Design and Fabrication of a New Wearable Pressure Sensor for Blood Pressure Monitoring

Abstract

In recent years, research into the field of materials for flexible sensors and fabrication techniques directed towards wearable devices has helped to raise awareness of the need for new sensors with healthcare applicability. Our goal was to create a wearable flexible pressure sensor that could be integrated into a clinically approved blood pressure monitoring device. The sensor is built from a microfluidic channel encapsulated between two polymer layers, one layer being covered by metal transducers and the other being a flexible membrane containing the microfluidic channel, which also acts as a sealant for the structure. The applied external pressure deforms the channel, causing changes in resistance to the microfluidic layer. Electrical characterization has been performed in 5 different configurations, using alternating current (AC) and (DC) direct current measurements. The AC measurements for the fabricated pressure sensor resulted in impedance values at tens of hundreds of kOhm. Our sensor proved to have a high sensitivity for pressure values between 0 and 150 mm Hg, being subjected to repeatable external forces. The novelty presented in our work consists in the unique technological flow for the fabrication of the flexible wearable pressure sensor. The proposed miniaturized pressure sensor will ensure flexibility, low production cost and ease of use. It is made of very sensitive microfluidic elements and biocompatible materials and can be integrated into a wearable cuffless device for continuous blood pressure monitoring.

Development of a Smart Clinical Bluetooth Thermometer Based on an Improved Low-Power Resistive Transducer Circuit

“…In our designed smart thermometer, its resistance range is 18~51 kΩ, or R 3 = 18 kΩ and R 4 = 51 kΩ, and the measurable temperature range is 25~50 • C. Taking R X2 = 18 kΩ as an example, Figure 6 shows the simulation results of the relationship between the output range and the circuit loss of the transducer grounding bleeder circuit using Equations ( 15)- (17). From Figure 5, the current through this circuit decreases with the increase in RX2, or V02 increases with the increase in RX2.…”

“…A fixed resistor grounding bleeder circuit was proposed in [15]; because it used a fixed resistor on the ground, its power consumption was relatively high (as discussed in Section 2.2.1). Although the aforementioned research results could realize the operation functions, their conversion circuits are either relatively complicated with higher costs or high power consumption, which may not be suitable for battery-powered products [16,17].…”

Estimation of Continuous Blood Pressure from PPG via a Federated Learning Approach

“…Smartwatches have become pervasive in recent years, but are still technically lacking in terms of sensors available to the end-users. Ion et al presents a wearable pressure sensor for blood pressure monitoring [ 13 ]. Their proposed pressure sensor has the potential for low production costs and integration into wearable devices, yet this technology needs time to mature until it reaches a pervasive computing status.…”

Ultra‐Flexible Biodegradable Pressure Sensitive Field Effect Transistors for Hands‐Free Control of Robot Movements

“…Flexible pressure sensors are needed in numerous application areas such as biomedical, robotics, sports, gaming, and rehabilitation. [1][2][3][4][5] In these applications, they either provide a measure of physiological parameters such as blood pressure [6] or the haptic feedback to control movements of robotic limbs, or the touch-based communication via wearable smart gloves [7,8] They could also allow controlled movements of assistive tools used by paralytic patients and amputees, for example, by capturing the muscle movements through electromyography (EMG). In such cases, the pressure sensors need to be highly sensitive as the EMG signals from muscles are often feeble (%few μV to 1 mV).…”