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Biomedical subjects

M Flückiger

Publications and source records attributed to M Flückiger.

At least 19 recordsLinked to original sources
PubMed1992

On the role of global and local visual information in goal-directed walking.

The aim of the present study was to determine what interactions occur between the visual information available to walking subjects in the global optical flow and those of a more local nature relating to the dilation rate of a target on the retina. A goal-directed walking task was used in which thirteen subjects were asked to stop spontaneously as near as possible to a stationary target. The experiment was carried out in a special room, by means of a texture flow generator with which the velocity and direction of the optical flow arising from the ground were varied. Twelve experimental conditions were tested, involving various combinations of target size and texture velocity. The results show that with both of the targets, modifications to the global flow significantly affected the subjects' performances (walking speed and time-to-contact with the target upon braking) in the fast-approaching texture situation, but not in the receding or slowly-approaching situations. The results are discussed as to what they reveal about the visual strategies used by an actively moving observer to anticipate a collision with a stationary target.

Acceleration↗
PubMed1992

[Elbow dysplasia in the dog].

Elbow dysplasia (ED) is a common developmental malformation in many breeds over 20 kg bodyweight. It may affect as many as 50% of all dogs within a breed. Arthrosis and poor performance may result. The most common forms of ED are fragmented medial coronoid process, osteochondrosis of the medial humeral condyle and loose anconeal process. There is evidence for the existence of a hereditary disposition for osteochondrosis in Labrador retrievers. In Sweden selection of ED-free dogs for breeding resulted in reduction of frequency and degree of severity of ED in the offspring. Adoption of a similar breeding program for Switzerland is suggested.

Animals↗
PubMed1991

[Use of a low dose prostaglandin F2 alpha in bitches].

The dosage of Prostaglandin F2 alpha used until the present (100, 250 and 1000 micrograms/kg bw), in order to treat pyometra in the bitch, was accompanied with side effects such as salivation, vomiting and diarrhea. In the present work, the efficiency of low dose Prostaglandin (20 micrograms/kg bw) was examined in two different groups of patients: Group 1: Included 9 bitches pregnant for a period of 5-7 weeks duration. Initially the bitches were treated 3 or 4 times per day with Prostaglandin F2 alpha. In these cases abortion took place within 4 to 11 days. Group 2: 12 dogs, suffering from pyometra, were treated 3 times per day with PGF2 alpha for 8 days. In 9 dogs the pyometra resolved and the bitches came in estrus 2-5 months after treatment. 7 bitches have been mated and 6 of these gave birth to healthy litters. During a follow-up period of at least 10 months there has not been a reoccurrence of pyometra. In 3 out of the 12 dogs the uteri were still enlarged after 8 days of treatment. These bitches underwent ovariohysterectomy and a cystic hyperplasia of the endometrium was diagnosed histologically. The low dose (20 micrograms/kg BW) Prostaglandin F2 alpha induced in all dogs the expulsion of the uterine contents. Side effects during the treatment were not observed.

Abortion, Induced↗
PubMed1991

[Ultrasonic diagnosis in dogs and cats. 2. Clinical use--a review].

Most organs, unless mineralized or gas containing, may be examined ultrasonographically, though with variable success. Echocardiography is a particularly valuable tool since the dynamic cardiac action can be quantified in detail. In parenchymal organs discrimination between solid and cavitary lesions such as cyst, hematoma, or abscess is possible. Focal disease is more easily recognized than diffuse disease. Establishment of an etiologic diagnosis is rarely possible. Many organs however may be biopsied under ultrasonographic guidance and control.

Abdomen↗
PubMed1990

Unintentional modulations of human gait by optical flow.

Visual whole-field motion is known to trigger motor responses which minimize retinal slip (VOR, OKN and control of balance). In locomotion, however, the retinal slip is utilized to control the velocity and direction of displacement. The present experiment was aimed at determining how the velocity of optical flow affects the regulation of locomotion. Unintentional modulations in velocity, stride length and cadence were analyzed using a task in which artificial optical flow gave the subjects the impression they were walking at a different speed than they actually were. Slight but systematic modifications in locomotion were observed: experimental variation of the optical flow resulted in a decrease in stride length. None of the subjects were aware of this decrease, despite the fact that their muscular and articular afferences provided them with supraliminal information. Although visual flow velocity is usually a direct consequence of walking velocity, experimental modifications of visual flow were found here to cause unintentional modulations in locomotor parameters (stride length and cadence) more than in their product (velocity).

