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Biomedical subjects

P Harber

Publications and source records attributed to P Harber.

At least 37 records · Page 2Linked to original sources
PubMed1994

Industrial hygienist as a clinical consultant.

The roles of industrial hygienists outside the traditional industrial setting have been expanding. This paper discusses the industrial hygienist's direct and active involvement with patients in the clinic setting. The types of roles played by the industrial hygienists in an occupational health clinic are categorized based upon experience in one academic clinic. Although experience demonstrated that there is an important function for the industrial hygienist as a clinical consultant, unresolved issues, ranging from payment to staff privileging, interfere with widespread participation.

Adult↗
PubMed1994

Work placement and worker fitness. Implications of the Americans with Disabilities Act for pulmonary medicine.

Pulmonary physicians have a significant role in assessing the ability of individuals with respiratory impairments to be placed in jobs or retain current jobs. The Americans with Disabilities Act mandates a high level of rational thought and justification for any recommendation against placement or work retention. This article reviews criteria for determining if an individual with a respiratory impairment or disability can currently and safely perform a job and if there is substantial direct threat of future risk. In addition, methods of modifying the workplace to accommodate individuals with respiratory disabilities are discussed.

Persons with Disabilities↗
PubMed1994

Primary care role in preventing occupational and environmental respiratory disease.

Occupational and environmental respiratory disease is relatively common and is usually of great significance for the individual and the broader community. With proper evaluation of both the individual and the exposure site, a specific diagnosis can be established or ruled out during the early stages. Primary care physicians are vital for the early diagnosis of occupational and environmental respiratory disease in individual patients and in populations. Furthermore, primary care practitioners may have a significant role in formal group-based medical surveillance programs for respiratory disease. In addition to diagnosing and treating such disorders, there is a major role for rational and effective counseling of individuals and communities about possible effects of agents ranging from air pollution to zeroconium. In such instances, objective data communicated in language that is easily understood can be invaluable.

Asbestos↗
PubMed1994

Subject-based rating of hand-wrist stressors.

Subject-based rating (SBR) methods (eg, Borg Scales) have been applied to lifting and exertion estimation. SBR methods were applied to hand-wrist motions in this controlled experimental study of rapid motion. Seven normal volunteers performed lift actions with several combinations of wrist position (flexion-extension), repetition frequency, force, and grip type (precision vs power) using an experimental apparatus. Wrist position and frequency were confirmed using an electrogoniometer. Subjects rated the tasks along 5 scales. Analysis showed that grip type had the predominant effect on the subjective ratings, but the other factors were also rated. However, cycle times between 3 and 8 seconds were not well differentiated. The study indicates that SBR does validly reflect actual stressors and suggests that SBR may be useful for "screening" jobs for more intensive study.

Adult↗
PubMed1993

Work-related symptoms and checkstand configuration: an experimental study.

Supermarket checkers are known to be at risk of upper-extremity cumulative trauma disorders. Forty-two experienced checkers checked a standard "market basket" of items on an experimental checkstand. The counter height could be adjusted (high = 35.5, low = 31.5 inches), and the pre-scan queuing area length (between conveyor belt and laser scanner) could be set to "near" or "far" lengths. Each subject scanned under the high-near, high-far, low-near, and low-far conditions in random order. Seven ordinal symptom scales were used to describe comfort. Analysis showed that both counter height and queuing length had significant effects on symptoms. Furthermore, the height of the subject affected the degree and direction of the impact of the checkstand configuration differences. The study suggests that optimization of design may be experimentally evaluated, that modification of postural as well as frequency loading may be beneficial, and that adjustability for the individual may be advisable.

Adult↗
PubMed1993

Supermarket checker motions and cumulative trauma risk.

The relationship between specific motions and symptoms consistent with upper extremity cumulative trauma disorders (UECTDs) was investigated in 50 supermarket checkers. Each completed a questionnaire concerning UECTD symptoms; four composite symptom indices were derived: any arm symptoms, hand-wrist-lower arm (S-DIST), upper arm, and symptoms specifically associated with carpal tunnel syndrome (S-SPC). Each participant was videotaped on at least two occasions while performing checking work. Analysis of these tapes assigned each subject a composite motion index for each of the following motions: wrist flexion, wrist extension, body (lumbar) flexion, pronation, grip type, and tendency to lift objects. "Positive" symptom status was defined by a score in the upper quartile for the symptom index. Relationships between an individual's motion indices and symptom indices were analyzed by determining the percent of subjects "positive" for symptoms in each quartile of motion index, by rank correlation, and by regression of symptom scores on principal components of motions. Trends toward relationship of wrist flexion and extension, lumbar flexion, and pronation with S-DIST and S-SPC were noted. Principal components regression confirmed that extension and flexion were related to these two symptom outcomes. This study suggests that postural loading can be determined on an individual basis in a meaningful fashion and that interventions that decrease such loading may be beneficial. It supports the role of certain repetitive motions as causes of UECTD symptoms.

