Custom-made Instrument Research Articles

Differences in muscle activity of extrinsic and intrinsic foot muscles in toe grip and push-down movements of the great toe

Toe flexor strength is generated primarily by the flexor hallucis longus (FHL) of the extrinsic foot muscles (EFMs) and the plantar intrinsic foot muscles (PIFMs) of the great toe. Toe flexion methods can be broadly classified into toe grip (TG) and toe push-down (TP). Additionally, TP's interphalangeal joint (IPJ) position may influence the FHL and PIFMs activity ratios. This study aimed to elucidate the differences in the muscle activity and muscle activity ratios of the FHL and AbdH during TG, TP with IPJ flexion (TPIF), and TP with IPJ extension (TPIE).Surface electromyography and a custom-made instrument were used to measure the FHL and AbdH muscle activity during TG, TPIF, and TPIE of the great toe in 28 healthy men. The muscle activity and AbdH/FHL muscle activity ratio in the three conditions were statistically compared.The FHL activity was significantly higher during TG and TPIF than during TPIE. The AbdH muscle activity was significantly higher during TPIF and TPIE than that during TG. The AbdH/FHL muscle activity ratio was significantly higher for TPIE, TPIF, and TG in that order.This study showed that the FHL and AbdH muscle activity differed depending on the TG and TP of the great toe, and that the AbdH/FHL muscle activity ratio was different in the IPJ position. These results suggest that selecting a toe flexion method according to the target muscle when measuring and training the great toe flexor strength is important.

Comparison of a Custom-Made Inexpensive Air Permeability Tester with a Standardized Measurement Instrument

The air permeability of a textile fabric belongs to the parameters which characterize its potential applications as garments, filters, airbags, etc. Calculating the air permeability is complicated due to its dependence on many other fabric parameters, such as porosity, thickness, weaving parameters and others, which is why the air permeability is usually measured. Standardized measurement instruments according to EN ISO 9237, however, are expensive and complex, prohibiting small companies or many universities from using them. This is why a simpler and inexpensive test instrument was suggested in a previous paper. Here, we show correlations between the results of the standardized and the custom-made instrument and verify this correlation using fluid dynamics calculations.

Mid-Infrared Photothermal Spectroscopy for the Detection of Caffeine in Beverages.

Caffeine is the most widely consumed stimulant and is the subject of significant ongoing research and discussions due to its impact on human health. The industry's need to comply with country-specific food and beverage regulations underscores the importance of monitoring caffeine levels in commercial products. In this study, we propose an alternative technique for caffeine analysis that relies on mid-infrared laser-based photothermal spectroscopy (PTS). PTS exploits the high-power output of the quantum cascade laser (QCL) sources to enhance the sensitivity of the mid-IR measurement. The laser-induced thermal gradient in the sample scales with the analytes' absorption coefficient and concentration, thus allowing for both qualitative and quantitative assessment. We evaluated the performance of our experimental PTS spectrometer, incorporating a tunable QCL and a Mach-Zehnder interferometer, for detecting caffeine in coffee, black tea, and an energy drink. We calibrated the setup with caffeine standards (0.1-2.5 mg mL-1) and we benchmarked the setup's capabilities against gas chromatography (GC) and Fourier-transform infrared (FTIR) spectroscopy. Quantitative results aligned with GC analysis, and limits of detection matched the research-grade FTIR spectrometer, indicating an excellent performance of our custom-made instrument. This method offers an alternative to established techniques, providing a platform for fast, sensitive, and non-destructive analysis without consumables as well as with high potential for miniaturization.

Unraveling biological responses to oceanographic equipment: Insights from forward-facing active acoustics and low-light imagery using small boats

Over six decades, extensive research has delved into the intricate interactions between marine animals and oceanographic sampling equipment, recognizing the impactful influence of light and sound emissions on mobile fauna behavior during surveys. This study, conducted through three mid-water experiments in the Solomon Islands (2019) and Bermuda (2021 and 2023), utilizing small boats, aims to unravel the effects of light on the distribution of biological scattering layers. Employing broadband active acoustics, dimmable lights, and low-light imaging on an observation-class ROV and a custom-made instrument frame, the experiments dynamically adjusted light intensity to track changes in volume backscattering strength. Amidst challenges encountered along the way, the study notably succeeded in observing avoidance behaviors from mesopelagic animals in response to the presence of our equipment. This study provides valuable insight for fisheries acoustics and echosounder applications, particularly in coral reef environments where small boats play a crucial role. This paper reviews the system setup, data processing, and presents fused backscatter data over depth, concluding with lessons learned, recommendations, and future study goals, contributing to the broader understanding of marine animal interactions with sampling equipment.

