The assessment of usability of pain medical device by physiatrists and physiotherapists: A Delphi survey.

ABSTRACT: When developing a new medical device, it is essential to assess the usability of such a device through various stakeholders.This study assessed the usability of pain medical devices through a Delphi survey administered to physiatrists and physiotherapists.A Delphi survey was conducted on the problems and improvements in hardware and software for a panel consisting of 10 physiatrists and 10 physiotherapists. A total of 3 rounds of surveys were conducted, and the third round of survey was confirmed through a Likert scale (1 = strongly agree to 5 = strongly disagree).The 2 groups generally had a common perception of the problems and improvements in pain medical devices. However, the physiatrist group mostly identified problems such as linking patient information, whereas the physiotherapist group deemed hardware problems such as device weight or connection cables as being more important (mean [standard deviation]; physiatrist, hardware 2.90 [0.93], software 2.28 [0.91] / physiotherapist, hardware 3.04 [0.84], software 3.03 [1.13]).To date, analysis has not been conducted by dividing the focus of various stakeholders using pain medical devices. The difference in view of the usability of these 2 stakeholder groups should be considered when improving the hardware or software of pain medical devices in the future. Further research is warranted to investigate other stakeholders such as patients and device developers to improve the devices.

A Randomized Trial Comparing Outcomes of 3 Types of Peripheral Intravenous Catheters.

BACKGROUND: There was an increase in peripheral intravenous catheter (PIVC) complications and adverse patient events after product conversion during the merger between a rural hospital and a larger hospital system. A review of the existing literature identified a gap in evidence evaluating 2 closed PIVC systems compared with an open PIVC system. PURPOSE: The purpose of the current project was to ascertain whether open or closed PIVCs are best for patients, staff, and the health care system in terms of 3 main criteria: quality, safety, and cost. METHODS: A prospective, 2-site randomized controlled trial was used to compare outcomes. RESULTS: There were no differences in the complication rates between catheter types. There was a statistically significant increase in blood leakage and a decrease in clinician satisfaction with the open-system catheter. CONCLUSIONS: Our project supports current clinical recommendation that a closed PIVC system, regardless of type, is not only safer and cost-effective but also preferred by patients and clinicians.

Low-flow assessment of current ECMO/ECCO2R rotary blood pumps and the potential effect on hemocompatibility.

BACKGROUND: Extracorporeal carbon dioxide removal (ECCO2R) uses an extracorporeal circuit to directly remove carbon dioxide from the blood either in lieu of mechanical ventilation or in combination with it. While the potential benefits of the technology are leading to increasing use, there are very real risks associated with it. Several studies demonstrated major bleeding and clotting complications, often associated with hemolysis and poorer outcomes in patients receiving ECCO2R. A better understanding of the risks originating specifically from the rotary blood pump component of the circuit is urgently needed. METHODS: High-resolution computational fluid dynamics was used to calculate the hemodynamics and hemocompatibility of three current rotary blood pumps for various pump flow rates. RESULTS: The hydraulic efficiency dramatically decreases to 5-10% if operating at blood flow rates below 1 L/min, the pump internal flow recirculation rate increases 6-12-fold in these flow ranges, and adverse effects are increased due to multiple exposures to high shear stress. The deleterious consequences include a steep increase in hemolysis and destruction of platelets. CONCLUSIONS: The role of blood pumps in contributing to adverse effects at the lower blood flow rates used during ECCO2R is shown here to be significant. Current rotary blood pumps should be used with caution if operated at blood flow rates below 2 L/min, because of significant and high recirculation, shear stress, and hemolysis. There is a clear and urgent need to design dedicated blood pumps which are optimized for blood flow rates in the range of 0.5-1.5 L/min.

