Usability in telemedicine systems-A literature survey.

INTRODUCTION: The rapid development of sensors and communication technologies enable the growth of new innovative services in healthcare, such as Telemedicine. An essential ingredient in the development of a telemedicine system and its final acceptance by end users are usability studies. The principles of usability engineering, evaluations and telemedicine are well established, and it may contribute to the adoption and eventually deployment of such systems and services. An in-depth usability analysis, including performance and attitude measures, requires knowledge about available usability techniques, and is depending on the amount of resources. Therefore it is worth investigating how usability methods are applied in developing telemedicine systems. Our hypothesis is: with increasing research and development of telemedicine systems, we expect that various usability methods are more equally employed for different end-user groups and applications. METHOD: A literature survey was conducted to find telemedicine systems that have been evaluated for usability or ease of use. The elements of the PICO framework were used as a basis for the selection criteria in the literature search. The search was not limited by year. Two independent reviewers screened all search results first by title, and then by abstract for inclusion. Articles were included up to May 2015. RESULTS: In total, 127 publications were included in this survey. The number of publications on telemedicine systems significantly increased after 2008. Older adults and end-users with cardiovascular conditions were among largest target end-user groups. Remote monitoring systems were found the most, in 90 publications. Questionnaires are the most common means for evaluating telemedicine systems, and were found in 88 publications. Questionnaires are used frequently in studies focusing on cardiovascular diseases, Parkinson's disease and older adult conditions. Interviews are found the most in publications related to stroke. In total 71% of the publications were trial-orientated and the remaining process orientated. An increase in telemedicine research, development and applications is found worldwide, with the majority of publications conducted in America. DISCUSSION AND CONCLUSION: Monitoring patients in their homes can lead to better healthcare at lower costs which implies an increased demand of new healthcare strategies like telemedicine. We expected that with the increase in telemedicine research and development, a greater range of usability methods would also be employed in the included publications. This is not the case. Researchers employed questionnaires as a preferred usability method for each type of telemedicine system and most end-users. However, in process-orientated studies a greater range of usability evaluations were applied, with fewer differences found in the amount of publications for each evaluation method. Questionnaires enable researchers to evaluate a system quickly on end users, as it requires less expertise on the evaluation method compared to the other methods. They are easily distributed and are customizable. The use of questionnaires is therefore an evaluation method of choice for a variety of telemedicine systems and end-users.

Toxic alcohol but not intoxicated--a case report.

Ethylene glycol is recognised as a potentially lethal poison if ingested. Approximately 100 mls may be fatal in a 70 kg adult. Current Toxbase guidelines are the accepted standard of treatment of such poisonings in the United Kingdom. These guidelines suggest that symptoms of significant poisoning are usually present within 30 minutes of ingestion i.e. ataxia, dysarthria, nystagmus, nausea and vomiting, haematemesis, coma and convulsions. In the absence of these symptoms, metabolic acidosis or ethylene glycol concentration more than 8 mmol/l a single loading dose of ethanol and observation were the recommended course of management until recently. We report a case of a patient who remained relatively asymptomatic for almost 24 hours but then developed clinical symptoms with marked metabolic acidosis and renal impairment requiring intensive treatment including haemodialysis.

[Safety of an influenza-split-vaccine in children]. / Verträglichkeit einer Influenza-Spalt-Vaccine bei Kindern.

BACKGROUND: The aim of this study was to investigate the safety of the split-product influenza vaccine Begrivac(R), containing the recommended virus strains for the influenza season 1998/99. PATIENTS: Eighty-three children aged 6 months - 12 years were enrolled in the study. METHODS: Adverse events (AEs) were reported for up to 21 days after the last immunization. A hemagglutination assay was performed of blood samples taken before and after vaccination. RESULTS: Only mild (40 %) to moderate and mainly local reactions (redness, swelling, induration and pain) were reported. Seroprotection after the first immunisation was reached against influenza strain A (H1N1) in 75 % of the vaccinees, against strain A (H3N2) in 83 % and against strain B in 33 %. After the second immunisation, 96 % of the population achieved seroprotection against A (H1N1), 100 % against A (H3N2) and 96 % against B. CONCLUSIONS: The influenza split vaccine is safe and effective in children.

Does the dangerous dogs act protect against animal attacks: a prospective study of mammalian bites in the accident and emergency department.

This comparative prospective study of mammalian bites attending one urban Accident and Emergency department before the implementation of the Dangerous Dogs Act 1991 and again 2 years later, was to see the effect of the Act on the pattern of injury. The study comprised a simple questionnaire detailing the injury, the implicated species, and the treatment or referral if applicable. In both groups studied (before and after implementation of the Act) 134 consecutive bites were recorded, contributing 1.2 per cent and 1.23 per cent of total attendances during these respective periods. Dogs were found to bite most commonly: in the pre-legislative group 73.9 per cent were due to dog bites and in the post-legislation group 73.1 per cent. In both groups studied, human bites occurred as the second most common mammalian bite; 17.9 per cent in the pre-legislation group and 12.7 per cent in the post-legislation group. Human bites were as common as those from the most implicated breed of dog. In general human bites were found to require more active treatment and specialist referral. The study demonstrates the vast majority of such injuries are treated within Emergency departments. This study also shows how dangerous breeds compare with others that bite, demonstrating that these breeds contribute to only a small proportion of these injuries. This comparative study clearly demonstrates little impact on rate of attendances for such injuries since the introduction of the 1991 Act. If legislation aims to reduce and prevent injury from animal bites, in its present form it does little to protect the public; this study suggests a wider control of the dog population may be required.

Myocardial enzyme depletion in infarcted human hearts: infarct size and equivalent tissue mass.

