Real-time kymographic imaging for visualizing human vocal-fold vibratory function.

A stand-alone kymographic system for visualizing human vocal-fold vibration in real time is presented. By using a dual charge-coupled-device construction, the system not only provides kymographic images but also simultaneously presents structural images for navigating the endoscope to a desired position. With a temporal resolution of 7200 lines/s, the kymographic imaging produces a sufficient speed to investigate most types of vocal-fold vibrations. Moreover, by buffering the kymographic images during the vertical blanking periods, the system can retrieve an uninterrupted kymographic image sequence even though the television standard is used. The results from preliminary clinical evaluation present evidence that the real-time kymographic imaging substantially reduces the time required for functional evaluation of the vocal-fold vibrations.

Real-time Simultaneous DKG and 2D DKG Using High-speed Digital Camera.

INTRODUCTION: For the evaluation of voice disorders, direct observation of vocal cord vibration is important. Among the various methods, laryngeal videostroboscopy (LVS) is widely used, but it was not a true image because it collects images from different cycles. In contrast, high-speed videoendoscopy and videokymography have much higher frame rates and can assess functional and mobility disorders. OBJECTIVE: The purpose of the study is to describe real-time, simultaneous digital kymography (DKG), two-dimensional scanning (2D) DKG, and multi-frame (MF) LVS system using a high-speed digital camera, and identify the efficacy of this system in evaluating vibratory patterns of pathologic voice. METHODS: The pattern of vocal fold vibration was evaluated in a vocally healthy subject and in subjects with vocal polyp, vocal nodules, vocal cord scar, and vocal cord paralysis. We used both quantitative (left-right phase symmetry, amplitude symmetry index) and qualitative (anterior-posterior phase symmetry) parameters for assessment of vocal fold vibration. RESULTS: Our system could record videos within seconds and required relatively little memory. The speed of replay in the DKG, 2D DKG, MF LVS, and high-speed videoendoscopy was controllable. The number of frame per cycle with MF LVS was almost the same as the fundamental frequency. CONCLUSION: Our system can provide images of various modalities simultaneously in real time and analyze morphological and functional vibratory patterns. It can be possible to provide a greater level of information for the diagnosis and treatment of vibratory disorders.

A new generation videokymography for routine clinical vocal fold examination.

OBJECTIVE: This study aims to introduce a new-generation videokymographic system, which provides simultaneous laryngoscopic and kymographic image, for routine clinical vocal fold examination. STUDY DESIGN: The authors explored a new imaging method for diagnosis and evaluation of voice disorders. METHODS: The new-generation videokymographic system includes two charge-coupled device image sensors, a color area image sensor, and a monochromic high-speed line-scan image sensor. The high-speed line-scan image sensor is used to capture the kymogram, and the color area image sensor is used to obtain the laryngoscopic image. The two images can be displayed simultaneously on a video monitor or stored in a standard video recorder. Three subjects with nonpathologic voice were investigated in detail with the new videokymographic system. RESULTS: The high-quality laryngoscopic image and kymogram can be used directly for clinical purposes with no further postprocessing. The scan position of the kymogram is always indicated in the laryngoscopic image, which provides feedback for the operator to easily locate the expected scanning position. All varieties of vocal fold vibration, including irregular vibrations, phonation onset and offset, can be observed with the presented method. The continuous kymogram of the vocal fold vibration can be retrieved from a kymographic image sequence for quantitative analysis. CONCLUSIONS: The new-generation videokymography provides a simple, quick means to investigate vocal fold vibration, especially for voice disorders. It can emerge as an important tool for routine clinical vocal fold examination.

The First Application of the Two-Dimensional Scanning Videokymography in Excised Canine Larynx Model.

OBJECTIVE: Evaluation of the vibratory pattern of vocal folds is of paramount importance to diagnose vocal fold disorders. Currently, laryngeal videokymography (VKG) and digital kymography from high-speed videolaryngoscopy are the available techniques for studying aperiodic vibrations of vocal folds. But VKG has the fundamental limitation that only linear portion of the vocal fold mucosa can be visualized. Digital kymography has the disadvantages of no immediate feedback during examination, considerable waiting time before kymographic visualization, recoding duration limited to seconds, and extreme demands on storage space. We developed a new system--two-dimensional (2D) scanning VKG--for evaluation of the vibratory pattern of vocal folds, and the method provided a possible alternative with its advantages and disadvantages. Thus, we aimed to evaluate the feasibility of the new device for the vocal fold vibration in excised canine larynx model. METHODS: The vibrating pattern for vocal folds was evaluated using high-speed videolaryngoscopic and 2D scanning videokymographic system in the excised canine larynx model. RESULTS: The images of canine vocal folds were captured with high-speed videolaryngoscopic system and converted to the kymographic images using the software. The kymographic image acquired by 2D scanning VKG was comparable with multi-line digital kymography at multiple locations. CONCLUSIONS: The vocal fold vibration could be evaluated in the excised canine larynx model using 2D scanning VKG. And this new device is expected to be a promising tool to evaluate the vocal fold vibration for clinical practice and voice research.

