Jan Hejda

Methods of Measurement and Evaluation of Eye, Head and Shoulders Position in Neurological Practice

The position of the eye, head and shoulders can be negatively influenced by many diseases of the nervous system, (particularly by visual and vestibular disorders) (Cerny R. et al, 2006). Disturbances of the cervical vertebral column are another frequent cause of abnormal head position. In this chapter we describe advanced methods of measuring the precise position of the eye, head and shoulders in space. The systems and methods are designed for use in neurology to discover relationships between some neurological disorders (such as disorders of vestibular system) and postural head alignment. We have designed a system and a set of procedures for evaluating the inclination (roll), flexion (pitch) and rotation (yaw) of the head and the inclination (roll) and rotation (yaw) of the shoulders with resolution and accuracy from 1 to 2 (Hozman et al, 2007). We will also deal with systems designed for parallel measurement of eye and head positions and a new portable system for studying eye and head movements at the same time is described as well (Charfreitag et al, 2008). The main goal of this study is to describe new systems and possibilities of the present methods determined for diagnostics and therapy support in clinical neurology. Furthermore, we describe the benefits of each method for diagnosis in neurology.

System for Precise Measurement of Head and Shoulders Position

The objective of our study is to develop a technique for precise head and shoulders posture measurement or, in other words, for measuring the native position of the head and shoulders in 3D space with accuracy to 1° in each direction. Until now, no cheap, widely applicable technique was presented.

Motion Capture Camera System for Measurement of Head and Shoulders Position

The objective of our study was to develop a technique for precise head and shoulder posture measurement or, in other words, for measuring the native position of the head and shoulders in 3D space with accuracy to 1 ̊. No technique or cheap MoCap camera system has been previously developed that can be widely and easily used in clinical practice. New technique and MoCap system could have important applications, as there are many neurological disorders that affect the postural alignment position of the head and shoulders. In many cases, the abnormalities of the head position can be small and difficult to observe. Although an accurate method could contribute to the diagnosis of vestibular disorders and some other disorders, this issue was not systematically studied. MoCap system of head and shoulder posture measurement is based on combination of infrared camera image recognition and evaluation of data recorded by gyroscope. This method was chosen to offer precision less than 1 ̊ in each angle. The system consists of separate components – a headset equipped by gyro-accelerometer and infrared LEDs, infrared LEDs placed on patients shoulders, and a stand with two infrared cameras. The first camera is placed above the patient and the other in front of him. Our designed system provides direct information for physicians on the current position of the patients head and patients shoulders represented by the angles. Our method is cheaper and offers better application in the field of quantitative assessment of head and shoulder posture.

Evaluation of the relative position of the head and shoulders in neurological practice

The article is dealing with the study of stability and posture by measuring and analyzing the angular movements of the head and shoulders. In neurological practice, however, this method of evaluating the relative angular movements of the head and shoulders is not a common practice. The objective of this study was to develop a method of precise measurement of relative angular movements of the head and shoulders, in other words, measuring the relative position of the head and shoulders in a 3-D space with the accuracy up to 1°. The camera system of our design provides direct information for physicians about the relative position of the patients head and shoulders, is described by the angles. The inclination and rotation of the head and shoulders were measured with the accuracy to 1°. Then, a 2-D plot of the relative rotation of the head and shoulders versus the relative inclination of the head and shoulders was obtained. The total length and mean velocity of the trajectory, in the plot, were used to measure and analyze head and shoulder movements. The plots helped in modeling the distribution of the measured 2-D data and evaluate stability and posture of the patients body. The new method offers quantitative assessment of head and shoulder postures. Consequently, they can also be used for specific rehabilitation tests and applications.

SYSTEM FOR MEASURING KINEMATICS OF VESTIBULAR SYSTEM MOVEMENTS IN NEUROLOGICAL PRACTICE

The article deals with the design of a system for studying kinematics of movement of the vestibular system. Up to now there has not existed a system which would enable to measure the kinematic quantities of movement of the individual parts of the vestibular system within its coordinate system. The proposed system removes these deficiencies by suitable positioning of five gyro-accelerometric units on the helmet. The testing of the system took place under two conditions, during Unilateral Rotation on Barany Chair and Head Impulse Test. During the testing, the system justified its application because the results show that the kinematic quantities of the movement of the left and right labyrinths of the vestibular system differ. The introduced device is mainly intended for application in clinical neurology with the aim to enable the physician to measure all linear and angular accelerations of the vestibular system during medical examinations.

Application of Portable Force Platforms Equipped with a Device for Measuring Position and Orientation

With the development of modern technology for studying the movements of the human body, a large number of new measurement techniques are being applied. However, a complex and expensive device is not always the best one for personal requirements or for professional needs. We havedesigned and tested a new universal way to study the forces under the feet based on force platformsequipped with a device for measuring position and orientation. The device for measuring position andorientation is used to identify the relative positions of the two inexpensive force platforms in 3-D space. Knowledge of the relative positions and orientations of the force platforms allows us to adjust the two force platforms in 3-D space. The technique allows the force platform system for measuring and calculating the forces under the feet and the position of the center of pressure to be set up rapidly. The new technique, based on inexpensive portable force platforms equipped with a device for measuring position and orientation, is used and described for the first time here. This work attempts to describe potential ways of applying the technique.

