Pub Date : 2018-12-03DOI: 10.3329/bjmp.v10i1.39149
H. Begum, M Abu Yousuf, K. S. Rabbani
Basin type solar stills were made with two types of top cover, transparent PVC sheet and another with glass sheet. A soaked black towel was at the base which was heated through green-house effect and contributed to the water for distillation. Productivity of these two basin type solar stills were studied at different tilt angles of the top transparent cover with ground surface (13o, 23o and 35o). The average amount of distilled water produced increased with the tilt angles for both types of cover materials, that for glass being much higher than that for PVC cover.Bangladesh Journal of Medical Physics Vol.10 No.1 2017 40-46
{"title":"Effect of top cover tilt angle with ground surface on productivity of basin type solar distillation unit","authors":"H. Begum, M Abu Yousuf, K. S. Rabbani","doi":"10.3329/bjmp.v10i1.39149","DOIUrl":"https://doi.org/10.3329/bjmp.v10i1.39149","url":null,"abstract":"Basin type solar stills were made with two types of top cover, transparent PVC sheet and another with glass sheet. A soaked black towel was at the base which was heated through green-house effect and contributed to the water for distillation. Productivity of these two basin type solar stills were studied at different tilt angles of the top transparent cover with ground surface (13o, 23o and 35o). The average amount of distilled water produced increased with the tilt angles for both types of cover materials, that for glass being much higher than that for PVC cover.Bangladesh Journal of Medical Physics Vol.10 No.1 2017 40-46","PeriodicalId":134261,"journal":{"name":"Bangladesh Journal of Medical Physics","volume":"66 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-12-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115452602","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2018-12-03DOI: 10.3329/bjmp.v10i1.39146
A. Amin, K. S. Rabbani
In biomedical instrumentation, computer based data acquisition system is required for recording of physiological parameters and bioelectric signals, which allows signal processing, display, analysis and storage in digital media. However, Most of the commercially available PC based Data Acquisition systems are of very high cost and requires specific commercial software, again at a very high cost. Moreover, if the data is not stored in raw binary or known format, it is not possible for the user to use the data in other system or software of their own choice. Therefore, a low cost, simple and open source PC based data acquisition system for biomedical application would be very useful for biomedical instrument developers and researchers in the low resource countries. In this work, we present such development of data acquisition system. The developed system utilizes an 8-bit ordinary low cost microcontroller and some electronic circuit component to develop the data acquisition system and implementation of USB 1.1 (Universal Serial Bus) interface to PC. The onboard 10-bit ADC of the microcontroller was used for analog data sampling. Two sampling and data transfer mode is implemented, (i) Continuous mode with low sampling rate (800 sample/sec) and practically real time plotting and (ii) Batch mode, with high sampling rate (76.9 k sample/sec) but with batch type plotting. To evaluate the system, PC side GUI (Graphical User Interface) software was also developed. The GUI of system shows that a test sinusoidal signal is reproduced very nicely without any amplitude and phase distortion within the frequency band of 1 to 10 KHz. The system is suitable for low frequency bioelectric signals like ECG, EEG etc. and as well as high frequency signal like EMG, NCV etc. The system is low cost, miniature, simple, and efficient and being used in several indigenously developed medical devices like ECG, EMG, NCV and FIM [Rabbani et al, 1999] at the authors’ department with excellent satisfactory results.Bangladesh Journal of Medical Physics Vol.10 No.1 2017 1-11
在生物医学仪器中，需要基于计算机的数据采集系统来记录生理参数和生物电信号，从而实现信号的处理、显示、分析和数字化存储。然而，大多数商业上可用的基于PC的数据采集系统成本非常高，并且需要特定的商业软件，成本也非常高。此外，如果数据不是以原始二进制或已知格式存储，则用户不可能在自己选择的其他系统或软件中使用该数据。因此，一个低成本、简单、开源的基于PC的生物医学应用数据采集系统对于资源匮乏国家的生物医学仪器开发和研究人员来说是非常有用的。在本文中，我们介绍了这样的数据采集系统的开发。所开发的系统采用一个8位普通低成本微控制器和一些电子电路元件来开发数据采集系统，并实现USB 1.1(通用串行总线)接口到PC机。采用单片机板载10位ADC进行模拟数据采样。实现了两种采样和数据传输模式，(i)低采样率(800个样本/秒)和实时绘图的连续模式和(ii)高采样率(76.9 k样本/秒)的批处理模式，但具有批处理式绘图。为了对系统进行评估，还开发了PC端GUI(图形用户界面)软件。系统的图形用户界面显示，在1 ~ 10khz的频率范围内，测试正弦信号可以很好地再现，没有任何幅度和相位畸变。该系统既适用于心电、脑电图等低频生物电信号，也适用于肌电、心电等高频生物电信号。该系统成本低、体积小、结构简单、效率高，已在笔者所处的几个自主研发的医疗设备中使用，如ECG、EMG、NCV和FIM [Rabbani et al .， 1999]，并取得了非常满意的效果。孟加拉国医学物理杂志Vol.10 No.1 2017 1-11