An Analysis of Cost-Effectiveness of Stents Used in the Treatment of Coronary Artery Disease

Background: There is only limited information about the cost-effectiveness of drug-eluting stents compared with bare-metal stents in Turkey. Aims: To evaluate bare-metal and drug-eluting stents used in the treatment of coronary artery disease from the perspective of the reimbursement institution with cost-effectiveness analysis. Study Design: Retrospective cost-effectiveness analysis. Methods: In our study, 329 patients diagnosed with coronary artery disease and treated with bare-metal or drug-eluting stents in the cardiology clinics of a public university hospital between January 1 and December 31, 2016 were investigated. Bare-metal and drug-eluting stents used in the treatment of coronary artery disease were evaluated retrospectively with cost-effectiveness analysis from the perspective of the reimbursement institution. Results: The cost of treatment with a bare-metal stent was 2,131.41 Turkish Liras, and the cost of treatment with a drug-eluting stent was 3,546.14 Turkish Liras; the Quality Adjusted Life Years value of treatment with a bare-metal stent was 0.8371, and the Quality Adjusted Life Years value of treatment with a drug-eluting stent was 0.8924. All these data were analyzed by decision tree. As a result of decision tree analysis, the weighted cost of treatment with a bare-metal stent was 2,340.71 Turkish Liras and weighted Quality Adjusted Life Years value was 0.8332; and the weighted cost of treatment with drug-eluting stent was 3,970.90 Turkish Liras and the weighted Quality Adjusted Life Years value of the treatment with drug-eluting stent was 0.8911. With these values, the additional cost-effectiveness ratio was calculated as 28,179.12 Turkish Liras per acquired Quality Adjusted Life Years. The additional cost-effectiveness ratio is in the first zone in the cost-effectiveness plane and below the very threshold of cost-effectiveness. Conclusion: In our study, it was concluded that drug-eluting stents are cost effective compared with bare-metal stents in the treatment of coronary artery disease. Considering the cost and effectiveness of the drug-eluting stent, it is thought that increasing reimbursement for this technology by the reimbursement agency would be beneficial for the service provider.

The development of search filters for adverse effects of medical devices in medline and embase.

BACKGROUND: Objectively derived search filters for adverse drug effects and complications in surgery have been developed but not for medical device adverse effects. OBJECTIVE: To develop and validate search filters to retrieve evidence on medical device adverse effects from ovid medline and embase. METHODS: We identified systematic reviews from Epistemonikos and the Health Technology Assessment (hta) database. Included studies within these reviews that reported on medical device adverse effects were randomly divided into three test sets and one validation set of records. Using word frequency analysis from one test set, we constructed a sensitivity maximising search strategy. This strategy was refined using two other test sets, then validated. RESULTS: From 186 systematic reviews which met our inclusion criteria, 1984 unique included studies were available from medline and 1986 from embase. Generic adverse effects searches in medline and embase achieved 84% and 83% sensitivity. Recall was improved to over 90%, however, when specific adverse effects terms were added. CONCLUSION: We have derived and validated novel search filters that retrieve over 80% of records with medical device adverse effects data in medline and embase. The addition of specific adverse effects terms is required to achieve higher levels of sensitivity.

First responder communication in CBRN environments: FIRCOM-CBRN study.

INTRODUCTION: Recent terror attacks and assassinations involving highly toxic chemical weapons have stressed the importance of sufficient respiratory protection of medical first responders and receivers. As full-face respirators cause perceptual-motor impairment, they not only impair vision but also significantly reduce speech intelligibility. The recent introduction of electronic voice projection units (VPUs), attached to a respirator, may improve communication while wearing personal respiratory protection. OBJECTIVE: To determine the influence of currently used respirators and VPUs on medical communication and speech intelligibility. METHODS: 37 trauma anaesthetists carried out an evaluation exercise of six different respirators and VPUs including one control. Participants had to listen to audio clips of a variety of sentences dealing with scenarios of emergency triage and medical history taking. RESULTS: In the questionnaire, operators stated that speech intelligibility of the Avon C50 respirator scored the highest (mean 3.9, ±SD 1.0) and that the Respirex Powered Respiratory Protective Suit (PRPS) NHS-suit scored lowest (1.6, 0.9). Regarding loudness the C50 plus the Avon VPU scored highest (4.1, 0.7), followed by the Draeger FPS-7000-com-plus (3.4, 1.0) and the Respirex PRPS NHS-suit scored lowest (2.3, 0.8). CONCLUSIONS: We found that the Avon C50 is the preferred model among the tested respirators. In our model, electronic voice projection modules improved loudness but not speech intelligibility. The Respirex PRPS NHS-suit was rated significantly less favourably in respect of medical communication and speech intelligibility.

