Open-source electronic data capture system offered increased accuracy and cost-effectiveness compared with paper methods in Africa

Objectives

Existing electronic data capture options are often financially unfeasible in resource-poor settings or difficult to support technically in the field. To help facilitate large-scale multicenter studies in sub-Saharan Africa, the African Partnership for Chronic Disease Research (APCDR) has developed an open-source electronic questionnaire (EQ).

Study Design and Setting

To assess its relative validity, we compared the EQ against traditional pen-and-paper methods using 200 randomized interviews conducted in an ongoing type 2 diabetes case–control study in South Africa.

Results

During its 3-month validation, the EQ had a lower frequency of errors (EQ, 0.17 errors per 100 questions; paper, 0.73 errors per 100 questions; P-value ≤0.001), and a lower monetary cost per correctly entered question, compared with the pen-and-paper method. We found no marked difference in the average duration of the interview between methods (EQ, 5.4 minutes; paper, 5.6 minutes).

Conclusion

This validation study suggests that the EQ may offer increased accuracy, similar interview duration, and increased cost-effectiveness compared with paper-based data collection methods. The APCDR EQ software is freely available (https://github.com/apcdr/questionnaire).

Can technology help to reduce underage drinking? Evidence from the false ID laws with scanner provision

Underage drinkers often use false identification to purchase alcohol or gain access into bars. In recent years, several states have introduced laws that provide incentives to retailers and bar owners who use electronic scanners to ensure that the customer is 21 years or older and uses a valid identification to purchase alcohol. This paper is the first to investigate the effects of these laws using confidential data from the National Longitudinal Survey of Youth, 1997 Cohort (NLSY97). Using a difference-in-differences methodology, I find that the false ID laws with scanner provision significantly reduce underage drinking, including up to a 0.22 drink decrease in the average number of drinks consumed by underage youth per day. This effect is observed particularly in the short-run and more pronounced for non-college students and those who are relatively younger. These results are also robust under alternative model specifications. The findings of this paper highlight the importance of false ID laws in reducing alcohol consumption among underage youth.

In situ measurements of phytoplankton fluorescence using low cost electronics

Chlorophyll a fluorometry has long been used as a method to study phytoplankton in the ocean. In situ fluorometry is used frequently in oceanography to provide depth-resolved estimates of phytoplankton biomass. However, the high price of commercially manufactured in situ fluorometers has made them unavailable to some individuals and institutions. Presented here is an investigation into building an in situ fluorometer using low cost electronics. The goal was to construct an easily reproducible in situ fluorometer from simple and widely available electronic components. The simplicity and modest cost of the sensor makes it valuable to students and professionals alike. Open source sharing of architecture and software will allow students to reconstruct and customize the sensor on a small budget. Research applications that require numerous in situ fluorometers or expendable fluorometers can also benefit from this study. The sensor costs US$150.00 and can be constructed with little to no previous experience. The sensor uses a blue LED to excite chlorophyll a and measures fluorescence using a silicon photodiode. The sensor is controlled by an Arduino microcontroller that also serves as a data logger.

Remanufacturing and energy savings

Remanufactured products that can substitute for new products are generally claimed to save energy. These claims are made from studies that look mainly at the differences in materials production and manufacturing. However, when the use phase is included, the situation can change radically. In this Article, 25 case studies for eight different product categories were studied, including: (1) furniture, (2) clothing, (3) computers, (4) electric motors, (5) tires, (6) appliances, (7) engines, and (8) toner cartridges. For most of these products, the use phase energy dominates that for materials production and manufacturing combined. As a result, small changes in use phase efficiency can overwhelm the claimed savings from materials production and manufacturing. These use phase energy changes are primarily due to efficiency improvements in new products, and efficiency degradation in remanufactured products. For those products with no, or an unchanging, use phase energy requirement, remanufacturing can save energy. For the 25 cases, we found that 8 cases clearly saved energy, 6 did not, and 11 were too close to call. In some cases, we could examine how the energy savings potential of remanufacturing has changed over time. Specifically, during times of significant improvements in energy efficiency, remanufacturing would often not save energy. A general design trend seems to be to add power to a previously unpowered product, and then to improve on the energy efficiency of the product over time. These trends tend to undermine the energy savings potential of remanufacturing.

A framework for evaluating the economic performance of recycling systems: a case study of North American electronics recycling systems

A framework for evaluating the economic performance of a recycling system is proposed, and data from four electronics recycling systems in North America (Alberta, California, Maine, and Maryland) that use different operating models are used as a preliminary test of the framework. The framework is built around a hierarchy of descriptors that clarify the function of the system components under consideration and the activities, cash flow elements, and resources within those functions; costs are incurred by specific stakeholders. Data from each system on fee and mass collection amounts and collection, processing, and management costs are used to create a matrix of several net costs for stakeholders within each system. Although all four systems are relatively new, thereby making data collection a challenge, some preliminary insights can be gleaned from comparing the systems. Processing costs vary significantly in the four systems, with Alberta and California having the highest reimbursement rates for processing. Alberta and California also have relatively high system management costs, but processors are generally quite satisfied with the systems. Maine has an additional cost for consolidation that is an implicit management cost because of the need to count incoming products by manufacturer.

