Biomedical subjects

J Petzäll

Publications and source records attributed to J Petzäll.

4 recordsLinked to original sources

PubMed1996

Ergonomics in parallelized car assembly: a case study, with reference also to productivity aspects.

In 1985 Volvo started the development of a new plant for the assembling of cars. This plant was situated in the town of Uddevalla in Sweden. One deliberate aim with this plant was to combine an enhanced productivity and product quality with good ergonomics conditions and improved work organization. The plant was designed with a production system where parallel work-teams of about five persons could assemble from 1/4 up to complete cars. A newly developed tilting device, a piece of equipment that could rotate, rise and lower the car body in order to facilitate assembly work, was introduced. Ergonomic analyses of postural and musculoskeletal strain showed that parallelized flow production, according to the production principles of the Uddevalla plant, was superior to traditional car assembly according to the serial flow production concept, i.e. the traditional assembly line. It was noted that this ergonomic standard was implemented without compromising productivity. In conclusion, increased knowledge and experience of parallelized production systems has been gained which should be considered in the development of future assembly plants, even though the Uddevalla factory itself was closed down in 1993.

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PubMed1996

Traversing step obstacles with manual wheelchairs.

In the public transport system, there are sometimes step obstacles, such as curbs, steps, entrance steps of vehicles, edges of lifting platforms, internal steps in vehicles, etc. This paper describes research work carried out in Sweden to specify the heights of step obstacles possible to traverse with a manual wheelchair manoeuvred by an attendant. The work included trials with the subjects manoeuvring two different kinds of wheelchairs, with dummies as occupants, over a step obstacle with adjustable height. It also included trials with a person in the wheelchair. The subjects were 20 healthy persons in the age range of 23-60 years, with no or only little experience of manoeuvring wheelchairs, chosen to represent bus drivers or other helpers. They rated their perceived feeling of effort on a 10-level rating scale with ratio properties. The occupant rated the feeling of comfort and safety in three grades. All trials were recorded using a video-camera. From the video-film, the situations and series of actions of the subjects were analysed and the length of time for each task was measured. The forces needed when traversing step obstacles with a wheelchair were calculated according to the principles of mechanics and processed by a computer for the different principal traversing situations. The results show that for the planning of systems for public transportation, where the passenger can get assistance, a step height of 50 mm is acceptable, and a step height of 100 mm can be acceptable if there is enough room to manoeuvre the wheelchair, so that it is possible to choose the most convenient way to traverse the step. Higher heights should be avoided.

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PubMed1995

The design of entrances of taxis for elderly and disabled passengers: an experimental study.

This paper presents an experimental study with the aim of finding suitable dimensions of the entrances of cars used in taxi service for disabled people. Ambulant disabled people and wheelchair users who were entitled to travel with the special transportation service and were used to travel by taxi participated in the trials. An investigation of the taxi service showed that taxis transport both ambulant disabled people and people using wheelchairs, who can move from the wheelchair to a car seat. The disabled travellers found it difficult to enter and leave the cars due to the narrow doorways. The most difficult action was the lifting of their feet into and out of the cars. In the experimental study the subjects had to get into and out of a mock-up car where the entrance could be altered by changes to the width and height of the doorway, the height of the sill, the location of the seat and the angle to which the door opens. The registration was made by video-filming, observation and interviews. The actions and duration of the different phases during the entering and exiting were analysed from the video-films. The results show that much the same entrance dimensions are required both by people confined to wheelchairs and ambulant disabled people. The paper presents suitable dimensions for the front entrances of cars in order to suit people with mobility impairments.

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PubMed1993

Ambulant disabled persons using buses: experiments with entrances and seats.

This paper describes research work carried out in Sweden to adapt buses to the requirements of ambulant disabled people. It contains an experimental study where subjects tried different entrances and seats. For the experiments a bus was rebuilt and equipped with new entrance and seating arrangements. Three categories of subjects participated: seriously ambulant disabled, representing people having severe ambulatory difficulties in their daily life; less seriously ambulant disabled, representing people that normally travel with the special transportation service; and slightly ambulant disabled, representing ordinary elderly people. The evaluation was based on observations, photographs, interviews and in some cases timing with a stopwatch. The results show that low similar steps and well-designed handrails in the bus entrance made boarding and alighting easier. The seat trials showed the importance of having suitable grab rails to allow people to pull or heave themselves up. Design requirements are presented in the paper. The Swedish Board of Transport have used the results when working out regulations to adapt public transport vehicles for use by disabled people.

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