**6. Effect of poverty on diagnosis treatment and control/eradication of CVD**

With the growing burden of NCDs worldwide, the 2011 United Nation (UN) high-level meeting adopted a political declaration on NCDs that aimed at a 25% reduction in premature mortality from the four main NCDs (cardiovascular diseases, chronic respiratory diseases, cancers, and diabetes) by 25% relative to their 2010 levels by 2025 (the 25 × 25 target) [36]. In 2015, the UN SGD-3 was adopted to reduce by one-third premature mortality from NCDs by 2030 [17]. To realise

**21**

*Poverty and Cardiovascular Diseases in Sub-Saharan Africa*

the SGD-3 target on health, a reduction in tobacco use, harmful alcohol use, salt intake, obesity, raised blood pressure, increased blood glucose and diabetes, and physical inactivity is essential [56]. Besides, treating people at high risk of CVD and ensuring a sustainable availability of medicines to treat NCDs and avoid potential complications is also critical [56]. The above measures are challenging to implement because of the regional poverty, underfunded healthcare systems and the absence of clear policies and strategies [57]. To overcome these challenges, governments and other key stakeholder groups need to instigate several measures that may reduce CVD morbidity and mortality, especially among the poor. These include researching to assess the optimal way to help diagnose CVD early and educate patients of the benefits of biomedical versus traditional medical approaches alongside lifestyle changes. In cognisance of the high levels of illiteracy among many of these patients, approaches such as pictograms are helpful in enhancing understanding [36, 58]. In addition, for governments to produce up-to-date guidelines that are robust and easy to use in electronic formats, with regular monitoring of prescribing patterns to improve the future quality of prescribing [59, 60]. This recognises that adherence to prescribing guidelines is seen as a better marker of the quality of prescribing than current WHO/INRUD criteria [61]. Alongside this, seek to instigate policies to enhance access to low-cost medicines, thereby reducing costly co-payments. This can potentially be achieved with the help of donors and pharmaceutical companies and exploring the potential for local manufacturing of multiple sourced medicines building on concerns during the COVID-19 pandemic [61]. In the meantime, exploration of the potential for aggressive procurement programmes since we have seen in Europe that such programmes have resulted in the prices of generic medicines used to manage CVD as low as 2% of pre-patent prices [62]. Issues of transport costs to clinics to effectively treat patients with CVD also needs to be researched further as lack of contact can be a significant barrier to adherence to medicines for NCDs [63]. In addition, exploring different methods to improve the convenience of medicine dispensing that reduces time off work building on current initiatives in

There are concerns about the rising burden of CVD in SSA, adding to the prevalent infectious diseases in the region. The increase in CVD is due to behavioural and metabolic risk factors resulting from the epidemiologic transition in the region. The intersection between poverty and CVD cuts through primordial, primary prevention and secondary prevention interventions. In the context of poverty in SSA, CVD prevention is a challenge due to competing demands to address the never conquered infectious diseases. With a weak healthcare system and out of pocket payment for the costs of CVD care, a significant proportion of individuals with CVD and their households are pushed into poverty. Besides, CVD affects a younger and productive

Consequently, CVD-related loss of productivity will push an additional number of individuals into poverty. Because of this, appropriate strategies are needed to address the rising burden of CVD across SSA, and these should include activities to address poverty issues. Activities include providing available funding and resources for effective screening for NCDs, especially CVD and diabetes, given high rates of patients not being diagnosed. Alongside this, improving the access and availability of medicines, especially where co-payments are an appreciable issue among patients. Multiple channels exist, including activities of donors as well as increasing local production. Alongside this, enhance educational input, especially

*DOI: http://dx.doi.org/10.5772/intechopen.98575*

South Africa and wider [27].

population in SSA than in the rest of the world.

**7. Conclusions**

#### *Poverty and Cardiovascular Diseases in Sub-Saharan Africa DOI: http://dx.doi.org/10.5772/intechopen.98575*

*Lifestyle and Epidemiology - The Double Burden of Poverty and Cardiovascular Diseases...*

crucial in reducing the overall burden and complications of RHD [44].

**4. The effect of CVD on poverty in Africa**

and an appreciable cause of premature mortality with a mean age of death as low as 25 years [43]. While medical and surgical management can reduce morbidity and mortality, poverty reduction and improvement of overall living standards are

CVDs occur approximately two decades earlier in SSA than in the rest of the world [5]. In the context of poverty and weak healthcare systems, patients with CVD in SSA have higher all-cause mortality and shorter lifespans than in the other parts of the world due to often limited access to healthcare. Over 50% of these patients die between 30 and 69 years of age, approximately ten years or more below the equivalent group in higher-income countries [45]. Consequently, death and disability attributable to CVD occur in the middle and economically productive age, affecting young families and the much-needed workforce in the region [45, 46]. Available evidence implicates stroke as the cause of the majority of CVD-related mortality in SSA [46]. With the absence of universal health coverage and robust health insurance systems among most SSA countries, patients and their families bear the costs of CVD care costs [47]. In some instances, patients forego treatment due to costs [47]. The impoverishing effect of out-of-pocket payments is increasingly pushing many individuals and families into poverty with family members affected by CVD [6].

**5. Poverty, illiteracy, and indigenous knowledge system effect on CVD**

**6. Effect of poverty on diagnosis treatment and control/eradication**

With the growing burden of NCDs worldwide, the 2011 United Nation (UN) high-level meeting adopted a political declaration on NCDs that aimed at a 25% reduction in premature mortality from the four main NCDs (cardiovascular diseases, chronic respiratory diseases, cancers, and diabetes) by 25% relative to their 2010 levels by 2025 (the 25 × 25 target) [36]. In 2015, the UN SGD-3 was adopted to reduce by one-third premature mortality from NCDs by 2030 [17]. To realise

Given the high cost and inaccessibility of biomedical care and medications for CVD, traditional healers are central to CVD treatment among patients in SSA [48, 49]. The spiritual underpinning of chronic diseases such as CVD, cultural beliefs, and taboos are reasons behind the preference of traditional healers over biomedicine as the first choice in some parts of SSA [50]. Consequently, it is not uncommon for individuals in the region to seek help from traditional healers to treat diabetes, hypertension, and stroke [51–53]. The belief that traditional healers are experts in treating and curing CVDs and their risk factors delays the transfer to biomedical care despite the clinical deterioration in some patients [50]. Those who transfer to biomedical care are less likely to maintain treatment compliance equivalent to traditional medicines. These culturally driven practices present the greatest threat to the treatment and control of CVDs and their risk factors [50]. Some cultural ideas partly explain the persistently low knowledge of CVDs, risk factors, and clinical symptoms in the SSA population [54]. Therefore, governments and other key stakeholder groups understanding these cultural-driven beliefs and practices are essential in devising strategies to improve health literacy in

**20**

**of CVD**

managing and controlling CVDs [55].

the SGD-3 target on health, a reduction in tobacco use, harmful alcohol use, salt intake, obesity, raised blood pressure, increased blood glucose and diabetes, and physical inactivity is essential [56]. Besides, treating people at high risk of CVD and ensuring a sustainable availability of medicines to treat NCDs and avoid potential complications is also critical [56]. The above measures are challenging to implement because of the regional poverty, underfunded healthcare systems and the absence of clear policies and strategies [57]. To overcome these challenges, governments and other key stakeholder groups need to instigate several measures that may reduce CVD morbidity and mortality, especially among the poor. These include researching to assess the optimal way to help diagnose CVD early and educate patients of the benefits of biomedical versus traditional medical approaches alongside lifestyle changes. In cognisance of the high levels of illiteracy among many of these patients, approaches such as pictograms are helpful in enhancing understanding [36, 58]. In addition, for governments to produce up-to-date guidelines that are robust and easy to use in electronic formats, with regular monitoring of prescribing patterns to improve the future quality of prescribing [59, 60]. This recognises that adherence to prescribing guidelines is seen as a better marker of the quality of prescribing than current WHO/INRUD criteria [61]. Alongside this, seek to instigate policies to enhance access to low-cost medicines, thereby reducing costly co-payments. This can potentially be achieved with the help of donors and pharmaceutical companies and exploring the potential for local manufacturing of multiple sourced medicines building on concerns during the COVID-19 pandemic [61]. In the meantime, exploration of the potential for aggressive procurement programmes since we have seen in Europe that such programmes have resulted in the prices of generic medicines used to manage CVD as low as 2% of pre-patent prices [62]. Issues of transport costs to clinics to effectively treat patients with CVD also needs to be researched further as lack of contact can be a significant barrier to adherence to medicines for NCDs [63]. In addition, exploring different methods to improve the convenience of medicine dispensing that reduces time off work building on current initiatives in South Africa and wider [27].


We are IntechOpen, the world's leading publisher of Open Access books Built by scientists, for scientists

7,100+ Open access books available

188,000+

International authors and editors

205M+ Downloads

156 Countries delivered to Our authors are among the

Top 1% most cited scientists

12.2%

Contributors from top 500 universities

Selection of our books indexed in the Book Citation Index in Web of Science™ Core Collection (BKCI)

## Interested in publishing with us? Contact<EMAIL_ADDRESS>
Numbers displayed above are based on latest data collected. For more information visit www.intechopen.com


**6. Conclusions**

This article aimed to examine the challenges confronting stakeholders in addressing the various strategies and methods of recruitment used by the Boko Haram terrorist group across the Lake Chad region. To do that, the article focused on understanding the recruitment strategies of terrorist organizations within the context of Boko Haram, assessed the various countermeasures by relevant stakeholders at the national, sub-regional, and regional levels and the challenges confronting them in curbing the threat of terrorist recruitment across the Lake Chad region.

The findings of the article suggest that Boko Haram, like most terrorist organizations, sustains itself by recruiting individuals and groups to carry out its attacks. It achieves that by applying various methods and tactics such as the *false of promise of better welfare and economic condition* in a society characterized by unemployment, poverty, and the absence of basic services for the people. Through abductions, kidnappings, and threats, individuals and groups are *forcefully conscripted* into joining Boko Haram. Using *cash loans* as a means to trap unsuspecting struggling traders by being willing to support their businesses is another strategy used by the terrorist group to recruit people. Finally, the instrumentalization of *religion and advancement in information technology, particularly the internet and its social media tools*, by the terrorists as a vehicle and a tool to radicalize individuals constitutes another strategy used by Boko Haram for recruitment. They brainwash unsuspecting individuals into believing that Western civilization is not only *haram* (forbidden), but underscores the essence of traditional family, religious, and societal values exhorted by *Islam*. Rogue clerics use this negative narrative to attract individuals into joining the movement into believing they are contributing to e ffecting meaningful social change in society.

The response by stakeholders to counter these strategies included various initiatives, policies, and legislation such as the National Action Plan for Countering Violent Extremism, the Regional Strategy

40 Interview with a Senior Lecturer and Cross-Cultural Negotiator with the Department of History and International Studies, University of Jos, Nigeria, 8 September 2019.

41 Interview, 8 September 2019.

for the Stabilization, Recovery, and Resilience among other multilateral engagements, which yielded minimal results. This is because stakeholders involved in combating the threat of Boko Haram are grappling with challenges relating to the inability to contextually identify the best strategy or approach to confront terrorism recruitment and terrorism in the region. As most terrorist organizations use violence to achieve their aims, countering their threat requires actors to understand the context and local dynamics that drive each terrorist group to determine the right strategy to prevent such groups. Another challenge identified in countering Boko Haram's recruitment strategy is centered on the gap or deficit in technology and the lack of trust among actors to identify, share, and report threat forces. For example, the lack of trust between o fficers of the MNJTF and members of a ffected communities has led to them accusing each other as acting as informants for the terrorists. This a ffects the e fforts to counter the activities of Boko Haram across Lake Chad. The third challenge is related to the inability of the state and its various agencies to show the capacity to coerce and convince citizens that it has the ability to address the threat of insecurity across the Lake Chad region. This is due to di fferent factors such as the failure of the state to implement various counterterrorism policies and initiatives, and the failure to secure and protect national and regional borders, thus creating an avenue for terrorist organizations to recruit and carry out various crimes. There is a lack of inter-agency collaboration to limit the activities of Boko Haram across Lake Chad, thus leading to a failure to address the endemic corruption of stakeholders involved in containing Boko Haram's presence in the northeast and Lake Chad.

Therefore, the article o ffers its recommendations and also suggests avenues for further studies as it relates to the measures to be taken by these actors in countering the challenges associated with counter-terrorist recruitment across the Lake Chad region:

42 Refers to a traditional community policing strategy where communities set up cells or clusters and meet regularly by sharing their security concerns and report suspected activities in their locality.

43 Phone Interview with a Senior Research Fellow at the Fort Hall School of Government in Nairobi, Kenya, 9 September 2019.

44 Phone Interview, 9 September 2019.

**Author Contributions:** Conceptualization, K.D.M. and U.K.; methodology, K.D.M., U.K. and S.A.; formal analysis, K.D.M., U.K. and S.A.; writing—original draft preparation, K.D.M.; writing—review and editing, K.D.M., U.K. and S.A.; supervision, U.K. and S.A. All authors have read and agreed to the published version of the manuscript.

**Funding:** This research received no external funding.

**Conflicts of Interest:** The authors declare no conflicts of interest.


*Article* **Application of an Improved Correlation Method in Electrostatic Gait Recognition of Hemiparetic Patients**

#### **Shanshan Tian, Mengxuan Li, Yifei Wang and Xi Chen \***

State Key Laboratory of Mechatronics Engineering and Control, Beijing Institute of Technology, Beijing 100081, China<EMAIL_ADDRESS>(S.T<EMAIL_ADDRESS>(M.L<EMAIL_ADDRESS>(Y.W.)

**\*** Correspondence<EMAIL_ADDRESS>Tel.: +86-010-6891-8017

Received: 2 April 2019; Accepted: 30 May 2019; Published: 3 June 2019

**Abstract:** Hemiparesis is one of the common sequelae of neurological diseases such as strokes, which can significantly change the gait behavior of patients and restrict their activities in daily life. The results of gait characteristic analysis can provide a reference for disease diagnosis and rehabilitation; however, gait correlation as a gait characteristic is less utilized currently. In this study, a new non-contact electrostatic field sensing method was used to obtain the electrostatic gait signals of hemiplegic patients and healthy control subjects, and an improved Detrended Cross-Correlation Analysis cross-correlation coefficient method was proposed to analyze the obtained electrostatic gait signals. The results show that the improved method can better obtain the dynamic changes of the scaling index under the multi-scale structure, which makes up for the shortcomings of the traditional Detrended Cross-Correlation Analysis cross-correlation coefficient method when calculating the electrostatic gait signal of the same kind of subjects, such as random and incomplete similarity in the trend of the scaling index spectrum change. At the same time, it can effectively quantify the correlation of electrostatic gait signals in subjects. The proposed method has the potential to be a powerful tool for extracting the gait correlation features and identifying the electrostatic gait of hemiplegic patients.

**Keywords:** gait analysis; gait correction; electrostatic gait signal; improved Detrended Cross-Correlation Analysis cross-correlation coefficient

#### **1. Introduction**

With the aging of the global population, strokes and other neurological diseases are occurring more frequently. Hemiparesis is one of the common sequelae of these diseases. Hemiplegic patients with body motor dysfunction often show a hemiplegic gait, among other symptoms. Assessing and restoring the walking ability of patients is the main objective of rehabilitation treatment for hemiplegic patients. The literature shows that the use of a variety of sensing methods to obtain hemiplegic gait information in clinical manifestations of hemiparesis [1,2], in order to study the kinematics and mechanics of gait signals and to objectively and quantitatively evaluate the pathological gait characteristics of hemiplegic patients, can provide effective support for the diagnosis and rehabilitation of hemiplegic patients [3,4].

At present, there are two main methods of gait measurement; one is the contact measurement method, which is usually obtained through the subject wearing an inertial unit sensor [5,6] or photoelectric sensor [7,8]; the other is the non-contact method, in which a video analysis system is used [9]. However, these common methods have some limitations. For example, wearing a sensor will affect the natural gait of the subject, while a video system compromises the privacy of the subject and is associated with data processing difficulties. Because of its non-contact, non-intrusive, and long-term continuous monitoring of gait signals, electrostatic detection has gradually become a research focus in the field of gait measurement [10,11]. In Chen's work [12], the equivalent capacitance model of the human body was established by theoretical deduction, and the correctness of the model was verified by simulations and measured signals. In the paper by Li [13], the gait parameters of the "gold standard" plantar pressure system were compared with the electrostatic measurement system, and this proved that the gait time parameters can be effectively measured by the electrostatic field sensing method. The electrostatic gait signal is a non-stationary time series, which contains various motion parameters of the human body, including time, frequency and nonlinear parameters, among others. The related research on feature extraction of the gait signal not only helps explain gait signal fluctuations, obtaining more gait parameters, but also helps to analyze the physiological health status of the human body.

Correlation is an important feature of the non-stationary time series. Correlation analysis of the electrostatic gait signal can demonstrate the inherent characteristics of the signal, and the implicit correlation between the signals. Detrended fluctuation analysis (DFA), first proposed by Peng, is used to study the long-range fluctuation of DNA sequences [14]. After that, DFA was widely used in financial time series [15], meteorological time series [16], and physiological signal series [17,18]. However, the traditional DFA cannot describe a complex biological signal sequence accurately because of its single scale index. In order to better describe the correlation of non-stationary time series, the bi-index analysis method and local index derivation method are studied in the works by Peng and Castiglioni [19,20]; however, there is a limitation in that they cannot describe in detail the dynamic correlation of the signal. Xia Jianan et al. [21] proposed a local moving window combined multiscale detrended fluctuation analysis (MSDFA) method in order to study the dynamics of the correlation of signals, wherein the scale index spectrum is obtained by fitting *logF*(*n*) and *log*(*n*) in a local moving window to distinguish the ECG signals of healthy and pathological groups, and effectively avoid the influence of extreme values with this method. The correlation expansion of a non-stationary time series can obtain the cross-correlation between two non-stationary time series. The Detrended Cross-Correlation Analysis (DCCA) method proposed by Podobnik and Stanley [22] was first used to calculate the cross-correlation between two non-stationary time series. It has been widely used in financial [23,24], atmospheric [25], physiological, and other fields [26]. However, the single scaling index in the DCCA results still has similar inadequacies to DFA; that is, only a single parameter is used to describe the sequence characteristics. In order to solve this problem, Yin Yi et al. [27] applied the improved multiscale detrended cross-correlation analysis (MSDCCA) method in order to obtain the scaling index spectrum. This method can better show the dynamic changes of the scaling index in different scaling windows, and effectively avoid the influence of outliers, so it has good robustness.

In order to quantitatively analyze the correlation of non-stationary signals, Zebende proposed a DCCA cross-correlation coefficient method based on DFA and DCCA [28]. However, we found that when this method was used to calculate electrostatic gait signals, the results would fluctuate abnormally near the crossover point [29,30]. Further, the traditional DCCA cross-correlation coefficient spectrum of electrostatic gait signals of the same type of subjects has random and incomplete similarity, so it was difficult to distinguish hemiplegic patients from healthy control subjects by the DCCA cross-correlation coefficient. In order to solve this problem, an improved DCCA cross-correlation coefficient method is proposed in this paper. Local moving windows are used instead of the fixed scales in the original algorithm. The results of the improved algorithm show a uniform and regular single peak structure at the crossover points, and have a stable curve structure; moreover, the results of different electrostatic gait signals for hemiplegic patients showed a relatively consistent trend. This method can effectively improve the stability of the DCCA cross-correlation coefficient, and quantify the correlation level of electrostatic gait signals under different scales.

The rest of this paper is arranged as follows: The second part will introduce the principle of electrostatic sensing method and the experimental process of electrostatic gait signal acquisition, as well as how to obtain electrostatic gait signals of hemiplegic patients and healthy control subjects; the third part will introduce in detail the improvement of the traditional DCCA cross-correlation coefficient method; and the fourth part uses the traditional method to analyze the electrostatic gait signals of subjects, from which we find that the traditional method has some shortcomings in the analysis of electrostatic gait signals. Then, we use the improved method to analyze the electrostatic gait signals. Through a comparison between the traditional method and the improved method, it can be concluded that the improved method is more suitable for the correlation analysis of electrostatic gait signals. This method can be better applied to the correlation analysis of human electrostatic gait signals.

#### **2. Methods**

#### *2.1. Principle of Electrostatic Field Induction in the Human Foot*

The electrostatic phenomenon is a ubiquitous physical phenomenon. The human body is charged with electrostatic energy during movement due to friction between the body and the clothes, as well as friction between the sole and the ground [31,32]. Therefore, with the movement of the foot during walking, the electric field around the human body will change [33]. In Chen's research [12], based on the principle of the electrostatic field, the equivalent model of the human body was established. Because the human body has a certain charge, it will produce equivalent capacitance with the surrounding environment, including the direct coupling capacitance *Cf* generated by human feet contacting the ground through the sole, and other capacitance *Cr* (*i* = 1, 2 ...). The two capacitors are connected in parallel to form the total capacitance of the human body (Formula (1)). The equivalent capacitance model of the human body is shown in Figure 1.

∞

*Cri* (1)

*Ch* = *Cf* +

**Figure 1.** Sketch of the human body equivalent capacitance model.

The left and right feet alternately leave the ground when walking. The capacitance between the foot and the ground is equivalent to a variable capacitance which connected to the height of the foot from the ground in series with *Cf*. The capacitance value becomes *C*, resulting in dynamic changes of electrostatic field around the human body. As in the literature [12], assuming that the charge of the human body is *QB*, the induced current *I* placed on the sensing electrode at a certain distance from the subject is shown in Formula (2).

$$I = \frac{dQ\_B}{dt} = \mathcal{C}\frac{d\mathcal{U}\_B}{dt} \propto \frac{1}{S\_s}\frac{d}{dt}(h(t)) - \frac{h(t)}{S\_s^2}\frac{dS\_s}{dt} \tag{2}$$

*UB* is the induced potential generated during human walking, *h*(*t*) is the height function of human feet leaving the ground when walking, and *Ss* is the effective bottom area of *h*(*t*) from the ground height. The first item in Formula (2) represents the current generated by the foot movement before the foot leaves the ground, and the second item in Formula (2) represents the current caused by the foot and leg movement after the foot leaves the ground completely. Therefore, when the tester moves near the electrodes, we can obtain the electrostatic induction current caused by human motion under non-contact conditions, and then obtain the relevant parameters of the gait by analyzing the current waveform obtained.

#### *2.2. Human Electrostatic Gait Measurement System*

The electrostatic signal sensing system includes the induction electrode, electrostatic sensing circuit, signal acquisition and processing circuit. The system schematic diagram is shown in Figure 2. In this system, a copper foil planar electrode is used as the electrode material. The shape of the electrode is a circle with a diameter of 90 mm. The electrostatic sensing circuit allows the amplification and filtering of the electrostatic signal, and realizes the conversion and amplification from the induced charge to the current to the voltage, thereby converting the weak induced charge amount into a voltage signal that can be processed. A low-pass filter with a cut-off frequency of 20 Hz was added before A/D conversion in order to prevent the measured signal from being disturbed by the power frequency signal of the power grid. The signal acquisition and processing circuit converts the amplified and filtered analog signals into digital signals using an A/D conversion with high precision and a wide voltage input, and then processes the collected signals using a microcontroller unit. The sampling frequency of the system is 1 kHz, and the sampled data is sent to a personal computer for storage and processing. According to [13], the current intensity of the induced current is inversely proportional to the distance between the human body and the induction electrode, and the maximum induced current can be generated when the human body directly faces the induction electrode. Therefore, in order to obtain a better gait electrostatic signal, the subject is required to tread 1 m in front of the electrostatic induction electrode.

**Figure 2.** Schematic of the electrostatic sensing system.

#### *2.3. Gait Measurement Experiment*

In this experiment, 10 hemiparetic patients and 10 healthy control subjects participated in data collection. The experiment recruited 10 hemiparetic patients (six males and four females) from the Zhongshan People's Hospital of Guangdong Province, China, as the pathological group. Their average height was 1.68 m (height range: 1.58~1.76 m), the average weight was 68.7 kg (56~78 kg), and the average age was 46 years (age range: 31~60 years old). The selection criteria for the hemiparetic patients was: (1) Unilateral hemiparesis after their first stroke, and the condition has been confirmed by computed tomography (CT) or nuclear magnetic resonance (MRI) imaging; (2) able to continuously step or walk for at least three minutes without any help or auxiliary equipment; (3) understands the external orders and follows the experimental procedures; (4) suffers no other diseases known to affect the gait [34]. This research was approved by the Ethics Committee of Zhongshan People's Hospital, and an informed consent form was signed by each subject.

The healthy control group had no neurological damage (six males and four females). Their average height was 1.73 m (height range: 1.58~1.81 m) and the average weight was 61.7 kg (45~78 kg). The average age was 28 years (age range: 24–33 years old).

All subjects gave their informed consent for inclusion before they participated in the study. The study was conducted in accordance with the Declaration of Helsinki, and the protocol was approved by the Ethics Committee of Zhongshan People's Hospital.

In the experiment, the electrostatic testing equipment was placed on a triangle stand at a height of 1 m from the ground. The healthy control group and the hemiplegic patients wore ordinary rubber sole shoes, and they were required to tread at a distance of 1 m in front of the electrostatic induction electrode. The subjects were required to tread in situ at a normal pace. Two groups of signals from the hemiplegic patients and healthy controls were obtained; that is, a total of 40 groups of electrostatic gait signals were collected, each of which was about 60 s in length. The ambient temperature and humidity ranged from 20 to 25 ◦C, and from 50% to 60%, respectively.

#### *2.4. Preprocessing of the Experimental Data*

Figure 3a,b shows the original gait signals of a healthy control person and a hemiplegic patient. The signals are digitally filtered and normalized to intercept 50 s of data from the complete signals. From the figure, we can see that the amplitude of the healthy control is more stable than that of the hemiplegic patient, and the gait cycle of the healthy control is shorter than that of the hemiplegic patient.

**Figure 3.** Schematic diagram of the original electrostatic gait signal. (**a**) Preprocessed electrostatic gait signals of a healthy control; (**b**) Preprocessed electrostatic gait signals of a hemiplegic patient.

#### *2.5. Improved DCCA Cross-Correlation Coe*ffi*cient Method*

The DCCA cross-correlation coefficient method has the characteristic of quantifying the cross-correlation level between two non-stationary time series. The DCCA cross-correlation coefficients of two non-stationary time series *x*(*i*) and *y*(*i*) are defined as:

$$\rho\_{\text{DCCA}}(n) = \frac{f\_{\text{DCCA}}^2(n)}{f\_{\text{DFA}}(n) \cdot f\_{\text{DFA}y}(n)}\tag{3}$$

The DCCA cross-correlation coefficient is calculated from the DFA and DCCA of the sequence. When dealing with electrostatic gait signals, this method is sensitive to the fluctuations of *fDFA* and *fDCCA*; it cannot accurately and quantitatively reflect the correlation level. The local moving window can display the details of physiological signal dynamic change and has good robustness. This paper proposes an improved DCCA cross-correlation coefficient algorithm based on the local moving window.

The improved DCCA cross-correlation coefficient method is described as follows: calculate the sample sequence to get the detrended variance function *fDFAx*(*n*) and *fDFAy*(*n*), and detrended covariance function *fDCCA*(*n*), where *n* is the scale. The fluctuation function curves are divided by the local moving window, then the data in each window is fitted. The expression of the fitted line can be expressed as (α·*n* + *b*), where α is the slope of the line, which can also be regarded as the scale index in each local window, while *b* is the only parameter of the currently fitted straight line in the correlation analysis [21,27]. We are only focused on using the scale index to quantify the correlation, so parameter *b* is not discussed. Therefore, every window DCCA cross-correlation coefficient can be represented as:

$$\rho\_{\text{DCCA}}(n) = \frac{\left(a\_{\text{DCCA}} \cdot n\right)^2}{\left(a\_{\text{DFA}} \cdot n\right) \cdot \left(a\_{\text{DFA}} \cdot n\right)}, \left(n \in \text{wi} \right) = [\text{c.d}], i = 1, 2, \dots, m\text{)}\tag{4}$$

The method for dividing the local moving window is described as follows: For the sample data with the data length *N*, set the range of *n* as (5 < *n* < *N*/10), then the partial moving window is divided. *wi* = [*c*, *d*] (*i* = 1, 2, ... , *m*) is expressed as each local moving window, *c* is the starting value, *d* is the ending value, the starting value interval is 5, and the ending value is five times the starting value, *m* is the number of local moving window. *swi* indicates the scaled median value of each window, α*wi* indicates the scale index in the corresponding window, and α*w* = {α*w*1, α*w*2, ... , α*wm*} is the scale index spectrum.

After calculating all the window data, the above formula can be improved to Formula (5):

$$\rho\_{\text{MSDCCA}}(\mathbf{s}\_{\text{wi}}) = \frac{\left(\alpha\_{\text{wi},\text{DCCA}}\right)^2}{\left(\alpha\_{\text{wi},\text{DFA}}\right)\cdot\left(\alpha\_{\text{wi},\text{DFA}}\right)'} (i = 1, 2, \dots, m) \tag{5}$$

We call ρ*MSDCCA* the multi-scale detrended cross-correlation coefficient. In the results, ρ*MSDCCA* > 0 indicates that there is positive cross-correlation between sequences, while ρ*MSDCCA* < 0 indicates that there is an anti-cross-correlation between sequences. The dynamics of the sequence and the inherent complex structure of the sequence can be observed from the curve of ρ*MSDCCA* changing with *swi*.

#### **3. Results**

In this part, we analyzed the electrostatic gait signal of the hemiplegic patients and the healthy control subjects with the traditional method. We found that the traditional method had some deficiencies in the analysis of the electrostatic gait signal correlation. Then, the electrostatic gait signal was analyzed by the improved method proposed in this paper. The results showed that the improved method improved the stability and accuracy of the data results compared with the traditional method, and helped to better identify the electrostatic gait signal of hemiparesis.

#### *3.1. Analysis of the Electrostatic Gait Signal with the Traditional Method*

DCCA is used to analyze the correlation between two non-stationary time series, and has been widely used in finance, atmosphere, physiology, and other fields [23–26]. In this paper, the electrostatic gait signals of hemiplegic patients and healthy control subjects are analyzed with the DCCA method, and the logarithmic curve of the cross-correlation fluctuation function and the scale of the electrostatic gait signals are obtained, as shown in Figure 4. From graph (a), we can see that all the cross-correlation wave functions of healthy controls have good consistency, and the curves have a crossover point (*n*=500). The cross-correlation index spectrum of the electrostatic gait signals of the healthy controls is obviously divided into two sections, with a single index (α*DCCA* = 1.84). From graph (b), we can see that the cross-correlation wave function curves of all hemiplegic patients are scattered. There are two crossover points (*n*1 = 60, *n*2 = 1200). The cross-correlation index spectrum of the electrostatic gait signals of hemiplegic patients is obviously divided into three segments. There are two indices for the electrostatic

gait signals of hemiplegic patients (α*DCCA*1 = 1.22, α*DCCA*2 = 1.54). In Figure 4b, the waveform functions of different samples of hemiplegic patients show chaotic waveform characteristics after the first crossover point. This phenomenon is related to the difference of walking ability between hemiplegic patients, but the waveform characteristics cannot be explained by a single index.

**Figure 4.** DCCA analysis of healthy controls (**a**) and hemiplegia patients (**b**).

Although the cross-correlation wave function spectrogram of the electrostatic gait signals of subjects calculated by the DCCA method can show the difference between them, the long-range cross-correlation of the electrostatic gait signals of hemiplegic patients can be seen from a single index that is weaker than that of the healthy controls. However, this difference is small, and the cross-correlation index cannot quantify the strength of cross-correlation between signals.

DCCA cannot quantify the correlation of electrostatic gait signals. In this paper, the DCCA cross-correlation coefficient method is used to analyze the electrostatic gait signals quantitatively. This method is also widely used in physiological signals [35]. The DCCA cross-correlation coefficient method is defined by DFA and DCCA to quantitatively study the cross-correlation between non-stationary time series. The electrostatic gait signals of hemiplegic patients and healthy controls were calculated and analyzed by the DCCA cross-correlation coefficient method. Figure 5 shows the analyzed electrostatic gait signals of hemiplegic patient 5 (hemi 5) and healthy control 1 (control 1). We can see from the graph that the spectrum of ρ*DCCA* in hemiplegic patient 5 fluctuates greatly. The first peak (ρ*DCCA* = 0.69) appears at the scale *n*1 = 54, and then the curve shows a downward trend and a disorderly fluctuation trend. The second peak (ρ*DCCA* = 0.68) appears at the scale *n*2 = 967, and then the curve decreases and produces two small peaks. The scales corresponding to wave peaks are similar to those of crossover points in DCCA, and on all scales, ρ*DCCA* = 0.54 ± 0.06. For healthy control 1, the fluctuation of the spectrogram of ρ*DCCA* was relatively stable, but there was a peak fluctuation on scale *n* = 540 (ρ*DCCA* = 0.83) and ρ*DCCA* = 0.69 ± 0.06 on all scales.

The DCCA cross-correlation coefficient can quantify the correlation of the electrostatic gait signals in hemiplegic patients and healthy controls. After DCCA cross-correlation coefficient analysis of data from all hemiplegic patients and healthy controls, we found that the fluctuation of ρ*DCCA* near the crossover point was a common phenomenon, showing a chaotic fluctuation of one main peak and several sub-peaks. The trend of the DCCA cross-correlation coefficient spectrum of electrostatic gait signals of the same type of test population was random and similar.

**Figure 5.** Spectrum of ρ*DCCA* in healthy control 1 and hemiplegic patient 5.

Due to the different fluctuation characteristics of time series on different time scales, the crossover point phenomenon appears in the DFA and DCCA results, and the complex fluctuation phenomenon appears near the crossover point of the cross-correlation index spectrum, which will affect the quantitative judgment of the cross-correlation. The traditional method has some limitations in the analysis of electrostatic gait signals, so we need to improve the traditional method for better analysis of electrostatic gait signals.

#### *3.2. Improved DCCA Cross-Correlation Coe*ffi*cient Method for Electrostatic Gait Signal Analysis*

Because the traditional DCCA cross-correlation coefficient method has some limitations, the improved method is used to analyze hemiplegic patient 5 and healthy control 1. As shown in Figure 6, we can see from the graph that the spectrum of ρ*MSDCCA* in hemiplegic patient 5 first decreases, then rises, and finally tends to be stable. The scale window *sw*1 = 160 has a trough, the correlation coefficient spectrum in the 160 < *sw* < 589 interval shows an increasing trend, the scale window *sw*2 = 589 has a peak, and the correlation coefficient of *sw* > 589 first decreases to a stable trend. The correlation coefficients near the peak and trough did not fluctuate significantly in the results of ρ*MSDCCA*. In contrast, the spectral line of healthy control 1 was relatively stable and showed no obvious fluctuation in the whole scale window, and the range of healthy control 1 was ρ*MSDCCA* = [1.4, 1.6].

**Figure 6.** ρ*MSDCCA* spectrograms of healthy control 1 and hemiplegic patient 5.

Finally, the improved method was used to analyze the electrostatic gait signals of all subjects, and the correlation coefficient spectra of ρ*MSDCCA* of hemiplegic patients and healthy controls were obtained, as shown in Figure 7. The red bold line in the figure represents the average of all data changes. Figure 7a is a spectrogram of the coefficients of ρ*MSDCCA* of the healthy control group. The curve tends to be stable in the window scale range. The range of ρ*MSDCCA* is [1.3, 1.8], and the mean and standard deviation are 1.45 ± 0.12. The gait signals of the healthy control group have a better correlation. The coefficient curve of ρ*MSDCCA* in the hemiplegic patient group is shown in Figure 7b. From the graph, we can see that the curve first has a downward trend and then an upward trend, and tends to be stable. The fluctuation of the ρ*MSDCCA* curve in the hemiplegic patients is closely related to the crossing point. The stability range of ρ*MSDCCA* is [0.6, 1.6], and the mean and standard deviation are 0.93 ± 0.26.

**Figure 7.** Result curve of ρ*MSDCCA*. (**a**) Analytical curves of ρ*MSDCCA* of all healthy controls with respect to the change of moving windows; (**b**) Analytical curves of ρ*MSDCCA* with the moving window in all hemiplegic patients.

From the spectrum of hemiplegic patients and healthy controls calculated by the improved method, we can clearly see the difference between them, meaning it is possible to effectively distinguish the hemiplegic patient from the healthy control easily. In addition, it can be seen from the spectrum of ρ*MSDCCA* that the local variation trend of correlation coefficients near the crossover point is identical, with many similarities and good stability. Moreover, the improved method can quantitatively show the difference between the correlation of the gait signals of two groups of subjects, and it can also reflect the differences of walking ability between individual hemiplegic patients.

#### **4. Conclusions**

This study analyzes the correlation between the electrostatic gait signals of hemiparetic patients and healthy controls by using an improved method which combines the local moving window method and traditional DCCA cross-correlation coefficient method. Using the improved method to analyze the electrostatic gait signal can mitigate the weaknesses of the traditional method, such as the random trend changes and incomplete similarity. In this paper, the electrostatic gait signals of hemiparetic patients and healthy controls were collected, and the improved method was used for gait analysis. Compared with the ρ*MSDCCA* coefficient of the healthy control group, the mean value of the ρ*MSDCCA* coefficient of the hemiparetic patients was smaller, and the trend of change was more complicated, reflecting that the gait stability of the hemiparetic patients was weaker than that of the healthy controls, additionally, a poor correlation was obtained. The improved method can obtain the dynamic changes of the scale index under the multi-scale structure, and quantify the gait difference between the hemiparetic patients and the healthy controls.

We only collected one minute of the patients' gait signal data due to their weakened mobility. This paper does not consider the difference in the gait signal between individual patients due to different rehabilitation stages, which can be considered a limitation. In future research, we will obtain more abundant experimental data, and conduct more in-depth research based on the different rehabilitation stages of hemiparetic patients, and then obtain more accurate and effective characteristic parameters. In the future, multiple characteristic parameters could be used to analyze various abnormal gaits, such as the hemiparesis and Parkinson gaits.

**Author Contributions:** Conceptualization, S.T. and X.C.; Data curation, M.L. and Y.W.; Formal analysis, M.L. and Y.W.; Funding acquisition, X.C.; Investigation, S.T. and M.L.; Methodology, S.T.; validation, S.T., M.L. and Y.W.; Resources, X.C.; Software, Y.W.; Writing—original draft, S.T.; Writing—review & editing, all authors.

**Funding:** This work was financially supported by grants from National Natural Science Foundation of China (#51407009, #51777010, #51707008, #U1630130).

**Acknowledgments:** The authors would like to thank all the participants for their contributions to the study. The authors are particularly grateful to Zhonghua Liu and Liyi Chen for assisting in the completion of the patient's gait data collection experiments.

**Conflicts of Interest:** The authors declare no conflict of interest.

#### **References**

© 2019 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/).


Total Systems Approach to Operational Decision-Making

*Concepts, Applications and Emerging Opportunities in Industrial Engineering*

Quality Management. 2017;**28**:405-426. DOI: 10.1108/17410401211188560

[33] Aqlan F, Al-fandi L. Prioritizing process improvement initiatives in manufacturing environments. International Journal of Production Economics. 2018;**196**:261-268

[34] Fullerton RR, Kennedy FA, Widener SK, Huntsman JM. Lean manufacturing and firm performance: The incremental contribution of lean management accounting practices. Journal of Operations Management.

[35] Gupta SK, Gunasekaran A, Antony J, Gupta S, Bag S, Roubaud D. Systematic literature review of project failures: Current trends and scope for future research. Computers

and Industrial Engineering.

[36] Gamal Aboelmaged M. Reconstructing six sigma barriers in manufacturing and service organizations: The effects of

Journal of Quality & Reliability Management. 2011;**28**(5):519-541

organizational parameters. International

2014;**32**:414-428

2019;**127**:274-285

**94**

**97**

**Chapter 7**

**Abstract**

**1. Introduction**

mance to thrive and gain competitive advantage.

them to improve business performance [3, 4].

A Hybrid Human-Data

Management Systems

*Diogo Ginjo Jantarada and Antonio Grilo*

Methodology for the Conception

To excel in the overall business performance, daily processes and activities connected to produce a good or service need to be outperformed. Even though there is extensive literature on performance management and performance management systems, there is still no consensus over the conceptual model of such systems, in what is designated as Operational Performance Management Systems (OPMS). This chapter proposes a new approach to conceive feasible and desirable OPMS tools to assist managers on controlling and responding to operational needs, by combining Design Thinking (DT) and Data Analytics (DA), that provide holistic and deep business knowledge, as well as a data-driven based management. The authors conduct an empirical application through a case study within the context of a European airport's Baggage Handling System (BHS). The case study procedure follows the proposed methodology's stages, where the authors construct the problem space with a wide array of collected data, along with the solution exploration and refinement.

**Keywords:** operational performance management, operational performance management systems, design thinking, data analytics, conception, design

With the rise of the modern society and its socio-economic structure based on companies (public or private, profit or non-profit based) and its interdependences, the need for performance excellence has become of the utmost importance. The twenty-first century marked the beginning of a new millennium where uncertainty is at its high and companies are constantly trying to outstand their business perfor-

To excel on their overall business performance, the same must apply to the operational performance. Thus, operational performance management systems must reflect the problems and impediments hindering the company's competitiveness. The trends show they are trying to gain knowledge about themselves and the market by leveraging ICT and Data Analytics (DA) capabilities to transform data into information [1, 2]. At the same time, they are focused on understanding the user's (internal or external) pains and needs and come up with a way of meeting

of Operational Performance


**10. Acknowledgment**

Many thanks to Mrs. Susan Harley and Mr. Christopher J. Garlick for their linguistic assistance.

*The project was supported by grants MZOFNM 2005/6904*

### **11. References**

Allergic Contact Dermatitis in Children 123

Goossens, A. & Morren, M. (2006). Contact Allergy in Children, In: Frosch PJ, Menne T,

Heine, G., Schnuch, A., Uter, W. & Worm, M. (2004). Frequency of contact allergy in German

Jacob, SE., Brod, B. & Crawford, GH. (2008). Clinically Relevant Patch Test Reactions in Children – A United States Based Study. *Pediatr Dermatol* 25: 520-527. Jacob, SE. & Castanedo-Tardan, MP. (2007). Pharmacotherapy for allergic contact dermatitis.

Jøhnke, H., Norberg, LA., Vach, W., Bindslev-Jensen, C., Høst, A. & Andersen, KE. (2004).

Jovanovic, DL. & Slavkovic-Jovanovic, MR. (2009). Allergic contact dermatitis from

Katsarou, A., Koufou, V., Armenaka, M., Kalogeromitros, D., Papanayotou, G. & Vareltzidis,

Kohl, L., Blondeel, A. & Song, M. (2002). Allergic contact dermatitis from cosmetics. Retrospective analysis of 819 patch-tested patients. *Dermatology* 204: 334-337. Koopmans, AK. & Bruynzeel, DP. (2003). Is PPD a useful screening agent? *Contact Dermatitis*

Lammintausta, K., Kalimo, K. & Fagerlund, VL. (1992). Patch test reactions in atopic

Le Coz, CJ., Lefebvre, C., Keller, F. & Grosshans, E. (2000). Allergic Contact Dermatitis

and p-Phenylenediamine and Its Derivates. *Arch Dermatol* 136: 1515-1517. Lee, PW., Elsaie, ML. & Jacob, SE. (2009). Allergic contact dermatitis in children: common

Lewis, VJ., Stathmam, BN. & Chowdhury, MMU. (2004). Allergic contact dermatitis in 191

Lugovic, L. & Lipozencic, J. (1997). Contact hypersensitivity in atopic dermatitis. *Arh Hig*

Machovcová, A., Čapková, Š., Konkol′ová, R. & Hercogová, J. (2001). První výsledky

Machovcová A. (2006). Frequency of Contact Allergy in Children and Adolescents in Czech

Manzini, BM., Ferdani, G., Simonetti, V., Donini, M. & Seidenari, S. (1998). Contact

Magnusson, B. & Wilkinson, DS (1975). Cinnamic aldehyde in toothpaste. Clinical aspects

Magnusson, B. & Moller, H. (1979). Contact allergy without skin disease. *Acta Derm Venereol*

Republic, *Proceedings of 15th EADV Congress From Hippocrates to Modern*

allergens and treatment: a review. *Curr Opin Pediatr* 21: 491-498.

consecutively patch tested children. *Contact Dermatitis* 51: 155-156.

epikutánních testů u dětí s atopickou dermatitidou. *Alergie* 1: 9-13.

*Dermatology,* Medimond, Rhodes (Greese), pp. 837-840.

sensitization in children. *Pediatr Dermatol* 15: 12-17.

and patch tests. *Contact Dermatitis* 1: 70-76.

Caused by Skin Painting (Pseudotattooing) With Black Henna, a Mixture of Henna

Hjorth, N. (1981) Contact dermatitis in children. *Acta Derm Venerol (Stockh)* 95: 36-39.

Group. *Contact Dermatitis* 51: 111-117.

*Expert Opin Pharmacother* 8: 2757-2774.

temporary henna tattoo. *J Dermatol* 36: 63-65.

patients. *Contact Dermatitis* 26: 234-240.

Kligman, AM. (1974). Poison ivy (*Rhus)* dermatitis. *Arch Dermatol* 90: 535.

*Dermatitis* 51: 141-147.

*Dermatitis* 34: 70-71.

*Rada Toksikol* 48: 287-296.

*Suppl (Stockh)* 59: 113-115.

48: 89-92.

830.

Lepoittevin J-P (Eds.), *Contact Dermatitis,* 4th ed., Springer-Verlag, Berlin, pp. 811-

children and adolescents patch tested between 1995 and 2002: results from Information Network of Departments and the German Contact Dermatitis Research

Reactivity to patch tests with nickel sulfate and fragrance in infants. *Contact*

A. (1996). Patch tests in children: a review of 14 years' experience. *Contact*

Carmichael, AJ., Foulds, IS. & Bransbury, DS. (1991). Loss of lanolin patch-test positivity. *Br*

Castanedo-Tardan, MP. & Jacob, SE. (2008). Allergic contact dermatitis to sorbitan

Clayton, TH., Wilkinson, SM., Rawcliffe, C., Pollock, B. & Clark, SM. (2006). Allergic contact

Cockayne, SE., Shah, M., Messenger, AG. & Gawkrodger, DJ. (1998). Foot dermatitis in children: causative allergens and follow-up. *Contact Dermatitis* 38: 203-206. Conti, A., Motolese, A., Manzini, BM. & Seidenari, S. (1997). Contact sensitisation to

De Groot, AC. & Herxheimer, A. (1989). Isothiazolinone preservative: cause of a continuing

De Groot, AC. (1990). The frequency of contact allergy in atopic patients with dermatitis.

De Groot, AC., Baar, TJ., Terpstra, H. & Weyland, JW. (1991). Contact allergy to moist toilet

De la Cuadra, J., Sanz, J. & Martorell, A. (1990). Prevalence of positive epicutaneous tests in atopic and non-atopic children without dermatitis. *Contact Dermatitis* 23: 242-243. De Waard-van der Spek, FB. & Oranje, AP. (2009). Patch Test in Children with Suspected

Dotterund, LK. & Falk, ES. (1995). Contact allergy in relation to hand eczema and atopic diseases in north Norwergian schoolchildren. *Acta Paediatr* 84: 402-406. Epstein, WL. (1961). Contact-type delayed hypersensitivity in infants and children:

Garg, S., McDonagh, AJG. & Gawkroder, DJ. (2009). Age- and sex-related variations in allergic contact dermatitis to common allergens. *Contact Dermatitis* 61: 46-47. Giordano-Labadie, F., Rancé, F., Pellegrin, F., Bazex, J., Dutau, G. & Schwarze, HP. (1999).

Goossens, A., Motolese, A., Manzini, BM. & Donini, M. (1995). Patch testing in infants. *Am J*

Goossens, A. (2001). Minimizing the Risks of Missing a Contact Allergy*. Dermatology* 202:

Goossens, A., Kohl, L., Blondeel, A. & Song, M. (2002). Allergic contact dermatitis from

Goossens, A., Kütting, B., