###### Abstract  
It is essential to measure and monitor the intravenous (IV) infusion rate of inpatients. Medical staff monitor the IV infusion rate continually to ensure that a constant value is maintained. Developing an IV infusion monitoring system can help alleviate the workload of medical staff. Therefore, this paper proposes a method based on optical sensors, in conjunction with the Internet of Things, to overcome the challenges of IV therapy. To increase the sensitivity of the system, both optical sensors and load cells are used to compensate for their disadvantages. Our system yielded accuracies of 87.9% and 89.9% under horizontal and vertical motion conditions, respectively. The proposed system can send notifications to nursing stations regarding the residual IV fluid, current infusion rate, and expected end time, which can be monitored remotely by medical staff. Furthermore, this system can help prevent possible medical accidents during fluid treatment. intravenous infusion; IV therapy; internet of things; patient monitoring; remote monitoring system +
Footnote †: journal: Medical  
proposed in conjunction with the use of a light-emitting diode (LED) and a photoresistor. However, as normal LEDs emit light in the visible spectrum, external lights can cause interference. Second, ultrasonic sound reflection is used to monitor the drip's flow rate [8]. However, additional transducers with low accessibility should be built in for this method. In addition, ultrasound attenuation depends on air temperature, specifically in closed chambers, and could yield unpredictable results. Third, a load cell is used to measure the loss of IV fluid [9; 10]. In this way, the decreased volume of IV fluid can be calculated based on the volume of the infused fluid. However, this method is vulnerable to a patient's movement because of the characteristics of the load cell. Previous studies have established many approaches to determine the appropriate communication method that can be used to connect the proposed technique to the network in order to send information. A monitoring system based on an Internet of Things (IoT) system can prevent unnecessary contact between medical staff and patients and alleviate the former's workload [11]. With IoT-based systems, the IV infusion rate can be monitored, the flow rate can be calculated, the remaining infusion time can be determined, monitored data can be sent to mobile devices, and a notification can be sent before the IV fluid is depleted. Several approaches have been reported based on the use of IoT to monitor IV infusion. Radio frequency identification (RFID) technology is used to send acquired data to nursing stations (NSs) [12]. However, RFID has limitations in terms of the reading range, which is around 3 m [13]. Bluetooth has also been used to send data to NSs [14]. Bluetooth has the advantage of low-power consumption, but it is hampered by its short-coverage range (within 10 m at a frequency of 2.4 GHz), which is still too low to allow communication between NSs and devices [15]. Wi-Fi has advantages of low-power consumption and long coverage (100 m), despite the external interferences (frequency: 2.4 GHz) [16]. Recently, a Wi-Fi network for an IV infusion monitoring system was suggested based on the use of only one sensor [17]. This was achieved with Wi-Fi's advantages of strong security and long transmission distances. Generally, a patient room's area is \(<\)10 m\({}^{2}\), and the distance between the room and the NS is \(<\)100 m. Thus, the distance of transmission is adequate to communicate with the server via Wi-Fi, particularly when taking its strong security profile into consideration. It is important to monitor patients not only when they are lying down in bed but also when they are exercising. The walking ward is the most common way to exercise for a fast recovery.