Validation in the General Population of the iHealth Track Blood Pressure Monitor for Self-Measurement According to the European Society of Hypertension International Protocol Revision 2010: Descriptive Investigation.

BACKGROUND: High blood pressure is one of the most common reasons why patients seek assistance in daily clinical practice. Screening for hypertension is fundamental and, because hypertension is identified only when blood pressure is measured, accurate measurements are key to the diagnosis and management of this disease. The European Society of Hypertension International Protocol revision 2010 (ESH-IP2) was developed to assess the validity of automatic blood pressure measuring devices that are increasingly being used to replace mercury sphygmomanometers. OBJECTIVE: We sought to determine whether the iHealth Track blood pressure monitor meets ESH-IP2 requirements for self-measurement of blood pressure and heart rate at the brachial level and is appropriate for use in the general population. METHODS: This study was a descriptive investigation. ESH-IP2 requires a total number of 33 participants. For each measure, the difference between observer and device blood pressure and heart rate values is calculated. In all, 99 pairs of blood pressure differences are classified into 3 categories (≤5, ≤10, and ≤15 mm Hg), and 99 pairs of heart rate differences are classified into 3 categories (≤3, ≤5, and ≤8 beats/min). We followed these protocol procedures in a convenience sample of 33 participants. RESULTS: iHealth Track fulfilled ESH-IP2 requirements and passed the validation process successfully. We observed an absolute difference within 5 mm Hg in 75 of 99 comparisons for systolic blood pressure, 78 of 99 comparisons for diastolic blood pressure, and 89 of 99 comparisons for heart rate. The mean differences between the test and standard readings were 4.19 (SD 4.48) mm Hg for systolic blood pressure, 3.74 (SD 4.55) mm Hg for diastolic blood pressure, and 1.95 (SD 3.27) beats/min for heart rate. With regard to part 2 of ESH-IP2, we observed a minimum of 2 of 3 measurements within a 5-mm Hg difference in 29 of 33 participants for systolic blood pressure and 26 of 33 for diastolic blood pressure, and a minimum of 2 of 3 measurements within a 3-beat/min difference in 30 of 33 participants for heart rate. CONCLUSIONS: iHealth Track readings differed from the standard by less than 5, 10, and 15 mm Hg, fulfilling ESH-IP2 requirements. Consequently, this device is suitable for use in the general population.

A New Device for Securing Sternal Wires After Median Sternotomy: Biomechanical Study and Retrospective Clinical Assessment.

OBJECTIVE: Morbidity due to sternotomy continues to be a significant clinical problem. Poor approximation of the sternum may lead to complications such as sternal dehiscence, infection, and pain. A device to assist in tensioning and twisting standard steel wires during sternal closure has been developed (TORQ sternal closure device). Manually tightened interrupted wire closures were compared with those tightened and secured with the aid of the device. Performance of the device was assessed clinically. METHODS: Four cardiovascular surgeons performed manual and device-assisted closures on a biofidelic model. Closure force was measured to determine the residual force and its intraoperator variation. A retrospective review of patients treated before and after the introduction of the device was conducted. Predicted and actual outcomes were compared for the two groups (manual closure and device-assisted closure). RESULTS: Biomechanical testing measured a 75% increase in residual closure force (P < 0.001) and a significant reduction in the variability of the closure force (P = 0.045) for device-assisted closures compared with manual closures. In the retrospective study, 3 of 173 manually closed patients had sterile sternal dehiscence and 1 of 173 had a deep sternal wound infection. In the device closure group, 2 of 127 had a sterile sternal dehiscence and no deep sternal wound infections were reported. No other device-related serious adverse events were reported. CONCLUSIONS: Biomechanical data showed stronger, more consistent closure forces with the device. The retrospective data attest to the performance of the device.