Adult↗
PubMed1993

Personal risk assessment under the Americans with Disabilities Act. A decision analysis approach.

A decision analysis model was designed and implemented to facilitate job placement decisions. It identified relevant input parameters such as typical probability and severity of adverse outcomes for three targets--the worker himself or herself, the public, and productivity. In addition, specific factors that differentiate this specific decision instance from the "typical" are identified, including a person's specific health history, job site risk modifiers, and possible accommodation methods. Relevant societal values are also integrated, including relative importance of the three target groups (person, public, productivity) and discounting of the importance of future events. The system also includes a calculation engine to quantitatively integrate these input parameters for any number of events and modifiers to yield a single cost (expected negative utility value) for the instant situation. Cost represents risk of substantial harm, not financial cost. The decision analysis model is illustrated using a progressively more complex series of decision examples. In addition, the method of sensitivity analysis is applied, determining the extent to which the outcome is affected by varying the value assigned to an uncertain input parameter. This decision analysis approach is useful both as a heuristic (explaining the process) and as an aid in decision-making for a person with disabilities. The recently implemented Americans with Disabilities Act requires that a rational approach be utilized in such decisions, and such a model may facilitate this process.

Accidents, Occupational↗
PubMed1992

Upper extremity symptoms in supermarket workers.

Upper extremity symptoms in supermarket workers, particularly those who performed checking using laser scanners, were evaluated using a questionnaire administered by trained interviewers to 124 supermarket workers. Summary indices of exposure (short-term and long-term) as well as indices of past personal illnesses and personal activities were employed. Outcome data were summarized by four composite symptom indices. Chi square and logistic regression analyses demonstrated that hours of checking work in the preceding 2 weeks and cumulative weighted years of work were associated with adverse upper extremity symptoms. Symptoms involved both the proximal and distal parts of the upper extremities.

Adult↗
PubMed1992

Assessing occupational disability from asthma.

Asthma is receiving increased attention as a cause of occupational disability, both by virtue of occupational causation and by interactions between work and pre-existing asthma. Reasons for the failure of pneumoconiosis-related disability evaluation systems to be applicable to asthma are discussed, including the inherent variability of asthma, its responsiveness to treatment, and its variable time course with respect to occupational exacerbation. A distinction is made between the trait of airway hyperresponsiveness and the disease of asthma. A scheme for organizing reports about asthma-related disability clearly specifies the questions that need to be addressed.

Airway Resistance↗
PubMed1992

Respiratory disability. The uncoupling of oxygen consumption and disability.

In the past it was believed that respiratory disability could be objectively assessed by comparing the measured O2 consumption requirement of the job with the subjects' measured or estimated maximal oxygen consumption. More recently, it has become clear that this "classic" paradigm does not completely apply to all situations. This article reviews recent aspects of respiratory disability assessment.

Asthma↗
PubMed1992

The new workplace accommodation guidelines.

The Scientific Board of the California Medical Association presents the following inventory of items of progress in occupational medicine. Each item, in the judgment of a panel of knowledgeable physicians, has recently become reasonably firmly established, both as to scientific fact and important clinical significance. The items are presented in simple epitome, and an authoritative reference, both to the item itself and to the subject as a whole, is generally given for those who may be unfamiliar with a particular item. The purpose is to assist busy practitioners, students, researchers, or scholars to stay abreast of these items of progress in occupational medicine that have recently achieved a substantial degree of authoritative acceptance, whether in their own field of special interest or another. The items of progress listed below were selected by the Advisory Panel to the Section on Occupational Medicine of the California Medical Association, and the summaries were prepared under its direction.

Persons with Disabilities↗
PubMed1992

The ergonomic challenge of repetitive motion with varying ergonomic stresses. Characterizing supermarket checking work.

