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Project 10737: BALROOM



People involved:


Dr.ir. Herman van der Kooij
Project function: Project Leader
Organisation: Universiteit Twente

Jantsje Pasma
Project function: PhD candidate
Organisation: LUMC

Denise Engelhart
Project function: PhD candidate
Organisation: Universiteit Twente

Prof.dr. Frans van der Helm
Project function: Co-applicant, Program Leader
Organisation: Technische Universiteit Delft

Dr.ir. Alfred Schouten
Project function: Co-applicant
Organisation: Technische Universiteit Delft

Dr.ir. Ronald Aarts
Project function: Co-applicant
Organisation: Universiteit Twente

Prof.dr. Rudi Westendorp
Project function: Co-applicant
Organisation: Leids Universitair Medisch Centrum

Dr. Andrea Maier
Project function: Co-applicant
Organisation: Leids Universitair Medisch Centrum

Prof.dr. Hans Arendzen
Project function: Co-applicant
Organisation: Leids Universitair Medisch Centrum

Dr. Carel Meskers
Project function: Co-applicant
Organisation: Leids Universitair Medisch Centrum

Prof. Vivian Weerdesteyn
Project function: Co-applicant
Organisation: Universitair Medisch Centrum St. Radboud

Prof.dr. B.R. Bloem
Project function: Co-applicant
Organisation: Universitair Medisch Centrum St. Radboud


Newsletter (2) November 2012

In the BALROOM project, mechanical and sensory perturbations are applied to perturb human subjects and to identify the underlying mechanisms of balance control. To identify the stabilizing mechanisms to keep the body upright, Closed Loop System Identification Techniques (CLSIT) are being developed. We have adopted an alternative identification technique: the Prediction Based Subspace Identification (PBSID) method, which has several advantages over the previous non-parametric CLSIT.

(1) A parametric model is obtained, that directly relates to the underlying neural feedback loops.
(2) The method implicitly handles Multiple-Input-Multiple-Output (MIMO) systems, so that in the case of the human stance model the contribution of the ankle and hip joint can easily be incorporated.
(3) The common structure shared by the signals and the perturbations is included and
(4) the method is robust against measurement noise. The final two points can potentially lead to a reduced experimental measurement time in humans, which is advantageous in pathological stance and for clinical use. For more information please contact Denise Engelhart (UT).

At the Leiden University Medical Center first experiments have been performed to identify the sensitivity of the Bilateral Ankle Perturbator (BAP) to detect the use of proprioceptive information in elderly. The BAP is the first module of the BALROOM and consists of two pedals which can rotate independently around the ankle axes. By these rotations, the proprioceptive information (information coming from the muscles) is disturbed.

Normally, people react on these perturbations by sensory reweighting; i.e. the proprioceptive information becomes less reliable and will be used less in balance control, while the information from the other sensory systems is used more. In the first experiments healthy young, healthy elderly and elderly with dysfunction of a specific sensory system were measured. Comparing the results of healthy young and elderly we concluded that healthy elderly use their proprioceptive information more compared to young. However, the healthy elderly had the same capability to use sensory reweighting compared to young.
Next step is to analyze the data of the elderly with dysfunction of specific sensory systems to see if the BAP can also detect differences between those groups. For more information please contact Jantsje Pasma (LUMC).

To verify the PBSID method, the next module of the BALROOM has been developed in collaboration with ForceLink B.V. This device perturbs the human balance mechanically at hip and shoulder level (MIMO system). First tests of the device in combination with the CLSIT will be performed on healthy young subjects. To further complete the BALROOM equipment, a module for applying visual scene perturbations is currently developed as a collaboration between the University of Twente and ForceLink. For more information please contact Denise Engelhart (University of Twente) or Peter Martens (ForceLink).



Newsletter (1) April 2012

The BALROOM project focuses on human balance control. Postural instability in elderly can result in falls which have a profound socioeconomic impact. Postural instability can have several underlying causes, namely dysfunction of muscles, sensory systems (proprioception, vision and vestibular organ), sensory integration and processing or a combination. A primary dysfunction of one system may be compensated by over action of the other systems or can result in balance deficits. Current management of balance deficits is hampered by the subjective and variable nature of the available clinical balance measures which do not identify the underlying causes of the balance deficits. Therefore a Balance test Room (BALROOM) is developed that quantifies balance deficits, unravels the underlying pathophysiological mechanisms, and predicts the risk of falling.  

