Biomedical subjects

S M Blaugrund

Publications and source records attributed to S M Blaugrund.

At least 19 recordsLinked to original sources

PubMed1996

Singing power ratio: quantitative evaluation of singing voice quality.

This paper presents a parameter for objectively evaluating singing voice quality. Power spectrum of vowel sound /a/ was analyzed by Fast Fourier Transform. The greatest harmonics peak between 2 and 4 kHz and the greatest harmonics peak between 0 and 2 kHz were identified. Power ratio of these peaks, termed singing power ratio (SPR), was calculated in 37 singers and 20 nonsingers. SPR of sung /a/ in singers was significantly greater than in nonsingers. In singers, SPR of sung /a/ was significantly greater than that of spoken /a/. By digital signal processing, power spectrum of sung /a/ was varied, and the processed sounds were perceptually analyzed. SPR had a significant relationship with perceptual scores of "ringing" quality. SPR provides an important quantitative measurement for evaluating singing voice quality for all voice types, including soprano.

Adult↗

PubMed1996

Quantitative criteria for predicting thyroplasty type I outcome.

The purpose of this study was to ascertain the relation between preoperative glottal gap and postoperative vocal function in thyroplasty type I. Twenty-two of 64 patients who underwent thyroplasty type I between 1987 and 1994 were studied. In preoperative digitized laryngostroboscopic images, the glottal-gap, width (GGW), shape, and area were examined at the maximum closure of vibration and normalized by membranous vocal-fold length (MVFL). Postoperative vocal function analysis was performed with aerodynamic and acoustic measurements and compared with preoperative videostroboscopic images. In patients with preoperative posterior GGW of less than 10% of MVFL, postoperative vocal function was significantly better than in other patients. Although thyroplasty type I is an excellent medialization technique, it may need to be combined with a posterior closure procedure in patients with large posterior gaps.

Adult↗

PubMed1996

Quantitative videostroboscopic measurement of glottal gap and vocal function: an analysis of thyroplasty type I.

The goal of surgical medialization of the vocal fold is to attain complete glottic closure. The purpose of this study is to quantify the glottal gap and to examine the relationship between glottal gap and vocal function perioperatively in thyroplasty type I. Glottal gap area was measured in 20 patients at the point of maximum closure of vocal fold vibration in digitized laryngeal stroboscopic images and was normalized by the square of vocal fold length. Glottal gap area thus measured was correlated with results obtained from well-accepted acoustic, aerodynamic, and perceptual measures of vocal function. The glottal gap was significantly reduced after thyroplasty type I. In patients with small preoperative glottal gaps, the amplitude of vocal fold vibration was significantly improved. This study verifies that quantitative videostroboscopic measurement of the glottal gap is a useful means of objective evaluation of glottic incompetence and of the results of thyroplasty type I.

Acoustics↗

PubMed1994

The turbulent noise ratio: an estimation of noise power of the breathy voice using PARCOR analysis.

The degree of turbulent noise in the breathy voice of 25 patients with incomplete glottal closure was determined by PARCOR (PARtial autoCORrelation) analysis. From 10,000 acoustic data points, 44 PARCOR coefficients were calculated to form the residue wave which is representative of the glottal source. The power difference between the residue wave and the original acoustic wave was calculated in order to define a new measurement of acoustic power termed the turbulent noise ratio (TNR). The 25 patients were studied before and after Isshiki thyroplasty type I (IttI). The TNR became smaller in 24 of these patients following IttI, and corresponded closely with acoustic (Fukazawa's Br-Index), aerodynamic (Isshiki's AC/DC ratio), mean airflow rate during phonation, and videolaryngostroboscopic findings. Data affirm that the TNR accurately reflects the degree of turbulent noise at the glottal source.

Adult↗

PubMed1994

Computer-generated presentations: current status and future directions.

The personal computer allows the user to create professional presentations as good as any created by commercially available services. With the new generation of inexpensive software, myriad fonts, layouts, graphics, and imported images can all be used by the novice. The technology is currently available that can project images directly from the computer, obviating the need for slides. This presentation will discuss the relative merits and costs of such systems and the problems that remain concerning implementation at a national level.

Audiovisual Aids↗

PubMed1993

Thyroplasty: a new approach.

A new type of thyroplasty implant (prosthesis) has been designed to be used of a surgical operation that accomplishes medial displacement of a paralyzed vocal cord. The implant is inserted through a rectangular window fashioned in the thyroid lamina on the side of the vocal cord paralysis. Instruments for measuring the location and outline of the window in the thyroid lamina are presented. A thyroplasty saw blade is introduced. By using this blade, a window of precise measurement can be constructed without injury to the underlying perichondrium. The implant is constructed from a biocompatible, medical-grade polymer. Four sizes each are available for the male and female larynges. The proper-size implant can be selected with a measuring device. It is not necessary to alter the implant at the time of surgery; it snaps into place and suturing is not necessary. Once the implant is inserted, its medial or lateral displacement is not possible; on the other hand, the implant can be easily removed if vocal cord function returns, or if a change to a different-size implant is indicated. The design of the implant will close the posterior commissure.

