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Biomedical subjects

K L Watkin

Publications and source records attributed to K L Watkin.

17 recordsLinked to original sources
PubMed2001

Effects of lingual gestures on blood flow into the tongue: a pilot study.

BACKGROUND: Reduced blood flow has been hypothesized to be a major factor in the formation of postradiation fibrosis. This study examined Doppler ultrasonography as a technique to detect changes in blood flow into the tongue during selected lingual gestures, /t/ and /k/. METHODS: Six normal subjects, three young men (mean age, 26 years) and three older men (mean age, 66 years) were examined in an upright position using Doppler ultrasound imaging of the external carotid artery just below the lingual artery. Measurements were made with a standardized segmentation technique before and after three repetitions of four speech production gestures /t/ and /k/, each with natural and maximal force. RESULTS: Blood flow peak systole increased significantly after the speech gestures (p < .001). Pooled before and after gesture values for older subjects were significantly lower than those for younger subjects (p < or = .05). CONCLUSIONS: Ultrasonography is a clinically useful technique for measuring blood flow during a dynamic gesture and may be useful for measuring effects of tumor treatment and in a lingual exercise program.

Adult↗
PubMed2001

Ultrasonic quantification of geniohyoid cross-sectional area and tissue composition: a preliminary study of age and radiation effects.

BACKGROUND: This study developed and used a new, noninvasive approach to quantify cross-sectional area and tissue composition within the geniohyoid (GH) muscle in normal adults and head and neck cancer patients. METHODS: B-mode ultrasound was used to measure GH cross-sectional area at rest and during four speech gestures and GH tissue composition at rest in normal young adults, patients with SCC head and neck cancer treated with primary radiotherapy, and normal older adults age matched with the patients. RESULTS: Patients exhibited significantly greater GH cross-sectional area than young subjects at rest and in effortful conditions. Significantly greater muscle tissue variability across GH quadrants was observed in patients compared with normal subjects and in older compared with younger subjects. CONCLUSIONS: B-mode ultrasound area analyses and tissue classification techniques can be used to quantify muscle changes, such as those resulting from age, radiotherapy, or rehabilitation for head and neck cancer.

Adult↗
PubMed2001

Effects of leuprolide acetate on adhesion formation and wound healing in the rat model.

STUDY OBJECTIVE: To assess the effects of a hypoestrogenic state on adhesion formation and reformation and on wound healing in the rat model. DESIGN: Prospective, randomized study (Canadian Task Force classification I). SUBJECTS: Forty-eight female Sprague-Dawley rats. INTERVENTIONS: Rats were injected with gonadotropin-hormone releasing hormone (GnRH) agonist and control rats with normal saline. Two weeks later (day zero) laparotomy was performed to create adhesions and a full-thickness wound on the flank. On day 14 the adhesions were scored and liberated. The rats were sacrificed on day 28 and adhesion reformation was evaluated. The wound surface area was measured serially until complete closure. MEASUREMENTS AND MAIN RESULTS: Mean adhesion scores on day 14 after adhesion formation were not significantly different between GnRH agonist and control groups. Preadhesiolysis and postadhesiolysis scores were not significantly different. There was no significant difference in size of wounds between groups on days zero, 7, or 14. CONCLUSION: Administration of a GnRH agonist does not seem to influence postoperative adhesion formation or wound healing in the rat model. (J Am Assoc Gynecol Laparosc 8(1):124-128, 2001)

Animals↗
PubMed1999

Ovarian stromal echogenicity in women with normal and polycystic ovaries.

Since the widespread use of transvaginal ultrasound to diagnose polycystic ovary syndrome (PCOS), a cardinal feature has been shown to be the presence of a bright, highly echogenic stroma. This is usually assessed subjectively. The objective of this study was to determine whether ovarian stromal echogenicity when measured objectively actually differed between women with polycystic ovaries and those with normal ovaries. A total of 67 women underwent a detailed ultrasound assessment before considering assisted conception treatment. Ovarian morphology was assessed and total ovarian volume, stromal volume, peak stromal blood flow velocity and mean stromal echogenicity were measured. The stromal index (ratio of mean stromal echogenicity to mean echogenicity of the entire ovary) and total stromal echogenicity were also calculated. Ovarian volume, stromal volume, and stromal peak blood flow velocity were all significantly higher in ovaries from women with PCOS. There was no difference in the mean stromal echogenicity, although the stromal index was significantly greater in women with polycystic ovaries. The apparent subjective increase in stromal echogenicity in women with polycystic ovaries, as exemplified by the greater stromal index, is due to a combination of the increased volume of ovarian stroma and the significantly lower mean echogenicity of the entire ovary in these women.

Dehydroepiandrosterone Sulfate↗
PubMed1999

A new predictive modality of cranial bone thickness.