Rear-facing versus forward-facing child restraints: an updated assessment.

OBJECTIVES: The National Highway Traffic Safety Administration and the American Academy of Pediatrics recommend children be placed in rear-facing child restraint systems (RFCRS) until at least age 2. These recommendations are based on laboratory biomechanical tests and field data analyses. Due to concerns raised by an independent researcher, we re-evaluated the field evidence in favour of RFCRS using the National Automotive Sampling System Crashworthiness Data System (NASS-CDS) database. METHODS: Children aged 0 or 1 year old (0-23 months) riding in either rear-facing or forward-facing child restraint systems (FFCRS) were selected from the NASS-CDS database, and injury rates were compared by seat orientation using survey-weighted χ2 tests. In order to compare with previous work, we analysed NASS-CDS years 1988-2003, and then updated the analyses to include all available data using NASS-CDS years 1988-2015. RESULTS: Years 1988-2015 of NASS-CDS contained 1107 children aged 0 or 1 year old meeting inclusion criteria, with 47 of these children sustaining injuries with Injury Severity Score of at least 9. Both 0-year-old and 1-year-old children in RFCRS had lower rates of injury than children in FFCRS, but the available sample size was too small for reasonable statistical power or to allow meaningful regression controlling for covariates. CONCLUSIONS: Non-US field data and laboratory tests support the recommendation that children be kept in RFCRS for as long as possible, but the US NASS-CDS field data are too limited to serve as a strong statistical basis for these recommendations.

Comparison of Metal and Plastic Disposable Laryngoscope Blade with Reusable Macintosh Blade in Difficult and Inhalation Injury Airway Scenario: A Manikin Study.

BACKGROUND: Single-use plastic blades (SUPB) and single-use metal blades (SUMB) for direct laryngoscopy and tracheal intubation have not yet been compared with reusable metal blades (RUMB) in difficult airway scenarios. OBJECTIVE: The purpose of our manikin study was to compare the effectiveness of these different laryngoscope blades in a difficult airway scenario, as well as in a difficult airway scenario with simulated severe inhalation injury. METHODS: Thirty anesthetists performed tracheal intubation (TI) with each of the three laryngoscope blades in the two scenario manikins. RESULTS: In the inhalation injury scenario, SUPB were associated with prolonged intubation times when compared with the metal blades. In the inhalation injury scenario, both metal laryngoscope blades provided a quicker, easier, and safer TI. In the difficult airway scenario, intubation times were significantly prolonged in the SUPB group in comparison to the RUMB group, but there were no significant differences between the SUPB and the SUMB. In this scenario, the RUMB demonstrated the shortest intubation times and seems to be the most effective device. CONCLUSIONS: Generally, results are in line with previous studies showing significant disadvantages of SUPB in both manikin scenarios. Therefore, metal blades might be beneficial, especially in the airway management of patients with inhalation injury.

Safety assessment characteristics of pedestrian legform impactors in vehicle-front impact tests.

This study investigated the characteristics of safety assessment results of front-area vehicle impact tests carried out using the Transport Research Laboratory (TRL) legform impactor and a flexible legform impactor (FLEX legform impactor). Different types of vehicles (sedan, sport utility vehicle, high-roof K-car, and light cargo van) were examined. The impact locations in the study were the center of the bumper and an extremely stiff structure of the bumper (i.e., in front of the side member) of each tested vehicle. The measured injury criteria were normalized by injury assessment reference values of each legform impactor. The test results for center and side-member impacts indicated that there were no significant differences in ligament injury assessments derived from the normalized knee ligament injury measures between the TRL legform impactor and the FLEX legform impactor. Evaluations made using the TRL legform impactor and the FLEX legform impactor are thus similar in the vehicle safety investigation for knee ligament injury. Vehicle-center impact test results revealed that the tibia fracture assessments derived from the normalized tibia fracture measures did not significantly differ between the TRL legform impactor and the FLEX legform impactor. However, for an impact against an extremely stiff structure, there was a difference in the tibia fracture assessment between the FLEX legform impactor and the TRL legform impactor owing to their different sensor types.

