Towards the personal healthcare

My name is Ming Huang, an assistant professor in Computational Systems Biology Laboratory. After I graduated from the University of Aizu in 2012, I was a postdoc fellow of NAIST for three and a half years. In this essay, I would like to share some of my thinking related to my study filed with you all.

The technologies featured with ‘wearable’, ‘nonconscious’ characteristics have been being popular in the past few years. It is one of the major domains that will output tremendous amount of data about personal health, and it is a major part of health informatics. Health informatics also involves the information of personal medical data in the form of electronic medical records (EMRs). On the other side, the blueprint of life−the genomic information, is the fundamental factor that bears great amount of information about the origin of life. These two domains together, with the personal health being its focus, are supposed to be able to describe how people adjust themselves to adapt to the external environment and stimulation. I had a great opportunity to engage in studies of the health informatics and now extend into bioinformatics in Computational Systems Biology Lab. Therefore, I would like to introduce parts of ours studies on health informatics and then my opinions about integrating the health informatics with bioinformatics for a novel understanding about human health.

Health informatics involves the aspects of acquiring, storing, retrieving and using of the healthcare information and I would only talk about the acquiring and using aspects here.

Acquiring healthcare information

There are two major sources of the healthcare information, one is generated in hospital describing personal medical, treatment histories and biopsy results. This information will become more useful and versatile when it is organized in the form of EMR. The other major source is the daily healthcare devices, which present in various forms such as wrist band, finger rings or even chair and bed. These real-time biomedical or health monitors allow for the characterization of intra-individual physiological variation and the inter-individual impact of circadian fluctuations on physiological measures. Further, they provide the clinicians and scientists with temporal resolutions to examine physiology and therefore a new way to study human diseases. Two studies about how to acquire vital signs (heart rate, respiration rate, blood pressure and temperature) by noninvasive/wearable modalities will be shown below.

Wearable deep body thermometer

Deep body temperature (DBT) is the temperature of the natural cavities, such as abdomen and thorax. It is conventionally measured by the invasive methods using catheter inserted into rectum or esophagus. Alternative measurements inside the mouth or ear canal are also adopted for intermittent measurement. However, the fluctuation of DBT bears more information in its temporal variation, e.g., the circadian rhythm, therefore a wearable DBT thermometer being able to keep track of the DBT will provide more information about the fluctuation of physiology.

To develop a wearable Deep Body thermometer, the dual heat-flux method (DHFM) has been used. It calculates the DBT based on the heat flux inside a probe as shown in Fig. 1 (a).  The double heat paths inside the probe shown by red arrows enable calculation of the DBT by the embedded temperature sensors. A substrate material with four embedded temperature sensors form the core of the probe. The substrate material has physical properties similar to those of skin and, when attached to the skin, most of the heat flow from the core body due to the difference between the DBT and the skin temperature will flow into the substrate material. After the initial period for heat equilibrium establishment, the DBT can be calculated with the four embedded temperature sensors. With this wearable modality, this DBT thermometer should be able to answer to the needs of realistic applications such as the prevention of heat stroke and the estimation/adjustment of disorder of circadian rhythm.

Fig. 1. Illustration (a) and the prototypes (b) of the wearable DBT thermometer.

Validations of device performance is on-going, what we can show is the studies about its accuracy and use in circadian rhythm estimation. We carried out a fast-changing CBT measurement (55 min, 12 subjects) inside a thermostatic chamber. When compared with a reference, the CoreTemp CM-210 by Terumo, the experiment shows 0.07 °C average difference of the prototype.

As for the circadian rhythm estimation, we performed long-term monitoring of CBT (24 h, 6 subjects), whose result shows no significant difference in parameters for the inference of circadian rhythm. A whole-length record of a subject is shown in Fig.2. It shows a very standard fluctuation of core body temperature that subjects to circadian rhythm. Red line denotes the measurement by the reference and blue line denotes the measurement by the DBT thermometer prototype. The cosine fitting curve was generated with the measurement by DHFM-based probe and shown in the broken black line.

Fig. 2. Instance of measurements of long-term monitoring of CBT and their fitting results by cosinor.