Equipment Design↗

PubMed1992

High-frequency power ratio of breathy voice.

Digital technological advances have made detailed voice analysis possible. This report proposes, with the use of such equipment, a new method of quantifying differences in the high-frequency content of normal and breathy voices. The high-frequency power ratio, a ratio of high-frequency power versus total power, was calculated as the lower limit of the high-frequency range (Fc) and varied from 1 to 10 kHz. The high-frequency power ratio values of two groups, 16 normal and 24 breathy voice individuals, were then compared. Three breathy individuals were also studied after type I thyroplasty. High-frequency power ratio values measured at an Fc of 6 kHz significantly separated normal from breathy voices. The specifications provided are appropriate for both the commercial voice lab and for clinical resources. Furthermore, a high-frequency power ratio (6 kHz) is a useful tool for the evaluation of phonosurgery.

Female↗

PubMed1992

H-Index: a new measure of glottal efficiency for the pathologic voice.

Taking advantage of the extended dynamic range of digital analysis of voice the H-Index represents the first proposed acoustical measure of glottal efficiency. "Hi" /hai/ was chosen to evaluate glottal efficiency since it provides an excellent test of glottal transformation from voiceless to voiced sound energy, the upper vocal tract having a neutral effect. Fifteen individuals with normal voices and 30 patients with hoarse voices were asked to say "hi." The power ratio of /h/ to /a/ was calculated from peak power of each measure from the power envelope. Voice quality had a highly significant effect on measured values (P < .001). A high degree of correlation (P < .001) was found with the AC/DC ratio, a standard aerodynamic measure of glottal efficiency. The results indicate that the H-Index represents an excellent measure of glottal efficiency, obviating the need of invasive techniques or expensive, highly specialized equipment.

Analysis of Variance↗

PubMed1992

Time series analysis of glottal airflow in normal and pathological phonation.

Time series analysis of glottal airflow was carried out on 26 normal controls and 40 patients with voice disorders, using a modification of Isshiki's original technique which uses a hot-wire flowmeter, taking cycle-by-cycle fluctuations into consideration. The mean flow rate and mean AC/DC were shown to have significant differences among normal and patient groups. The standard deviations of AC/DC and AC/DC perturbation were calculated from the AC/DC value of 50 cycles and shown not to vary significantly among the normal and patient groups. The relationship between AC/DC and perceptual impression of voice was also studied among 20 selected patients with breathy voices. Using Spearman's rank correlation coefficient, this relationship was found to have statistical significance (P < .05).

Glottis↗

PubMed1991

Head and neck trauma in taxicabs. A growing urban problem.

The passage of mandatory seat belt legislation has markedly decreased the incidence of head and neck trauma to passengers in private automobiles. However, taxicabs are exempt from seat belt laws in many states. Seat belts, which are included as standard equipment by automobile manufacturers, are often made inaccessible by taxicab operators. We present five cases of head and neck trauma sustained by passengers in taxicabs in which seat belts were not accessible. Injuries included laryngeal fractures, maxillofacial trauma, and severe trauma to the cervical spine. All injuries could have been avoided by the use of an accessible safety belt. The nationwide scope of this problem and strategies for modification of existing laws for better protection of passengers in cars for hire are presented.

Accidents, Traffic↗

PubMed1991

Diagnostic dilemmas in soft tissue tumors of the head and neck.

Classifying soft tissue tumors of the head and neck is often difficult for both surgeon and pathologist because of the potential similarities in appearance of metastatic lesions, epithelial tumors, lymphomas, and inflammatory processes. This paper discusses four unusual soft tissue tumors of the head and neck: osteosarcoma of the mandible, biphasic synovial cell sarcoma of the hypopharynx, soft part sarcoma of the maxillary sinus/alveolus, and adult rhabdomyoma of the larynx. Precise diagnosis of these lesions requires adequate tissue sampling, immunocytochemical staining, and electron microscopy. The clinical and pathological features of these tumors, as well as a practical approach to the diagnosis, is presented.

Adolescent↗

PubMed1990

Effects of lateral manual compression upon glottic incompetence: objective evaluations.

Forceful manual compression of the thyroid and cricoid cartilages modifies the position, shape, and tension of the vocal folds. This is the basis of the four laryngeal manual compression tests, adjunctive examinations used as a means of preoperative assessment of patients for medialization laryngoplasty, ie, Isshiki thyroplasty types I and IV and arytenoid adduction. The laryngeal manual compression tests are simple to perform and noninvasive. Each of the four examinations yields valuable information on the effects on the voice of changes in vocal cord characteristics produced by manual compression. In this report, one of the four tests, lateral manual compression, is evaluated objectively with well-attested methods of videostroboscopic, aerodynamic, and acoustic analysis. The technique of performing lateral manual compression is described, and advantages and disadvantages are noted and compared in 10 patients. Preliminary findings in 4 patients in this group indicate that medialization laryngoplasty should be considered when test results are conclusive of effective glottic closure. Data derived in this preliminary study will be augmented as patients are added to the series.

