Continuous blood pressure measurement with ultrasound

Abstract

Cardiovascular diseases are the main cause of death in Germany. A long-term blood pressure measurement is crucial to identify hypertension which can lead to cardiovascular disease. Conventional techniques use the automatic arm cuff method which is painful and provides only intermittent results. A new method for continuous measurement is developed using a DOPPLER ultrasound sensor on a superficial artery and a small balloon. A voice coil actuator is used to change the balloon pressure using a control loop. Holding the control variable -the ultrasound signal -constant and low by controlling the balloon pressure permits a continuous measurement. The system was tested using a blood pressure simulator with variable pressure curves and abrupt pressure changes. The controller-induced balloon pressure tracks the pressure in the model artery very closely.

Continuous Wrist Blood Pressure Measurement with Ultrasound

“…An iterative learning controller (ILC) and a proportionalintegral-derivative controller were implemented on the microcontroller Arduino DUE R3 board, Arduino TM , Italy. The controller setup was tested on the experimental setup described in [2]. The principle of the technique is described in [2].…”

“…The controller setup was tested on the experimental setup described in [2]. The principle of the technique is described in [2]. The balloon pressure is controlled to generate a constant blood velocity close to but always above zero in the vessel.…”

Iterative Learning Cascade Control of Continuous Noninvasive Blood Pressure Measurement

“…The experimental setup described in [23] and in Figure 1 is used. Measurable signals include the arterial blood flow via ultrasound and the air balloon pressure.…”

“…Thereby, the desired arterial pressure is obtained as the pressure in the measurement volume. In [23], the original approach is enhanced by using ultrasound to measure the arterial blood flow and maintain it at a small constant value. In that control system, the manipulated variable is the pressure of an inflatable air balloon which is attached to the lower arm such that it pushes upon the radial artery.…”

“…Figure 1 depicts the main components of the measurement system. In [23], a simple feedback controller was employed to regulate the arterial blood flow. In general, this goal was achieved.…”