Investigating the effect of terminals’ service attributes on attracting shipping lines: a stated choice approach

Container terminals in the Mediterranean region have a high competition level between them to achieve a greater share of the regional seaborne trade volume. The national container companies in Egypt face low performance and productivity issues because liners prefer other ports/terminals in the East Mediterranean. One reason for this problem is due to policy makers’ belief that spending much money on terminal infra- and super-structure is the best practice for attracting more shippers. However, terminal capital investments and yearly maintenance costs are substantial and may not be useful if other factors control port/terminal choice from a shipping company’s point of view. Recently, the Egyptian Maritime Transport Sector went through a number of new projects through the construction of quay walls, yards, and terminals in various Egyptian ports such as Alexandria, Abu Kir, and El-Sokhna in attempt to improve the available freight capacity (i.e. supply)Nevertheless, and as long as shippers insist on choosing a specific port/terminal, such new improvements may not reap their intended benefits. This research investigates the important factors that control shipping liners decisions when selecting a container terminal by using a custom-made instrument design. Two data collection methods are used; namely, Revealed Preference (RP) and Stated Preference (SP) or Stated Choice (SC). Then, discrete choice models of terminal switching behavior will be used to help policy makers prescribe efficient strategies to alter shipping lines decisions and ensure that each port/container terminal has a fair market share. However, this paper reports only on the first part, while the latter is still work in progress. The preliminary data analysis showed that port charges and port infrastructure are the most critical factors shipping lines look for when choosing a container terminal. As such, policy makers need to focus on these factors in attempt to promote their terminals and make them more attractive to shipping lines.

Do Physical Education Teachers Use Socioconstructivist Communication Patterns in Their Classes?

Purpose: This study aims to identify socioconstructivist communication patterns used by physical education teachers and their evolution after participating in a training intervention. Method: The authors analyzed 812 units (messages containing constructivist discursive strategies) employed by two physical education teachers in two teaching modules using observational methodology. The data were analyzed by polar coordinate analysis. Results: In the pretraining phase, Teacher 1 presents two discursive patterns with questions–answers–literal incorporation of student-answers into the teachers’ communication, and another formed by praise questions. Teacher 2 generated praise-questions only. In the posttraining phase, Teacher 1 maintains one of the initial patterns and generates another consisting of questions-incorporation of students’ actions into the teacher’s communication. Teacher 2 incorporates two new patterns composed of information demands that are associated with the use of a specific frame of reference, or meta-statement. Discussion: The use of polar coordinate analysis revealed the presence of communication patterns and their evolution. Conclusion: The training intervention has resulted in changes in the communicative patterns of teachers. The custom-made instrument has allowed knowing the discursive strategies

Peer Review of "Burst Beliefs - Methodological Problems in the Balloon Analogue Risk Task and Implications for its Use"

Studies in the field of psychology often employ (computerised) behavioural tasks, aimed at mimicking real-world situations that elicit certain actions in participants. Such tasks are for example used to study risk propensity, a trait-like tendency towards taking or avoiding risk. One of the most popular tasks for gauging risk propensity is the Balloon Analogue Risk Task (BART; Lejuez et al., 2002), which has been shown to relate well to self-reported risk-taking and to real-world risk behaviours. However, despite its popularity and qualities, the BART has several methodological shortcomings, most of which have been reported before, but none of which are widely known. In the present paper, four such problems are explained and elaborated on: a lack of clarity as to whether decisions are characterised by uncertainty or risk; censoring of observations; confounding of risk and expected value; and poor decomposability into adaptive and maladaptive risk behaviour. Furthermore, for every problem, a range of possible solutions is discussed, which overall can be divided into three categories: using a different, more informative outcome index than the standard average pump score; modifying one or more task elements; or using a different task, either an alternative risk-taking task (sequential or otherwise), or a custom-made instrument. It is important to make use of these solutions, as applying the BART without accounting for its shortcomings may lead to interpretational problems, including false positive and false negative results. Depending on the research aims of a given study, certain shortcomings are more pressing than others, indicating the (type of) solutions most needed. By combining solutions and openly discussing shortcomings, researchers may be able to modify the BART in such a way that it can operationalise risk propensity without substantial methodological problems.

