Biomedical subjects

K Tschopp

Publications and source records attributed to K Tschopp.

31 records · Page 2Linked to original sources

PubMed1993

[Hearing disorders in childhood].

Hearing impairment in children may severely affect language acquisition. Therefore, early identification and expedient auditory rehabilitation is important. Hearing impairment should be diagnosed within the first year of life. Unfortunately, hearing handicap is still recognized at an average age of two years. In 70% of the cases, the hearing impairment is first suspected by the parents. The hearing of children at risk should be assessed using systematic screening programs. Parents who suspect that their child is hearing impaired must be taken seriously, and a thorough pedaudiologic evaluation is necessary. The principles of auditory rehabilitation are outlined.

Auditory Threshold↗

PubMed1992

[Temporomandibular myoarthropathy syndrome--a frequent cause of facial pain].

The temporo-mandibular joint syndrome (syn.: myofascial pain syndrome) is a frequent cause of facial pain. Originally, occlusal disturbances were thought to be of primary etiopathogenetic importance. However, the significance of psychological factors has been recognized during the past few years. Therefore, the treatment of patients with myofascial pain syndrome not only concerns dentists, but also general practitioners. In this report, the clinical examination, differential diagnosis and the therapeutic concept are described in order to increase interdisciplinary understanding of the temporo-mandibular joint syndrome. Additionally, the authors present their own experiences using local anesthesia therapeutically in 34 patients with myofascial pain syndrome. The symptoms remained unchanged in eight patients (24%), clinical improvement was seen in 17 patients (50%) and nine patients (26%) were free of disease after treatment.

Adolescent↗

PubMed1992

[A recommendation for calibration and choice of masking noises used in speech audiometry].

Tests to evaluate speech recognition ability against background noise have still not been adequately standardized. This is due in part to the lack of a calibration procedure for the various noises used in testing. In the present study, a psychoacoustic method for the calibration of fluctuating background noises was evaluated. Three types of noise were used: babble noise, stationary noise and fluctuating speech simulating noise in accordance with (CCITT Rec. G 227). Following calibration, the masking effect of each type of noise was evaluated. Results indicated that stationary and fluctuating speech simulating noise had similar effect on speech understanding ability. The steepness of the intensity-intelligibility function was significantly greater using babble noise as compared with stationary or fluctuating speech simulating noise. Babble noise was well accepted by our subjects. However, since its measurement can be calibrated, stationary speech simulating noise may also be used in speech audiometry.

Adult↗

PubMed1992

A randomized, double-blind, placebo-controlled study of dextran/pentoxifylline medication in acute acoustic trauma and sudden hearing loss.

The effectiveness of any therapy in acute acoustic trauma or sudden hearing loss of unknown origin has not been demonstrated convincingly. The assessment is difficult because of a relatively high rate of spontaneous recovery. Nevertheless, many different forms of treatment are recommended. We tested one form, treatment with rheoactive substances, in a prospective, randomized, double-blind trial and compared treatment with (a) infusions of dextran-40 with pentoxifylline, (b) saline infusions with pentoxifylline, and (c) saline infusions with placebo medication. Pure-tone hearing thresholds served as control parameters and were taken before treatment and at 1 and 4 weeks after the onset of therapy. Three hundred eighty-two patients were included in the trial, 331 (87%) could be analyzed, 184 patients were treated because of sudden hearing loss, 147 because of acute acoustic trauma. The three treatment groups were comparable in their basic characteristics including the amount of initial hearing loss. In patients with sudden hearing loss, no significant differences of hearing recovery were detected between the three treatment groups. Hearing recovery was also similar in patients with acute acoustic trauma. A power analysis of the study revealed that possible true treatment differences of a hearing recovery of 10 dB would have lead to significance with a probability of over 90%. It is concluded that there were, in fact, no clinically relevant differences in hearing gains of sudden hearing loss or acute acoustic trauma between treatments with saline infusions together with placebo medication and treatment with dextran-40 and/or pentoxifylline.

Acoustic Stimulation↗

PubMed1992

Acoustical changes of loudly spoken speech and their effects on speech recognition in hearing-impaired listeners.

