD

[001] The present invention relates to automatic electromechanical device to op erate Artificial Manual Breathing Unit (AMBU) Bag.

BACKGROUND ART

[002] In many developing countries critical care still lies in infancy, where basic healthcare facilities are limited and high cost is a major impediment to availability of ventilators in hospitals. Getting a ventilator on arrival of patient in emergency or trauma centres is a real challenge. This leads to a situation where many sal vageable patients are unable to get the best care and succumb to their illness. There is no reliable epidemiological data available and substantial disparity in quality of care within developing countries. It is worth mentioning here that ade quate intensive care services may not be available especially in rural areas where 70-80% of Indian population resides and the situation will be very much similar in other developing countries also. However, this potentially high burden of patients and mortality with respiratory failure can be minimized if provision of alternative to mechanical ventilators is implemented in a thoughtful fashion.

[003] Manual resuscitator in the form of Artificial Manual Breathing Unit (AM BU) is used for basic ventilation since ages. These manual mechanical resuscita- tors are in use since late 1950 have and provide excellent means of short term ven tilation in both out of hospital and in-hospital environment.

[004] Presently, a large number of patients are being ventilated with help of AMBU which is a simple hand held self-inflatable device, needs to be compressed manually by patient’s attendant/caretaker on regular basis to deliver air or oxygen to patient’s lungs. Providing continuous manual ventilation has certain inherent drawbacks; the first and foremost is maintenance of required regular rate and vol- ume of oxygen/air, and the same cannot be ensured. It is very labour intensive, tiring to operators and expose attendant as well as hospital staff to infection risks. [005] KR101456876B1, invention relates to a hand-held AMBU digital appa ratus in order to quantify ventilator volume, respiratory rate in a single supply amount for evaluating pulmonary function.

[006] WO2016203289A1, A D-Box containing a cavity for an Ambu-Bag, mechanized levers from the side to compress the bag, and a rechargeable battery unit to power the D-Box the manually operated Ambu-bag.

[007] US20150096559, a manual resuscitator device that comprises a bag valve mask, a one-way valve, a manual ventilation bag, and a sensing module, wherein the sensing module can comprise a pressure sensor and/or flow transducer. Sens ing module may further comprise a controller for processing information from the pressure sensor and/or flow transducer; namely for determining and indicating a ventilation rate. Indicators are provided to guide the user with respect to a target or desired ventilation rate.

[008] Therefore, no prior art providing viable solution to above stated problems. This invention discloses a device to provide survival chances to the patients re quiring ventilation in the face of dearth of ventilators.

DISCLOSURE OF THE INVENTION

[009] The designed device connected to a regular adult AMBU. The device works on the principle of electric linear actuator, which converts the rotary motion into a linear motion. It has a mechanism to rhythmically compress the AMBU. A Direct Current (DC) motor (12-24 Volts) gives the linear motion through electric linear actuator arrangement. In addition, this DC motor has a speed regulator which is used to modulate the frequency of respiratory rate (varying from 12 to 20 squeezes per minute) for supplying the air/oxygen mixture into the lungs of the patient. There is a provision of the common platform so that AMBU bag can squeeze automatically as per the regulated speed setting in speed regulator of DC motor. Each rotation of the motor creates one complete linear motion of squeezing the bag and then coming back to the start. Therefore, 12 rotations per minute will give 12 squeezes per minute and it can be varied up to 20 squeezes per minute. The variation in speed is adjustable depending on patient age, weight and condi tion of the lungs. The tidal volume generated is regulated and displayed using a flow meter sensor. The complete unit is noiseless requiring no manual assistance. [010] To test the functioning of device, mechanical test lung is used to deter mine the effectiveness of ventilation simulating patients not able to breathe unas sisted. The compliance is also tested for rate and range of lung volumes per mi nute. The safety of this device is ensured by incorporating volume and pressure microsensors at patient end. Moreover device is incorporated with disconnection alarm. It is a viable, efficient and cost effective short term alternative to critical care ventilators, which are expensive, complex microprocessor driven devices. [Oil] Artificial ventilation is life saving for a vast majority of patients in respir atory failure. Unfortunately, high cost of ventilators forbids their common use, especially in emergency departments of many hospitals in developing countries with high patient load. To tide over this crisis, manual resuscitators or AMBU bags are used which have to be rhythmically compressed at a set rate manually. This is no easy task and has inherent shortcomings and dangers. They are tiresome to operate and have no control over the amount of air pumped in to inflate the lungs during each breath as it depends entirely on how much patient’s attendant squeezes the AMBU bag. In response to risks associated to manual resuscitators, guidelines have been issued by American Heart Association and European Resus citation Council which specify ventilation rates and tidal volumes for patients. Non-professional use of AMBU in emergency wards lead to lung injuries i.e. volutrauma related to over-inflation and barotrauma related to excessive pressure thereby, increasing the morbidity of already compromised patients. Despite laid down safety guidelines, none of the studies have reported the complications asso ciated with uncontrolled manual resuscitator usage, and incidences of over inflation with manual resuscitators continue to be “endemic”.

