Hans Larsson

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OBJECTIVES To evaluate a new analysis system, High-Speed Tool Box (H. Larsson, custom-made program for image analysis, version 1.1, Department of Logopedics and Phoniatrics, Huddinge University Hospital, Huddinge, Sweden, 1998) for studying vocal fold vibrations using a high-speed camera and to relate findings from these analyses to sound characteristics.(More)
In order to determine the influence of breath-by-breath measurement of inspiratory occlusion pressure (P0.1) on the pulmonary ventilation, the respiratory timing and the central inspiratory activity as reflected by P0.1 per se, nine healthy males were studied as they breathed in a valve assembly including an externally controlled occlusion valve. A new(More)
Utilisation of the semitendinosus and gracilis tendons in reconstruction of the anterior cruciate ligament (ACL) has become more common during the last few years. In recent studies a regeneration potential in the harvested tendons has been observed. In this study, 11 consecutive patients who underwent ACL reconstruction with a quadruple semitendinosus graft(More)
The purpose of this study was to develop an analysis system for studying the relationship between vocal fold vibration and the associated transglottal airflow. Recordings of airflow, electroglottography (EGG), oral air pressure, and acoustic signals were performed simultaneously with high-speed imaging at a rate of approximately 1900 frames/s. Inverse(More)
The pharmacokinetics of propranolol after the administration of 40, 80, and 120 mg p.o. and 10 mg i.v. was studied in nine healthy male volunteers. Propranolol was analyzed after extraction and derivatization by gas-liquid chromatography. A multiexponential curve-stripping program was used for the pharmacokinetic analysis. The volume of distribution was(More)
Objective. The value of MRI for the evaluation of anterior shoulder instability can be enhanced by shoulder positions that stress the stabilising structures. The ABER position is one that has been described in combination with intra-articular gadopentetate dimeglumine arthrography. We believe that MRI in the Apprehension test position with 90° abduction and(More)
An open circuit tracer gas washout method for measurement of lung volume in patients during anesthesia and intensive care is described and tested. The method employs a device for dispensing the tracer gas, sulfur hexafluoride (SF6), a fast SF6 analyzer, a pneumotachograph, and a computer. The dispensing device delivers SF6 into the airway in proportion to(More)
Objective. To design and evaluate a clinical monitor of respiratory drive (P0.1) and other respiratory variables in a simple way, using a commercial ventilator. Methods. Nine healthy males were studied as they were breathing spontaneously in a Servo 900C Ventilator, at rest and during light exercise (50 W). The ventilator was slightly modified to improve(More)
This study aimed to compare vocal fold elasticity data from a new method for non-invasive analysis by stimulations of the mucosa with short air pulses. The depth of the mucosal deflections is measured with laser pulses by means of a special algorithm. Ten scarred New Zealand rabbit vocal folds and four normal rabbit folds were measured directly after(More)
A method was developed for absolute calibration of endoscopic vocal fold images using laser triangulation. The laser is attached to a rigid endoscope with 8-degrees angle in relation to the optical axis of the endoscope. A special software is used for calibration and measurements from high-speed images. The equipment can provide measurements both in(More)