[1] M. Huang et al, “A Wearable thermometry for core body temperature measurement and Its Experimental Verification,” IEEE J. Biomed. Health Inform., 2016, Feb. for Epub 

Non-occlusive blood pressure measurement

Blood pressure (BP) is another important physiological parameter that can’t be measured in an easy way. The standard occlusive method is for intermittent measurement and needs an inflatable cuff to occlude the arterial supply to the distal limb, so as to estimate the systolic and diastolic BP. But actually, the temporal variation of the BP provides important information about the cardiovascular physiology. A non-occlusive way, the so-called cuffless method, that can measure BP continuously can fully retain the temporal information.

we therefore tried to develop an unobtrusive cuffless BP monitoring system. This system is based on pulse transit time (PTT), which is defined as the time taken for an artery pulse to travel between two arterial sites, to facilitate long-term home BP monitoring.

PTT can be simplified as the time delay between the peak of the R wave in the electrocardiogram (ECG) and the corresponding point in photoplethysmogram (PPG) signals as shown in Fig. 3.

Fig. 3. Definition of PTT. PTT is the time between the R-wave of ECG signal and the point in the ascending phase of PPG with maximum first derivative.

Theoretically, we can consider that the pulse wave velocity (PWV), the velocity at which the blood travels along the vessel, is proportional to the square root of elastic module (EM) of the vessel. Further, the EM of the vessel increases exponentially with BP. Therefore, we may be able to estimate the BP based on the PWV.

The proposed system mainly includes an ECG module, a PPG module and the control unit and was implemented into a chair as shown in Fig. 4.

Fig. 4. proposed chair-based cuffless blood pressure monitoring system for home healthcare. ECG electrodes and PPG sensor are mounted on the two armrests of the chair, respectively. The estimated BP results can be displayed on a tablet PC or a smartphone via Bluetooth communication.

This method can estimate the BP fluctuation around the basic point, and therefore, needs calibration periodically. The duration, the longer the better, is closely related to the way of the calibration, such as the user should calibrate under peaceful condition, the gesture should be consistent in both calibration and measurement. Our system takes advantage from the setup in the form of the chair and we carried out the experiment to monitor the BP for 60 days with only one calibration at the very first day. Fig. 5 shows the result in whole length, where most differences are within the range of ± 10 mmHg for the former 42 days. Data from more subjects should be collected, but it shows the possibility that this system is capable to provide a stable BP measurement within one month.

Fig. 5. Comparison of the reference BP and estimated BP for 60 days with only one calibration.

[2] Z. Tang et al, “A Chair-based Unobtrusive Cuffless Blood Pressure Monitoring System Based on Pulse Transit Time.,” IEEE J. Biomed. Health Inform., Accepted for publication Oct. 2016.

Using the healthcare information

With the great amount of data, we could do more than just plotting the raw data, in other words, using this data for modeling and prediction for the personal physiology will make full use of the data.  We should also bear in mind that the wearable and nonconscious devices are vulnerable to external influences, an appropriate way to remove the noisy signal so as to fully reveal its physiological significance initially, the so-called pre-processing, would be indispensable for the successive analyses.

As an example, a widely-acknowledged procedure for the pre-processing of electrocardiograph is the removal of high frequency noise and baseline wandering by corresponding filters. A low-pass finite impulse response (FIR) filter with its cut-off frequency around 40 Hz is suitable to remove high frequency noise, while a high-pass FIR filter with its cut-off frequency around 0.8 Hz is appropriate to remove the baseline wandering. For the signal acquired by wearable modality of relatively low quality, techniques such as biorthogonal wavelets would have a better performance.

With carefully processed healthcare information, we will be able to develop more sophisticated and elegant models for individual normal physiology, and enable identification of subtle or event-induced changes toward pathophysiology early in the course of disease progression.

Integration of health informatics with bioinformatics

Translating the finding from data-intensive biological studies to effective therapies, diagnostic acids and clinical interventions is common nowadays. Temporal profiling of a subject over 14 days using biological (genomics, proteomics, metabolomics and transcriptomics) and clinical phenotypes have revealed how longitudinal measurements of multiscale biological data showed the dynamics of biological pathway during illness and wellness [3].

This kind of works can be attributed to the relatively new domain of translational bioinformatics. Translational Bioinformatics is the development of storage, analytic, and interpretive methods to optimize the transformation of increasingly voluminous biomedical data, and genomic data, into proactive, predictive, preventive, and participatory health.