[012] Various case reports published in literature reported that due to non availability of ventilators, AMBU was used manually for mechanical ventilation for prolonged durations. These reports have emphasized upon the role of patients’ attendants and family members who have to assist the hospital staff for providing care to their closed ones.

[013] Most common conditions requiring mechanical ventilation are: postsur- gical treatment, trauma, infectious diseases, stage of peripartum and maternal and neonatal complications. The majority of these conditions are reversible and may require short duration of mechanical ventilation. AMBU ventilation has also been found very helpful in circumstances where short-term respiratory support is need ed.

[014] Ventilators are definitely not a cheaper intervention and certainly entail a very high cost even in developed countries. It becomes important to address this issue, embarking upon the need for basic low cost ventilation devices in develop ing countries with thick population, where primarily the treatment cost has to be borne out of pocket of the patient. This clearly reiterates the need to design an automatic mechanical ventilatory device.

[015] The proposed design has advantages like sparing human being of tiresome effort, low cost, delivering required volume per breath, easily transportable and easy to assemble. The vast majority of patients require “minimal settings” and the majority evidence based manoeuvres do not require complex ventilation strategies (i.e., lung-protective ventilation) and that can be easily provided by proposed model.

[016] Henceforth, this attempt of designing an automatic easy to operate me chanical device to operate/ drive AMBU bag for ventilation will not only compen sate for the dearth of ventilators in poor and developing nations clinical environ ment, but also provide regulated rate as well as tidal volume thus decreasing the overall complications caused due to these manual resuscitators. The agony of pa tients attendants will also be taken care of simultaneously.

BRIEF DESCRIPTION OF THE DRAWINGS [017] The present invention will become more understandable from the descrip tion given herein and the accompanying drawings below. These are given by way of illustration only and therefore not limited to present invention and wherein: [018] Figure 1: An electromechanical device (100) to automatically operate AMBU bag comprising of a linear actuator body, two brushless stepper motors (3, 10), a lead screw mechanism, two plungers (1, 4), an AMBU bag (15) and a non compact type proximity sensor.

[019] Figure 2: Touch screen display that enables the user to modify the venti lation, alarm, and technical settings, and to view real time patient data, alarms, battery status and logs

BEST MODE(S) FOR CARRYING OUT THE INVENTION [020] The following presents a simplified description of the invention in order to provide a basic understanding of some aspects of the invention. This description is not an extensive overview of the present invention. It is not intended to identify the key/critical elements of the invention or to delineate the scope of the inven tion. Its sole purpose is to present some concept of the invention in a simplified form.

[021] Accordingly, those of ordinary skill in the art will recognize that various changes and modifications of the embodiments described herein can be made without departing from the scope of the invention. In addition, descriptions of well-known functions and constructions are omitted for clarity and conciseness. [022] Features that are described and/or illustrated with respect to one embodi ment may be used in the same way or in a similar way in one or more other em bodiments and/or in combination with or instead of the features of the other em bodiments.

[023] The terms and words used in the following description and claims are not limited to the bibliographical meanings, but, are merely used by the inventor to enable a clear and consistent understanding of the invention. Accordingly, it should be apparent to those skilled in the art that the following description of ex emplary embodiments of the present invention are provided for illustration pur- pose only and not for the purpose of limiting the invention as defined by the ap pended claims and their equivalents.

[024] It is to be understood that the singular forms “a,” “an,” and “the” include plural referents unless the context clearly dictates otherwise.

[025] By the term “substantially” it is meant that the recited characteristic, pa rameter, or value need not be achieved exactly, but that deviations or variations, including for example, tolerances, measurement error, measurement accuracy lim itations and other factors known to those of skill in the art, may occur in amounts that do not preclude the effect the characteristic was intended to provide.

[026] It should be emphasized that the term “comprises/comprising” when used in this specification is taken to specify the presence of stated features, integers, steps or components but does not preclude the presence or addition of one or more other features, integers, steps, components or groups thereof.