The influence of the position of the laryngeal endoscope on videokymography.

Videokymography is a new high-speed imaging technique to investigate vocal fold vibration. The system has been considered useful in the analysis of irregular signals, making it possible to observe left-right asymmetries, open quotient, propagation of mucosal waves, and movement of the upper and lower margins. The aim of the present study was to verify the correspondence of the videokymographic images with larynx exposition angle variation. Three Brazilian adult female subjects, with no vocal complains, were evaluated. Videokymographic images were obtained with the laryngeal endoscope 90 degrees positioned on the measuring line, perpendicular to the glottal axis-zero degree, during a sustained "ae" vowel, using habitual frequency and intensity. The procedure was repeated twice and adjusted by rotating the camera in fifteen degrees from the perpendicular line to the right and to the left. The results showed clear differences depending on the position of the endoscope, suggesting the standardization of laryngeal exposition to interpret videokymographic images correctly.

[Cardiokymography: relative quantification of results in normal probands]. / Kardiokymographie: Relative Quantifizierung der Ergebnisse bei Normalpersonen.

The main problem with cardiokymography (CKG) and the principal reason for its limited clinical application to date is the deficiency of calibration and quantification of results. We tried to improve the value of the procedure by quantification of the results in 14 healthy young men (age: 23, 18-31 years) in place of subjective assessment. Before and after a bicycle exercise stress test CKG tracings were obtained in a lying position at rest, immediately after exercise and after recovery. Two different methods were applied to quantify the CKG tracings (distance method and area method). The relative height of the curves at rest was 89 +/- 72% (68 +/- 39%), immediately after exercise 111 +/- 60% (73 +/- 27%) and, after recovery 121 +/- 88% (78 +/- 49%). The relative change in the height of the curves between rest and exercise was not significant according to both methods (+22 +/- 64%/+5 +/- 32%), but the variation of values in an individual patient between rest and exercise was large. Interobserver variability was rather large, according to two independent investigators. Hence, it was not possible to establish limits of normal values in quantitative CKG, but only mean values.

Isochronal map of chest wall vibration with cardiokymography.

Mapping analysis of cardiokymography is helpful in clarifying the relationship between vibratory pattern and recording sites, but needs a highly stable recording technique. We have therefore studied the stability of recording cardiokymograms, and present here a new method for creating stable maps which enables diagnosis of chest-wall vibration abnormalities. Cardiokymograms were recorded on 16 points of the chest wall located at regular intervals horizontally and vertically. The time interval between a R-wave peak of the electrocardiograms and an E-point of the cardiokymograms were measured for all the 16 records. Isochronal maps in 23 healthy subjects were classified into four types. The map of a patient with myocardial infarction was quite different from any one of the four normal patterns and seemed to show a paradoxical movement of the chest wall.

New simple ink writing pen system for kymograph recording.

Extraordinarily simple, inexpensive and easily available kymograph ink writing pen system for physiological and pharmacological recordings has been described. The writing part of the pen, consisting of a small porous fibrous writing rod to which a small spongy absorbing cylinder (as an ink container) is added, is attached to one end of a very light plastic strip of which opposite end is connected to a common mechanical lever. The function of the pen was investigated by recording spontaneous frog heart contractions in situ. The pen worked quite well and the recordings were reproducible. The pen can be interesting for researchers working in those physiology and pharmacology laboratories where more sophisticated recorders are not available, and is especially convenient for mass use in students' physiology and pharmacology labs, as alternative for smoked-drum kymograph method.

Ventricular fold vibration in voice production: a high-speed imaging study with kymographic, acoustic and perceptual analyses of a voice patient and a vocally healthy subject.

