MANTRA: a serious game improving knowledge of maternal and neonatal health and geohazards in Nepal

Background

Mobile technology is increasingly important for delivering public health interventions to remote populations. This research study developed, piloted, and assessed a serious game for mobile devices that teaches geohazard, maternal, and neonatal health messages. This unique mHealth intervention aimed at low-literacy audiences in low resource settings is part of the Maternal and Neonatal Technologies in Rural Areas (MANTRA) project: Increasing maternal and child health resilience before, during, and after disasters using mobile technology in Nepal. Specifically, we assess impact of the serious game to improve knowledge gain in our target audience.

Methods

Co-creation with the MANTRA team and local stakeholders in Nepal identified core needs, developed appropriate pictograms and mechanics, and tailored the pilot game to the local cultural context. Through picture matching with immediate audio and visual feedback, the game teaches 28 learning objectives in three modules: maternal health, neonatal health, and geohazards. To assess the game, 35 participants were recruited in Kathmandu and villages in Kavre district. Sessions consisted of pre-test assessment, playing the game, post-test assessment, and a focus group to elicit qualitative feedback.

Results

The knowledge assessment quantified knowledge gain. Overall, the group averaged a normalized 6.8 point improvement (p = 0.000022). Change in the geohazard module was 9.5 points (p = 0.001), followed by maternal health (7.4 points, p = 0.007), and neonatal health (4.3 points, p = 0.83). Four learning objectives had statistically significant change (p < 0.05). Feedback demonstrated high engagement, motivation, and usability of the game.

Conclusions

This MANTRA study is a unique mhealth intervention of a serious game to teach core health and hazards messages to low-literacy audiences in rural Nepal. The pilot intervention demonstrated statistically significant knowledge improvement among participants.

Key messages

The pilot MANTRA mobile serious game intervention is a novel idea, to bring public health knowledge to difficult to reach vulnerable populations, including often ignored illiterate audiences. The pilot MANTRA mobile serious game intervention demonstrated a statistically significant knowledge improvement of geohazard, maternal, and neonatal health learning objectives among participants.

Dynamic intracochlear pressure measurement during cochlear implant electrode insertion

Background: Electrode insertion into the cochlea can cause significant pressure changes inside the cochlea with assumed effects on the cochlea's functionality regarding residual hearing. Model-based intracochlear pressure (ICP) changes were performed statically at the cochlear helix. Aims/objectives: The aim of this study was to observe dynamic pressure measurements during electrode insertion directly at the cochlear implant electrode. Material and methods: The experiments were performed in an uncurled cochlear model that contained a volume value equivalent to a full cochlea. A microfibre pressure sensor was attached at one of two positions on a cochlear implant electrode and inserted under different insertional conditions. Results: We observed the ICP increase depending on the insertional depth. A sensor-position-specific pressure change is insertional-depth dependent. Interval insertion did not lead to a lower peak insertional ICP. Conclusions and significance: In contrast to the static pressure-sensor measurement in the artificial model's helix, a dynamic measurement directly at the electrode shows the pressure profile to increase based on the insertional depth. A mechanical traumatic relevance of the observed pressure values cannot be fully excluded.

P4665High sensitivity troponin t and n-terminal pro brain natriuretic peptide plasma levels predict long-term postoperative survival in patients with severe aortic stenosis admitted for valve implantation

Aims

Optimal timing of valve implantation in patients with severe aortic stenosis (AS) is under debate, considering the subjective nature of symptom onset. We aimed to investigate the pre-procedural value of routinely available cardiac biomarkers in predicting postoperative long-term outcome in a large cohort undergoing either surgical or transcatheter aortic valve implantation.

Methods

The Tyrolean Aortic Stenosis Study-2 (TASS-2) group, a consortium of four university hospital centers in Austria, analysed pre-procedural high-sensitivity troponin T (hsTnT) and N-terminal pro brain natriuretic peptide (NT-proBNP) plasma levels in 3595 patients admitted for valve implantation because of severe aortic stenosis since 2007.

Results

Transcatheter aortic valve implantation was performed in 1517 (42.2%) of patients. During a median follow-up of 2.93 (1.91–4.92) years, 919 patients (25.6%) died, among them 556 (15.5%) due to cardiovascular causes. In multivariate cox regression analysis - adjusting for STS risk score (intermediate risk 4–8%, high risk >8%), degree of left ventricular systolic dysfunction (ejection fraction 30–50% and <30%), atrial fibrillation, sex, age, renal function, COPD, arterial hypertension, diabetes mellitus, concomitant significant coronary artery disease and type of procedure (surgical aortic valve replacement or transcatheter aortic valve implantation) - pre-procedural hsTnT as well as NT-proBNP plasma levels were strong independent predictors for postoperative survival: hazard ratio [HR] 1.82, 95% confidence interval [CI] 1.07–3.11, P=0.028 for mildly to moderately elevated hsTnT (14–50 ng/l); HR 2.80, CI 1.61–4.89, P<0.001 for severely elevated hsTnT (>50 ng/l); HR 1.38, CI 1.06–1.81, P=0.018 for mildly to moderately elevated NT-proBNP (defined by an increase of up to threefold of age- and sex-corrected normal range); HR 1.68, CI 1.29–2.18, P<0.001 for severely elevated NT-proBNP (defined by an increase of more than threefold of age- and sex-corrected normal range). For direct comparison of these two biomarkers a second cox regression model was conducted including only hsTnT and NT-proBNP revealing the strength of hsTnT as a predictive biomarker: HR 2.20, 95% CI 1.29–3.77, P=0.004 for minimally elevated hsTnT (5–13.99 ng/l); HR 4.05, CI 2.41–6.82, P<0.001 for mildly to moderately elevated hsTnT (14–50 ng/l); HR 8.63, CI 5.07–14.70, P<0.001 for severely elevated hsTnT (>50 ng/l); HR 1.47, CI 1.13–1.91, P=0.004 for mildly to moderately elevated NT-proBNP; HR 1.96, CI 1.54–2.51, P<0.001 for severely elevated NT-proBNP.

Conclusion

hsTNT and NT-proBNP strongly predict long-term postoperative survival in patients with severe AS admitted for valve implantation.

Acknowledgement/Funding

This work was supported by the Tiroler Wissenschaftsförderung: grant number TWF-2017-1-5, GZ: UNI-0404-2104

P3383Left atrial appendage and left atrial morphology is associated with cryptogenic stroke

Background

Stroke causes a high burden of morbidity and mortality worldwide. Approximately 30% of stroke cases remain cryptogenic (CS), of which one third is due to occult atrial fibrillation (AF) with left atrial appendage (LAA) being the most frequent thrombus source.

Hence, aim of our study was to assess if LAA morphological parameters analysed by computed tomography angiography (CTA) are associated with CS.

Methods and materials

In 184 patients (Table 1), 82 CS patients and 102 controls (age median 62 (52,2–72), 40.2% females), matched for BMI, a CTA was performed, and LAA morphology evaluated retrospectively.

LAA morphology was classified into 5 types (Figure 1): Cactus, Cauliflower, Chicken-wing, Windsock and the new “Seahorse” with a distinctive tip angulation of ≤90° and 2 bends (Z-shape). Further measurements included: LAA tip angulation (≤90°, 91–110°, >110°), LAA lobe number, LAA ostium size (length) and angulation, left atrium wall thickness (LAWT).

Results

LAA and left atrium (LA) parameters associated with CS on multivariable analysis after adjusting for CHA2DS2-VASc score were: Chicken-wing type (OR 2.15; 95% CI: 1.01–4.56, p=0.046), a greater lobe number (OR 2.01; 95% CI: 1.52–2.64, p<0.001), a greater middle and mean LAWT (respectively, OR 2.13; 95% CI: 1.49–3.05, p<0.001, OR 2.64; 95% CI: 1.63–4.29, p<0.001), a larger (length, OR 1.08; 95% CI: 1.0–1.16, p=0.039) and a less bent LAA ostium (OR 1.02; 95% CI: 1.01–1.03, p=0.006). In contrast, a sharp-angled LAA tip (≤90°) was protective from CS (OR 0.43; 95% CI: 0.23–0.83, p=0.012) on multivariable analysis.

Table1. Clinical patient characteristics CS (n=82) Non-stroke (n=102) p value Females 21 (25.6%) 53 (52%) p<0.001 Age, y 66.5 (57–73) 57.5 (50–70) 0.001 BMI, kg/m2 25.6 (23.9–28.2) 26 (23.3–30.1) 0.320 CHA2DS2-VASc score 2 (1–3) 2 (1–3) 0.387 AF (paroxysmal/permanent) 0 4 0.071 Hypertension 68 (82.9%) 54 (56.3%) p<0.001 Diabetes mellitus, type 2 16 (19.8%) 11 (11.5%) 0.145 Values are given in median ± IQR. AF, atrial fibrillation; BMI, body mass index.

LAA and LA morphology in CTA.

Conclusion

In CS, a Chicken-wing LAA, a greater number of lobes and a thicker LA wall are independently associated with CS while a sharp LAA tip (≤90°) mostly seen in Seahorse type LAA is protective. Such “high-risk” LAA and LA morphology could help to select CS patients benefiting from extended rhythm-monitoring to detect an occult AF, however, further prospective studies are needed to confirm this hypothesis.

Benchmarking Monte-Carlo dose calculation for MLC CyberKnife treatments

Background

Vendor-independent Monte Carlo (MC) dose calculation (IDC) for patient-specific quality assurance of multi-leaf collimator (MLC) based CyberKnife treatments is used to benchmark and validate the commercial MC dose calculation engine for MLC based treatments built into the CyberKnife treatment planning system (Precision MC).

Methods

The benchmark included dose profiles in water in 15 mm depth and depth dose curves of rectangular MLC shaped fields ranging from 7.6 mm × 7.7 mm to 115.0 mm  × 100.1 mm, which were compared between IDC, Precision MC and measurements in terms of dose difference and distance to agreement. Dose distributions of three phantom cases and seven clinical lung cases were calculated using both IDC and Precision MC. The lung PTVs ranged from 14 cm³ to 93 cm³. Quantitative comparison of these dose distributions was performed using dose-volume parameters and 3D gamma analysis with 2% global dose difference and 1 mm distance criteria and a global 10% dose threshold. Time to calculate dose distributions was recorded and efficiency was assessed.

Results

Absolute dose profiles in 15 mm depth in water showed agreement between Precision MC and IDC within 3.1% or 1 mm. Depth dose curves agreed within 2.3% / 1 mm. For the phantom and clinical lung cases, mean PTV doses differed from − 1.0 to + 2.3% between IDC and Precision MC and gamma passing rates were > =98.1% for all multiple beam treatment plans. For the lung cases, lung V20 agreed within ±1.5%. Calculation times ranged from 2.2 min (for 39 cm³ PTV at 1.0 × 1.0 × 2.5 mm³ native CT resolution) to 8.1 min (93 cm³ at 1.1 × 1.1 × 1.0 mm³), at 2% uncertainty for Precision MC for the 7 examined lung cases and 4–6 h for IDC, which, however, is not optimized for efficiency but used as a gold standard for accuracy.

Conclusions

Both accuracy and efficiency of Precision MC in the context of MLC based planning for the CyberKnife M6 system were benchmarked against MC based IDC framework. Precision MC is used in clinical practice at our institute.

Swiss consumers' willingness to pay and attitudes regarding dual-purpose poultry and eggs

Chick culling is an efficient and cost-effective method in modern poultry farming, but it raises ethical concerns. Dual-purpose poultry (DP), in which males are fattened and females are used for egg production, is currently the most realistic alternative to culling, as in ovo sexing is not yet viable for practical application. Consumers' acceptance of DP products and their willingness to pay (WTP) for them have not been studied yet, and we expect that both aspects are closely related to the acceptance of and WTP for products from systems claiming beyond-conventional animal welfare, such as organic products. Results from a survey conducted among 402 consumers at 8 Swiss supermarkets revealed that the practice of chick culling was largely unknown (75% of respondents). Generally, respondents' knowledge about poultry production was low. The DP alternative was preferred to chick culling, but no preference emerged between DP and in ovo sexing. Furthermore, the WTP for DP products was proportionally lower for chicken than for eggs, probably because of the different price elasticity between these products. A regression analysis was used to determine the factors influencing consumers' WTP for DP products. Consumers' WTP was positively related to knowledge about poultry production, habits tied to purchasing organic or free-range poultry products, and familiarity with DP products. Therefore, a combination of the DP alternative with an organic label is recommended.

Part 2: Dynamic mixed beam radiotherapy (DYMBER): Photon dynamic trajectories combined with modulated electron beams

PURPOSE

The purpose of this study was to develop a treatment technique for dynamic mixed beam radiotherapy (DYMBER) utilizing increased degrees of freedom (DoF) of a conventional treatment unit including different particle types (photons and electrons), intensity and energy modulation and dynamic gantry, table, and collimator rotations.

METHODS

A treatment planning process has been developed to create DYMBER plans combining photon dynamic trajectories (DTs) and step and shoot electron apertures collimated with the photon multileaf collimator (pMLC). A gantry-table path is determined for the photon DTs with minimized overlap of the organs at risk (OARs) with the target. In addition, an associated dynamic collimator rotation is established with minimized area between the pMLC leaves and the target contour. pMLC sequences of photon DTs and electron pMLC apertures are then simultaneously optimized using direct aperture optimization (DAO). Subsequently, the final dose distribution of the electron pMLC apertures is calculated using the Swiss Monte Carlo Plan (SMCP). The pMLC sequences of the photon DTs are then re-optimized with a finer control point resolution and with the final electron dose distribution taken into account. Afterwards, the final photon dose distribution is calculated also using the SMCP and summed together with the one of the electrons. This process is applied for a brain and two head and neck cases. The resulting DYMBER dose distributions are compared to those of dynamic trajectory radiotherapy (DTRT) plans consisting only of photon DTs and clinically applied VMAT plans. Furthermore, the deliverability of the DYMBER plans is verified in terms of dosimetric accuracy, delivery time and collision avoidance. For this purpose, The DYMBER plans are delivered to Gafchromic EBT3 films placed in an anthropomorphic head phantom on a Varian TrueBeam linear accelerator.

RESULTS

For each case, the dose homogeneity in the target is similar or better for DYMBER compared to DTRT and VMAT. Averaged over all three cases, the mean dose to the parallel OARs is 16% and 28% lower, D2% to the serial OARs is 17% and 37% lower and V10% to normal tissue is 12% and 4% lower for the DYMBER plans compared to the DTRT and VMAT plans, respectively. The DYMBER plans are delivered without collision and with a 4-5 min longer delivery time than the VMAT plans. The absolute dose measurements are compared to calculation by gamma analysis using 2% (global)/2 mm criteria with passing rates of at least 99%.

CONCLUSIONS

A treatment technique for DYMBER has been successfully developed and verified for its deliverability. The dosimetric superiority of DYMBER over DTRT and VMAT indicates utilizing increased DoF to be the key to improve brain and head and neck radiation treatments in future.