The level of speech is usually increased in conversations with unaided hearing-impaired listeners. However, the speaker may talk at conversational levels to aided hearing-impaired persons. In this case, the level of speech is electronically increased by the hearing aid. In the present study, the acoustical changes of loudly spoken speech and their effects on speech recognition were investigated in 20 patients with sensorineural hearing loss. Eight test words of the German Speech Intelligibility Test ('Freiburger Sprachtest') were recorded at original levels of 60 and 75 dB SPL by a male speaker. Both recordings were presented to hearing-impaired subjects at a playback level of 75 dB SPL. Thus, the level of the 60 dB SPL recording was increased electronically by 15 dB. For the 75 dB SPL recording, playback and recording levels were identical. The average whole-word score was 49% for the 60 dB SPL recording and 39% for the 75 dB SPL recording. This difference was statistically significant (0.002 less than P less than 0.005). The results of the speech recognition ability tests could be explained by the acoustical changes of the loudly spoken speech. In the 75 dB SPL recording, the levels of voiceless fricatives, nasals and plosives were significantly lower than in the 60 dB SPL recording. Spectrally, the fundamental frequency was increased and the configuration of the first formant was altered in the 75 dB SPL recording. The significance of the findings for clinical speech audiometry and hearing aid evaluation is discussed.

Acoustic Stimulation↗

PubMed1991

[Silicone endoprosthesis in the treatment of tracheobronchial stenosis. Report of the first 12 patients treated with this method].

Inoperable tracheobronchial stenoses are most often due to malignant disease. Apart from systemic therapy, various local treatment modalities such as laser resection, cryotherapy and endobronchial radiation therapy have been designed to maintain airway patency. Recently, various models of tracheobronchial stents (or endoprostheses) have been designed to maintain airway patency. They prevent recurring endobronchial tumor growth or progressive extrinsic compression of dilated airways. Silicone stents are highly suitable for this purpose. We treated 12 patients (11 males, 1 female, median age 68,5 years) suffering from bronchial carcinoma (6), esophageal carcinoma (4), metastatic colon carcinoma (1) and metastatic osteosarcoma (1). One stent per patient was inserted at the following sites: 6 in the right main bronchus, 4 in the trachea, 1 in the left main bronchus and 1 tracheobronchial left. We observed 2 complications: one obstruction of a bronchial stent by secretions which could be managed by fiberbronchoscopy and one short fire to a bronchial stent on repeat laser therapy. Rapid and lasting relief of dyspnea was observed in all patients. Our initial experience with a median follow-up of 2 months confirmed the easy insertion technique, the excellent effect and tolerance as well as the simple postoperative care of these silicone stents. Their use immediately after relief of a tracheobronchial obstruction by local means can be recommended.

Aged↗

PubMed1991

Resection of endobronchial tumors using a tracheoscope and neodymium:YAG laser.

A modified technique for palliative resections of malignant endobronchial tumors with the Nd:YAG laser is described. A special tracheoscope was used in conjunction with the instrument guide of a laser bronchoscope. The main advantage of this technique is easy and simultaneous access to both lungs for ventilation and surgical procedures. The method helps to separate surgical from anesthetic manipulations. The experience of over 70 operations using this technique provides evidence that the use of a tracheoscope is a safe and efficient method of endoscopic resections of larger intrabronchial tumors.

Bronchial Neoplasms↗

PubMed1991

Objective measures of sentence level with respect to loudness.

The best method for objectively measuring the level of running speech has not yet been established. In the present study, subjective and objective measures of the level of sentence pairs were compared. Psychoacoustic judgments of the loudness of ten sentence pairs were made by ten listeners. The level of the sentences was measured using four objective methods. The purpose was to determine which of the objective measures best matched the psychoacoustic data. The objective methods included: Sound level meter (SLM), percentile level, average power level (Leq) and the loudness calculation procedure according to ISO 532 B. There were no significant differences between the estimates using the SLM set on either 'Impulse', 'Fast' or 'Slow' settings, the Leq, the percentile level Lmax and the percentile loudness Nmax to N30 using conventional calculation techniques. The measures obtained using A-weighting on the SLM were not found to be superior to the unweighted measures. These findings have implications for the measurement of the level of sentences used in clinical audiology.