The BALROOM will be a stand-alone device to be placed in a clinical environment. The maximum test time will be 15 minutes, in which the cause of the balance problem will be detected focusing on a physiological defect (vision, vestibular, proprioception, muscle performance or cognition) and the compensation strategy (sensory reweighting and body coordination).


Human balance control is a closed loop system. To detect the underlying (patho-)physiology, perturbations (external and sensory) are needed to open this loop and to identify the behavior of the stabilizing mechanisms. These techniques we call Closed Loop System Identification Techniques (CLSIT).

The development of the BALROOM takes place in collaboration with universities (University of Twente), hospitals (Leiden University Medical Centre (LUMC), Radboud University Nijmegen Medical Centre (RuNMC)) and companies (Forcelink B.V, Motek Medical, Centre of Human Drug Research (CHDR)). The equipment is developed in modules by the University of Twente and Forcelink B.V.. The first module, the BAP (Bilateral Ankle Perturbator), can rotate the support surfaces around the ankle axes and measure ankle torques. The response to the rotation gives an indication of the accuracy of proprioception and how information from each leg is used in generating a corrective torque, called sensory reweighting.
 
The first clinical trial in 60 subjects (healthy young and older subjects, and patients with sensory problems or balance problems) is taking place in the Bronovo Hospital in the Hague in collaboration with the LUMC.
When studying compensation strategies, not only the stabilizing mechanism of the ankle plays a role in balance control, but also the hip contributes especially to fast balance corrections that prevent people from falling. CLSIT techniques are currently extended to include the hip joint. To analyze a multiple input multiple output (MIMO) system, an additional perturbation is needed. Therefore in the second BALROOM module, a new device is currently developed by the University of Twente in collaboration with ForceLink B.V.. The device perturbs the human balance externally at hip and shoulder level. First tests of the device in combination with the CLSIT will take place on healthy young adults before testing it on elderly people.

To complete the BALROOM, also the modules for visual scene perturbations and galvanic stimulations will be developed. Furthermore, the test will be extended with a cognitive task and the influence of medication on human balance control will be investigated in collaboration with the CHDR.

Future studies will focus on the relation between the stability during standing measured in BALROOM and the stability during walking. In this part of the project the RuNMC at Nijmegen will study balance in ecologically valid environments. Motek Medical will collaborate in the development of a virtual environment.

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Introduction
 


Postural instability and falls are common and devastating features of ageing and many neurological, visual, vestibular or orthopedic disorders. Current management of these problems is hampered by the subjective and variable nature of the available clinical balance measures. Therefore we aim to develop a Balance test Room (BALROOM) that quantifies balance deficits, unravels the underlying pathophysiological mechanisms, and predicts the risk of falling.

The BALROOM is part the national research programme NeuroSIPE. The goal of the NeuroSIPE programme (System Identification and Parameter Estimation of Neurophysiological Systems) is to improve and develop new diagnostic tools for neurological disorders, through the use of closed-loop system identification techniques for the peripheral and central nervous system. In the BALROOM project besides the UT and LUMC also Radboud University Nijmegen Medical Centre (RUNMC), and three companies participate. At the University of Twente you will be involved in the development of the hardware of the BALROOM. The focus of your work will be on the development and applications of multivariate time varying system identification techniques. To test your equipment, protocols and algorithms you will do experiments with healthy control subjects. At the University of Leiden you will be involved in the evaluation of the newly developed techniques in population of elderly that are prone to falling. The focus of your work is to validate these new techniques trough drug intervention studies, comparison with medical records and existing measures for balance control.

Information

For more information, please contact:
Dr. H. van der Kooij (+31 53 484779 or h.vanderkooij@utwente.nl) and visit the website of biomechanical engineering at the UT (www.bw.utwente.nl).
Dr. A.B. Maier (+31 71 5263457), Department of Geriatrics, Leiden University Medical Center, a.b.maier@lumc.nl.
Dr. C.G.M. Meskers (+31 71 5263457), Department of Rehabilitation Medicine, Leiden University Medical Center, c.g.m.meskers@lumc.nl.

 

Partners

ForceLink (High-end Treadmills), CHDR (Centre for Human Drug Research), Motek Medical