The objective of this study was to evaluate A-mode ultrasound in the assessment of cranial bone thickness utilizing an in vivo animal model. A prospective study was performed that identified four standardized calvarial points in 10 Landrace porcine skulls. The individual points were scanned with an A-mode ultrasonic transducer to obtain bone thickness measurements. The same points were measured subsequently using digital calipers for objective comparison. The accuracy of each of the measurement modalities was evaluated for inter- and intrarater reliability. The association between ultrasonic and caliper measurements was evaluated using Student's t-test, Pearson's correlation coefficient, and linear regression models to assess the effect of confounding variables. The mean difference between the ultrasonic and the caliper values was 0.31 +/- 0.22 mm (standard deviation). The statistical analyses employed strongly supported the predictive value of ultrasound as a function of the true calvarial thickness (p < 0.05, r > 0.88, R2 = 0.89). The results suggest that ultrasound is an accurate reflection of cranial bone thickness in an in vivo animal skull model. The development of a portable, noninvasive ultrasonic device can have substantial clinical implications for craniomaxillofacial surgery.

Animals↗
PubMed1997

Lateral pharyngeal wall motion during swallowing using real time ultrasound.

B-mode ultrasound imaging has been used primarily to detect temporal and spatial movements of the tongue during the oral preparatory and oral stages of swallowing. The purpose of this study was to investigate the application of M-mode (motion mode) ultrasound imaging as a method to quantify the duration and displacement of single regions along the lateral pharyngeal wall during swallows of two bolus volumes and during three swallow maneuvers (supraglottic, super-supraglottic and Mendelsohn maneuver). In 5 normal subjects, simultaneous B/M-mode images were captured at two regions along the lateral pharyngeal wall. Computer-assisted video analysis of each swallow sequence provided spatial coordinates and durational measures. Results indicated no significant differences in displacements of the lateral pharyngeal wall across bolus volumes, swallow maneuvers, or recording sites. Significant differences (p < 0.001) in lateral pharyngeal wall duration occurred as a function of volitional swallow maneuvers. Greater durations (p < 0.05) were found for the Mendelsohn and super-supraglottic swallow maneuvers. The data demonstrate that B/M-mode ultrasound imaging provides a simple, noninvasive method to visually examine movements of the lateral pharyngeal wall and may provide a clinical method for assessing the effects of direct swallowing therapies at the level of the mid-oropharynx.

Adult↗
PubMed1996

The influence of bolus volume and viscosity on anterior lingual force during the oral stage of swallowing.

The influence of bolus volume and viscosity on the distribution of anterior lingual force during the oral stage of swallowing was investigated using a new force transducer technology. The maximum force amplitudes from 5 normal adults were measured simultaneously at the mid-anterior, right, and left lateral tongue margins during 10 volitional swallows of 5-, 10-, and 20-ml volumes of water, applesauce, and pudding. Results indicated significant increases in peak force amplitude as viscosity increased. Volume did not significantly influence maximum lingual force amplitudes. Individual subjects demonstrated consistent patterns of asymmetrical force distribution across the lingual margins tested. The results suggest that bolus-specific properties influence the mechanics of oral stage lingual swallowing. This finding has important clinical implications in the assessment and treatment of dysphagic individuals.

Adult↗
PubMed1993

Lung volume changes during relatively fluent speech in stutterers.

We investigated breathing patterns in stutterers during relatively fluent speech and compared these with normal subjects for similar speech tasks. Rib cage and abdominal displacements and esophageal, gastric, and transdiaphragmatic pressures provided indexes of diaphragmatic, rib cage, and abdominal muscle contraction. We found that stutterers spoke either at substantially higher or lower lung volumes than normal subjects, confining their speech to the inspiratory capacity or expiratory reserve volume. During spontaneous speech, stutterers did not cross functional residual capacity (FRC) for most breaths. In addition, stutterers used several different motion pathways from breath to breath. At high lung volumes stutterers used the diaphragm to provide inspiratory braking. At lung volumes below FRC stutterers recruited their abdominals. This contrasted with normal subjects who spoke in the middle part of the vital capacity and who recruited inspiratory and expiratory rib cage muscles above and below FRC, respectively. Breath sizes were log-normally distributed in stutterers compared with a gaussian distribution in normal subjects (P < 0.001). During reading, stutterers tended to cross FRC (P < 0.01), used very similar initiation lung volumes from breath to breath (P < 0.001), and used similar motion pathways to achieve deflation. We conclude that stutterers sustain fluency by speaking at abnormally high or low lung volumes and that this may account for the different muscle patterns observed in stutterers compared with normal subjects.

Diaphragm↗
PubMed1989

Pseudo-three-dimensional reconstruction of ultrasonic images of the tongue.