Acceleration↗
PubMed1990

[Urachal disorders in calves: clinical and sonographic findings, therapy and prognosis].

Clinical findings, therapy, and prognosis of 20 calves with urachal problems were studied and are discussed. Ultrasonography proved to be a valuable adjunct diagnostic procedure to manual palpation. It allowed exact evaluation of the intraabdominal umbilical cord size and was an important aid in the selection of the correct therapy. A complete omphalourachectomy was performed in calves with an extra- and intraabdominal umbilical cord diameter of up to 10 cm, otherwise drainage was established. Based on our results prognosis for calves with urachitis is independent of the size of the umbilicus and can be judged as favourable in cases without systemic complications.

Animals↗
PubMed1990

[Ultrasonic diagnosis in dogs and cats. 1. Manner of function, instruments, biological effects].

Ultrasonography utilizes high frequency sound waves between 2 and 10 MHz. Returning echos from reflecting surfaces in the body are displayed as two-dimensional images on a CRT screen. Ultrasonography is particularly useful for analysis of internal structures of parenchymal organs such as liver, spleen, kidneys, prostate and uterus, as well as fluid filled organs such as heart, urinary bladder, gallbladder, and pregnant uterus. The clinical examination is safe. Sector transducers with frequencies between 5 and 10 MHz are useful for dogs and cats.

Animals↗
PubMed1990

[Text, archiving, coding--integration with electronic data processing].

For a successful computer-installation in the medical area you need a staff, which is used to work with computers in the daily routine. We tried with this project to establish the computer in a medical office by doing the whole patient-related writings on a specially tailored software. Most of the daily routine can now be done with the help of the computer. A certain time-saving effect could be achieved, although this was not our first aim. On this base we are now able to solve other problems such as coding, statistics or archiving routines by using our established computer environment.

Archives↗
PubMed1989

[Clarification of teat stenoses in cattle by ultrasound].

Ultrasonography and radiography were used as an adjunct to clinical examination in the evaluation of 73 obstructed teats in 63 dairy cows. The images obtained with a 3.5 MHz and a 5 MHz linear array transducer were compared with radiographs and correlated with findings obtained at surgery. Ultrasonography and radiography allowed a correct assessment of the lesions in 68 respectively 58 teats. In five cases the obstructive lesions in the teat canal were not clearly discernible when ultrasonography was used. Radiography was the method of choice for the evaluation of the teat canal and small mucosal folds in the milk cistern. Ultrasonography was the method of choice for the detection of obstructive lesions at the base of the teat; all 14 of these cases were assessed correctly using ultrasonography versus three of 14 when radiography was used. Ultrasonography is a useful tool for the practitioner to evaluate obstructive teat lesions.

Animals↗
PubMed1988

The perception of an optical flow projected on the ground surface.

In most experiments in which the importance of visual control on postural stability is studied, optical stimuli attached to vertical surfaces are used. Analyses of long-term standing readjustments generally involve back-and-forth movements of a visual scene or its projection on vertical circular screens. In a natural environment, however, visual information is largely available from the ground. The aim of the experiment reported was to assess the effect of a flow pattern simulating an open outdoor setting on motion perception and postural control. Subjects were presented with an optical texture projected onto the ground. Periods of motionless texture alternated with equivalent durations of unidirectional flows. The change of position of the subject's centre of gravity over time was recorded on a force platform. Results show that the direction of body sway corresponded with that of texture motion. Important aftereffects, as shown in linear vection experiments, were also observed. However, the latency of postural responses was much shorter than with prolonged unidirectional flows produced in other locations of the visual environment. The hypothesis of an ecological specificity of the flows perceived on the ground during terrestrial displacements is discussed.

Adult↗
PubMed1988

[Urachal abscess without pathologic changes in the extra-abdominal navel in a cow. Case report].

A rarely diagnosed case of urachal abscessation without any signs of inflammation of the extra-abdominal navel in a seven-month-old Braunvieh heifer is described. The symptoms of this disease, its diagnosis by the means of ultrasonographic examination and its therapy are explained. The technique of ultrasonographic examination is supposed to be a facilitation of presurgical diagnosis of umbilical disease. Nevertheless the value of this diagnostic procedure should be checked up on more patients.

Abscess↗