Burst Beliefs – Methodological Problems in the Balloon Analogue Risk Task and Implications for Its Use

Studies in the field of psychology often employ (computerized) behavioral tasks, aimed at mimicking real-world situations that elicit certain actions in participants. Such tasks are for example used to study risk propensity, a trait-like tendency towards taking or avoiding risk. One of the most popular tasks for gauging risk propensity is the Balloon Analogue Risk Task (BART; Lejuez et al., 2002), which has been shown to relate well to self-reported risk-taking and to real-world risk behaviors. However, despite its popularity and qualities, the BART has several methodological shortcomings, most of which have been reported before, but none of which are widely known. In the present paper, four such problems are explained and elaborated on: a lack of clarity as to whether decisions are characterized by uncertainty or risk; censoring of observations; confounding of risk and expected value; and poor decomposability into adaptive and maladaptive risk behavior. Furthermore, for every problem, a range of possible solutions is discussed, which overall can be divided into three categories: using a different, more informative outcome index than the standard average pump score; modifying one or more task elements; or using a different task, either an alternative risk-taking task (sequential or otherwise), or a custom-made instrument. It is important to make use of these solutions, as applying the BART without accounting for its shortcomings may lead to interpretational problems, including false-positive and false-negative results. Depending on the research aims of a given study, certain shortcomings are more pressing than others, indicating the (type of) solutions most needed. By combining solutions and openly discussing shortcomings, researchers may be able to modify the BART in such a way that it can operationalize risk propensity without substantial methodological problems.

Impacted Steel Sleeves for a minimally invasive approach in intramedullary nailing

A custom-made instrument set of Steel Sleeves was developed to assist the insertion of reamers and intramedullary devices for fixation of long bone fractures or lengthening procedures with intramedullary nails. By use of the Steel Sleeves, migration of the entry point is prevented and protection of the bone and soft tissue at the entry point is guaranteed. In addition, the principle of a closed working channel for trans-articular approaches can be provided.In this article, a description of properties and clinical application of custom-made steel sleeve instrument set is provided.

Water relations determine short time leaf growth patterns in the mangrove Avicennia marina (Forssk.) Vierh.

High-resolution leaf growth is rarely studied despite its importance as a metric for plant performance and resource use efficiency. This is in part due to methodological challenges. Here, we present a method for in situ leaf growth measurements in a natural environment. We measured instantaneous leaf growth on a mature Avicennia marina subsp. australasica tree over several weeks. We measured leaf expansion by taking time-lapse images and analysing them using marker tracking software. A custom-made instrument was designed to enable long-term field studies. We detected a distinct diel growth pattern with leaf area shrinkage in the morning and leaf expansion in the afternoon and at night. On average, the observed daily shrinkage was 37% of the net growth. Most of the net growth occurred at night. Diel leaf area shrinkage and recovery continued after growth cessation. The amount of daily growth was negatively correlated with shrinkage, and instantaneous leaf growth and shrinkage were correlated with changes in leaf turgor. We conclude that, at least in this tree species, instantaneous leaf growth patterns are very strongly linked to, and most likely driven by, leaf water relations, suggesting decoupling of short-term growth patterns from carbon assimilation.

Variations and sources of nitrous acid (HONO) during a severe pollution episode in Beijing in winter 2016

HONO is an important precursor of OH radical and plays a key role in atmospheric chemistry, but its source and formation mechanism remain uncertain, especially during complex atmospheric pollution processes. In this study, HONO mixing ratios were measured by a custom-made instrument during a severe pollution event from 16 to 23 December 2016, at an urban area of Beijing. The measurement was divided into three periods: I (haze), II (severe haze) and III (clean), according to the levels of PM2.5. This pollution episode was characterized by high levels of NO (75 ± 39 and 94 ± 40 ppbV during periods I and II, respectively) and HONO (up to 10.7 ppbV). During the nighttime, the average heterogeneous conversion frequency during the two haze periods were estimated to be 0.0058 and 0.0146 h−1, and it was not the important way to form HONO. Vehicle emissions contributed 52% (±16)% and 40% (±18)% to ambient HONO at nighttime during periods I and II. The contribution of homogeneous reaction of NO with OH should be reconsidered under high-NOx conditions and could be noticeable to HONO sources during this pollution event. Furthermore, HONO was positively correlated with PM2.5 during periods I and II, suggesting a potential chemical link between HONO and haze particles.

