Telemonitoring of Home Oxygen Therapy: A Review of the State of the Art and Introduction of a New Cloud-based System

Home oxygen therapy allows patients requiring long-term oxygen therapy to receive care at home and helps improve the prognosis of patients with chronic respiratory failure. The usage conditions of oxygen concentrators, which are used to supply gaseous oxygen, and the effects of oxygen inhaled at a prescribed flow rate have not been confirmed in adequate detail. As a result of advances in information and communications technology, internet communication functions can now be incorporated into medical devices installed in patients’ homes. This allows time-series data on oxygen concentrator usage and biological variables to be stored on a server and accessed remotely by health care providers, enabling them to check the validity of home oxygen therapy and intervene appropriately. In Japan, telemonitoring of home oxygen therapy is covered by social insurance systems and is recognized as a new medical technology. This article reviews the usefulness of telemonitoring of home oxygen therapy and describes the cloud-based analytical system we have developed

A 48-Hour Holter ECG Study in Migraineurs during Usual Daily Activities

In order to clarify the condition of cardiac autonomic nervous activity in migraineurs, 48-h Holter electrocardiograms (ECGs) were carried out under free activity on 20 migraineurs during headache free periods and 20 healthy controls. We calculated hourly standard deviation (SD), root mean square successive differences (RMSSD), the proportion fo cycles during which the RR difference is > 50 ms (%RR50), low frequency heart rate fluctuation (LF), high frequency heart rate fluctuation (HF) and LF/HF ratio from heart rate variability, and obtained serial 24 data of these parameters. SD, RMSSD, %RR50 and HF are parasympathetic parameters, and LF/HF is sympathetic. These parameters were fit to cosines curve and analyzed circadian rhythms using the cosinor method. By group mean cosinor analysis, the vectors of the amplitude-acrophases of SD, RMSSD, %RR50, LF, HF and LF/HF significantly differed in the migraineurs from those in the controls. The significant differences of vectors of SD, RMSSD, %RR50 and HF indicate cardiac parasympathetic dysfunction. Midline estimating statistic of rhythms (MESORs) of those parameters did not significantly differ except in LF and LF/HF between both groups. MESORs of LF and LF/HF were significantly decreased in the migraineurs, which indicates cardiac sympathetic hypofunction. We concluded that migraineurs might have cardiac parasympathetic dysfunction and sympathetic hypofunction. By evaluating circadian rhythms using cosinor methods, the parameters of heart rate variability in migraineurs were significantly different from controls. Migraineurs may have some disturbance in their rhythm generator

Sample Entropy in Electrocardiogram During Atrial Fibrillation

【Background】 Atrial fibrillation (AF) is an arrhythmia commonly encountered in clinical practice. There is a high risk of thromboembolism in patients with AF. Nonlinear analyses such as electroencephalogram (EEG), electrocardiogram (ECG), and respiratory movement have been used to quantify biological signals, and sample entropy (SampEn) has been employed as a statistical measure to evaluate complex systems. In this study, we examined the values of SampEn in ECG signals for patients with and without AF to measure the regularity and complexity. 【Methods】 ECG signals of lead II were recorded from 34 subjects without arrhythmia and 15 patients with chronic AF in a supine position. The ECG signals were converted into time-series data and SampEn was calculated. 【Results】 The SampEn values for the group without arrhythmia were 0.252 ± 0.114 [time lag (τ) = 1] and 0.533 ± 0.163 (τ = 5), and those for the chronic AF group were 0.392 ± 0.158 (τ = 1) and 0.759 ± 0.246 (τ = 5). The values of SampEn were significantly higher in the group with chronic AF than in the group without arrhythmia (P < 0.01 for τ = 1, P < 0.004 for τ = 5). The constructed three-dimensional vectors were plotted in time-delayed three-dimensional space. We used time lags of τ = 5 and τ = 1. The shape of the loops of the three-dimensional space was better for τ = 5. 【Conclusion】 The values of SampEn from ECG for chronic AF patients were higher than for subjects without arrhythmia, suggesting greater complexity for the time-series from chronic AF patients. SampEn is considered a new index for evaluating complex systems in ECG

Circadian Rhythms of the Indices in the Diffusing Function of the Lung in Healthy Men