Statistical inference involving binomial and negative binomial parameters.

Statistical inference about two binomial parameters implies that they are both estimated by binomial sampling. There are occasions in which one aims at testing the equality of two binomial parameters before and after the occurrence of the first success along a sequence of Bernoulli trials. In these cases, the binomial parameter before the first success is estimated by negative binomial sampling whereas that after the first success is estimated by binomial sampling, and both estimates are related. This paper derives statistical tools to test two hypotheses, namely, that both binomial parameters equal some specified value and that both parameters are equal though unknown. Simulation studies are used to show that in small samples both tests are accurate in keeping the nominal Type-I error rates, and also to determine sample size requirements to detect large, medium, and small effects with adequate power. Additional simulations also show that the tests are sufficiently robust to certain violations of their assumptions.

Inference and sample size calculation in the fit assessment of filtering facepiece respirators.

Filtering facepiece respirators have recently been cleared by the U.S. Food and Drug Administration (FDA) for use by the general public in public health medical emergencies such as pandemic influenza. In the fit assessment of these devices it is important to distinguish between the two sources of variability: population heterogeneity and random fluctuations over repeated donnings. The FDA Special Controls Guidance Document (SCGD) which describes these devices and their evaluation, recommends that the fit performance of a filtering facepiece respirator be evaluated in terms of the proportion of users who will receive a specified level of protection 95% of the time. A point estimator of this proportion is easily obtained under an analysis of variance model, and the SCGD suggests bootstrap as one possible approach to interval estimation. This paper describes a closed-form procedure to obtain confidence intervals and provides sample size formulas. Simulation results suggest that the proposed procedure performs well in realistic settings and compares favorably to two simple bootstrap procedures.

[Navigated osteosynthesis of the proximal femur. An experimental study]. / Navigierte Osteosynthese des proximalen Femurs. Eine experimentelle Studie.

Screw position in femoral head has been considered the most important predictive factor for mechanical failure in pertrochanteric osteosynthesis, and correct positioning is assisted by fluoroscopic control. Although fluoroscopy leads to precise and reproducible results, it is associated with scattered radiation to the patient and surgical staff. Computer-assisted surgery (CAS) may be an alternative in means of achieving precise screw insertion with a low radiation dose. We designed a laboratory study in which artificial proximal femora were submitted to insertions of a dynamic hip screw (DHS) and an anti-rotational screw (ARS). Three set-ups were tested: (1) conventional implantation with two simultaneous C-arms using a guide wire; (2) drilling and implantation controlled by CAS solely with a 3.2-mm drill bit, then insertion of a guide wire and drilling for the dynamic hip screw; (3) after navigated drilling (3.2 mm) a fluoroscopic control was performed. Five variables were used comparing methods and surgeons: operation time, radiation time, tip-apex distance (TAD), and the insertion neck-shaft angles of DHS and ARS. Considering TAD as a precision parameter, CAS led to screw insertion as accurate as with fluoroscopic control, with a reduction of radiation time up to 93%.

Stereotactic synchrotron microbeam radiotherapy.