Spectroscopic Influence of Virtual Reality and Augmented Reality Display Devices on the Human Non-Visual Characteristics and Melatonin Suppression Response

It has been elucidated that the responses to light by the human eye influence not only color and brightness recognition but also physiological aspects such as hormones. Melatonin, which affects human circadian rhythms, is sensitive to the blue wavelength region of light. We have investigated the spectroscopic effects of light from virtual reality (VR) and augmented reality (AR) display devices on nonvisual characteristics by means of an analysis of the spectral power distribution (SPD). The circadian illuminance and melatonin suppression value were introduced as representative figures of merits for spectroscopically evaluating nonvisual characteristics. A VR/AR-like custom-made instrument was used to study how the SPD of the display light source affects nonvisual characteristics. Moreover, using multilayer thin-film filters, optimal conditions for minimizing the change of the visual color characteristics of the display while reducing the influence on the non-visual characteristics are also discussed. For the AR device, we found that its spectrum was mostly affected by external light rather than by the spectrum of the AR display itself.

Localized RPE Removal with a Novel Instrument Aided by Viscoelastics in Rabbits.

PurposeWe developed a surgical method for localized and atraumatic removal of the retinal pigment epithelium (RPE) with a novel instrument.MethodsBleb retinal detachments (bRD) were raised with balanced salt solution (BSS) following vitrectomy in 27 rabbits. The RPE was scraped with 3 loop variants (polypropylene [PP], 0.1 mm; PP, 0.06 mm; metal, 0.1 mm) of a custom-made instrument. Stabilization of bRDs with BSS or various concentrations (0.1%–0.5%) of hyaluronic acid (HA) was video analyzed. Perfusion-fixed samples of scraped areas and controls were studied by light and transmission electron microscopy.ResultsThe bRDs were sufficiently stabilized by ≥0.25% HA. Using the PP 0.1 mm loop with a single forward/backward stroke, an area of ca. 2.5 × 1.5 mm was nearly devoid of RPE, yet did show occasional Bruch's membrane (BM) defects combined with choriocapillaris hemorrhages in 13% of the bRDs. A single scrape with PP 0.06 mm resulted in unsatisfactory RPE denudement, while repeated scraping maneuvers caused more BM defects and hemorrhages. The metal loop resulted in incomplete RPE removal and massive intraoperative subretinal hemorrhages. Histologically, intact photoreceptor outer segments (POS) were observed above the RPE wounds in bRDs. Controls with bRDs alone showed an intact RPE monolayer with microvilli, with few engulfed remains of POS.ConclusionsLocalized removal of RPE in HA stabilized bRD can be achieved by a PP 0.1 mm loop instrument.Translational RelevanceRemoval of degenerated RPE may aid RPE cell replacement strategies.

Reliability and validity of a custom-made instrument including a hand-held dynamometer for measuring trunk muscle strength.

Measuring isometric strength is necessary in many areas of health and sport. However, trunk muscles have some particular characteristics that make them difficult to evaluate with simple, inexpensive instruments. To evaluate the reliability and validity of an instrument constructed with a hand-held dynamometer and a metallic structure (HHD+S) for measuring maximum isometric voluntary trunk muscle strength. Maximum isometric voluntary trunk muscle strength (extension, flexion and lateral flexion) was measured in 20 healthy individuals using the custom-made instrument (HHD+S) and the gold standard Back-Check (BC). The results showed that the two instruments had high and similar intra-subject reliability. The validity of the HHD+S was demonstrated by the high Pearson coefficient correlation between the two instruments (r ⩾ 0.78). Given the good trial reliability and the close correlation between the two instruments, we believe that the use of a hand-held dynamometer together with the custom-made metallic structure (HHD+S) allows an evaluation of the maximum isometric voluntary trunk muscle strength to be made, that is very similar in quality, accuracy and reliability to the BC.

