NeuroCIMT Project 3: Barocontrol

Sensing and action to counteract maladaptive responses of the autonomous nervous system to postural changes

Fall prevention by sensing blood flow and pressure

Many elderly experience an exaggerated or prolonged drop in blood pressure in response to postural change. This so called orthostatic hypotension can lead to falling or fainting.  At the moment, this disease is clinically diagnosed by measuring the blood pressure in the arm while people are standing up abruptly. However, this method not always represents risky situations in daily life.

Minimal and most sensitive measures
This project aims at developing an unobtrusive system that measures blood pressure and blood flow, as well as movement and posture, during daily activities. The researchers want to establish a set of minimal and most sensitive measures to detect orthostatic hypotension in relation to postural changes. With these measurements, the researchers hope to gain more insight into the cause-effect relations in orthostatic hypotension.

From diagnostics to prevention
The main advantage of such a system is expected in the field of diagnostics. Is a sudden drop in blood pressure related to dangerous situations in and around the house? And if so, what can the patient do to prevent a fall? By recording vital information during a longer period of time in the daily situation, there will be more clues as to what activities introduce the highest risk of falling. The project will also explore if these insights can be used to build a preventive warning system. Furthermore, as in the NeuroCIMT programme the controller function of the nervous system is a central research topic yielding information on underlying causal processes, strong cross-fertilization is to be expected with the other projects of NeuroCIMT.

Smaller wireless sensor
Previous research has already yielded a sensor which measures the blood pressure and blood flow to the brain with sufficient sensitivity. This sensor will be transformed into a wireless version and will be validated in a clinical environment. To develop a model describing the control mechanisms correlating blood pressure to posture, experiments will be performed with patients suffering from orthostatic hypotension or Parkinson’s disease. Patients will be asked to lie down and rise suddenly. With different techniques, the amount of oxygen flowing to the brain, blood flow and blood pressure will be measured.

At the moment, there is no treatment for orthostatic hypotension. All knowledge about the mechanisms involved is welcome to enable development of an effective therapy.

Application perspective
Marc van Houwelingen, ‎Manager Research and Development  Finapres Medical Systems
Currently Finapres sells a portable blood pressure measurement device, the Portapres. Although it is considered the gold standard for wearable non-invasive continuous blood pressure measurement, for the intended patient measurements it is rather large, heavy and energy inefficient. In addition it lacks the required measurements of detecting blood flows, posture and movement. The project partners are teaming up to create and validate a device that measures all of the required signals and is also smaller, lighter, more energy efficient and can be worn more or less unnoticed. This project enables Finapres to open up a new market. Together with 2M Engineering we will strive to turn the potential proof of concept into an actual new product.’

Artinis, Delft University of Technology, Demcon/Finapress, 2M Engineering, Radboud University Nijmegen, Twente University, VU/VU University Medical Center