Patrick Patterson

Design and evaluation of a sensory feedback system that provides grasping pressure in a myoelectric hand

Providing accurate sensory information to the individual with a myoelectric limb is of great importance for improving device use in a wide variety of tasks. A number of feedback systems presently being investigated rely on either vibrotactile or electrotactile skin stimulation, which does not provide sensory patterns similar to those in a natural grasping hand. A prototype system was developed to enhance sensory information transfer by using a technique in which the feedback modality (pressure) was the same as the grasping pressure. The present study compared the developed system (pressure) with vibrotactile feedback, vision, and compounds of these three modes. It was found that the pressure-pressure concept reduced grasping pressure replication errors and error variability.

Tactile stimulus receptor for a hand prosthesis

A means and method for tactile stimulus reception for use with a myoelectric prosthesis includes a pressure transducer positioned on the prosthesis. The pressure transducer senses the level of pressure experienced by the gripping portion of the prosthesis and converts the sensed pressure into a corresponding signal. A pressure stimulus member is positionable upon the user and creates a pressure stimulus proportionally corresponding to the sensed pressure of the pressure transducer by utilizing the signal from the pressure transducer. The pressure stimulus is tactile so that the user can be given direct tactile pressure stimulation corresponding directly with the pressure sensed by the pressure transducer.

The effects of load knowledge on stresses at the lower back during lifting

This study investigated the effects of load uncertainty on the lifting characteristics of 40 male volunteers during the initial portion of a lift. Twenty subjects were experienced weightlifters while another 20 were subjects who had never lifted weights nor held a job that required them to on a regular basis. The subjects each lifted a container 20 × 45 × 40 cm, with handles, from floor to waist height 12 times with loads of 68, 10·2 or 13·6 kg. The loads were lifted under conditions of either havingor not having verbal and visual knowledge of the load magnitude prior to the lift. The subjects were allowed to perform the lift in a manner of their choosing. A 2 (groups) × 3 (loads) × 2 (load knowledge) ANOVA was performed on the data. Maximim force (Fmax) value analysis revealed group and technique differences. The experienced lifters had lower stress levels at L4/L5 and utilized two technique strategies that were dependent upon the load knowledge condition, whereas the non-lifters used the same strategy f...

Icon and user interface design for emergency medical information systems: A case study

A usable medical information system should allow for reliable and accurate interaction between users and the system in emergencies. A participatory design approach was used to develop a medical information system in two Turkish hospitals. The process consisted of task and user analysis, an icon design survey, initial icon design, final icon design and evaluation, and installation of the iconic medical information system with the icons. We observed work sites to note working processes and tasks related to the information system and interviewed medical personnel. Emergency personnel then participated in the design process to develop a usable graphical user interface, by drawing icon sketches for 23 selected tasks. Similar sketches were requested for specific tasks such as family medical history, contact information, translation, addiction, required inspections, requests and applications, and nurse observations. The sketches were analyzed and redesigned into computer icons by professional designers and the research team. A second group of physicians and nurses then tested the understandability of the icons. The user interface layout was examined and evaluated by system users, followed by the systems installation. Medical personnel reported the participatory design process was interesting and believed the resulting designs would be more familiar and friendlier.

Low back stress, muscle usage, and the appearance of transient load movement during manual lifting

Abstract Neuromuscular involvement should be considered in biomechanical evaluations of a workers job-related stresses as a potential aid to understanding and reducing the rising incidence of low back problems in industry. Because such interactions have seldom been investigated in multisegmental movements, the present study was undertaken to determine the effects of the involvement of the neuromuscular system during lifting by creating conditions in which subjects had prior knowledge (PK) of a loads magnitude as well as when they had no prior knowledge (NK). Two groups of subjects, experienced and inexperienced lifters ( N =40), lifted loads varying from 6.8 to 13.6 kg under both the PK and NK conditions. Results indicated that two general patterns of load movement were used by the subjects: smooth and oscillatory (irregular transient), with higher peak L4/L5 forces and higher peak trunk movements found in the oscillatory pattern. Significant differences on all stress values were demonstrated by the inexperienced lifters. The inclusion of lift preparation and load knowledge considerations in training programmes and biomechanical models is recommended.

Usability of pointing devices for office applications in a moving off-road environment.

Three pointing devices (mouse, touch pad, touch screen) were evaluated for usability with a Windows-style menu selection task while in a moving off-road environment. A pilot study determined which commercially available devices had the potential to promote good performance in the environment. Eighteen subjects performed a series of complex pointing tasks that simulated the use of a standard application in a moving tractor. The devices were also rated for subjective usability. The mouse and the touch screen produced the best performances, with the mouse receiving the best subjective usability ratings. The participants had a significantly lower performance with the touch pad, which also received lower ratings in the subjective usability ratings.

Hydraulic Transducer for Assessing Grip Strength; RESEARCH NOTE

An instrument for assessing grip strength and endurance is described. The instrument provides an alternative type of measurement, as compared with conventional dynamometers (e.g., lever action dynamometers). It may be particularly useful for assessing the capabilities of handicapped workers.

Grip and Forearm Position Effects on Tests of Static and Dynamic Upper Body Endurance

Abstract The effects of grip and forearm position on two tests of upper body muscular endurance were investigated in 109 male subjects 18–21 years of age. Subjects were systematically presented 12 tasks: six pull-up and six straight-arm hang grip and forearm variations. Each of the six tasks for both endurance tests represented a different combination of grip (thumb over bar and thumb under bar) and forearm position (pronated, supinated and semi-pronated). Task results were analyzed utilizing 2 × 3 (grip × forearm) ANOVA with repeated measures on the two factors. Analysis of pull-up data revealed that the semi-pronated and supinated forearm positions were not statistically different from each other, but superior to the pronated condition. Results of straight-arm hang performance revealed a significant difference between grips at the semi-pronated position, with the “thumb under bar” being superior. Results for forearm positions at grips indicated a significant difference for the “thumb under bar,” with th...

Relationship and comparison of selected anthropometric measures to muscular endurance and strength in children aged 3-5 years

This study investigated the relationships and differences between grip strength, hang time (upper body muscular endurance), sum of skinfold measures, body weight and height among 103 children 3-5 years of age. The results indicated that the only significant (P less than 0.05) difference between groups on skinfold was at the umbilical site, where the 3-year-olds measurements were larger than the 4- or 5-year-old group. All strength and body weight measures increased with age and in each case were significantly (P less than 0.01) different between groups. Analysis of the correlation matrix representing key variables revealed no correlations which could be regarded as high practical indicators; thus it was concluded that body weight, height, and selected skinfold measurements were not practical indicators of grip strength and muscular endurance.

Application of Transition-Phase Management Model for an Electronic Health Record System Implementation: A Case Study

Abstract The implementation of an electronic health record (EHR) system requires changes in processes, which in turn requires management of the transition phase to EHR systems. EHR system implementations are composed of various subsystems that manage medical, clerical, administrative, and billing data. The complexity of an EHR implementation in each of these subsystems is affected by current organizational capabilities, the number of places it is deployed, and whether the deployments will be in series or in parallel, among other factors. This begs the question of how to determine the objective function and related strategy to conduct an EHR implementation. In this article, an evaluation of the previously-proposed transition-phase management model is presented through three different EHR process change case studies. Analysis of the adequacy and accuracy of the model is provided, and guidelines for interpretation and implementation are suggested.