GalvaPot, a custom-made combination galvanostat/potentiostat and high impedance potentiometer for decentralized measurements of ionophore-based electrodes

We report here on a portable, custom-made instrument for decentralized measurements with ionophore based electrodes. It allows one to perform most common electrochemical protocols based on applied current or potential as well as zero current potentiometry measurements. Each protocol is customizable via a programmable interface by use of either an external PC or a touch screen panel on the device. The programmable interface provides flexibility to trigger peripheral devices for the additional implementation of actuators, pumps and other external devices in the electrochemical routines.To characterize the electronic performance of the instrument, three different electrochemical protocols were used with ionophore based electrodes and compared with a commercial work station: (1) open circuit potentiometric measurements with calcium ion-selective membranes; (2) chronoamperometry based on three successive pulses with simultaneous control of fluidic delivery by a peristaltic pump and switching valve, followed by on board current integration to obtain a coulometric readout; (3) a chronopotentiometric protocol using protamine selective membranes with current pulses of 5-s duration, including an automatic computation of the time-derivative to find the transition time as the analytical signal. At 500g, the instrument is portable yet sufficiently versatile for performing and analyzing most electrochemical measurements without the need for an external computer. It may become an attractive tool for applications in environmental and clinical analysis where field portability, flexibility and integration are desired.

Reply to letter to the editor: “Is balloon osteoplasty attractive or questionable treatment for Hill-Sachs lesions?”

Dear Editor, We appreciate the important annotations of the readers and agree with them that the treatment regime of Hill-Sachs lesions is diverse and therefore difficult. In our feasibility study, we evaluated the use of balloon osteoplasty as a new treatment option in a cadaver model [1]. We have considerable experience with the kyphoplasty system in the treatment of spinal compression fractures and tibial plateau fractures [2]. Herein we discuss five points addressed by the readers. However, our experience in treating Hill-Sachs lesions with this method is limited to the cadaver study described. But when transferring data and experience to daily clinical life we would strongly recommend performing an MRI—as suggested by the readers—prior to surgery (point 1). An MRI with the suggested STIR sequence enables the detection of fresh Hill-Sachs lesions and concomitant injuries such as Bankart lesions or lesions of the long biceps tendon, e.g. SLAP lesions [3]. We believe that fresh Hill-Sachs lesions will be much easier to reduce since fibrotic tissue is easier to repair than old bony consolidated Hill-Sachs lesions. This leads us to the recommendation of early restoration during the first six weeks. We also think that the force required for osteoplasty reduction is lower at this earlier stage and therefore the risk for leakage or joint fracture limited. (Point 2) We have tried several custom-made instruments ranging from a curved instrument to the cannula we used in the publication. We have performed all restorations by the entry point at the greater tuberosity as we believe that this entry point is comfortable to reach and enables a restoration of Hill-Sachs and reversed Hill-Sachs lesions. It would be desirable to have an instrument with a balloon expanding to the front, but so far various companies have not been in the position to adopt or develop new instruments to our specifications. Nevertheless, our custom-made instruments worked well and we could achieve an almost anatomical reduction of the fractures in all cases. (Point 3) The exposure to radiation ranged between 60 and 90 seconds. (Point 4) We used a standard kyphoplasty cannula and adopted it to our specifications. For osteoplasty in humeral heads we think that a set of different angulated, fenestrated cannulas would be very helpful since the circumference of humeral heads varies. We fenestrated the instrument to have a “directed balloon” for positioning under the defect. The costs of our custom-made instrument were equal to the standard kyphoplasty system. (Point 5) We thank you for this valuable comment. It would be desirable to reconstruct the joint almost anatomically, bearing in mind that the aim of the balloon osteoplasty is not reconstruction of the cartilage but avoidance of recurrent instability due to engaging Hill-Sachs lesions. Future research is needed in this field to find the ideal solution for augmentation—whether it is cancellous bone or bone cement. If using the latter, one would have to be sure to use the cement at a semi-solid stage to avoid leakage to the joint. All in all we believe our technique to be an important step in the minimally-invasive treatment of Hill-Sachs lesions. We appreciate the comments of the authors and are looking forward to transfer the experience of our cadaver study to the clinical situation. Further clinical studies covering this topic will follow in the future. With kind regards, Gunther H. Sandmann