Adult↗

PubMed1991

A proposal for the measurement of the level of fluctuating background noise used in audiology.

Disturbances of communication in noisy environments may be identified sooner in patients with sensorineural hearing loss when speech audiometry is performed using fluctuating rather than stationary background noises. In the present study, the factors determining the loudness of fluctuating noises were examined using psychoacoustical procedures. The results indicated that loudness of fluctuating noises was best represented by the same percentile loudness N15 or percentile level L15. This is the value that is reached or exceeded in 15% of the analysed measurement time. The percentile level L15 or the percentile loudness N15 may be used to measure the level of noises with identical spectra. However, subjective loudness is approximated only by the percentile loudness N15 if the stationary and the fluctuating noises are spectrally different.

Adult↗

PubMed1991

A comparison between the electrically reproduced loudness and the original loudness of speech at high levels.

Four words lists of a German Speech Intelligibility Test (DIN 45621) were recorded at 60 and 75 dB SPL. Both recordings were presented to 20 normally hearing subjects at 75 dB SPL via free-field equalized earphones. Discrimination in noise was significantly better in the original recording at 60 dB SPL. The better understanding may be explained by a more favourable consonant-vowel intensity ratio. Moreover, a significant increase in fundamental frequency could be demonstrated at the higher recording level. The implications for speech audiometry and hearing aids are discussed. Furthermore, it was found from loudness comparisons that both recordings were equally loud at a level of 75 dB SPL. However, significantly increased loudness was indicated in the 75 dB SPL recording by the loudness calculation procedure ISO 532 B.

Acoustics↗

PubMed1990

[Medical informatics systems exemplified by the diagnosis of equilibrium disorders].

An interdisciplinary field, namely the differential diagnosis of balance disorders and vertigo, is used to describe how a medical expert system can be developed using modern computer analysis, medical expertise, and human pattern recognition techniques. The advantages, results, and unresolved issues of close cooperation between biomedical engineers and physicians are described. The aim of this cooperation was to ensure that complicated data were presented in simple graphic form and that large amounts of diagnostic data were optimally linked together for the generation of a recommended diagnosis. Similar techniques may usefully be employed in other areas of medicine.

Caloric Tests↗

PubMedDate not supplied

Allergic contact dermatitis from tixocortol pivalate in a nasal spray masquerading as infectious complication of sinusitis.

Allergic contact dermatitis to corticosteroids is not uncommon and is increasingly reported. Contact allergy to nasal corticosteroids is rare and may present with atypical symptoms, which may be confused with infectious complications. We report on a patient in whom the misinterpretation of her allergic nasal symptoms to the corticosteroid tixocortol pivalate resulted in hospitalization and considerable medical expenses.

Adult↗

PubMedDate not supplied

Acute acoustic trauma. A retrospective study of influencing factors and different therapies in 268 patients.

The files of 268 patients with acute acoustic trauma acquired during military service were analysed in a retrospective study. The following factors were examined: age, profession, degree of hearing loss, audiometric contour, and drug treatment. No influence of age or profession on recovery of hearing loss could be detected. The absolute hearing gain, defined as the difference between the hearing loss at onset and, on average, 7 days later, was dependent on the degree of initial hearing loss. The relative hearing gain, defined as absolute hearing gain divided by initial hearing loss, was independent of the degree of initial injury. The audiometric contour after the acoustic trauma had no prognostic relevance. Nine different types of drug treatment were compared in a subgroup of patients (n=199), in all of whom treatment was started within 2 days of the acoustic trauma. There were no significant differences in relative hearing gain between the nine types of treatment. Patients receiving early treatment had significantly better hearing one week after the acoustic trauma, as compared with the group of patients (n=69) not receiving treatment during the first 7 days. However, it was not possible to determine retrospectively whether this difference was due to treatment effects, or whether it was due to the exclusion of spontaneous remissions among those who were neither examined nor treated within the first 7 days.

Adult↗