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Biomedical subjects

G R Fernie

Publications and source records attributed to G R Fernie.

At least 37 records · Page 2Linked to original sources
PubMed1987

Migration, attachment, and orientation of human gingival fibroblasts to root slices, naked and porous-surfaced titanium alloy discs, and Zircalloy 2 discs in vitro.

Cell migration, attachment, and orientation of cultured human gingival fibroblasts (HGF) were measured in relation to four types of specimens: Ti-6Al-4V alloy discs with either ground surfaces or porous structured surfaces, and Zr alloy discs (Zircalloy 2) with either ground surfaces or surfaces modified by being heated to form a thicker oxide cover. Surface-demineralized and non-demineralized root slices were used as controls. Initial cell attachment was measured by means of a 51Cr assay, and cell attachment and orientation following migration by an assay that measures development of the resulting refractile material in relation to the specimen. No significant difference between initial cell attachment to Ti alloy and control demineralized root slices could be detected after one hr using the 51Cr assay. However, with the second assay, cell attachment and orientation at three, seven, 10, and 14 days were significantly higher in relation to surface-demineralized root slices than to all of the metal discs and the non-demineralized root slices. While cell attachment to the surface-ground Ti alloy discs appeared to be higher than that to the porous-surfaced Ti alloy discs at three days and seven days, cell orientation to the porous-surfaced Ti alloy discs and the non-demineralized root slices at days 7, 10, and 14 was greater than that to all of the other metal discs. These data suggest that surface geometry could affect attachment and orientation of cells in vitro.

Alloys↗
PubMed1986

An anatomical comparison of the human and bovine thoracolumbar spine.

The bovine spine has been frequently selected as the model for in vitro mechanical studies. A comparative anatomical study has been presented describing important differences and similarities between selected areas in the adult human and calf thoracolumbar spinal segment. Differences in column length and curvature were observed. The total length of the adult bovine vertebral column was found to be on average 209 cm longer than the adult human spine. Equivalent thoracolumbar lengths were obtained by selecting 6-8 week-old dairy calves, which because of their young age had the benefit of consistent bone density. The bovine spine was found to have only a single cervical lordotic curve and a single thoracolumbar kyphotic curve (2). A quantitative comparison of selected dimensions of vertebrae T6, T12, and L3 was performed, and significant findings are discussed. The bovine spinous processes were found to be on average 111% greater in length at level T6, which contributed to a 56% greater total anterior/posterior length at this level in comparison to the vertebrae of an adult male. A 23% greater bovine intertransverse length at level L3 was also shown. The orientation of the human and bovine superior facets, while being in the same general plane and direction, varied as much as 10.5 and 107% at vertebral level L3 on the two axes measured. These significantly different measurements were considered important factors that can influence experimental results when using the bovine spine as a model.

Anatomy, Comparative↗
PubMed1986

Results of the pilot phase of a clinical evaluation of computer aided design of trans-tibial prosthesis sockets.

This study served as a pilot to develop the methodology for a larger number of clinical trials. Ten trans-tibial amputees compared sockets made by conventional methods with sockets made using computer aided socket design (CASD). Prosthetists, paired for experience, fitted each subject with one prosthesis using each method. A preferred socket was selected by the subject on the basis of comfort without knowledge of the method by which the socket was designed. Prosthetists also evaluated the sockets. Three subjects preferred sockets built using CASD and one subject preferred the conventional socket only slightly more than the CASD socket. Six subjects clearly preferred the conventional fitting.

Aged↗
PubMed1986

Biomechanical study of full-contact karate contrasted with boxing.

It is known that boxers suffer a characteristic cumulative brain injury from repeated blows to the head that correlates well with the number of bouts fought. Much less is known about full-contact karate (kickboxing), which is relatively new. In full-contact karate, punches and kicks are actually landed, rather than being focused to culminate just short of an opponent, as practiced in traditional karate. Although a combatant can win on points, the surest means of victory is a knockout. Consequently, fighters strive to land blows to the head. To investigate the relative force of kicks and punches, a dummy head was mounted 175 cm above the floor (to simulate a 50th-percentile man standing erect) and 125 cm above the floor (to simulate the man in a crouched position) on a universal joint permitting motion about three axes. The mechanism was contrived to provide constant rotational stiffness, and springs provided constant restorative moments about the three axes. The texture of soft tissue was simulated by a mask of visco-elastic foamed materials. Fourteen karate experts punched and kicked the dummy. Accelerometer measurements in the 90- to 120-G range indicated that safety-chops (hand protectors) and safety-kicks (foot padding) did not reduce acceleration of the dummy. Ten-ounce boxing gloves mitigated peak acceleration to some extent. Kicks and punches produced accelerations in the same range. Violent acceleration of the head by any means produces injury. The authors conclude that, if full-contact karate is widely practiced, cases of kickboxer's encephalopathy will soon be reported.

