Assessing operational readiness: Regulatory landscape and compliance in zimbabwe for medical devices and in vitro diagnostic medical devices.

The regulation of medical devices and In Vitro Diagnostic (IVD) medical devices have lagged significantly, especially in low- and middle-income countries. Disparities in regulating medical and IVD medical devices in Africa are below the global average. This may translate to poor access to quality-assured medical and IVD devices, resulting in undesirable health outcomes. Operational readiness to regulate medical and IVD devices at the Medicines Control Authority of Zimbabwe (MCAZ) was assessed. The aim was to determine the strengths and gaps and propose an action plan that can be monitored and evaluated to assess progress over time. We used the World Health Organization (WHO) Global Benchmarking Tool for medical devices and IVDs methodology to evaluate regulatory oversight of these products. Purposive sampling was used for data collection using researcher-administered global benchmarking tool factsheets and document reviews to evaluate the implementation of the regulatory functions. The regulatory functions assessed were the National Regulatory System, Registration and Market Authorization, Vigilance, Market Surveillance and Control, Licensing Establishment, Regulatory Inspection, Laboratory Testing, and Clinical Trials Oversight. The MCAZ attained maturity level 1, with a regulatory system score of 79%, registration and market authorization 44%, vigilance 27%, market surveillance and control 40%, licensing establishment 62%, regulatory inspection 68%, laboratory testing 88%, and clinical trials 18%. Condoms and gloves were the only regulated medical devices in Zimbabwe. IVDs were not regulated by the MCAZ. This review showed that the regulatory system is not robust, fit for purpose, responsive, transparent, or proportionate to the risk classification of medical devices and IVDs. It is crucial to amend the Medicines and Allied Substance Control Act to incorporate the definition and classification of medical devices and IVDs, regulatory authority establishment, licensing and registration, quality management system, conformity assessment, post-market surveillance, labeling and instructions for use, capacity building and training, and international harmonization.

National inventory of authorized diagnostic imaging equipment in Ghana: data as of September 2020.

Introduction: to address the challenge of inadequate and non-equitable distribution of diagnostic imaging equipment, countries are encouraged to evaluate the distribution of installed systems and undertake adequate monitoring to ensure equitability. Ghana´s medical imaging resources have been analyzed in this study and evaluated against the status in other countries. Methods: data on registered medical imaging equipment were retrieved from the database of the Nuclear Regulatory Authority and analyzed. The equipment/population ratio was mapped out graphically for the 16 regions of Ghana. Comparison of the equipment/population ratio was made with the situation in other countries. Results: six hundred and seventy-four diagnostic imaging equipment units from 266 medical imaging facilities (2.5 units/facility), comprising computed tomography (CT), general X-ray, dental X-ray, single-photon emission computed tomography (SPECT) gamma camera, fluoroscopy, mammography and magnetic resonance imaging (MRI) were surveyed nationally. None of the imaging systems measured above the Organization for Economic Co-operation and Development (OECD) average imaging units per million populations (u/mp). The overall equipment/population ratio estimated nationally was 21.4 u/mp. Majority of the imaging systems were general X-ray, installed in the Greater Accra and Ashanti regions. The regional estimates of equipment/population ratios were Greater Accra (49.6 u/mp), Ashanti (22.4 u/mp), Western (21.4 u/mp), Eastern (20.6 u/mp), Bono East (20.0 u/mp), Bono (19.2 u/mp), Volta (17.9 u/mp), Upper West (16.7 u/mp), Oti (12.5 u/mp), Central (11.9 u/mp), Northern (8.9 u/mp), Ahafo (8.9 u/mp), Upper East (6.9 u/mp), Western North (6.7 u/mp), Savannah (5.5 u/mp) and North-East (1.7 u/mp). Conclusion: medical imaging equipment shortfall exist across all imaging modalities in Ghana. A wide inter-regional disparity in the distribution of medical imaging equipment exists contrary to WHO´s recommendation for equitable distribution. A concerted national plan will be needed to address the disparity.

