Session: 03-05: Advanced Materials and Transduction Applications

Paper Number: 90793

90793 - Simulating Age Related Radial Pulses Using Magneto-Rheological Fluids 

Measured in the radial artery at the terminal region of the wrist, radial pulses are widely used to infer one’s health. For thousands of years, oriental medicine practitioners have employed palpations of radial pulses using three fingers as its primary diagnosis method. In recent years, wearable technology has enabled continuous monitoring of many vitals in real time, and wrist-worn devices, such as smart watches, strive to measure blood pressure (BP) non-invasively using radial pulses. Thus, pulse simulators that can generate a range of radial pulses consistently and repeatably can play an important role for the advancement the radial pulse-based technologies and medical practices. Regenerated actual human radial pulses can be applied to validate or calibrate wearable sensors and to study the pulse diagnosis method toward standardization of radial pulses. The goal of this study is to design and test a new pulse simulator that incorporates a Magneto-Rheological (MR) fluid device to reproduce a wide range of radial pulses. The overall experimental set up includes a cam system, an MR device, an electromagnet, and sensors (laser displacement and pressure transducer). The cam system generates a base pulse waveform. This base pulse waveform is sent to an MR device which consists of a silicone tube (representing the radial artery) submerged in MR fluid. An electromagnet is placed beneath the MR fluid chamber which applies a specified magnetic field to control the MR fluid. This, in turn, enables the MR fluid to reshape the base pulse waveform to the desired pulse waveform. The mounted sensors collect data and measure the outputs for further analysis. Using this setup, a series of testing will be conducted by varying the input magnetic field with the pulse width modulation (PWM) control. PWM signals can be altered by changing the duty cycle and delay input to the electromagnet. These factors will affect the magnetic field, thus changing the MR fluid surrounding the silicone tube, and shaping the base pulse generated by the cam system. This study will then examine the pulse shaping performance of the MR device by comparing the reproduced radial pulses with those of in vivo radial pulses. The findings of this study can lead to the development of a sensor evaluation platform which will contribute to enhancing the sensor technology for wearable healthcare devices. Moreover, they could aid in the modernization the pulse diagnosis technique and training healthcare professionals with pulse diagnosis.

Presenting Author: Miranda Eaton Miami University