Ahmet Ozdemir

An Analysis on Sensor Locations of the Human Body for Wearable Fall Detection Devices: Principles and Practice

Wearable devices for fall detection have received attention in academia and industry, because falls are very dangerous, especially for elderly people, and if immediate aid is not provided, it may result in death. However, some predictive devices are not easily worn by elderly people. In this work, a huge dataset, including 2520 tests, is employed to determine the best sensor placement location on the body and to reduce the number of sensor nodes for device ergonomics. During the tests, the volunteer’s movements are recorded with six groups of sensors each with a triaxial (accelerometer, gyroscope and magnetometer) sensor, which is placed tightly on different parts of the body with special straps: head, chest, waist, right-wrist, right-thigh and right-ankle. The accuracy of individual sensor groups with their location is investigated with six machine learning techniques, namely the k-nearest neighbor (k-NN) classifier, Bayesian decision making (BDM), support vector machines (SVM), least squares method (LSM), dynamic time warping (DTW) and artificial neural networks (ANNs). Each technique is applied to single, double, triple, quadruple, quintuple and sextuple sensor configurations. These configurations create 63 different combinations, and for six machine learning techniques, a total of 63 × 6 = 378 combinations is investigated. As a result, the waist region is found to be the most suitable location for sensor placement on the body with 99.96% fall detection sensitivity by using the k-NN classifier, whereas the best sensitivity achieved by the wrist sensor is 97.37%, despite this location being highly preferred for today’s wearable applications.

The Efficacy of Propranolol in Retinopathy of Prematurity and its Correlation with the Platelet Mass Index

ABSTRACT Purpose: Retinopathy of Prematurity (ROP) is a proliferative vitreoretinopathy which is one of the most frequent causes of blindness in children. In an attempt to find a solution to this important problem in preterm children, the search for new, effective treatment modalities with fewer side effects is underway. In our study, which was planned for this reason, we aimed to investigate the effects of propranolol treatment applied to cases of ROP in various stages during the second phase (known as the neovascularization-hypoxia phase) and to determine the correlation of these effects with the platelet mass index (PMI). Method: A total of 171 preterm infants at risk of ROP were selected randomly for inclusion in the study. All of the patients were classified according to their stage of ROP and were divided into control and treatment groups. While the cases in the control group were administered physiological saline solution, those in the treatment group were administered propranolol in the period that corresponded to the second stage of the disease. The thrombocyte and PMI values in the first and second stages of each study group were recorded. Results: A significant difference was found between the control and treatment groups of the stage 2 ROP study subjects. In the stage 2 ROP study group, no significant difference was detected between the control and treatment cases in terms of platelet counts in phase 1 or in the PMI values and the thrombolytic counts in phase 2. On the other hand, in phase 2 of the stage 2 ROP study subjects significant differences were detected between the control and treatment group in terms of PMI values. Conclusion: In the study, it was found in the stage 2 ROP study group that propranolol reduced the need for laser photocoagulation significantly. Also, in parallel to the efficacy of propranolol in this study group, a decrease was observed in PMI values.

Anaphylaxis due to ruptured pulmonary hydatid cyst in a 13-year-old boy.

Hydatid cyst, a common disease in the world, is usually transmitted to humans through dog feces. Hydatid cyst is caused by Echinococcus granulosus. Diagnostic interventions for hydatid cyst include physical examination and chest x-ray tomography. Although the treatment options of hydatid cyst vary according to the clinical findings of the patients, the primary treatment may be considered as surgery. We herein reported the case of a child hospitalized due to pneumonia who developed anaphylaxis as a result of the rupture of a pulmonary hydatid cyst.

Protective effect of vitamin D against hyperoxia-induced lung injury in newborn rats.

Preterm infants have risks of developing vitamin D deficiency. Thus we aimed to investigate the effect of vitamin D on hyperoxia‐induced lung injury in newborn rats.

Dermal and Ophthalmic Findings in Pseudohypoaldosteronism

Pseudohypoaldosteronism (PHA) is defined as a state of resistance to aldosterone, a hormone crucial for electrolyte equilibrium. The genetically transmitted type of PHA is primary hypoaldosteronism. Secondary hypoaldosteronism develops as a result of hydronephrosis or hydroureter. PHA patients suffer from severe hyponatremia and a severe clinical condition due to severe loss of salt can be encountered in the neonatal period. Dermal findings in the form of miliaria rubra can also develop in these patients. With the loss of salt, abnormal accumulation of sebum in the eye due to a defect in the sodium channels can also occur. In this paper, a case of PHA in a newborn showing typical dermatological and ophthalmological findings is presented.

Investigation of Sensor Placement for Accurate Fall Detection

Fall detection is typically based on temporal and spectral analysis of multi-dimensional signals acquired from wearable sensors such as tri-axial accelerometers and gyroscopes which are attached at several parts of the human body. Our aim is to investigate the location where such wearable sensors should be placed in order to optimize the discrimination of falls from other Activities of Daily Living (ADLs). To this end, we perform feature extraction and classification based on data acquired from a single sensor unit placed on a specific body part each time. The investigated sensor locations include the head, chest, waist, wrist, thigh and ankle. Evaluation of several classification algorithms reveals the waist and the thigh as the optimal locations.

