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Biomedical subjects

G Bergmann

Publications and source records attributed to G Bergmann.

At least 19 recordsLinked to original sources
PubMed1991

[Theory and model in psychosomatic medicine--a historical sketch].

Starting with "personal medicine" as it was formed by Ludolf von Krehl in the frame of a medical clinic at a university, psychosomatic medicine, in its narrow sense, is described in its historical development. Differences to the conception of behavioral medicine are noted. Some theoretical models following the conversion model of Freud like stress concept, life-event or coping are historically explained. Actual research such as change of paradigm towards a systemic approach describes the actual situation, the conception of the "Gestaltkreis" completes this. Practice of today's psychosomatic medicine can be outlined by the concepts of simultaneous diagnostic and simultaneous therapy.

Germany↗
PubMed1991

Four-channel telemetry system for in vivo measurement of hip joint forces.

The long-term loosening of artificial hip joints remains a serious clinical problem. Optimization of implant design and material will improve the fixation, but it requires a detailed knowledge of the forces which act on the implant. A four-channel telemetric transmitter was developed and arranged completely inside a hermetically closed artificial hip joint. This permits long term in vivo measurements of the three-dimensional forces without endangering the patient. The external telemetry system consists of an inductive power supply, an RF receiver, a microcomputer with hardware extension and a VHS video system. The personal computer offers real-time data processing of three orthogonal force components as well as slow motion analysis of recorded measurements. After several years of animal tests, two instrumented prostheses were implanted in the first patient (male) in May and August of 1988. In March 1990 a third prosthesis was implanted in a second patient (female). Joint force measurements have regularly been performed from the first post-operative day until now for several kinds of activity.

Biomechanical Phenomena↗
PubMed1989

The quantitative spectrum of inositol phosphate metabolites in avian erythrocytes, analysed by proton n.m.r. and h.p.l.c. with direct isomer detection.

The spectrum of inositol phosphate isomers present in avian erythrocytes was investigated in qualitative and quantitative terms. Inositol phosphates were isolated in micromolar quantities from turkey blood by anion-exchange chromatography on Q-Sepharose and subjected to proton n.m.r. and h.p.l.c. analysis. We employed a h.p.l.c. technique with a novel, recently described complexometric post-column detection system, called 'metal-dye detection' [Mayr (1988) Biochem. J. 254, 585-591], which enabled us to identify non-radioactively labelled inositol phosphate isomers and to determine their masses. The results indicate that avian erythrocytes contain the same inositol phosphate isomers as mammalian cells. Denoted by the 'lowest-locant rule' [NC-IUB Recommendations (1988) Biochem. J. 258, 1-2] irrespective of true enantiomerism, these are Ins(1,4)P2, Ins(1,6)P2, Ins(1,3,4)P3, Ins(1,4,5)P3, Ins(1,3,4,5)P4, Ins(1,3,4,6)P4, Ins(1,4,5,6)P4, Ins(1,3,4,5,6)P5, and InsP6. Furthermore, we identified two inositol trisphosphate isomers hitherto not described for mammalian cells, namely Ins(1,5,6)P3 and Ins(2,4,5)P3. The possible position of these two isomers in inositol phosphate metabolism and implications resulting from absolute abundances of inositol phosphates are discussed.

Animals↗
PubMed1989

[Anxiety, the heart patient and the organization of psychosomatic medicine].

Using a simplified biopsychosocial model, it is possible to outline several aspects of the partly real, partly unreal anxieties of the patient with heart disease, also in connection with defense strategies. Questions regarding the formal introduction of psychosomatic medicine are raised exemplary findings in the area of heart transplants, resuscitation and denial aspects are mentioned. The medical-care system and the patient complement each other in perception and strategic handling of anxiety, partly in stabilized, partly in destabilized ways. The development of a future organisation of psychosomatic medicine must differentiate between consultant services, liaison services, working groups and independent departments. As in the analytical-therapeutical situation, the understanding of the function of defense strategies is the prerequisite to overcome the symptom, which - experienced or not experienced, expressed or not expressed - means anxiety both for patient as well as for those who work in institutions.

Anxiety↗
PubMed1988

Multichannel strain gauge telemetry for orthopaedic implants.