Myocardial activities of several enzymes were measured in infarcted and non-infarcted areas of heart sections obtained from eight patients who died after acute myocardial infarction. Similar data were obtained from four patients with cardiovascular disorders who died from causes other than myocardial infarction and from six patients without previously known heart disease. It was found that both non-infarcted and infarcted tissue samples contained considerably altered enzyme activities. This finding explains the low correlations between enzymatic and histological estimates of infarct size previously reported. However, when the residual myocardial activities of different enzymes were compared with each other, a close correlation was found between creatine kinase, alpha-hydroxybutyrate dehydrogenase, and aspartate aminotransferase. It appears that the pathological changes in the myocardial activities of these enzymes may be explained by the phenomenon of diluted myocardium. This indicates that myocardial injury, as estimated from plasma enzyme activities, may still be expressed meaningfully in gram equivalents of healthy myocardium.

DNA sequence of the 5' terminus containing the replication origin of parvovirus replicative form DNA.

The nucleotide sequence of the 5' terminus of the parvovirus H-1 was determined. There are two orientations of the 242-base-pair terminal palindrome in native replicative form DNA, one inverted with respect to the other. Adjacent to the terminal palindrome is an AT-rich region that is noncoding and contains a 55-base-pair tandem repeat. The addition mutant of H-1, DI-1, was also sequenced in this region and shown to have three copies of the tandem repeat sequence. Similarly, the related parvovirus H-3 contains only one copy of this repeat sequence. This region contains the replication origin for parvovirus replicative form DNA replication. Some of the implications of these results are discussed.

The effect of gamma-carboxyglutamate residues on the enzymatic properties of the activated blood clotting factor X. I. Activity towards synthetic substrates.

The esterolytic and amidolytic properties of activated blood coagulation factor X (factor Xa) and the analogous decarboxy species were compared in order to find out if the gamma-carboxyglutamic acid residues influence the function of the active centre. It was found that the two proteins (1) showed similar kinetic parameters when titrated with p-nitrophenyl-p'-guanidinobenzoate hydrochloride (2) had a similar Km and kcat for various synthetic chromogenic tri- and tetrapeptides and (3) were inhibited in the same way by benzamidine. Further it was observed that (4) Ca2+ inactivates factor Xa, but has no influence on the amidase activity of decarbyxyfactor Xa (5) factor V prevents Ca2+-induced inactivation of factor Xa but does not influence the amidase activity of both factor Xa and decarboxyfactor Xa. We conclude that the interaction of the gamma-carboxyglutamic acid residues with Ca2+ in factor X has no measurable influence on the properties of the active site per se.

Activation of decarboxyfactor X by a protein from Russell's viper venom. Purification and partial characterization of activated decarboxyfactor X.

1. Incubation of decarboxyfactor X with the factor X-activating enzyme from Russell's Viper venom revealed the generation of amidase activity towards Bz-Ile-Glu-Gly-Arg-pNA, but not of activity in blood coagulation. 2. The rate of activation of both factor X and decarboxyfactor X depends on the ability of the zymogens to bind Ca2+. The relationship between Ca2+ concentration and velocity of the activation reaction is sigmoid in the case of factor X, but hyperbolic with decarboxyfactor X. 3. Activated decarboxyfactor X was purified by powder column electrophoresis. 4. Identical changes of primary structure accompanied the activation of factor X and decarboxyfactor X. Identical molecular weight and common antigenic determinants were found in factor Xa and decarboxyfactor Xa. The amino acid composition was identical except for 12 glutamic acid residues in decarboxyfactor Xa and gamma-carboxyglutamic acid residues in factor Xa. 5. Unlike factor X, activated factor X has a very low electrophoretic mobility in the presence of Ca2+ at pH 8.6. This is probably due to self association of factor Xa under the influence of Ca2+. The electrophoretic mobility of activated decarboxyfactor X is only slightly decreased compared to decarboxyfactor X in the presence of Ca2+.

Purification and properties of the phenprocoumon-induced decarboxyfactor X from bovine plasma. A comparison to normal factor X.

1. By a procedure involving adsorption to barium sulfate, chromatography on DEAE-Sephadex and QAE-Sephadex and preparative polyacrylamide gel electrophoresis, decarboxyfactor X was purified from plasma of phenprocoumon-treated cows. No contaminants could be detected in the final preparation by polyacrylamide gel electrophoresis and zone-electrophoresis. 2. The molecular weight of decarboxyfactor X, as determined by sodium dodecyl sulfate polyacrylamide gel electrophoresis is approximately 55 000, which is equal to that of factor X. The protein consists of two polypeptide chains with molecular weights of 44 000 and 17 000. 3. Decarboxyfactor X has antigenic determinants in common with normal factor X. 4. The amino acid composition and aminoterminal amino acids of normal factor X and decarboxyfactor X are identical. 5. Less than one residue of gamma-carboxyglutamate could be detected per mole of decarboxyfactor X. 6. In the absence of Ca2+, normal factor X has a slightly higher electrophoretic mobility than decarboxyfactor X. In the presence of Ca2+ the mobility of factor X decreases considerably while the mobility of decarboxyfactor X remains unaltered.

Demonstration of three anomalous plasma proteins induced by a vitamin K antagonist.

With the aid of precipitating antibodies against the bovine coagulation factors II, IX, and X three immunologically non-identical proteins can be demonstrated that are induced by the administration of a vitamin K antagonist (phenprocoumon). Each of these proteins is immunologically identical to one of three coagulation factors mentioned. The proteins differ from normal coagulation factors (a) by a lack of biological activity; (b) by a faster anodic migration rate in the presence of Ca2+. The proteins appear in the plasma concomitantly with the decrease of the normal factor.