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This work was taken up to design a cost effective and simple domestic scale solar water distillation device for use in the coastal villages of Bangladesh where saline free drinking water is scarce. This study mainly looked at the feasibility of using stretched transparent PVC cover in solar distillation devices in lieu of traditionally used transparent glass sheet. To increase total evaporative surface area of the bottom of stills, those were covered with black cotton fabrics with extended fibers. For the same angle of inclination (130) of the transparent cover, the average amount of distilled water produced by the transparent PVC sheet covered still was about 42% of that collected from a glass sheet covered still. The reason behind this poor performance could be traced to the increased surface adhesion of condensed water droplets with the PVC cover, which essentially scattered sunrays away from the solar still. So the way to go is to find a suitable plastic sheet material that has reduced surface adhesion to water or to find a coating material that can reduce surface adhesion too. Unless this can be done, traditional glass covered solar distillation device still remains the cover material of choice.Bangladesh Journal of Medical Physics Vol.9 No.1 2016 11-16
{"title":"Effect of top cover material on productivity of solar distillation unit","authors":"H. Begum, M Abu Yousuf, K. S. Rabbani","doi":"10.3329/BJMP.V9I1.37303","DOIUrl":"https://doi.org/10.3329/BJMP.V9I1.37303","url":null,"abstract":"This work was taken up to design a cost effective and simple domestic scale solar water distillation device for use in the coastal villages of Bangladesh where saline free drinking water is scarce. This study mainly looked at the feasibility of using stretched transparent PVC cover in solar distillation devices in lieu of traditionally used transparent glass sheet. To increase total evaporative surface area of the bottom of stills, those were covered with black cotton fabrics with extended fibers. For the same angle of inclination (130) of the transparent cover, the average amount of distilled water produced by the transparent PVC sheet covered still was about 42% of that collected from a glass sheet covered still. The reason behind this poor performance could be traced to the increased surface adhesion of condensed water droplets with the PVC cover, which essentially scattered sunrays away from the solar still. So the way to go is to find a suitable plastic sheet material that has reduced surface adhesion to water or to find a coating material that can reduce surface adhesion too. Unless this can be done, traditional glass covered solar distillation device still remains the cover material of choice.Bangladesh Journal of Medical Physics Vol.9 No.1 2016 11-16","PeriodicalId":134261,"journal":{"name":"Bangladesh Journal of Medical Physics","volume":"4 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-07-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122059923","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Distribution of F-Latency (DFL) is a new neurological parameter conceived by the Biomedical Physics group of Dhaka University. Previous experimental studies have indicated that DFL, obtained from median nerve, varies with postures of the subject, particularly with the bending of the head. It agreed with the contention that bending of head might produce compression or stretching of nerve fibers as they come out of the vertebra, and that DFL is a sensitive parameter that gets affected by even such temporary changes. The present work was taken up with two objectives, i) to improve upon the earlier work by taking measurements with a few specific angles of head bending, particularly in the left and right directions, and ii) to provide a verification of earlier results. For bending of head to left and right sides, we chose 300 and 450 respectively. For forward and backward directions the angles were not measured and the subjects were asked to bend as much as they could without going beyond a comfort level. The study was carried out on 6 student volunteers aged between 24 and 26. The DFLs obtained with different postures of the head were analyzed to look for systematic trends in the changes, if any. Changes in several parameters like peak, mean, standard deviation, skewness and half-width in the rising and falling edges (down to 50 % height of the peak) were studied for different postures of head and neck which showed consistent changes.Bangladesh Journal of Medical Physics Vol.9 No.1 2016 1-10
f -潜伏期分布(DFL)是达卡大学生物医学物理小组提出的一种新的神经学参数。先前的实验研究表明，从正中神经获得的DFL随受试者的姿势而变化，尤其是头部的弯曲。它同意头部弯曲可能产生压迫或拉伸出椎体的神经纤维的论点，并且DFL是一个敏感参数，即使是这种暂时的变化也会受到影响。目前的工作有两个目标，1)通过测量头部弯曲的几个特定角度，特别是在左右方向上，来改进早期的工作，2)对早期的结果进行验证。对于头部向左和向右弯曲，我们分别选择300和450。对于向前和向后的方向，没有测量角度，受试者被要求在不超出舒适水平的情况下尽可能地弯曲。这项研究是在6名年龄在24到26岁之间的学生志愿者身上进行的。分析不同头部姿势的dfl，以寻找变化的系统趋势，如果有的话。研究了不同头颈部姿势的峰、均值、标准差、偏度和上升边缘和下降边缘的半宽等参数的变化(下降到峰高度的50%)，结果显示出一致的变化。孟加拉国医学物理杂志Vol.9 No.1 2016 1-10