Towards woven logic from organic electronic fibres

The use of organic polymers for electronic functions is mainly motivated by the low-end applications, where low cost rather than advanced performance is a driving force. Materials and processing methods must allow for cheap production. Printing of electronics using inkjets or classical printing methods has considerable potential to deliver this. Another technology that has been around for millennia is weaving using fibres. Integration of electronic functions within fabrics, with production methods fully compatible with textiles, is therefore of current interest, to enhance performance and extend functions of textiles. Standard polymer field-effect transistors require well defined insulator thickness and high voltage, so they have limited suitability for electronic textiles. Here we report a novel approach through the construction of wire electrochemical transistor (WECT) devices, and show that textile monofilaments with 10-100 mum diameters can be coated with continuous thin films of the conducting polythiophene poly(3,4-ethylenedioxythiophene), and used to create micro-scale WECTs on single fibres. We also demonstrate inverters and multiplexers for digital logic. This opens an avenue for three-dimensional polymer micro-electronics, where large-scale circuits can be designed and integrated directly into the three-dimensional structure of woven fibres.

A low-cost bipolar pulse generator for high-frequency ultrasound applications

A design of a low-cost bipolar pulse generator for high-frequency (HF) ultrasound applications is presented. The pulse generator can produce N cycle (1-255 cycles) bipolar pulses with center frequency over 60 MHz. The measured pulse amplitude was over 160 Vpp, and the pulse ringing was less than 0.3 Vpp (i.e., signal-to-ring ratio is 55 dB). The pulser can be used in high-frequency ultrasound Doppler and B-mode imaging applications with arrays.

Technology. Behind the hype

Having proven successful in retail, military and other industries, radio frequency identification is making its way into health care. But can the technology live up to the bold claims?

Cost evaluation of the use of conventional and electronic identification and registration systems for the national sheep and goat populations in Spain1,2

A cost model was developed to compare different implementation strategies of the new European Commission regulation for sheep and goat identification and registration (EC 21/2004) in Spain. Strategies were as follows: 1) conventional identification (CID) by two ear tags; 2) electronic identification (EID) by one bolus and one ear tag; and 3) mixed CID and EID strategy (MID), consisting of CID for fattening stock and EID for breeding stock. Complete and simplified implementations of the regulation were considered as options. Total costs per animal identified for all strategies and options varied according to the implementation option, ranging from Euros 2.48 and 4.64. The EID was the most expensive strategy (Euros 4.47 to 4.64) for all implementation options. Cost of CID and MID strategies ranged from Euros 2.63 to 2.98 and from Euros 2.48 to 3.03, respectively. The model was submitted to a sensitivity analysis without considering extra benefits of sheep and goat identification. Critical values for which the cost of MID equaled CID depended on strategy and option, and ranged from 7.5 to 11.5% for ear tag losses and from Euros 1.80 to 3.30 for bolus price. In conclusion, the use of a mixed strategy combining conventional ear tags (animals intended for slaughter) and electronic boluses (breeding stock) seems to be an affordable strategy that fulfills the European Commission regulation requirements for the identification of sheep and goats in Spain. Price reductions for devices and equipment would make the full electronic identification strategy less expensive in the future.

A low-cost, multi-channel, EMG signal processing amplifier

There is a growing need in studies of movement control to expand the number of muscles from which EMG activity is recorded during performance of motor tasks. Optimal viewing and analysis of this EMG activity requires signal processing which provides adjustable gain and baseline offset as wells as selectable AC coupling, rectification and filtering. This paper presents a low-cost circuit that combines two channels of EMG signal processing capability in one module.

Footswitch system for measurement of the temporal parameters of gait

Gait analysis relies upon accurate measurement of initial and end foot contact times. These times act as a reference point for correlating all other gait data and as a mean of distinguishing normal and pathologic gait. We have developed a simple, inexpensive footswitch system that provides accurate estimates of the start and end of stance phase for sequential steps. The estimates of the beginning and end of stance phase do not require custom footwear, extensive calibration, or precise placement of the sensor within the shoe. The system is based on a commercially available transducer and can be readily reproduced for use in a laboratory setting for less than $50. We describe this system, as well as its validation. To assess the accuracy of this footswitch system, we compared footswitch based estimates of initial and end foot contact times with those obtained using a force platform as 10 people took 30 steps (10 each at slow, normal and fast walking rates) across a force platform. Both estimates coincided within +/- 10 ms (mean: 0 +/- 3 ms; N = 300) for the start of stance phase and within +/- 22 ms (mean: -1 +/- 8 ms; N = 300) for the end of stance phase. For stance duration, the differences ranged from -24 to 28 ms (mean: 1 +/- 10 ms; N = 300). In combination, these measures can be used to estimate stance duration to within 3% of force plate determined values for steps with stance durations ranging from 446 to 1594 ms. Estimates of swing and stride duration also are within 5% of force plate determined values. This system should therefore prove to be a useful tool for augmenting laboratory based investigations of gait.