In vivo measurements of the loads and deformations occurring in orthopaedic implants will allow future improvements to be made. This paper describes an extremely small telemetry for long term measurements with three strain gauges and methods for an absolutely safe implant design. Developed for measuring the load at hip prostheses, the telemetry can also be used for other implants. Its size makes feasible instrumentation of devices with only slight mechanical modifications. In addition to the description of our own measuring system, the paper gives a survey on the problems of telemetrized implants, on methods for measuring spatial loads, and on the investigations of other authors. Future publications will present in vivo measurements with this telemetry, among others on hip endoprostheses.

Equipment Design↗
PubMed1988

A nonlinear finite element analysis of interface conditions in porous coated hip endoprostheses.

We used a geometrically simplified finite element model to investigate load transfer between a porous coated hip endoprosthesis and a femur. Assuming both rigidly bonded and nonlinear interfaces, we analyzed fully and partially coated stems that had coatings of different elastic moduli. Our results indicate that maximum values for relative motion in the interface between bone and implant occur for implants with the same elastic modulus as compact bone. By comparison, interface motion is reduced by about half for Co-Cr-Mo alloy stems. We also showed that the elastic modulus of the porous coating had only a small influence on bone stresses.

Biomechanical Phenomena↗
PubMed1987

Effects of stem design and material properties on stresses in hip endoprostheses.

With the aid of a three-dimensional finite element stress analysis a parameteric study of the essential aspects of the femoral component of hip endoprostheses was carried out. Various designs were investigated; these included the prosthetic stem length, the existence or non-existence of the prosthetic collar and the elastic modulus of stem and cement. Variations in the stem length have only minor effects on the stress distribution for a stem length greater than 100 mm, but the elastic modulus of the prosthetic stem has a considerable influence on the stresses. A high elastic modulus of the stem increases the stresses in the stem but it decreases stresses in the cement. The cement stresses increase with an increase in the modulus of elasticity of the cement.

Bone Cements↗
PubMed1986

Studies in stuttering as a prosodic disturbance.

In two experiments, various aspects of prosody in adult male stutterers and nonstutterers were studied. The results showed that stutterers did not speak with a generally reduced pitch pattern, they were able to place sentence accent correctly but had difficulty executing this prosodic feature, stuttering episodes were located mainly on stressed syllables, a fixed timing pattern of speech enhanced fluency, and the intervals between stressed syllables were more variable in the speech of stutterers, even in symptom-free passages, than in the speech of nonstutterers. Results support the conclusion that stuttering, seen on the symptomatic level of disfluencies produced, is a prosodic disturbance.

Adult↗
PubMed1979

[A technique for reproducible roentgenograms of the intercondylar sulcus for the study of the femoropatellar (author's transl)].

Roentgenographic documentation of certain features of FP-joint geometry and orientation may serve as guideline in deciding on the form of treatment for chondromalacia or recurrent patellar dislocation. Reproducible conditions for taking roentgen films are equally important for this purpose as well as for quantitative measurements and possible statistical work. A new positioning device for the patient's legs has been designed utilizing a parallellogram frame. The roentgenographic technique for skyline views at 30 degree, 60 degree and 90 degree inclination of the central beam relative to the femoral axis is described. The advantages over previous techniques are the ease of handling the positioning frame, the need for only vertical and horizontal adjustment of the roentgen tube, independence of the type of tube or table, reproducibility of cassette and patient positioning.

Adult↗
PubMed1978

[Walking with canes and forearm-crutches (author's transl)].

Partial weight bearing is frequently prescribed but cannot be controlled adequately. In a previous paper the change of forces at the hip joint as effected by a one sided cane was determined by instrumentation of the cane and a mechanical analysis of gait on a walkway. In the present study we looked at the conditions for control of partial weightbearing when two forearm crutches are used. Instrumented crutches and a forceplate were used. In walking with two forearm crutches the total of the ground reaction forces and the force pattern differ from those in free walking. The total of two crutch forces plus the force at the leg with partial weightbearing exceeds that caused by body weight alone. This is due to mass accelerations in a changed gait pattern. When the maximal leg force is reduced from 100% body weight to zero, the additional dynamic forces exceed those caused by body weight alone by 4%-19%. Only 2% of the additional dynamic forces act on the controlateral crutch while the rest is transmitted through the ipsilateral crutch. The crutch force pattern on the ipsilateral side depends more on individual gait characteristics than does that on the controlateral side. Load reduction is more pronounced in the late stages of the stand phase than in the early ones.

Adult↗