Acceleration↗
PubMed1985

Shape sensing for computer aided below-knee prosthetic socket design.

Shape sensing is useful in the computer aided prosthetic fitting process for two purposes. 1. To input characteristic prosthetic shapes that have been developed over the years through the experience of prosthetists. 2. To provide an accurate and rapid measurement of the anatomical shape of the stump. This paper describes two instruments which have been built to meet these objectives.

Amputation Stumps↗
PubMed1984

Shape sensing as an educational aid for student prosthetists.

An automatic method of measuring the shape of plaster replicas of residual limbs has been developed. This instrument enables the full three-dimensional shape to be digitized and stored on computer. The shape modifications produced by student prosthetists are examined by requesting the computer to draw sections of the unmodified replica with corresponding sections following modification superimposed. This paper reports experiences with the use of this instrument as a teaching aid for student prosthetists.

Allied Health Personnel↗
PubMed1983

Urodynamic characterization of incontinence in the elderly by bladder volume.

Incontinence in the elderly patient usually is of the urgency pattern owing to inappropriate detrusor contraction often termed detrusor instability. We herein describe a bladder volume-based method of urodynamic assessment that may help to characterize subsets of incontinent patients with detrusor instability. The conventional parameters of flow, pressure and electromyography are more difficult to measure and may be less appropriate for selection of therapy.

Aged↗
PubMed1982

The relationship of postural sway in standing to the incidence of falls in geriatric subjects.

A double-blind study was undertaken to determine the relationship (if one exits) between the extent of postural sway in standing of individual elderly subjects and their frequency of falling. A total of 205 subjects were studied; their average age was 81.8 years. Thirty per cent of the men, and 46% of the women, had one or more falls; the proportion of all subjects with one or more falls was 42%. The average speed of sway was significantly greater (P less than 0.05) for those who fell one or more times in a year than for those who did not fall. In this group of institutionalized elderly, there was no sex-related difference in the mean speed of sway; moreover, no age-related trend was demonstrated by the regression of mean speed upon age for all subjects. The mean speed of sway even for the non-fallers was found to be greater than that measured in a sample of non-institutional elderly subjects studied in the past. Thus, mean speed of postural sway was found to be only of statistical value for determining the risk of falling among these institutionalized elderly. We found postural sway to be an indicator of a tendency to fall, but the difference was less than might have been expected. No trend of increasing postural sway correlating with the increased frequency of falls was found.

Accidents↗
PubMed1982

Volume fluctuations in the residual limbs of lower limb amputees.

This study evaluated residual limb volume fluctuations of new and mature amputees in order to better plan for definitive limb prostheses. A measurement system based on a water displacement technique was used to measure cross-sectional area profiles of lower extremity amputation residual limbs. Reliable data were obtained for 32 of the 49 subjects participating in this study. Residual limb shrinkage cannot be characterized by any single pattern and therefore the date for fitting of a final prosthesis cannot be predicted precisely from regular volume measurements. Every amputee studied demonstrated an increase in body weight. Changes in residual limb volume early postoperatively were dictated by interaction of shrinkage and opposite effect of weight gain . Mature amputation limbs were observed to fluctuate in volume, and these fluctuations tended to correspond to body weight changes. For 3 general patterns of volume change observed early postoperatively, the best estimate of time to fit a final prosthesis appears to be about 150 days postamputation.

Adolescent↗
PubMed1981

Urinary dysfunction in a geriatric long-term care population: prevalence and patterns.