Adult↗

PubMed1990

Controlled laryngoplasty for vocal cord medialization: a technique using tissue expansion.

Laryngeal framework surgery has become an increasingly popular alternative to Teflon injection for vocal rehabilitation. Vocal cord medialization requires custom tailoring of the implant's size and shape to optimize individual vocal quality, whether it be via the interposition of Silastic implants between the thyroid ala and the inner thyroid perichondrium or through a cartilage window. A new technique is described for vocal cord medialization using an implanted miniature tissue expander. Intraoperative and postoperative vocal cord medialization was achieved in a canine model by controlled percutaneous filling of a remote injection valve. The implants were well tolerated and allowed continued control of vocal cord position for several weeks. Using this technique, vocal quality can be fine-tuned with a degree of precision not previously possible. The advantages, limitations, and technical aspects of expansion laryngoplasty are discussed.

Animals↗

PubMed1989

The histopathologic diagnosis of head and neck tumors by special stains.

Various histochemical and immunocytochemical stains were useful in the diagnosis of six unusual head and neck neoplasms that included spindle-cell squamous carcinoma, synovial sarcoma, mucoepidermoid carcinoma, melanoma, T-cell lymphoma, and B-cell lymphoma. Close cooperation with a pathologist ensured rapid diagnosis and the initiation of appropriate therapy. Three cases required special histochemical stains to make a diagnosis or determined tumor differentiation. The three other cases would have been identified as poorly-differentiated tumors of unknown origin without the use of special immunocytochemical stains. These latter findings influenced our final therapeutic strategy, which emphasizes the uses of special stains and studies to accurately identify tumors of the head and neck.

Adolescent↗

PubMed1989

Nasal obstruction. The nasal septum and concha bullosa.

Nasal septal defects impair nasal physiology, leading to progressively more severe rhinosinusitis and the development of chronic disease. Anatomy and physiology are described. Treatment for the deviated nasal septum is discussed.

Airway Obstruction↗

PubMed1988

Paranasal sinus disease with intracranial extension: aspergillosis versus malignancy.

Aspergillus is a fungus with world-wide distribution and a common endogenous contaminate of the upper respiratory tract. It has become an increasingly recognized pathogen in the paranasal sinuses. In its pathologic state it presents in one of several forms that may represent a continuum of the disease: allergic, noninvasive, invasive, and fulminant. The progression and prognosis of these disease depends on the location and immunologic status of the patient. This case represents the fourth reported case of a nonimmunologic compromised patient with intracranial extension of aspergillosis. The patient presented with unilateral pansinusitis and radiographic evidence of orbital and anterior cranial fossa invasion. This case illustrates the difficulty of establishing the diagnosis of invasive aspergillosis and differentiating it from neoplastic entities. Radiographs and photomicrographs will be presented to establish this premise.

Adult↗

PubMed1988

Salivary gland lymph nodes. The site of lymphadenopathies and lymphomas associated with human immunodeficiency virus infection.

Normally, lymph nodes are intimately associated with the salivary glands, particularly the parotid gland. Several lymph nodes are embedded in the parotid gland, other lymph nodes are adjacent to the submaxillary gland, and ectopic salivary gland acini and ducts are commonly present in cervical lymph nodes. These salivary gland lymph nodes may become the primary site of the benign lymphadenopathy and the malignant lymphomas characteristically associated with human immunodeficiency virus (HIV) infection. This report of a series of HIV-associated lymphatic lesions originating in salivary gland lymph nodes comprises nine cases of salivary gland masses that were surgically excised, it includes six cases of lymphadenitides and three cases of lymphoma--all originating in salivary gland lymph nodes and showing the histologic lesions known to occur in association with the acquired immunodeficiency syndrome. The HIV-related infections and neoplasias located in the salivary gland lymph nodes raise interesting questions about the possible etiologic role of an oral portal of entry and of the virus-infected saliva. The recognition of their clinical and pathologic features is indispensable to enable correct diagnosis and treatment.

Acquired Immunodeficiency Syndrome↗

PubMed1984

Voice onset in pathologic speakers.

The time interval between the release and beginning of vocal cord vibration in word-initial /p/ and /b/ was measured. The data from subjects with laryngeal pathology are described. /b/ showed larger values compared with the data from normals. It is suggested that such a test of vocal initiation could provide a useful measure for the evaluation of laryngeal dysfunction.

Adolescent↗