[027] As used herein, the terminology “flow rate sensor” refers to the are pres sure sensors to measure respiratory flow by measuring the pressure drop via a flow element, which involves flow induced differential pressure.

[028] As used herein, the terminology “feedback sensor” refers to the IR prox imity sensor which keeps transmitting infrared light and when any object comes near, it is detected by the sensor by monitoring the reflected light from the object. [029] As used herein, the terminology “carbon dioxide sensor” refers to the non-invasive monitoring system that helps improve the ventilation quality. It is also an Infrared type gas sensor.

[030] As used herein, the terminology “tidal volume” refers to the volume of air moved into and out of the lungs during each ventilation cycle.

[031] As used herein, the terminology “lung volume” refers to the maximum volume of air the lungs can accommodate after maximum inspiration.

[032] As used herein, the terminology “mechanical test lung” refers to simu lates physiological human breathing patterns.

[033] As used herein, the terminology “duty cycle” refers to the proportion of time during which a device is operated and is expressed as a ratio.

[034] Embodiments Example 1:

[035] Artificial Respiration Control Machine Salient Design: The designed de vice is connected to a regular adult AMBU. The device works on the principle of electric linear actuator, which converts the rotary motion into a linear motion. It has a mechanism to rhythmically compress the AMBU.

[036] Figure 1 describes the device (100) used for squeezing the AMBU bag (15). It has two brushless stepper motors, the right stepper motor (3) and the left stepper motor (10) which are integrated to the right lead screw (7) and the left lead screw (6). The left lead nut (2) and the right lead nut are threaded onto the respec tive lead screws provided with left hand and right hand helical trapezoidal threads to limit the motion radially. So that when the lead screw is rotated, the nuts are driven along the threads, which result in linear motion of the plungers (1) & (4) on the AMBU bag. Linear bearing (13) and linear guide (14) allow the nuts to run smoothly on the screws as per the required specification of the frequency of squeezing the AMBU bag. Bearing block (5) is used to provide support to the ro tating screws (6) & (7). Left limit switch (11) and right limit switch (12) de energize the electric motors when the plungers have reached a specific position. The designed device is connected to a regular adult AMBU. The device works on the principle of electric linear actuator, which converts the rotary motion into a linear motion. It has a mechanism to rhythmically compress the AMBU. A Direct Current (DC) motor (12-24 Volts) gives the linear motion through electric linear actuator arrangement. Each step of the motor amounts to 1.8 degree rotational travel. Hence, 200 motor steps amount to one full rotation which subsequently leads to a linear motion of 22 mm via the lead nut. In addition, this DC motor has a speed regulator which is used to modulate the frequency of respiratory rate (var ying from 12 to 20 squeezes per minute) for supplying the air oxygen mixture into the lungs of the patient. There is a provision of the common platform so that AM BU bag can squeeze automatically as per the regulated speed setting in speed reg ulator of DC motor. Each rotation of the motor creates one complete linear motion of squeezing the bag and then coming back to the start. Therefore, 12 rotations per minute will give 12 squeezes per minute and it can be varied up to 20 squeezes per minute. The variation in speed is adjustable depending on patient age, weight and condition of the lungs. The tidal volume generated is regulated and displayed using a flow meter sensor. The complete unit is noiseless requiring no manual as sistance.

Example 2:

[037] The designed device is connected to a regular adult AMBU. It has a mech anism to rhythmically compress the AMBU. A Direct Current (DC) motor (12-24 Volts) gives the linear motion through electric linear actuator arrangement. In ad dition, this DC motor has a speed regulator which is used to modulate the fre quency of respiratory rate (varying from 12 to 20 squeezes per minute) for supply ing the air oxygen mixture into the lungs of the patient. There is a provision of the common platform so that AMBU bag can squeeze automatically as per the regu lated speed setting in speed regulator of DC motor. Each rotation of the motor creates one complete linear motion of squeezing the bag and then coming back to the start. Therefore, 12 rotations per minute give 12 squeezes per minute and it can be varied up to 20 squeezes per minute. The variation in speed will be adjust able depending on patient age, weight and condition of the lungs. The tidal vol ume generated is regulated and displayed using a flow meter sensor. The complete unit is noiseless requiring no manual assistance.

Example 3:

[038] To test the functioning of device, mechanical test lung is used to determine the effectiveness of ventilation simulating patients unable to breathe unassisted. The compliance is also tested for rate and range of lung volumes per minute. The safety of this device is ensured by incorporating volume and pressure micro sensors at patient end. Moreover device is incorporated with disconnection alarm. It is a viable, efficient and cost effective short term alternative to critical care ven tilators, which are expensive, complex microprocessor driven devices.

