Rudolf Cerny

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.

Bilateral Holmes–Adie syndrome as an early manifestation of the HIV neuropathy

A 38-year-old HIV-1 infected woman affected with bilateral tonic pupils. Ophthalmologic examination confirmed Holmes–Adie syndrome (HAS), and peripheral distal polyneuropathy, orthostatic hypotension and leg hyperhidrosis were detected on further workup. The HAS can be either idiopathic or associated with neuropathy of various etiology (autoimmune, paraneoplastic and infectious). In our patient, the pupillotonia was the first and early symptom of hitherto unrecognized HIV neuropathy. HAS has been previously observed in association with syphilis, Lyme borreliosis, herpes simplex and parvovirus B19 infection. Our case is the first report of HAS in a case of HIV infection.

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.

COMPARATIVE MEASUREMENTS OF HEAD ANGULAR MOVEMENTS USING A CAMERA SYSTEM AND A GYROSCOPE SYSTEM

Assessments of body-segment angular movements are very important in the rehabilitation process. Head angular movements are measured and analyzed for use in studies of stability and posture. However, there is no methodology for assessing angular movements of the head, and it has not been verified whether data measured by fundamentally different MoCap systems will lead to the same results. In this study, we used a camera system and a 3DOF orientation tracker placed on the subject’s head, and measured inclination (roll) and flexion (pitch) during quiet stance. The total length and the mean velocity of the traces of the pitch versus roll plots were used to measure and analyze head orientation. Using these methods, we are able to model the distribution of the measured 2D data, and to evaluate stability and posture. The results show that the total lengths and the mean velocities related to the 3DOF orientation tracker do not differ significantly from the total lengths and the mean velocities of traces related to the IR medical camera. We also found that the systems are not interchangeable, and that the same type of system must be used each time. The designed methods can be used for studies not only of head movements but also of movements of other segments of the human body, and can be used to compare other types of MoCap systems, depending on the requirements for a specific rehabilitation examination.

Digital Wireless Craniocorpography with Sidelong Scanning by TV Fisheye Camera

This paper is devoted to the optimization and innovation of the method investigating vestibular system from the technical point of view. The specific method how to evaluate gait function with respect to equilibrium function is cranio-corpo-graphy - CCG. The main aim of this paper is to describe design and development of the system for contactless measurement of immediate body posture based on the evaluation mutual position of join going across shoulders and join of the forehead and occiput CCG. Previous solution was based on utilization of Polaroid and spherical mirror, it means on the analogue technology. System of craniocorpography has been recently computerized. The new system is based on the videotechnology, it means on the TV system with sidelong scanning by TV fisheye camera for increasing of the field of view and the wireless transmission of analogue videosignal. The videosequences are processed by specialized software and data is saved into database. Drawback of the new system is time-consuming videosequence processing only. Advantages of the new system are the following: more evaluated parameters, reduction of trajectory distortion by spherical mirror, exact evaluation of parameters, possibility to evaluate stand test and further parameters, detailed analysis of movement trajectory and imposition of investigation results and off-line analysis. The new system has a lot of advantages and one drawback. Based on the comparison and experiments it seems that the new system is more appropriate than the old one for clinical neurological practice.

Position of the Head Measured by Digital Photograph Analysis

Many diseases of the nervous, visual and vestibular systems can cause abnormal head position in the space. Thus the need for non-invasive, precise and reliable measurement of the head posture is obvious. We have described an originally developed method of head posture measurement by digital picture analysis. Pictures of the head marked on tragus and outer eye canthus are taken simultaneously by two digital cameras aligned by laser beam. Head position is measured with precision of 0,5° in all three space dimensions (rotation-yaw, flexion-pitch and inclination-roll). Mean values of head position from a group of 100 healthy subjects: retroflexion 21,7°, inclination to the right 0,2°, and head rotation to the left 1,7°.

Quantifying Movement of the Head and Shoulders During Quiet Standing Using MatLab Software and Promising Parameters

In this paper, we describe a method for quantifying movement of the head and shoulders during quiet standing. The method proposed allows for the determination of postural stability of the head and shoulders, especially during the Romberg’s test, by recording the relative angular movements. The proposed software is used to calculate new parameters of the head and shoulder movements. These parameters are: the area of the confidence ellipse of the inclination of the head versus the inclination of the shoulders and the area of the confidence ellipse of the head rotation versus the shoulder rotation, the size of the main and minor axis of the confidence ellipse of the inclination of the head versus the inclination of the shoulders and the size of the main and minor axes of the confidence ellipse of the head rotation versus the shoulder rotation. The proposed method was implemented using MatLab software. To test this method, we compared the movements of the fourteen healthy subjects/volunteers and nine patients with an inner ear viral infection. Based on the data results, we identified that the parameters can be used to evaluate postural stability in neurology.

Methods of Motion Data Analysis of Animal’s Body on Rotating Platform

The article introduces methods of data analysis and new parameters for evaluating angular movement response of animals to changes in their body orientation in 3-D space. The motion capture system of rotating platform offering a record of anatomical angles of head movements and angles of the movement of platform. The calculation of parameters has been implemented in MatLab sw. Methods have been tested for quantitative evaluating head angular movements of reptiles and amphibians. Parameters are based on evaluation of time domain data and relationship between measured variables. New parameters include: correlation coefficient between the angle of platform movement and the angle of head movement, variance of the angle of head movement, the angle between the line of the angle values of head movement and platform movement, the inclination angle of angle-angle diagram. The assumption is the application of methods for studying the evolution of nervous system.

A Technique for Quantifying the Relative Angular Movement of the Head and Shoulders

The objective of this study was to develop a method for quantifying the relative angular movements of the head and shoulders. To analyze and quantify the movement of aforementioned body parts, a turns index (TI) and range of motion (ROM) methods were chosen and used. It should be noted that the TI method hasn’t been used before in neurological practice. By using the TI, the physicians are directly informed about the intensity of patient movements. The measurements of both inclination and rotation were done to accuracy of 1˚ by MoCap system containing a combination of camera and gyroscope systems. Then, 2-D plot comparing the head and shoulder rotations and another 2-D plot comparing the head and shoulder inclinations were obtained. Combination of TI and ROM was then used to model the measured data distribution and evaluate the patient’s stability of his body posture. The correlation between the TIs and ROMs is negative moderate to negative strong. It is possible to use the new method for rehabilitation and diagnosis purposes.