{"title":"Changes in the distribution of F-latency (DFL) for different postures of head and neck","authors":"S. Sharmin, K. S. Rabbani","doi":"10.3329/BJMP.V9I1.37302","DOIUrl":"https://doi.org/10.3329/BJMP.V9I1.37302","url":null,"abstract":"Distribution of F-Latency (DFL) is a new neurological parameter conceived by the Biomedical Physics group of Dhaka University. Previous experimental studies have indicated that DFL, obtained from median nerve, varies with postures of the subject, particularly with the bending of the head. It agreed with the contention that bending of head might produce compression or stretching of nerve fibers as they come out of the vertebra, and that DFL is a sensitive parameter that gets affected by even such temporary changes. The present work was taken up with two objectives, i) to improve upon the earlier work by taking measurements with a few specific angles of head bending, particularly in the left and right directions, and ii) to provide a verification of earlier results. For bending of head to left and right sides, we chose 300 and 450 respectively. For forward and backward directions the angles were not measured and the subjects were asked to bend as much as they could without going beyond a comfort level. The study was carried out on 6 student volunteers aged between 24 and 26. The DFLs obtained with different postures of the head were analyzed to look for systematic trends in the changes, if any. Changes in several parameters like peak, mean, standard deviation, skewness and half-width in the rising and falling edges (down to 50 % height of the peak) were studied for different postures of head and neck which showed consistent changes.Bangladesh Journal of Medical Physics Vol.9 No.1 2016 1-10","PeriodicalId":134261,"journal":{"name":"Bangladesh Journal of Medical Physics","volume":"39 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-07-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126327391","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Spirometry, or measurement of respiration conventionally involves measurement of the time variation of volume or flow of air breathed in or out through the mouth using an air-flow sensor. Electrical impedance of thorax changes during breathing and conceptually this modality should be applicable in spirometry, but no attempts have been made so far. This paper describes the development of an electrical impedance based spirometer placing electrodes on four limbs so that the whole lung volume may contribute to the measurement. An impedance based measurement system (IBS) consisting of a constant current drive at 11 kHz and necessary voltage measurement circuitry was designed and developed for this purpose. A portable oscilloscope (PicoScope 2208A) was used for acquisition of the measured voltage signal to a PC and an algorithm in Matlab software was used to demodulate the time varying impedance from a carrier signal. The variation of impedance with time during forced expiration as measured by the implemented impedance measurement system was compared with that obtained using a standard bellows type commercial spirometer (Vitalograph) on eight volunteers, between 22 and 32 years of age. The subjects included smokers, non-smokers, and asthma patients. Repeatability of the measurements were satisfactory. The correlation coefficient between the spirogram obtained using the IBS and that obtained using standard spirometer varied from 0.81 to 0.99 indicating preliminary success of the proposed technique. However, a possible source of error is the bending of the body during forced expiration which, if prevented, may give a better outcome.Bangladesh Journal of Medical Physics Vol.9 No.1 2016 17-27
{"title":"Development of an electrical impedance based spirometer","authors":"Md Anas Ali, M. A. Kadir, K. S. Rabbani","doi":"10.3329/BJMP.V9I1.37304","DOIUrl":"https://doi.org/10.3329/BJMP.V9I1.37304","url":null,"abstract":"Spirometry, or measurement of respiration conventionally involves measurement of the time variation of volume or flow of air breathed in or out through the mouth using an air-flow sensor. Electrical impedance of thorax changes during breathing and conceptually this modality should be applicable in spirometry, but no attempts have been made so far. This paper describes the development of an electrical impedance based spirometer placing electrodes on four limbs so that the whole lung volume may contribute to the measurement. An impedance based measurement system (IBS) consisting of a constant current drive at 11 kHz and necessary voltage measurement circuitry was designed and developed for this purpose. A portable oscilloscope (PicoScope 2208A) was used for acquisition of the measured voltage signal to a PC and an algorithm in Matlab software was used to demodulate the time varying impedance from a carrier signal. The variation of impedance with time during forced expiration as measured by the implemented impedance measurement system was compared with that obtained using a standard bellows type commercial spirometer (Vitalograph) on eight volunteers, between 22 and 32 years of age. The subjects included smokers, non-smokers, and asthma patients. Repeatability of the measurements were satisfactory. The correlation coefficient between the spirogram obtained using the IBS and that obtained using standard spirometer varied from 0.81 to 0.99 indicating preliminary success of the proposed technique. However, a possible source of error is the bending of the body during forced expiration which, if prevented, may give a better outcome.Bangladesh Journal of Medical Physics Vol.9 No.1 2016 17-27","PeriodicalId":134261,"journal":{"name":"Bangladesh Journal of Medical Physics","volume":"18 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-07-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116868279","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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