Highly collimated synchrotron x-ray beams with high fluence rate may be used in stereotactic radiotherapy of brain tumours. Several monochromatic x-ray beams having uniform microscopic thickness ie (microplanar beams) are directed to the center of the tumour from varying directions, delivering lethal dose to the target volume while sparing normal cells. This proposed technique takes advantage of the hypothesised repair mechanism of capillaries between closely spaced microplanar beam zones. The sharply dropping lateral dose profile of a microplanar beam provides low scattered dose to the off-target interbeam volume. In close proximity to the target volume, relatively high secondary electron doses close to the edge of the beams overlap and produce a high dose region between angled beams. This allows precise targeting and prevents gradual blurring of the higher and lower dose margins in the target volume. The advantages of stereotactic microplanar beam radiotherapy will be lost as the dose between microplanar beams exceeds the tolerance dose of the dose limiting tissues. Therefore to minimize the risks of delayed radiation damage it is essential to optimize the interbeam doses inside a human head phantom. The EGS4 Monte Carlo code is used to calculate the lateral dose profiles and depth dose of a 100 keV single microplanar beam in the phantom. A general equation for absorbed dose as a function of depth and lateral distances is derived for the single beam. Several microplanar beams are directed into the target volume at the center of the phantom. Using the equation, maximum dose on the beam axis (primary + total scattered dose) and the minimum interbeam dose (total scattered dose) are calculated at different depths and an isodose map of the phantom is obtained. A stereotactic microplanar beam radiotherapy model is proposed for a 10 mm diameter (approximately spherical) tumour at the center of the phantom.

Optimisation of electron cone design in high energy radiotherapy using the Monte Carlo method.

Cylindrical solid-walled steel electron collimators are used at the Royal Adelaide Hospital with a Siemens KD2 Mevatron accelerator to produce circular fields 2-8 cm in diameter. The cones are used in contact with the patient's skin. A flat treatment field is required at the treatment depth and the beam should also satisfy the uniformity standards as specified by the International Electrotechnical Commission (IEC). However, the seven and eight centimetre diameter cones provided by the manufacturer did not meet these specifications. In particular, the maximum dose relative to the depth-dose maximum on the central axis exceeded 126% as compared with the IEC recommended value of 109%, when used with a 21 MeV electron beam. Cone modifications were previously investigated by others with the results demonstrating some improvement in the 'horn' (as it appears on surface dose profiles) but still not satisfying IEC requirements. In the present paper the EGS4 code was used to model the existing treatment head geometry and cones, as well as new suggested modifications to the cone. The results of the simulation for the existing cone geometry corresponded closely to previously obtained measurements. The suggested collimator modifications involved a plastic insert along the internal wall of the collimator. Variations of the insert width and height were simulated for a 21 MeV electron beam and the results plotted to indicate the optimal insert dimensions. A plastic insert with the dimensions taken from one of the best models was produced and tested. The measurements showed close agreement with the simulation results (for the 'horn' height, dose within 1% and radial position within 2 mm) and improvement of the "maximum ratio of absorbed dose" from 126% before modification to 108% with the plastic insert. The tested insert was also simulated for a 12 MeV electron beam, to see whether permanent fitting of such an insert would have a deleterious effect at lower energies. Neither penetration nor flatness was significantly compromised, with a small penalty being a slight increase in the central axis dose near the surface.

Purchase and design preferences for cardiac pacemakers.

This analysis of the criteria for selecting pacemakers highlights the design features that medical practitioners and patients believe are important in the devices they use and their reasons for brand selection.

Case study:-calender covers in a hospital laundry. Energy Efficiency Office, Department of Energy.

Whipps Cross Hospital laundry is typical of many laundries, both in the commercial sector and NHS, in that it uses old calenders which are substantially less efficient than more modern machines. Although calendering is a relatively efficient method of moisture removal, the quantity of flatwork processed by this laundry means that the calendering section uses a significant proportion of the total laundry energy consumption. In common with many other laundries, the four calenders were producing a great deal of airborne lint which required expensive cleaning at regular intervals, and made the working environment uncomfortable, reducing the performance and morale of the operators. In an effort to improve this situation, covers were fitted to all the calenders in early 1989. These were claimed to improve energy efficiency by reducing the heat losses from the calender's upper surfaces and to improve the local atmosphere by reducing the quantity of lint and moist air escaping into the laundry. This case study examines the savings (both energy savings and others) achieved by the installation of the covers, and assesses any drawbacks which may have become apparent after extended use.