The effects of thyroid function on retinopathy of prematurity

OBJECTIVES To assess whether TSH and fT4 have a role in the angiogenesis of vaso-obliteration and neovascularization which are the basic pathophysiology of ROP. METHODS In this retrospective case-control study, the control group (n = 56) included preterm newborns with risk for ROP while the laser group (n = 63) was recruited from cases who developed severe neovascularization and needed laser photocoagulation therapy. Considering the first (vaso-obliteration) and second (neovascularization) phases of the disease, in this study we researched the distribution of thyroid function tests between groups. RESULTS With regard to the first phase of the disease, TSH and fT4 showed no significant differences between the control and laser groups accordingly (P > 0.05). Likewise, in the second phase of ROP, there was no significant difference between the control and laser groups with respect to TSH and fT4 levels (P > 0.05). CONCLUSION We found that between the study groups, the levels of thyroid function tests did not have any significant differences, either in the first or the second phases of ROP which are the principal pathophysiology of the disease. Therefore, it was concluded that thyroid hormone values were not informative markers in the course of the disease in preterm babies at risk of developing ROP.

Comparing the Efficacy of 7%, 3% and 0.9% Saline in Moderate to Severe Bronchiolitis in Infants

BACKGROUND There is no standard treatment option in acute bronchiolitis. 3-7% hypertonic saline (HS) seems to be the effective treatment choice for reducing the hospitalization day. AIMS To compare the effect of nebulized 7% HS/salbutamol and 3% HS/salbutamol to 0.9% saline/salbutamol. The primary outcome measure was the effect of study drugs on the length of hospital stay (LOS). Secondary outcome measures were safety and efficacy in reducing the clinical severity score (CSS) at the 24 hours of the study. STUDY DESIGN Prospective, double-blinded randomized clinical study. METHODS The study consists of 104 infants. Groups were constituted according to the treatment they received: These are, group A - 0.9% saline/salbutamol, group B -3% HS/salbutamol and group C-7% HS/salbutamol. Heart beat, Bronchiolitis CSS and oxygen saturation of the patients were determined before and after nebulization. The patients were monitored for adverse reactions. RESULTS Length of hospital stay in group A, B and C were as follows; 72.0 (20-288) hours in group A, 64.0 (12-168) hours in group B and 60.0 (12-264) hours in group C. No significant differences was observed among three groups (p>0.05). CONCLUSION 7% HS and 3% HS does not have any effect to decrease LOS for infants with bronchiolitis.

Thyroid status of iodine deficient newborn infants living in central region of Turkey: a pilot study

BackgroundIodine deficiency (ID) during the fetal and neonatal periods can lead to neonatal hypothyroidism. This study was conducted to evaluate the effect of ID on the thyroid hormone level of newborns living in Turkey.MethodsBetween 1998 and 2013, 71 newborns with a urinary iodine concentration <100 μg/L were recruited into the study. Data on thyroid volume, free triiodothyronine (fT3), free thyroxine (fT4), thyroid stimulating hormone (TSH), and thyroglobulin (Tg) were collected from all newborns, and on breast milk iodine from their mothers. Infants who were classified as having congenital hypothyroidism (TSH >40 mU/L and fT4 <8.5 pmol/L) were treated with levothyroxine (n=26, T group), while the remaining infants remained untreated (n=45, UT group). Thyroid hormones were subsequently measured 7-14 days later in a sub-sample of both treated and untreated infants.ResultsThe average values at the time of admission were as follows [median (min-max)]. fT3: 5.0 (2.8-7.1) pmol/L, fT4: 7.7 (0.13-19.1) pmol/L, TSH: 75 (14-426) mU/L, Tg: 464 (226-1100) ng/mL, urinary iodine concentration (UIC): 30 (0-61) μg/L, breast milk iodine levels: 21 (10-150) μg/L, thyroid ultrasound (USG): 1.10 (0.24-1.95) mL for the T group; and fT3: 5.7 (1.7-12.7) pmol/L, fT4: 16.2 (9.9-33.5) pmol/L, TSH: 5.4 (0.63-41.8) mU/L, Tg: 171 (15-2124) ng/mL, UIC: 39 (0-90) μg/L, breast milk iodine levels: 47 (10-120) μg/L, thyroid USG: 0.75 (0.35-1.72) mL for the UT group. A significant difference was found between groups in respect to fT3, fT4, TSH and Tg levels. No significant difference in thyroid ultrasonography, UIC, and breast milk iodine levels was found between the two groups. The Tg levels of 50 out of 71 patients were measured, 40 (80%) of whom had Tg levels above the normal range (101 ng/mL).ConclusionsIn our country, despite the use of iodized salt, congenital hypothyroidism due to ID remains a problem. The Tg level of newborns can be used as a good indicator of ID.

A Newborn With Familial Hemophagocytic Lymphohistiocytosis Complicated With Transfusion Associated Graft Versus Host Disease

Hemophagocytic lymphohistiocytosis (HLH) is characterized by activation of cytotoxic T and natural killer (NK) cells, and macrophages related to a spectrum of hyperinflammatory disorders. The clinical findings mainly include high fever, cytopenia, splenomegaly, phagocytosis, and proliferation of histiocytes in lymphoreticular tissue. To the best of our knowledge, transfusion-associated graft versus host disease (TA-GVHD) in a 13-day old male newborn with HLH is being reported first time in the literature. The aim of this report was to emphasize the importance of blood products irradiation in the prevention of the development of graft versus host disease especially among high-risk subjects such as newborns with HLH.