In the context of translational bioinformatics, individualized risk model being able to discern innocuous deviation from the average population from pathologic changes is of paramount importance.

It certainly is a fast-evolving and exciting domain, for there are a broad space to be explored. For example, how to choose the data streams and determine their clinical significances; how to embed these streams into EHR so as to integrate with biomedical data should be addressed before it can exert great impact on human health.

This domain will finally compose the intact image about personal health. And I do believe it will change the conventional clinical thinking about health in a way.

[3] R. Chen, et al. “Personal omics profiling reveals dynamic molecular and medical phenotypes.” Cell 148.6 (2012): 1293-1307.


私はソフトウェア設計学研究室の助教の崔恩瀞(チェ ウンジョン)です.私はソフトウェア設計学研究室で「ソフトウェア開発・保守の支援」に関する研究に取り組んでいます.私がこの「ソフトウェア開発・保守の支援」を自分の研究テーマとして選択した理由は,自分のIT会社で仕事をした経験からです.私は一度,韓国の大学を卒業した後にIT会社でソフトウェア開発者として仕事をしていました.ソフトウェアの開発や保守の仕事は楽しかった反面,仕事で様々な問題で苦労もありました.そして,その苦労を解決する技術に関して研究したいと思い,大学院に進学しました.


「コードクローン」とはソースコード中に存在する一致または類似したコード片であり,コピーアンドペーストなどのさまざまな理由により生成されます.ソースコードの中に修正されるコード片のコードクローンが存在すれば,その全てのコードクローンに対して修正の是非を検討する必要があり,一般的にコードクローンの存在が保守作業を困難にさせると言われています.下の図はapache ant 1.6.3から検出されたコードクローンの例です.互いにコードクローンになってるコード片に色がつけられています.











  1. 前処理:入力ソースコードに異なる正規化(空白の除外,識別子の正規化等)を適用し, MD5ハッシュ値に変換します.また,そのハッシュ値に基づいて同値類(同一ファイル群)に分割し,次にコーパス(同値類の代表であるファイルのセット)を生成します.
  2. クローン検出:コードクローン検出ツールCCFinderを使用してコーパス上のコードクローンを検出します.
  3. 後処理:CCFinderの出力,同値類などの情報に基づいてマッピングし,すべてのクローンセットを生成します.




ネットワークシステム学研究室助教 Duong Quang Thang (ズオン クアン タン)



具体的には,まず,自律分散管理型周波数共用技術において帯域使用率制御を適用しました.自律分散管理型周波数共用技術とは図1に示すように,複数の無線リンクが同一周波数帯域で同時に伝送する場合,各リンクが集中管理を受けず自律的に自分が使用すべき部分帯域を決定するメカニズムです.このようなメカニズムを実現する1つの方法として,各リンクが自分の信号電力が落ち込まない部分帯域を必要な量だけ獲得する周波数共用技術を提案しました.当然ながらこのように各リンクが利己的な周波数獲得方法を施すと,使用帯域の一部にリンク間干渉は発生するが,使用帯域率を適切に小さく設定することで干渉レベルを誤り訂正技術の許容範囲内に収めることができます.そこで,ネットワーク内で存在するリンクスの数に応じた帯域使用率制御方法を提案しました.上述した利己的周波数獲得方式を実現するために,各リンクでは通信路利得を推定しなければならないが,各リンクが観測できるのは共用周波数帯域のピンポイントな部分帯域しかありません.そこで,この拘束条件を満たしたNon-uniform Sampling理論に基づく通進路利得推定方法も併せて提案しました.

sdsc     sdsc_detail

図1 自律分散管理型周波数共用における帯域使用率制御方式の概念図



図2 非再生中継伝送における帯域使用率制御方式の概念図



図3 電界磁界ハイブリッド結合による平行二線路式ワイヤレス給電の安定化技術



図4 現行移動体通信システムの概略    図5 目指す次世代移動体通信システムの概略

これまで無線通信分野の研究で得られた知識を,今後,ワイヤレス給電技術の研究に適用したいと考えます.具体的な課題としては,寄生素子付きアンテナを用いたMagMIMO 給電技術の簡易化です.MagMIMOは,多数の送電コイルを用いて各コイルに流れる電流の周波数を制御することで受電機が存在する場所に磁界を集中させる技術です.このシステムでは,1つの送電コイルにつき1つの電源措置と制御措置が必要であるため,ハードウェアが複雑になります.そこで,無線通信において,アンテナの簡易化のために,寄生素子付きアンテナは有効です.寄生素子付きアンテナは,能動素子と周囲寄生素子との電磁界結合を適切に制御することで,少数の能動素子で本来と同等のビームフォーミング利得が期待できます.したがって,MagMIMOのハードウェア簡易化を目的とし,寄生素子付きアンテナを用いたビームフォーミング方式について検討したいと思います.


ソフトウェア基礎学研究室(教授:伊藤 実)は,2015年4月にモバイルコンピューティング研究室(モバ研)へ変わりました! モバ研では主に,実社会に存在する問題を抽象的に捉えて数学的にモデル化し,計算機で効率よく解くためのアルゴリズムを考案しています.今回はモバ研で行っている研究のいくつかをテーマに分けて紹介します.


交通渋滞は以前から大きな社会問題であり,二酸化炭素排出などの環境への悪影響や社会活動の滞りなどによって, 社会に悪影響を及ぼしています.当研究室では高度交通システム(Intelligent Transport Systems; ITS)を利用し,交通の効率化や快適化,渋滞の軽減のための研究を行っています.

Keywords: 高度交通システム(ITS), 信号制御, 車々間通信, ナビゲーション, ロードプライシング

GreenSwirl: Combining Traffic Signal Control and Route Guidance for Reducing Traffic Congestion


[1] Jiaxing Xu, Weihua Sun, Naoki Shibata and Minoru Ito : “GreenSwirl: Combining Traffic Signal Control and Route Guidance for Reducing Traffic Congestion,” in Proc. of IEEE Vehicular Networking Conference 2014 (IEEE VNC 2014), pp. 179-186, 2014-12-15.


Keywords: 無線ネットワーク, 移動体通信, モバイルアドホックネットワーク(MANET), センサネットワーク, 遅延耐性ネットワーク(DTN), データオフロード, 位置推定, 災害復旧, IoT



[2] 冨永 拓也, 柴田 直樹, 孫 為華, 伊藤 実 : 地下街におけるスマートフォンの光を用いた避難誘導方式の提案, DICOMO2014シンポジウム論文集, pp. 266-277, 2014.7.9.

A Proposal of an Endorsement Based Mobile Payment System for A Disaster Area

A payment system in a disaster area is essential for people to buy necessities such as groceries, clothing, and medical supplies. However, existing payment systems require the needed communication infrastructures (like wired networks and cellular networks) to enable transactions, so that these systems cannot be relied on in disaster areas, where these communication infrastructures may be destroyed. In [3], we propose a mobile payment system, adopting infrastructureless mobile adhoc networks (MANETs), which allow users to shop in disaster areas while providing secure transactions. Specifically, we propose an endorsement-based scheme to guarantee each transaction and a scheme to provide monitoring based on location information, and thus achieve transaction validity and reliability. Our mobile payment system can also prevent collusion between two parties and reset and recover attacks by any user. Security is ensured by using location-based mutual monitoring by nearby users, avoiding thereby double spending in the system.

[3] Babatunde Ojetunde, Naoki Shibata, Juntao Gao, and Minoru Ito : An Endorsement Based Mobile Payment System for A Disaster Area, in Proc. of The 29th IEEE International Conference on Advanced Information Networking and Applications (AINA-2015), pp. 482-489, Mar. 2015.


Keywords: 分散処理, GPGPU, クラウド, タスクスケジューリング, P2P, 負荷分散, 映像処理, 可視化, 3Dバーチャル空間, ストリームデータ処理



[4] 川上 朋也, 石 芳正, 義久 智樹, 寺西 裕一 : ライブ放送のための映像処理システムにおける負荷分散方式の設計と実装, 第8回データ工学と情報マネジメントに関するフォーラム (DEIM2016) 論文集, 2016年3月.





自然言語処理というのは、コンピュータの上で言語を扱う研究全般を指します。分かりやすい研究分野だと、ある言語の文章を別の言語の文章に変換する機械翻訳などが該当します。私はこの分野の研究を始めて5年ぐらいですが、今日は私がこれまで取り組んできた、自然言語処理の中でも少し変わった切り口の研究を紹介してその面白さを伝えられたらなと思っています。 “計算機で言語の謎を明らかにする” の続きを読む