The purpose of the present investigation was to develop a method for the three-dimensional reconstruction of the surface of the tongue using serial ultrasonic images gathered during the production of the sustained fricative /s/. Using a phased linear array ultrasonic monitoring system, transducer position, subject position, and ultrasonic scan data were recorded simultaneously on composite video for off-line analysis. Reconstruction of a series of ultrasound images was completed using a microcomputer programmed to transform the ultrasonic image contours into three-dimensional space. Additional transformations converting the three-dimensional tongue contours into two dimensions for screen plotting were also developed. Results are discussed in light of previously reported models of the tongue surface.

Adult↗
PubMed1985

Effects of aerosol corticosteroids on the voice: triamcinolone acetonide and beclomethasone dipropionate.

The present investigation compared the effects of triamcinolone acetonide (Aristocort Aerosol) and beclomethasone dipropionate (Vanceril Inhaler) on the vocal functioning of 11 chronic asthmatics. Using conventional aero-acoustic techniques, subjects' vocal fundamental frequency, maximum phonation time, and oral air volume velocity were sampled at baseline (oral corticosteroid use) and at the end of the first and second year of aerosol triamcinolone acetonide use. At the end of the second year of aerosol triamcinolone acetonide use, all subjects discontinued use of this compound and began use of aerosol beclomethasone dipropionate. Subjects' vocal performance then was sampled after 1 year of aerosol beclomethasone dipropionate use. Results of this study suggest that aerosol triamcinolone acetonide reduced the vocal dysfunction observed during the baseline period. When aerosol beclomethasone dipropionate was used, however, subjects' vocal performance was similar to that observed during the baseline period (oral steroid use).

Aerosols↗
PubMed1979

The effects of triamcinolone acetonide on the voice.

With the exception of the pioneering work by Damsté in the mid 1960s and early '70's, no long term quantitative research on voice changes subsequent to drug therapy has been reported. This study reports the effects of a specific cortico-steroid, triamcinolone acetonide, on selected aerodynamic and acoustic parameters reflecting the vocal performance of twenty-one chronic asthmatic steroid dependent individuals. Measurements of the subjects' vocal fundamental frequency, maximum phonation time, oral air volume velocity, and peak intra-oral air pressure during production of selected speech stimuli were made before the introduction of triamcinolone and following the first and second years of drug use. After two years of triamcinolone therapy, significant changes were noted in parameters reflecting laryngeal functioning. Respiratory performance remained unchanged for most subjects. The results are discussed in terms of the possible physiological changes that might have occurred and their implications for the speech-language pathologist and speech scientist in medical management.

Adult↗
PubMed1978

An ultrasonic--EMG transducer for biodynamic research.

This note describes a newly developed single-element muscle action potential/motion transducer. The transcuer was specially designed for speech research. Techniques for use of the transducer are described. Sample data are presented illustrating the capability of the transducer, and applications of the device are discussed.

Action Potentials↗
PubMed1976

Jaw mechanics during release of the stuttering moment: some initial observations and interpretations.

As a part of a larger study (Hutchinson and Watkin, 1974), this investigation was undertaken to examine jaw mechanics during the release of stuttering moments. Six adult subjects (four stutters, ranging in severity, and two normal talkers) read a series of sentences containing phonetic sequences requiring jaw depression. Strain-gauge transducers were employed to record articulatory movement. Only those stutterings occurring immediately prior to and during jaw opening were studied. The results confirmed generally faster jaw velocities for the opening and closing gestures; which was interpreted to suggest that the spindle motor system is maximally active to preserve synchrony in on-going vocal tract events following the dysfluency. In cases where an asynchrony between vocalization and jaw opening was noted, it was suggested that imprecision in predicting voice onset resulted in articulatory-laryngeal incoordination. It would appear from these interpretations that the clinical efficacy of the "pull out" procedure results from reduced demands on the gamma loop system and facilitation of articulatory-laryngeal synchrony through reduced supraglottal velocities.

Adult↗
PubMed1975

Two dimensional ultrasonic demonstration of lateral pharyngeal wall movement in real time--a preliminary report.

Preliminary observations are reported in three normal subjects using a multi-element, ultrasonic transducer unit for demonstrating in real time and two dimensions the movements of the lateral nasal and oropharyngeal walls during phonation. Ultrasonic images produced are similar to those seen on frontal roentgen motion recordings. Present limitations, potential applications and advantages of this technique are discussed.

Deglutition↗
PubMedDate not supplied

Ultrasound and swallowing.

Diagnostic ultrasound plays an important role in logopedics and phoniatrics. In this article the basic principles of ultrasound are introduced along with the various ultrasonic methods used for assessment and intervention: B-mode, TM-mode, spectral Doppler, color Doppler and enhanced color Doppler. The application of each method to the study of swallowing is explored along with recent state-of-the-art advances in three-dimensional ultrasonic imaging of the upper airway.

Deglutition↗