Example 4:

[039] The Precision linear actuator is double acting providing symmetric squeez ing force on the AMBU bag (15) from two sides via left plunger (1) and right plunger [4] respectively. This action ensures a high repeatability, continuous duty cycle and precise positioning of the plungers and has precision as far as the dis placed volume is concerned.

Example 5:

[040] The actuator has two brushless stepper motors (3, 10) as prime movers. Each step of the motor amounts to 1.8 degree rotational travel. Hence, 200 motor steps amount to one full rotation which subsequently leads to a linear motion of 22 mm via the lead nut. These motors are highly reliable and give very precise motion which can be controlled by an external guidance in the form of an open loop control. The open loop control system provides a one way signal flow system and has many inherent advantages such as low cost, simple design, low mainte nance and convenient to use. The respiration rate and volume can be changed manually due to the controllable feature of the open loop control feature of these motors.

Example 6:

[041] The lead screw mechanism which converts the rotary motion of the step per motors into linear motion of the plungers is responsible for squeezing the AMBU bag (15) and creating a precise linear movement of the plungers. Speed is vital especially in case of such motion controlled equipment, so that the DC motor is provided with a speed regulator to modulate the frequency of compressions of the bag to 12 - 20 squeezes per minute, so as to achieve the optimum frequency of respiratory rate for supplying air oxygen mixture into the lungs of the patient. The efficiency brought about by actuators makes them a cost effective alternative to human operation. Since no oil is involved, the electrical actuator provides the cleanest and readily available form of actuators to automate the compression pro cess and make this tedious manual job of AMBU squeezing easier.

Example 7:

[042] To limit the tidal volume and barometric pressure following safety features are provided: i) A non-contact type proximity sensor is attached to the limit switches (11, 12) which restrict the plunger moment by giving position feedback to the control ler. The proximity sensor is a magnetic hall effect sensor which senses the mag- netic field intensity of the attached permanent magnet on the respective lead nut body. The sensor has high efficiency, low cost and compact size. It is energy sav ing and is not affected by any magnetic interference. ii) The physical length of the actuator limits the maximum displaced volume. Inadvertent actuation beyond a point disengages the lead nut (2) from the lead screw (6). iii) A CO2 sensor, volume flow rate sensor and a pressure sensor are installed in the vicinity of the endotracheal tube inlet to measure the dynamic pressure and indirectly the volume flow sensor. The feedback from these sensors is used for display as well as in actuation of the alarm in case of undesired values.

Example 8:

[043] The device is provided with a control human machine interface having an OLED screen, potentiometer and a disconnection alarm.

[044] According to an embodiment in the device (100) the Linear screw is EN 353.

[045] According to an embodiment in the device (100) the Linear Guide is SS 306

[046] According to an embodiment in the device (100) the Linear Nut is made up of any metal, polymer of combination thereof.

[047] In an preferred embodiment in the device (100) the Linear Nut is made up of brass.

[048] According to an embodiment in the device (100) the Ambu bag is made up of any polymer of combination of polymers thereof.

[049] In a preferred embodiment in the device (100) the Ambu bag is made up of silicon.

[050] In a preferred embodiment to an embodiment the dimension of the box in the device (100) is 340 x 300 x 400 mm

[051] According to an embodiment the device 100 also comprises a touch screen display that enables the user to modify the ventilation, alarm, and technical set tings, and to view real time patient data, alarms, battery status and logs (Ligure-2) INDUSTRIAL APPLICABILITY

[052] Designing a low cost automatic mechanical device to operate mechanical AMBU which will help to deliver positive pressure ventilation to the patients who are not able to obtain ventilators on arriving at emergency or trauma centres and thus reducing the agony of the patient as well as attendants. This device will de liver controlled tidal volume as well as rate thereby taking care of complications. The device is to provide survival chances to the patients requiring ventilation in face of shortage of ventilators.

[053] Accordingly, the present invention can measure and quantify the tidal vol ume that cannot be measured by a conventional artificial respirator, so that general users without expertise can easily use the product in an emergency situation. It will possibly not only prevent an untoward accident, but will also improve the quality of medical service. In addition, since the portable device can be easily miniaturized, it can be prepared in emergency situations at any time, and it is pos sible to monitor the state of the patient and the once-supplied amount by the digi tal sensor, so that it is possible to respond appropriately to the medical condition according to the patient's condition