Detection Limits of Thin Layer Coulometry with Ionophore Based Ion-Selective Membranes

We report here on a significant improvement in lowering the low detection limit of thin layer coulometric sensors based on liquid ion-selective membranes, using a potassium-selective system as a model example. Various possible processes that may result in an elevated residual current reading after electrolysis were eliminated. Self-dissolution of AgCl on the Ag/AgCl inner element may result in a residual ion flux that could adversely affect the lower detection limit. It was here replaced with an Ag/AgI inner pseudoreference electrode where the self-dissolution equilibrium is largely suppressed. Possible residual currents originating from a direct contact between inner element and ion-selective membranes were eliminated by introducing an inert PVDF separator of 50 μm diameter that was coiled around the inner element by a custom-made instrument. Finally, the influence of electrolyte fluxes from the outer solution across the membrane into the sample was evaluated by altering its lipophilic nature and reducing its concentration. It was found that this last effect is most likely responsible for the observed residual current for the potassium-selective membranes studied here. For the optimized conditions, the calibration curves demonstrated a near zero intercept, thereby paving the way to the coulometric calibration-free sensing of ionic species. A linear calibration curve for the coulometric cell with valinomycin potassium-selective membrane was obtained in the range of 100 nM to 10 μM potassium in the presence of a 10 μM sodium background. In the presence of a higher (100 μM) concentration of sodium, a reliable detection of 1-100 μM of potassium was achieved.

Experimental study on the thermal performance of a traditional house with one-sided wind catcher during summer and winter

The Nagapattinam district lies on the east coast to the south of Cuddalore and is bordered by the Bay of Bengal. The general geological formation of the district is plain and coastal. Energy conservation issues and environmental problems in recent years have increased interest in traditional architecture which is well known for its energy saving designs. This paper presents the quantitative evaluation of traditional buildings in the coastal region of Nagappattinam during summer and winter periods with the custom-made instrument called Mini-meteorological station to understand the various solar passive elements used in the traditional buildings that provide thermal comfort. In this paper, the comparison of thermal performance during winter and summer is explained.

Occlusal Plane Analyzer: A Customized Device for Determining the Occlusal Plane

ABSTRACTSince times immemorial, dentists have faced the challenge of providing accord between function and esthetics. The occlusal plane, lost in patients rendered edentulous, should be relocated if complete dentures are to be esthetically and functionally satisfactory. Changes in the plane of occlusion modify the physical and functional relationship of the oral musculature leading to an alteration in function, comfort and also the esthetic value. Considering the importance of the accurate establishment of the location and the effect of the inclination of the established occlusal plane on function, esthetics and speech, a method to conform it to the occlusal plane that existed in the natural teeth seems necessary. This paper describes a custom-made instrument to check for the parallelism of ala-tragus line to the occlusal plane and also to check for the parallelism of occlusal plane to interpupillary line.

Study on Swell Pressure Stress of Bentonite in Geosynthetic Clay Liners

: The geosynthetic clay liner (GCL) is a kind of waterproofing material used widely in engineering. The waterproof mechanism is understood in terms of bentonite particles becoming water-obstruct colloid layers after they sorb water and swell. The swell pressure stress, however, has not been determined directly till now. In our experiment, swell pressure stress of the GCL under saturated water-sorbing condition was measured directly using a custom-made instrument. The results show that (1) the instrument designed by the authors performs satisfactorily and the test results are reproducible; and (2) the trend line of swell pressure stress variation with time can be divided into three segments. The first segment is characterized by a quick increase of the swell force in the first 0–50 hours. The swell pressure stress increases by 7.00times10−4-1.00times10−3 MPa/h. The second segment shows a slow increase of the swell pressure stress from the 50th to 1730th hour. The swell force increases by 7.54times10−6-2.02times10−5MPa/h. The third segment is characterized by a little variation in swell pressure stress after 1730 hours. In this segment, the average value of the swell pressure stress measurements is 0.0719 MPa and the maximum value is 0.0729 MPa. It is suggested that the swell pressure stress is mainly raised by water entering pores among montmorillonite particles and interstitial layers in individual montmorillonite crystals, leading to an increase of volume.