Comparación entre el análisis automático y manual de 301 poligrafías respiratorias domiciliarias con ApneaLink / Comparison between automatic and manual scoring of 301 home respiratory polygraphs with ApneaLink device

Resumen Introducción: El síndrome de apnea obstructiva del sueño (SAOS) se asocia a aumento de morbimortalidad cardiovascular y metabólica, y a mala calidad de vida. Su diagnóstico y tratamiento eficaz mejora la salud individual y pública. Objetivo: evaluar concordancia entre análisis automático versus manual del dispositivo ApneaLink para diagnosticar y clasificar SAOS en pacientes con sospecha clínica. Material y Método: Evaluación retrospectiva de 301 poligrafías respiratorias del HOSCAR. Se mide correlación, acuerdo general y concordancia entre parámetros obtenidos manual y automáticamente usando coeficiente de Pearson, coeficiente de correlación intraclase y gráfico de Bland y Altman. Resultados: En 11,3% de casos el análisis automático interpreto erróneamente la señal de flujo. No hubo diferencias significativas entre índices de apnea-hipopnea automático (AHIa 18,9 ± 17,5) y manual (AHIm 20,8 ± 19,4) r + 0,97 (95% CI: 0,9571 a 0,9728; p < 0,0001) y tampoco entre la saturación mínima de oxígeno automática (82,1 ± 7,6) y manual (83,1 ± 6,8) r + 0,85 (95% CI: 0,8108 a 0,8766; p < 0,0001). No hubo buena correlación entre análisis automático y manual en clasificación de apneas centrales, r + 0,51 (95% CI: 0,4238 a 0,5942; p < 0,0001). Hubo subestimación de gravedad de SAOS por análisis automático: en 11% de casos. Conclusión: El diagnóstico entregado automáticamente por ApneaLink podría aceptarse sin confirmación manual adicional solamente en casos clasificados como severos. Para AHI menores se requeriría confirmación mediante análisis manual de experto.

Abstract Introduction: Obstructive sleep apnea syndrome (OSAS) is associated with increased cardiovascular and metabolic morbidity and mortality, and poor quality of life. Its effective diagnosis and treatment improve individual and public health. Aim: To evaluate concordance between automatic versus manual analysis of the ApneaLink device to diagnose and classify OSAS in patients with clinical suspicion. Material and Method: Retrospective evaluation of 301 respiratory polygraphs from HOSCAR. Correlation, general agreement and concordance between parameters obtained manually and automatically are measured using Pearson's coefficient, intraclass correlation coefficient, and Bland and Altman graph. Results: In 11.3% of cases, the automatic analysis misinterpreted the flow signal. There were no significant differences between automatic (AHIa 18.9 ± 17.5) and manual (AHIm 20.8 ± 19.4) apnea-hypopnea indices r + 0.97 (95% CI:0.9571 to 0.9728, p < 0.0001) and nor between automatic (82.1 ± 7.6) and manual (83.1 ± 6.8) minimum oxygen saturation r + 0.85 (95% CI: 0.8108 to 0.8766, p < 0.0001). There was no good correlation between automatic and manual analysis in the classification of central apneas, r + 0.51(95% CI:0.4238 to 0.5942, p < 0.0001). There was an underestimation of the severity of OSAS by automatic analysis in 11% of cases. Conclusion: The diagnosis delivered automatically by ApneaLink could be accepted without additional manual confirmation only in cases classified as severe. For minors AHI, confirmation through manual expert analysis would be required.

Home sleep apnea testing: an accuracy study.

AIM: There are no studies comparing tests performed at home with those carried out in the laboratory, using the same device. The only studies that have been performed have compared the device used at home with the standard polygraph used in the laboratory. The purpose of this study was therefore to verify the accuracy of the home diagnosis of obstructive sleep apnea syndrome (OSAS) via unassisted type 2 portable polysomnography, compared with polysomnography using the same equipment in a sleep laboratory. METHODS: To avoid any possible order effect on the apnea-hypopnea index (AHI), we randomly created two groups of 20-total 40 patients, according to the test sequence. One of the groups had the first test at home and the second test in the laboratory (H-L); the other group had the first test in the laboratory and the second at home (L-H). The second test always took place on the night immediately following the first test. All polysomnographic monitoring was undertaken with the same equipment, an Embletta X100 system (Embla, Natus Inc., Middleton, USA). The Embletta X100 is a portable polygraph that records eleven polygraph signs: (1) electroencephalogram C4/A; (2) electroencephalogram O2/M1; (3) submental EMG; (4) electrooculogram of the right side; (5) nasal cannula (air flow); (6) respiratory effort against a plethysmographic chest strap; (7) respiratory effort against an abdominal plethysmographic belt; (8) heart rate; (9) saturation of oxyhemoglobin; (10) snoring; and (11) body position. RESULTS: There was no difference in sleep efficiency between the group monitored in the laboratory and the group tested at home (p = 0.30). There was no difference in total sleep time (p = 0.11) or sleep latency (p = 0.52), or in the latency in phases N2 and N3 between the monitoring in the laboratory and at home (N2 p = 0.24; N3 p = 0.09). Some differences occurred regarding the PSG that took place at home, with longer duration of wake after sleep onset (WASO) and longer latency for REM sleep, due to failure of the patient to start the monitoring by pressing the "events" button on the device. In the distribution of sleep phases, there was no difference between the group monitored in the laboratory and the group tested at home. CONCLUSION: Results from home sleep monitoring correlate well with the laboratory "gold standard" and may be an option for diagnosing OSAS in selected patients.

Frailty Assessment in Community-Dwelling Older Adults: A Comparison of 3 Diagnostic Instruments.

OBJECTIVES: Compare the diagnostic performance of FRAIL against Fried Phenotype and Frailty Index (FI), and identify clinical factors associated with pre-frailty/frailty. DESIGN: Cross-sectional analysis. SETTING: Community-based screenings in Senior Activity Centres, Residents' Corners and Community Centres in northeast Singapore. PARTICIPANTS: 517 community dwelling participants aged >55 years and ambulant independently (with/ without walking aids) were included in this study. Residents of sheltered or nursing homes, and seniors unable to ambulate at least four meters independently were excluded. MEASUREMENTS: The multidomain geriatric screen included assessments for social vulnerability, mood, cognition, sarcopenia and nutrition. Participants completed a battery of physical fitness tests for grip strength, gait speed, lower limb strength and power, flexibility, balance and endurance, with overall physical performance represented by Short Physical Performance Battery (SPPB). Frailty status was assigned on FRAIL, Fried and 35-item FI. RESULTS: Prevalence of frailty was 1.3% (FRAIL) to 3.1% (FI). Pre-frailty prevalence ranged from 17.0% (FRAIL) to 51.2% (FI). FRAIL demonstrated poor agreement with FI (kappa=0.171, p<0.0001), and Fried (kappa=0.194, p<0.0001). A lower FRAIL cut-off ≥1 yielded significantly improved AUC of 0.70 (95%CI 0.55 to 0.86, p=0.009) against Fried, and 0.71 (95%CI 0.55 to 0.86, p=0.008) against FI. All 3 frailty measures were diagnostic of impaired physical performance on SPPB, with AUCs ranging from 0.69 on FRAIL to 0.77 on Fried (all p values <0.01). Prevalence of low socio-economic status, depression, malnutrition and sarcopenia increased significantly, while fitness measures of gait speed, balance, and endurance declined progressively across robust, pre-frail and frail on all 3 frailty instruments (p <0.05). CONCLUSIONS: Our results suggest that different frailty instruments may capture over-lapping albeit distinct constructs, and thus may not be used interchangeably. FRAIL has utility for quick screening, and any positive response should trigger further assessment, including evaluation for depression, social vulnerability and malnutrition.

3D-Printing to Address COVID-19 Testing Supply Shortages.

The recent SARS-CoV-2 outbreak has placed immense pressure on supply chains, including shortages in nasopharyngeal (NP) swabs. Here, we report our experience of using 3D-printing to rapidly develop and deploy custom-made NP swabs to address supply shortages at our healthcare institution.

Declaración de posición del Grupo de la Comisión Lancet de Hipertensión con respecto a la mejora mundial de las normas de exactitud para los dispositivos de medición de la presión arterial / Lancet Commission on Hypertension Group position statement on the global improvement of accuracy standards for devices that measure blood pressure / Posicionamento do Grupo da Lancet Commission on Hypertension sobre a melhoria global dos padrões de acurácia para aparelhos que medem a pressão arterial

Objetivos. El boletín de notas de México correspondiente al 2018 evalúa las oportunidades a disposición de la población infantil y joven mexicana para que puedan desarrollar niveles adecuados de actividad física y sueño, y disminuyan el sedentarismo.Métodos. El boletín es un sistema de vigilancia que recopila los datos obtenidos en las encuestas nacionales, censos, documentos gubernamentales, sitios web, literatura gris y estudios publicados con respecto al análisis de 16 indicadores en 4 categorías: comportamientos diarios, estado físico, entornos y fuentes influyentes, y estrategias e inversión. Los datos fueron cotejados con los puntos de referencia establecidos. A cada indicador se le asignó una calificación entre 1 y 10 (< 6 significa reprobado) o fue marcado como "incompleto" si los datos eran nulos o insuficientes. Resultados. Las calificaciones obtenidas para los comportamientos diarios fueron: actividad física en general: 4; participación en actividades deportivas organizadas: 5; juego activo: 3; modalidades de transporte activas: 5; sueño: 7; y sedentarismo: 3. El estado físico obtuvo un 7. Las calificaciones para los entornos y fuentes influyentes fueron: familiares y pares: "incompleto"; escuela: 3; comunidad y entorno: 4. Para las estrategias e inversión: estrategias gubernamentales: 6; entidades no gubernamentales: 2.Conclusiones. Las bajas calificaciones obtenidas en 11 de los 16 indicadores demuestran que las escuelas, las familias, las comunidades y el gobierno tienen que aunar esfuerzos para mejorar las oportunidades que tiene la población infantil y joven en México para desarrollar niveles de actividad física satisfactorios.(AU)

ABSTRACT The Lancet Commission on Hypertension identified that a key action to address the worldwide burden of high blood pressure (BP) was to improve the quality of BP measurements by using BP devices that have been validated for accuracy. Currently, there are over 3 000 commercially available BP devices, but many do not have published data on accuracy testing according to established scientific standards. This problem is enabled through weak or absent regulations that allow clearance of devices for commercial use without formal validation. In addition, new BP technologies have emerged (e.g. cuffless sensors) for which there is no scientific consensus regarding BP measurement accuracy standards. Altogether, these issues contribute to the widespread availability of clinic and home BP devices with limited or uncertain accuracy, leading to inappropriate hypertension diagnosis, management and drug treatment on a global scale. The most significant problems relating to the accuracy of BP devices can be resolved by the regulatory requirement for mandatory independent validation of BP devices according to the universally-accepted International Organization for Standardization Standard. This is a primary recommendation for which there is an urgent international need. Other key recommendations are development of validation standards specifically for new BP technologies and online lists of accurate devices that are accessible to consumers and health professionals. Recommendations are aligned with WHO policies on medical devices and universal healthcare. Adherence to recommendations would increase the global availability of accurate BP devices and result in better diagnosis and treatment of hypertension, thus decreasing the worldwide burden from high BP.(AU)

RESUMO A Comissão Lancet sobre Hipertensão Arterial identificou que uma iniciativa central para enfrentar a carga mundial da hipertensão arterial seria a melhoria na qualidade da mensuração da pressão arterial pelo uso aparelhos de pressão arterial validados quanto à acurácia. Atualmente, existem mais de 3 000 aparelhos de pressão arterial disponíveis comercialmente; entretanto, muitos não têm dados publicados sobre testes de acurácia realizados de acordo com padrões científicos estabelecidos. Este problema resulta de regulamentação fraca ou inexistente, o que permite a aprovação para uso comercial de dispositivos sem validação formal. Além disso, surgiram novas tecnologias de mensuração da pressão arterial (por exemplo, sensores sem algemas) sem consenso científico quanto aos padrões de acurácia. No conjunto, essas questões contribuem para a oferta generalizada de dispositivos de pressão arterial clínica e domiciliar com acurácia limitada ou incerta, levando a diagnóstico, gerenciamento e tratamento inadequados da hipertensão em escala global. Os problemas mais significativos relacionados com a acurácia dos dispositivos de pressão arterial podem ser resolvidos por regulamentação que imponha a obrigatoriedade de validação independente dos aparelhos de pressão arterial, de acordo com a norma universalmente aceita pela Organização Internacional de Normalização. Esta é uma recomendação fundamental para a qual existe uma necessidade internacional urgente. Outras recomendações essenciais incluem o desenvolvimento de padrões de validação especificamente para novas tecnologias de mensuração da pressão arterial e listas on-line de aparelhos com acurácia adequada que sejam acessíveis aos consumidores e profissionais de saúde. As recomendações estão alinhadas com as políticas da Organização Mundial da Saúde (OMS) sobre dispositivos médicos e atenção universal à saúde. A adesão às recomendações aumentaria a oferta global de dispositivos de pressão arterial com acurácia adequada e resultaria em melhor diagnóstico e tratamento da hipertensão arterial, diminuindo assim a carga mundial dessa doença.(AU)

[Freezing of Gait Detection System for Parkinson's Patients Based on Inertial Measurement Unit].

In order to detect freezing of gait of Parkinson's patients automatically, a system based on inertial measurement unit to detect freezing of gait for Parkinson's patients is established. The two inertial measurement units are respectively fixed on the left and right ankles of the patient to be measured, the freezing index is calculated by windowed Fourier transform, the freezing threshold is calculated based on the freezing index during normal walking, and the freezing index and the freezing threshold are compared to complete the detection of freezing of gait. The experimental results show that the number of freezing of gait occurrences in Parkinson's patients is accurately detected, and it has high sensitivity and specificity, which can assist doctors to objectively assess the patient's condition.

SLAM Project - Second-Level Diagnostic Assessment: Multidisciplinary approach to HIV Patients.

The aim of the study is to propose a multidimensional second-level diagnostic assessment to allow follow- up in the event physicians observe the presence of risk factors and/or active co-morbidities in HIV-infected patients. To develop our proposal, we chose the Delphi method that has been used for about 30 years in the healthcare field. The CISAI Group (Coordinamento Italiano per lo Studio dell'Allergia in Infezione da HIV) conducted this study. The first phase of the study provided identification of the questionnaire for second-level diagnostic assessment of HIV-infected patients. From March to July 2018 the questionnaire was submitted to 48 experts from 10 Italian HIV-dedicated sites. The questionnaire consisted of 102 items divided into 7 survey areas. The results can be summarized as follows: infectious disease diagnostics, 18 items reached agreement in 9 cases; osteoporosis diagnostics 12 items with 3 agreements; metabolic and cardiovascular diagnostics 13 items with 4 agreements; nephrology diagnostics 19 items with 8 agreements; hepatology diagnostics 12 items with 9 agreements; CNS diagnostics: 18 items with 7 agreements; psychological diagnostics and quality of life assessment (QoL) 10 items with no agreement. If these considerations are confirmed in required discussions and in-depth analyses, they will be able to produce an important indication in the drafting of national guidelines.

Comparison of posturographic outcomes between two different devices.

The Interactive Balance System (IBS), a posturography device for assessing posture control, is widely used in clinical and rehabilitation settings. However, data on the validity of the device are unavailable. Fluctuations of the center of pressure (COP) were measured in 24 healthy participants (age: 29 ±â€¯5 (mean ±â€¯SD) years, 12 females) synchronously using the IBS, which was rigidly mounted on a Kistler platform. Four different bipedal conditions were examined: eyes open or closed on stable or soft surfaces. Time series were compared using congruity (CON, proportion of the measurement time during which values of both devices changed similarly in direction), whereas IBS-specific postural outcomes were correlated with traditional postural control outcomes of the Kistler force platform. The time-displacement curves showed similar shapes for CON (>0.9) for each of the four standing conditions without differences between male and female participants (P > 0.39). The path length results of both devices showed very high linear associations, explaining on average 92% (medio-lateral) or 96% (anterior-posterior) of the common variance. The Kistler path length of the anterior-posterior direction revealed nearly perfect linear associations with the stability index of the IBS (r2 > 0.99). The results of this study indicate that the IBS provides valid posturographic results. Since the medial-lateral and anterior-posterior trajectories of the IBS can be used to calculate COP fluctuations, comparisons between different measurement systems are possible.

Accessibility of Medical Diagnostic Equipment for Patients With Disability: Observations From Physicians.

OBJECTIVE: To explore attitudes and practices of physicians relating to accessible medical diagnostic equipment in serving patients with mobility disability. DESIGN: Open-ended individual telephone interviews, which reached data saturation. Interview recordings were transcribed verbatim for qualitative conventional content analysis. SETTING: Massachusetts, the United States, October 2017-January 2018. PARTICIPANTS: Practicing physicians from 5 clinical specialties (N=20). INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Common themes concerning physical accessibility. RESULTS: Mean ± SD time in practice was 27.5±12.5 years; 14 practices had height-adjustable examination tables; and 7 had wheelchair-accessible weight scales. The analysis identified 6 broad themes: height-adjustable examination tables have advantages; height-adjustable examination tables have drawbacks; transferring patients onto examination tables is challenging; rationale for examining patients in their wheelchairs; perceptions of wheelchair-accessible weight scales; and barriers and facilitators to improving physical accessibility. Major barriers identified by participants included costs of equipment, limited space, and inadequate payment for extra time required to care for persons with disability. Even physicians with accessible examination tables sometimes examined patients seated in their wheelchairs. CONCLUSIONS: Even if physicians have accessible equipment, they do not always use it in examining patients with disability. Future efforts will need to consider ways to eliminate these access barriers in clinical practice. Given small sample size, results are not generalizable to physicians nationwide and globally.

Prospective study of the sensitivity of the Wood's lamp for common eye abnormalities.

OBJECTIVE: The Wood's lamp, a handheld instrument that uses long-wave ultraviolet (UV) light with magnification of 2-3 times, is commonly used by non-ophthalmologists for examining patients with eye complaints. The goal of current research was to determine the sensitivity and specificity of the Wood's lamp for common eye abnormalities. STUDY DESIGN: We examined a convenience sample of patients, 18 years of age and older, who presented for eye complaints to an urgent clinic of a large ophthalmology practice. This prospective observational trial was performed from December 2016 until July 2017. An ophthalmologist examined the patient's eyes with a Wood's lamp, followed by examination of the eyes using a slit lamp. The Wood's lamp was compared with the slit lamp, which served as the gold standard. RESULTS: There were 73 patients recruited. The mean age of study subjects (29 female and 44 male) was 49 years. The overall sensitivity of the Wood's lamp was 52% (38/73; 95% CI 40% to 64%). Based on the principal final diagnosis made with the slit lamp, the Wood's lamp only detected 9 of 16 corneal abrasions, 5 of 10 corneal ulcers, 5 of 9 corneal foreign bodies, 0 of 4 cases of non-herpetic keratitis, 1 of 2 cases of herpes keratitis, 1 of 5 rust rings and 18 of 28 other diagnoses. CONCLUSIONS AND RELEVANCE: Examination using the Wood's lamp fails to detect many common eye abnormalities. Our findings support the need for a slit lamp examination of patients with eye complaints whenever possible.

Comparison of a smartphone-based ECG recording system with a standard cardiac event monitor in the investigation of palpitations in children.

BACKGROUND: The AliveCor (Kardia) monitor attaches to a smartphone and allows a single-lead ECG to be recorded during symptoms. In 2016, we introduced the use of this smartphone device for investigating palpitations, without syncope, in children. The aim of our study was to review our experience with the smartphone device, comparing it with our previous standard conventional approach to cardiac event monitoring using the Cardiocall monitor, which uses skin electrodes and is given for a finite period. METHODS: Over a period of 24 months, 80 smartphone monitors were issued and compared with the most recent 100 conventional event monitors. The number of ECG recordings received, arrhythmias documented, quality of ECG recordings and patient satisfaction were evaluated. RESULTS: Median patient age was 11 years in the smartphone monitor group compared with 10 years in the conventional group. Seventy-nine of 80 (98%) patients with a smartphone monitor sent an ECG recorded during symptoms, compared with 62/100 (62%) from the conventional group. A total of 836 ECG recordings were sent from the smartphone monitors compared with 752 from the conventional group. Eight per cent of ECG recordings in each group were of inadequate quality for analysis. Twenty of 80 (25%) patients with a smartphone monitor had documented tachyarrhythmia compared with 6/100 (6%) patients with the conventional monitor (p<0.001). On comparison with the conventional approach, the smartphone monitor outperformed with respect to diagnostic yield and patient satisfaction. CONCLUSIONS: A smartphone-based event monitor allows simple, effective, long-term ECG event monitoring in children that is highly acceptable to the patient and parent.

Neurophysiological analysis of the clinical pull test.

Postural reflexes are impaired in conditions such as Parkinson's disease, leading to difficulty walking and falls. In clinical practice, postural responses are assessed using the "pull test," where an examiner tugs the prewarned standing patient backward at the shoulders and grades the response. However, validity of the pull test is debated, with issues including scaling and variability in administration and interpretation. It is unclear whether to assess the first trial or only subsequent repeated trials. The ecological relevance of a forewarned backward challenge is also debated. We therefore developed an instrumented version of the pull test to characterize responses and clarify how the test should be performed and interpreted. In 33 healthy participants, "pulls" were manually administered and pull force measured. Trunk and step responses were assessed with motion tracking. We probed for the StartReact phenomenon (where preprepared responses are released early by a startling stimulus) by delivering concurrent normal or "startling" auditory stimuli. We found that the first pull triggers a different response, including a larger step size suggesting more destabilization. This is consistent with "first trial effects," reported by platform translation studies, where movement execution appears confounded by startle reflex-like activity. Thus, first pull test trials have clinical relevance and should not be discarded as practice. Supportive of ecological relevance, responses to repeated pulls exhibited StartReact, as previously reported with a variety of other postural challenges, including those delivered with unexpected timing and direction. Examiner pull force significantly affected the postural response, particularly the size of stepping. NEW & NOTEWORTHY We characterized postural responses elicited by the clinical "pull test" using instrumentation. The first pull triggers a different response, including a larger step size suggesting more destabilization. Thus, first trials likely have important clinical and ecological relevance and should not be discarded as practice. Responses to repeated pulls can be accelerated with a startling stimulus, as reported with a variety of other challenges. Examiner pull force was a significant factor influencing the postural response.

Self-Taught Learning Based on Sparse Autoencoder for E-Nose in Wound Infection Detection.

For an electronic nose (E-nose) in wound infection distinguishing, traditional learning methods have always needed large quantities of labeled wound infection samples, which are both limited and expensive; thus, we introduce self-taught learning combined with sparse autoencoder and radial basis function (RBF) into the field. Self-taught learning is a kind of transfer learning that can transfer knowledge from other fields to target fields, can solve such problems that labeled data (target fields) and unlabeled data (other fields) do not share the same class labels, even if they are from entirely different distribution. In our paper, we obtain numerous cheap unlabeled pollutant gas samples (benzene, formaldehyde, acetone and ethylalcohol); however, labeled wound infection samples are hard to gain. Thus, we pose self-taught learning to utilize these gas samples, obtaining a basis vector θ. Then, using the basis vector θ, we reconstruct the new representation of wound infection samples under sparsity constraint, which is the input of classifiers. We compare RBF with partial least squares discriminant analysis (PLSDA), and reach a conclusion that the performance of RBF is superior to others. We also change the dimension of our data set and the quantity of unlabeled data to search the input matrix that produces the highest accuracy.

Assessment of the accuracy of portable monitors for halitosis evaluation in subjects without malodor complaint. Are they reliable for clinical practice?

Halitosis is defined as a foul odor emanated from the oral cavity, with great impact in quality of life and social restraints. Recently, the use of Breath Alert™ in research increased significantly. Halimeter™, another portable device, is often used in clinical practice. Nevertheless, not many studies have verified the accuracy and compared the results of both devices simultaneously. OBJECTIVE: To verify the accuracy of Breath Alert™ and Halimeter™ in patients without chief complaint of halitosis, using the organoleptic test (OT) as "gold standard." The second aim was to verify whether their concomitant use could enhance the diagnostic accuracy of halitosis. MATERIAL AND METHODS: A cross-sectional analytical study was performed. The quality of expired air of 34 subjects without chief complaint of halitosis was assessed. Two experienced examiners carried out the OT. Afterward, a third blinded examiner performed Halimeter™ (HT) and Breath Alert™ (BA) tests. RESULTS: The OT identified halitosis in 21 subjects (62%). The area under the ROC curve (95% confidence interval) was 0.67 (0.48-0.85) and 0.54 (0.34-0.75) for HT and BA, respectively. The accuracy for HT and BA was 59% and 47%, respectively. The combined usage of HT and BA provided 11 positive results, being 9 subjects (43%) out of the total of 21 positive cases. CONCLUSIONS: Halimeter™ and Breath Alert™ were not able to diagnose halitosis in non-complainer subjects at the same level as the organoleptic examination, since their accuracy were low. Our results suggest that such portable devices are not reliable tools to assess halitosis and may neglect or misdiagnose a considerable number of patients in clinical practice.