Question

Could you give a list of recommended temperature sensor that has a good figure of merit and at the same time small sized for Biomedical Temperature BLE wireless sensor development. The sensor has to be tissue embeddable too.

Answer 1

WHAT IS BLE (BLUETOOTH LOW ENERGY Bluetooth Low Energy is a wireless personal area network technology used for transmitting data over short distances. It was basically invented with a great idea of low power consumption & has achieved it in an efficient manner. All Bluetooth enabled smart application can now actually communicate with BLE devices that require comparatively low power such as heart rate monitors, fitness devices, proximity sensors & the list goes on & on. The importance of Bluetooth lies in fact that it enables thousands of developers to create new innovative products that can communicate with millions of Bluetooth enabled devices already available in the market. It is cost effective, inhibits low energy &has flexible development architecture.

SIGNIFICANT FEATURES OF BLE -O "The main feature for which it is designed i.e. low power consumption, with this single feature it provides the ability to run for several months on single coin cell batteries. " No issue of interoperability among different bluetooth vendor products. It is easy to set up robust, and reliable in tough environments. "Its most common applications are smart home, smart cars, smart health, smart retail, smart sensors, smart farming, smart appliances etc.

and consistently. There are four commonly used temperature sensor types: 1. Negative Temperature Coefficient (NTC) thermistor A thermistor is a thermally sensitive resistor that exhibits a large, predictable, and precise change in resistance correlated to variations in temperature. An NTC thermistor provides a very high resistance at low temperatures. As temperature increases, the resistance drops quickly. Because an NTC thermistor experiences such a large change in resistance per °C, small changes in temperature are reflected very fast and with high accuracy (0.05 to 1.5 °C). Because of its exponential nature, the output of an NTC thermistor requires linearization. The effective operating range is-50 to 250 °C for glass encapsulated thermistors or 150°C for standard 2. Resistance Temperature Detector (RTD) An RTD, also known as a resistance thermometer, measures temperature by correlating the resistance of the RTD element with temperature. An RTD consists of a film or, for greater accuracy, a wire wrapped around a ceramic or glass core. The most accurate RTDs are made using platinum but lower- cost RTDs can be made from nickel or copper. However, nickle and copper are not as stable or repeatable. Platinum RTDs offer a fairly linear output that is highly accurate (0.1 to 1 °C) across -200 to 600 °C. While providing the greatest accuracy, RTDs

600 °C. While providing the greatest accuracy, RTDs also tend to be the most expensive of temperature sensors 3. Thermocouple This temperature sensor type consists of two wires of different metals connected at two points. The varying voltage between these two points reflects proportional changes in temperature. Thermocouples are nonlinear, requiring conversion when used for temperature control and compensation, typically accomplished using a lookup table. Accuracy is low, from 0.5 °C to 5 °C However, they operate across the widest temperature range, from -200 °C to 1750 °C. 4. Semiconductor-based sensors A semiconductor-based temperature sensor is placed on integrated circuits (ICs). These sensors are effectively two identical diodes with temperature-sensitive voltage vs current characteristics that can be used to monitor changes in temperature. They offer a linear response but have the lowest accuracy of the basic sensor types at 1 °C to 5 °C. They also have the slowest responsiveness (5 s to 60 s) across the narrowest temperature range (-70 °C to 1 50°C).

4 Most Common Types of Temperature Sensor A temperature sensor plays an important role in many applications. For example, maintaining a specific temperature is essential for equipment used to fabricate medical drugs, heat liquids, or clean other equipment. For applications like these, the responsiveness and accuracy of the detection circuit can be critical for quality control. More frequently, however, temperature detection is part of preventative reliability. For example, while an appliance might not actually perform any high temperature activities, the system itself could be at risk to overheating. This risk arises from specific external factors such as a harsh operating environment or internal factors like self-heating of electronics. By detecting when overheating occurs, the system can take preventative action. In these cases, the temperature detection circuit must be reliable over the expected operating temperature range for the application.

Medical Biosensors Lisa LaFleur, Paul Yager, in Biomaterials Science (Third Edition), 2013 Biomedical sensors are sensors that detegt medically relevant parameters; these could range from simple physical parameters like blood pressure or temperature, to analytes for which biosensors are appropriate (e.g., blood glucose) This chapter focuses on the overlap between two fields that fulfill the criteria for both classes of sensors. Medical biosensors play a large and growing role in medical diagnostics and patient monitoring; this chapter is merely a brief overview of biosensors. The use of biological molecules, tissues, and organisms has made biosensors uniquely suited to many diagnostic and real-time detection challenges, and their high potential for sensitivity and specificity promises to continue this trend