METHODOLOGY The temperature of the incubator is monitored using an LM35 precision centigrade temperature sensor. According to an article published by Infant Centre (2018), the threshold range of temperature to be maintained inside the incubator is 37.2°C to 37.8° C. A reflection-type pulse sensor is used to monitor the heartbeat rate of the baby. The heartbeat rate of the premature baby has been fixed from 140 to 170 which is considered to be normal for a baby born at 24 to 28 weeks of pregnancy. The weight of the premature baby inside the incubator is monitored using a load cell and HX71 weight sensor module. HX711 is a widely used industria standard precision sensor interface module with a 24-bit analog to digital conversion, which provides the required resolution suitable for the proposed system’s requirement. The discomfort of the baby inside the incubator is monitored using a sound sensor. If the baby cries due to discomfort, the sound sensor will generate a signal to the controller, which in turn alerts the doctor. A slide switch in the system is used by the doctor to let the system know that he/she has acknowledged the abnormalities. The system will change its state from monitor mode to idle mode. After treatment, the baby is kept inside the incubator. Then the doctor has to press the slide switch it back from idle mode to monitoring mode. FIGURE |. Block diagram of the transmitter section FIGURE 2. Block diagram of the receiver section FIGURE 3. Workflow of the proposed system will be turned off and the system will stop sending the alert message to the doctor. The significance of sending the alert every minute will be helpful for the doctor to understand the health condition of the baby. The flowchart of the proposed system is shown in Figure 3. This flowchart, clearly explains the process followed in GSM based baby incubator monitoring system. The corresponding algorithm is given below. FIGURE 4. Prototype of the hardware design The block diagram of the transmitter section of the proposedsystem is shown in Figure 1. The transmitter section continuously monitors the parameters like temperature, weight, heartbeat, and sound of the baby inside the incubator and displays the value in the LCD. If anyone of the abovesaid parameter values goes abnormal then values of the corresponding parameter were sent to the doctor through GSM at regular intervals. During abnormal conditions LED placed outside the incubator will glow until it becomes normal or the doctor changes the mode of operation. The mode of operation is decided by the doctor with the help of a slide switch. The doctor receives the alert message as shown in Figure 5. It shows the abnormal condition inside the incubator; where, the message contains the values of all the parameters during abnormal conditions like temperature, Weight, Sound, and Heartbeat. The transmitter module sends the alert message to the doctor every minute until the doctor acknowledges the baby’s condition. Here acknowledgment means, the doctor has to pay a visit to the incubator and physically change the position of the slide switch. Once the doctor has acknowledged, the system will know that the doctor has arrived for diagnosis, hence there is no need to send the SMS. The SMS received every minute can be vital for diagnosis purposes and can help understand the criticality of the situation. FIGURE 5. The output of the system The prototype hardware implementation of the proposed system is given in Figure 4. In Figure 5, the first alert message is received as the temperature inside the incubator is above the threshold limit. It indicates that care must be taken to protect the life of the baby in the incubator immediately. Notice the second SMS received by the doctor, where the sound parameter is varied.