Many jobs leading to a risk of cumulative trauma do not have highly stereotyped motions. This study developed and employed a novel method of ergonomic characterization to describe quantitatively the actions associated with grocery checking. Fifty workers were videotaped for three 15-minute segments each. Eight object types were selected to represent the variety of items in a supermarket. Nine types of motion were coded for each of the eight objects for 10 replications for each subject. The motions coded were: grip type (power versus pinch), wrist flexion, wrist extension, radial deviation, ulnar deviation, supination, pronation, body (lumbar) flexion, and drag versus lift. The results were then weighted according to relative frequency of the object type. In this manner, an ergonomic risk index can be assigned to each specific object type. This method permits identification of objects presenting the greatest risk. It also allows specificity of preventive interventions (object redesign, work practice change) as well as providing a quantitative measure to evaluate work station redesign. Furthermore, it has the potential of quantitatively describing the risk of each individual worker.

Cumulative Trauma Disorders↗
PubMed1991

The structure of expert diagnostic knowledge in occupational medicine.

Development of an artificial intelligence expert system for diagnosing occupational lung disease requires explicit specification of the structure of knowledge necessary in clinical occupational medicine independent of the process by which the knowledge is utilized. Furthermore, explicit recognition of sources of uncertainty is necessary. Seven categories of knowledge define the diagnostic knowledge base in occupational pulmonary medicine. These include four objects (jobs, industries, exposures, and diseases) and three relationships between pairs of objects. This analysis demonstrates some of the unique aspects of occupational medicine expertise.

Algorithms↗
PubMed1991

Physiologic and subjective effects of respirator mask type.

The effect of alternate airflow path designs on full-face mask air-purifying respirators was assessed in 14 healthy volunteers during submaximal exercise. Respirator designs included no respirator (N), full-face mask, dual-cartridge with no nasal deflector (FN), full-face mask respirator with nasal deflector (FD), and a powered air-purifying respirator (PA). Physiologic effects were measured by using respiratory inductive plethysmography and subjective responses by two visual analog scales. There were significant effects of airflow path design upon the physiologic parameters of ventilation, tidal volume, and mean flow rate. There were no significant physiologic or subjective differences between the full-face mask respirators with and without the nasal deflector in place. The PA had less physiologic impact than the nonpowered models but did not show significant subjective benefit. The study suggests that both subjective and objective physiologic responses must be utilized in assessing respirator design.

Adult↗
PubMed1991

Respirator physiology research: answers in search of the question.

Adverse effects of respirators have been the focus of considerable research over the past decade. Individual research projects have generally focused on one specific category of effects: ventilatory, respiratory control, work limitation, subjective discomfort, psychologic effects, thermal loading, and cardiovascular changes. Most were studied in experimental laboratory situations rather than in actual worksites. Very little attention has been given to compliance with use and actual effectiveness in preserving health. Inasmuch as many types of effects have been demonstrated, there is a need to carefully define which type(s) of effects is/are most important for respirator design selection and worker medical certification in particular situations. In general, respirators should be assessed for their effect on all relevant variables.

Adaptation, Physiological↗
PubMed1991

Artificial intelligence-assisted occupational lung disease diagnosis.

An artificial intelligence expert-based system for facilitating the clinical recognition of occupational and environmental factors in lung disease has been developed in a pilot fashion. It utilizes a knowledge representation scheme to capture relevant clinical knowledge into structures about specific objects (jobs, diseases, etc) and pairwise relations between objects. Quantifiers describe both the closeness of association and risk, as well as the degree of belief in the validity of a fact. An independent inference engine utilizes the knowledge, combining likelihoods and uncertainties to achieve estimates of likelihood factors for specific paths from work to illness. The system creates a series of "paths," linking work activities to disease outcomes. One path links a single period of work to a single possible disease outcome. In a preliminary trial, the number of "paths" from job to possible disease averaged 18 per subject in a general population and averaged 25 per subject in an asthmatic population. Artificial intelligence methods hold promise in the future to facilitate diagnosis in pulmonary and occupational medicine.

Artificial Intelligence↗
PubMed1991

Relative effects of flow-resistive and pressure-biased respiratory loading.

The effects of pressure-biased breathing (PBB), which simulates positive pressure respirator use, were studied in 15 volunteer subjects during laboratory exercise. PBB was compared with inspiratory resistance: dead space (ID) load and a no-load (N) situation. PBB had adverse subjective effects comparable with those of ID. Physiologically, PBB led to a small decrease in inspiratory time and an increase in expiratory time as well as an increase in the intensity of ventilatory effort as measured by the mean inspiratory flow rate. It is postulated, based on these findings, that PBB has significant effects on the resting lung volume, leading to both physiologic and subjective consequences.

Adult↗