Co-vibrations of the ventricular folds are a common finding in the clinical setting. It is not always obvious how much of the perceived voice change can be attributed to the presence of such vibrations. The aim of the present study was to describe laryngeal vibrations as observed by high-speed imaging in cases where ventricular fold vibrations had been observed. The findings at kymographic display of the recordings were correlated to perceptual measures and spectrographic observations. Two subjects, a 65-year-old man with chronic laryngitis and one vocally healthy man, were examined during pressed and breathy sustained phonation. Perceived roughness in the voice quality correlated to irregularities in true vocal fold vibrations as well as to irregular ventricular fold vibrations with large amplitude combined with sufficient closure. In none of the recorded sections did ventricular fold vibrations occur without simultaneous true vocal fold vibrations. Regular vibrations of the ventricular folds of the same frequency as those of the true vocal folds and with a reciprocal pattern did not contribute to any roughness in the perceived voice.

Experimental device for detecting laryngeal movement during swallowing.

It has been reported that swallowing is a rhythmic movement, in which the onset of the oro-pharyngeal stage of swallowing starts from the mylohyoid muscle, followed by movement of the oral and pharyngeal muscles, and reaching the superior esophageal sphincter muscle. This is defined as the oro-pharyngeal stage of swallowing. It has also been reported that along with this movement, the larynx elevates in an antero-superior direction. To investigate the swallowing movement, it would be useful to be able to detect the start of swallowing movements from the body surface. Such a device was designed in this study to investigate the relationships between the onset of laryngeal movement and the EMG initiation of the anterior digastric muscle. Although experimental conditions must be further examined, we were able to record the reproducible movement and the position of larynx using our device provides another tool for studying the swallowing movement.

[Experience in using the DLTB-01 hysterotubator for the diagnosis and treatment of tubal infertility]. / Opyt primeneniia gisterotubatora DLTB-01 dlia diagnostiki i lecheniia trubnogo besplodiia.

The paper presents some experience in applying a DLTB-01 hysterotubator to diagnose and treat tubal infertility in females. The patients underwent kymoperturbation from either diagnostic or therapeutical points of view. A hundred seventy eight sessions were performed in 151 females. Analysis of the results of examinations and treatment suggests that the DLTB-01 hysterotubator is beneficial.

[Experience in using kymographic pertubation in the diagnosis and treatment of infertility in a consultation office for women]. / Opyt ispol'zovaniia kimograficheskoi pertubatsii v diagnostike i lechenii besplodiia v usloviiakh zhenskoi konsul'tatsii.

The paper describes the authors' experience in using a [symbol: see text]JITB-01 hysterotubator in the diagnosis of amphora at a women's dispensary from 1991 to 1995. All females who had complaints of being infertile for two years were examined with the hysterotubator. They included 290 females aged 21 to 43 years. Taking into account reexaminations, such studies were 317 altogether. Long-term outcomes could be followed up in 67% of the examinees undergone kymopertubation. Pregnancy occurred in 7% of cases within the first six months after kymoperturbation.

A portable high-speed camera system for vocal fold examinations.

AIM: In this article, we present a new portable low-cost system for high-speed examinations of the vocal folds. Analysis of glottal vibratory parameters from the high-speed recordings is compared with videostroboscopic recordings. METHODS AND RESULTS: The high-speed system is built around a Fastec 1 monochrome camera, which is used with newly developed software, High-Speed Studio (HSS). The HSS has options for video/image recording, contains a database, and has a set of analysis options. The Fastec/HSS system has been used clinically since 2011 in more than 2000 patient examinations and recordings. The Fastec 1 camera has sufficient time resolution (≥4000 frames/s) and light sensitivity (ISO 3200) to produce images for detailed analyses of parameters pertinent to vocal fold function. The camera can be used with both rigid and flexible endoscopes. The HSS software includes options for analyses of glottal vibrations, such as kymogram, phase asymmetry, glottal area variation, open and closed phase, and angle of vocal fold abduction. It can also be used for separate analysis of the left and vocal fold movements, including maximum speed during opening and closing, a parameter possibly related to vocal fold elasticity. A blinded analysis of 32 patients with various voice disorders examined with both the Fastec/HSS system and videostroboscopy showed that the high-speed recordings were significantly better for the analysis of glottal parameters (eg, mucosal wave and vibration asymmetry). CONCLUSIONS: The monochrome high-speed system can be used in daily clinical work within normal clinical time limits for patient examinations. A detailed analysis can be made of voice disorders and laryngeal pathology at a relatively low cost.

Laryngoscopy, stroboscopy and other tools for the evaluation of voice disorders.

This article discusses and analyzes the diagnosis and management of voice disorders. Beginning with an insightful description of dysphonia as a sign and symptom rather than diagnosis, and an analysis of its unifying principles, the discussion continues with a review of evaluation, laryngoscopy, stroboscopy, and their respective advantages and disadvantages.