Methods of Motion Assessment of Smart Orthosis of Upper Limb for Rehabilitation at the Clinic and at Home

The aim of this work is to describe proposed and tested methods for evaluation of short-term and long-term movement activity of a smart orthosis for the upper limbs during a rehabilitation process carried out at a clinic or at home. To quantify the description of motion we used methods of evaluation of the time domain data. To test the functionality of the methods, we compared the movement of the dominant and non-dominant limbs, assuming cyclical and acyclic movement, to obtain the expected values for a healthy population. In accordance with the goal, a group of cyclic and non-cyclic movements common to the home environment were proposed. The movements were divided according to the activities performed during sitting, standing and walking. It was: pen writing, typing on the keyboard/using the mouse, eating with a spoon and eating a croissant combing, lifting weights, reading a book, etc. Twenty healthy subjects participated in the study. Four gyro-accelerometers (Xsens Technologies B.V.) attached to the forearms and upper arms of both upper limbs were used to record the upper limb movements. The results show that the calculated values of dominant and non-dominant limb parameters differ significantly in acyclic movements. The smart orthosis which uses the proposed methods can be used to evaluate the physical activity, quantify the evaluation of the rehabilitation process, and thus, it finds use in clinical practice.

Evaluation Methodology and Measurement of Physiological Data to Determine Operational Preparedness of Air Defense Staff: Preliminary Results

The aim of the article is to introduce new evaluation methodology to determine operational preparedness of air defense staff based on measurement of physiological data. The individuals working with air defense systems are under very high level of stress and long‐term monotone air picture observation workload during the mission. We designed an experiment and a method of measuring the biomedical signals for monitoring the actual operator condition during long‐term work on air picture simulator that shows real‐time aircraft flight information. Long‐term monitoring and recording of potential airborne targets in the area of interest to which operators are subjected is accompanied by monitoring the physiological data such as heart rate, body temperature, movement activity and perspiration intensity of operators. The proposed methodology and measurements were tested on four air defense system operators of the Army of the Czech Republic. Operators took part in a 4‐h intensive measurement without any break and their training was evaluated. Designed methods could help to monitor, on the base of physiological data and data from simulators, the stress load level and operational preparedness.

Design of Smart Orthosis of Upper Limb for Rehabilitation

Movement problems of the upper limb are a common consequence of many diseases and can drastically affect the daily life impairing normal activities. To regain motor function and muscle power is necessary to treat these diseases with an intense physical therapy. The smart orthosis is an effective and modern method used in the process of muscle rehabilitation. We propose a design of motorized orthosis subsystems for the upper limbs. The orthosis is a motor assist robotic system that, with the help of actuators, will allow the movement of selected parts of the upper limb. The main point is to offer a reliable low weighted exoskeleton with selected sensors to move and control the upper limbs covering 6 motions: shoulder adduction and abduction, shoulder flexion and extension and elbow flexion and extension. The device is a junction of a hard orthosis with a soft orthosis in order to perform passive physical therapist exercises in clinical practice. The actuation is made by Bowden cables connected in one end to the limb and another to a stepper motor located at a backpack carried by the patient decreasing the apparatus weight substantially. The project also includes a selection of sensors comprising accelerometers, strain gages, thermostats, oximeters, that can provide the necessary information to move the limbs quantifying the muscle activity and physical condition through time. Also, a cooling subsystem based on Peltier thermoelectric modules was implemented to control the muscle temperature in case of an inflammatory reaction. The design was certified by kinematic and structural strength simulation using SolidWorks software.

Physiological Data Monitoring of Members of Air Forces During Training on Simulators

Many complex situations can be induced to the members of air forces during training on simulators, which may result in mentally vigorous situations or even overload. The aim of the paper is to describe the current state and our contribution to development of systems for measurement of the physiological data of basic member of air force including mission commander, pilots, air traffic controllers and ground support staff. The reason for physiological data monitoring is to test the possibility of usage them to estimate the physical and psychological state of the team members. The base for the design of physiological data monitoring was the FlexiGuar system, originally developed at the FBMI CTU. The core of simulators for training of military personnel in aviation was Lockheed Martin’s Prepar3D simulation software. Two airplane cockpits were used as simulators for training of two pilots, air traffic control simulator, i.e. a control tower simulator, and an airport ground station for the preparation of aviation ground staff. The proposed systems are used for simultaneous measurement of the working performance and physiological data of members of the four‐member team during their training. The physiological data, heart rate, body temperature, movement activity and perspiration intensity, are transferred to the commander visualization unit for further evaluation. Designed systems and methods could help to monitor, on the base of physiological data and data from simulators, the stress load of team members.