More complete data on th prevalence and types of urinary dysfunction in geriatric institutional patients are essential for the management of their urologic problems. Over a 13-month period, a prospective study was conducted of all new admissions to a hospital for long-term care. Eighty percent (277/347) of the newly admitted patients were geriatric (65 or older). Urinary dysfunction was identified in 69.3 percent of the geriatric group; 38.3 percent were incontinent, 20.2 percent bore a urinary diversion device, and 10.8 percent were symptomatic without incontinence. Obtaining reliable information about urologic status posed a significant problem, particularly as 27 percent of the subjects had a mental disorder, including organic brain syndrome or confusion. Thirty percent of all patients questioned were unable to give any history of their own health status. Questioning of both staff and patient to determine reliability of the data revealed that the given information was correct in 77 percent of patients who acknowledged genitourinary dysfunction, and in 83 percent of those who denied it. The study failed to elicit useful data concerning the specificity of symptoms, urologic history, diagnosis and management of urinary dysfunction in this series of geriatric patients under long-term institutional care.

Aged↗
PubMed1979

An assessment of a system to monitor the activity of patients in a rehabilitation programme.

The need for an objective quantitative method of monitoring performance in the natural environment for use in a rehabilitation programme is discussed. A system of monitoring the number of steps taken has been developed for an amputee programme as a first attempt towards this goal. Instrumentation consists of an inexpensive foot switch, a storage unit and a retrieval unit. Early clinical experience indicates this system may be of value in the rehabilitation programme by (1) indicating low or unusual activity and alerting clinical staff to identify the cause. (2) Restricting the over-anxious patient when excessive activity is contra-indicated. (3) Identifying poor use of the prosthesis in the home environment. (4) Providing motivation for patients to set personal goals. (5) Acting as a base line for the evaluation of research and development of new techniques.

Activities of Daily Living↗
PubMed1978

An instrument for monitoring stump oedema and shrinkage in amputees.

A new system for measuring the cross-sectional area profiles of amputation stumps and whole limbs has been designed at the Amputee Research Centre. The instrument consists of a cylindrical tank supported on an elevator. The tank is raised to the height of the amputation stump and filled with water. A graph of the cross-sectional area profile of the amputation stump is generated by a mini-computer as the elevator descends. The cross-sectional area (A) is calculated from the expression: formula: (see text) where Hw = height of water in the tank He = height of the elevator Ac = a constant, related to the size of the measuring tank. This paper describes the instrument, which may find application in many other areas where there is a need to study shape.

Adult↗
PubMed1978

Visual input: its importance in the control of postural sway.

A new and measurable parameter in the study of static equilibrium is described. Using a minicomputer, the locus of postural sway was measured during 1 minute periods in 144 volunteer subjects, including 105 control subjects and 39 persons with above-knee amputations. It was hypothesized that the above-knee amputee group had lost a relatively predictable degree of proprioception and kinesthetic sense. Vestibular mechanisms were normal and, therefore, constant in both groups. Using a simple arithmetic formula, the effect of such loss of proprioception was estimated by comparing the amputee group with the nonamputee group, while the contribution of visual input was estimated by comparing both groups with their eyes open and closed. Using this parameter, no clear age dependency was demonstrated. The mean locus of sway for the amputee group was the same as the nonamputee group with the eyes open. However, a comparison of the eyes open/eyes closed ratio in both groups demonstrated a significantly greater increase for the amputee group than for control subjects (p less than 0.001). In the future, mean locus of sway might provide a useful clinical method of measurement and the eyes open/eyes closed ratio might provide a simple and useful method to communicate the dependency upon vision in individual patients.

Adolescent↗
PubMed1978

Postural sway in amputees and normal subjects.

The postural sway of amputees was investigated quantitatively in fifty patients with above-the-knee amputations and in twenty-nine patients with below-the-knee amputations. The factors evaluated were: (1) the mean speed of sway: (2) the range of movement in the sagittal and coronal planes; and (3) the dependence on vision as indicated by the ratio of eyes-open to eyes-closed values. The results demonstrated that in amputees there is an increased dependence on vision for maintenance of the erect posture. Postural sway in patients with below-the-knee amputations was found to be significantly greater than that in those with above-the-knee amputations. Postural sway increased with age; but the visual dependence for the control of postural sway was independent of age.

Age Factors↗
PubMed1977

A percutaneous implant using a porous metal surface coating for adhesion to bone and a velour covering for soft tissue attachment: results of trials in pigs.

A percutaneous implant for the attachment of an artificial limb has been designed and tested in 14 pigs. Firm fixation to bone was achieved with the porous-surface layered metal intramedullary stem design in some cases. Dacron velour was used at the soft tissue interface. Evidence of soft tissue ingrowth was seen. However, the velour was unable to maintain adequate epithelial adhesion to form an anatomical seal and a barrier to bacteria.

Animals↗