Diurnal variation in the lung diffusing function can influence the results of clinical evaluations. We investigated circadian rhythms from diurnal variations of the indices in the diffusing function of the lung. We measured the single breath lung diffusing capacity for carbon monoxide (DLCO) and alveolar volume (VA) in 13 healthy men, and also measured pulse rate at 7:00, 11:00, 15:00, 19:00 and 23:00. To identify the presence of a circadian rhythm from daily variations, data were analyzed by the group mean cosinor method. Significant circadian rhythms were apparent for DLCO/VA, VA and pulse rate. The acrophases for these parameters occurred at 20:15, 5:26 and 18:08, respectively. The double amplitude of DLCO/VA was statistically 4.72%. Our results suggest that diurnal variations in VA and pulse rate may contribute to the variation in DLCO/VA. Although DLCO/VA showed only a small change throughout the day, our findings suggest that the examination of DLCO/VA should be performed preferably at the same time of day in an individual

Human pulmonary dirofilariasis presenting as a small nodule with a cavity

A 73-year-old woman had a 4-year history of lung fibrosis from collagen vascular disease. She presented with a complaint of dry cough. A chest radiograph showed a 2-cm solitary pulmonary nodule with a small cavity in the right lower lobe. Preoperatively, we performed computed tomography of the chest and measured tumor markers. Video-assisted thoracotomy was performed because we could not rule out lung cancer. Pathologic analysis confirmed the presence of a granuloma with Dirofilaria immitis. In Japan, the incidence of human dirofilariasis has steadily increased and must be considered in the workup of cavitary pulmonary nodules

Pulmonary Alveolar Proteinosis Treated with Oral Ambroxol Hydrochloride and Bronchoalveolar Lavage

A 59-year-old man visited our hospital in June 1997 because of cough and dyspnea at rest. He was diagnosed as pulmonary alveolar proteinosis (PAP) by bronchoalveolar lavage (BAL) and transbronchial lung biopsy. The alveoli were distended with pink homogeneous material that showed staining with the periodic acid Schiff method. The concentration of surfactant protein A in BAL fluid was significantly increased. We treated the patient with oral ambroxol hydrochloride and therapeutic BAL. We believe that this combination of therapies is the first choice for the treatment of PAP

Membrane Humidifier That Does Not Require Addition of Water

We developed a new device called "a membrane humidifier" which does not require an external water supply. Fifteen patients inhaled humidified-oxygen from the membrane humidifier and were asked about their subjective impression. The relative humidity of room air and that of humidified-oxygen from the membrane humidifier or a conventional bubble water humidifier were measured with a digital hygrometer. The relative humidity of the oxygen humidified by humidifiers was measured after the gas was flowed into a partially opened 500-mL container for 30 min. None of the patients experienced dryness of the nose or throat. All patients answered that there was no difference in their subjective impression between breathing oxygen from the membrane humidifier and from the conventional bubble water humidifier. A significant regression was observed between the relative humidity of room air and that of the oxygen humidified from the membrane humidifier. The membrane humidifier was able to produce humidification very well. This new compact device can be used not only in hospitals, but can also be incorporated in home oxygen concentrators. This new device also saves the procedure of changing water

Idiopathic Interstitial Pneumonia with Increased Serum Levels of Cancer-Associated Antigens, CA19-9 and SLX

We report a case of idiopathic interstitial pneumonia (IIP) with elevated serum levels of carbohydrate antigen 19-9 (CA19-9) and sialyl Lewisx-i (SLX). A 67-year-old Japanese woman was admitted to our hospital with a fever, dry cough and dyspnea on exertion. She had previously been admitted and had then been diagnosed as IIP. The serum level of SLX, measured by radioimmunoassay (RIA), was markedly elevated (120 U/mL; cut-off, < 38 U/mL). The serum level of CA19-9, measured by RIA, was at a slightly high level (46 U/mL; cut-off, < 40 U/mL). The values of CA19-9 and SLX were changed during her clinical course. These cancer-associated antigens were immunohistochemically expressed on the hyperplastic bronchiolar epithelium, on the surface epithelium cells of microscopic honeycombing and on exudates in air space. Repeated damage to the lungs may have forced these antigens of the markers into the blood circulation, which may have resulted in the elevated serum levels of CA19-9 and SLX observed in this patient