Design and Implementation of a Low-Cost Breathing Support Device

Abstract

Respiratory diseases affect a large part of world population, especially in developing world. In this invention, we present a breathing support system to provide life-saving support to such patients. The system automates and regulates the use of a bag valve mask (commonly known as an ambu bag). The system uses mechanical actuators, sensors and a smart feedback control mechanism to automate and regulate the operation of the ambu bag to implement core functions of mechanical ventilation for life-saving applications. The system can also be used to provide better breathing support to newborns (e.g. to prevent hypoxia). The system can be used to save hundreds of thousands of lives in the developing world, in emergencies and during transportation globally.

1 . A mechanical ventilator to treat patients with respiratory disease comprising:
 a user-interface designed to receive desired breathing parameters for a patient from a medical practitioner inclusive of ventilator mode selected from the group comprising continuous mandatory ventilation (CMV) and assist-control ventilation (ACV) and to display device status;   a gas volume generator for storing air, oxygen or their mixture;   a mechanical actuation unit comprising a pair of compressors that are moved by an electric motor to compress the gas volume generator to force a breath to the patient and generate the desired breathing parameters;   a sensing unit through which on the way to the patient the breath generated by the mechanical actuation unit's compression of the gas volume generator passes comprising pressure and flow sensors;   a device control unit that, considering signals from the pressure and flow sensors of the sensing unit as well as the desired breathing parameters from the medical practitioner through the user-interface, generates signals to control the mechanical actuation unit's compression of the gas volume generator;   a battery; and   a power management unit comprising a regulator and switching management circuitry to provide seamless switching between a mains power source and the battery to provide uninterrupted power to the user interface, mechanical actuation unit, sensing unit, and device control unit.   
     
     
         2 . The mechanical ventilator to treat patients with respiratory disease of  claim 1 , wherein the gas volume generator is a bag of a bag valve mask. 
     
     
         3 . The mechanical ventilator to treat patients with respiratory disease of  claim 1 , wherein the device control unit comprises a micro-controller to process the signals from the gas flow and pressure sensors as well as the desired breathing parameters from the medical practitioner and to generate the signals to control the mechanical actuation unit. 
     
     
         4 . The mechanical ventilator to treat patients with respiratory disease of  claim 2 , wherein the pair of compressors of the mechanical actuation unit are a pair of rounded jaws. 
     
     
         5 . The mechanical ventilator to treat patients with respiratory disease of  claim 1  that supports a respiratory rate of 0 to 100 breaths per minute. 
     
     
         6 . The mechanical ventilator to treat patients with respiratory disease of  claim 2 , wherein the bag of the bag valve mask can support gas volumes from 1 milli-liters to 2000 milli-liters. 
     
     
         7 . The mechanical ventilator to treat patients with respiratory disease of  claim 1 , wherein the gas flow and pressure sensors are configured to determine the flow rate, gas volume, and pressure during device operation. 
     
     
         8 . The mechanical ventilator to treat patients with respiratory disease of  claim 1 , wherein the power management unit mains power source is an alternating current source. 
     
     
         9 . The mechanical ventilator to treat patients with respiratory disease of  claim 8 , wherein the user interface is designed to additionally receive a desired breathing parameter of set positive end-expiratory pressure and the mechanical ventilator further comprises a solenoid valve through which patient exhalation passes which receives signals generated by the device control unit to maintain the set positive end-expiratory pressure considering signals from the pressure and flow sensors as well as the desired breathing parameters received for the patient from the medical practitioner. 
     
     
         10 . The mechanical ventilator to treat patients with respiratory disease of  claim 9 , wherein the user interface comprises a display for breath waveforms. 
     
     
         11 . The mechanical ventilator to treat patients with respiratory disease of  claim 10 , wherein the display is an LCD. 
     
     
         12 . The mechanical ventilator to treat patients with respiratory disease of  claim 10 , wherein the display is a touch screen. 
     
     
         13 . The mechanical ventilator to treat patients with respiratory disease of  claim 10 , wherein the user interface is designed to additionally receive a desired breathing parameter of synchronous intermittent mandatory ventilation. 
     
     
         14 . The mechanical ventilator to treat patients with respiratory disease of  claim 1 , wherein the sensing unit further comprises an oxygen sensor connected to the device control unit. 
     
     
         15 . The mechanical ventilator to treat patients with respiratory disease of  claim 1 , wherein the electric motor comprises an encoder connected to the device control unit. 
     
     
         16 . The mechanical ventilator to treat patients with respiratory disease of  claim 14 , wherein the power management unit further comprises recharging circuitry and voltage measurement circuitry. 
     
     
         17 . The mechanical ventilator to treat patients with respiratory disease of  claim 16 , wherein the battery is a rechargeable battery selected from the group consisting of lead-acid, lithium ion, and lithium polymer. 
     
     
         18 . The mechanical ventilator to treat patients with respiratory disease of  claim 2 , wherein atmospheric air passes through a filter before entering the bag of the bag valve mask through a bag valve mask air inlet. 
     
     
         19 . The mechanical ventilator to treat patients with respiratory disease of  claim 3 , wherein the microcontroller is Arm based. 
     
     
         20 . The mechanical ventilator to treat patients with respiratory disease of  claim 19 , further comprising an encrypted wireless communication link.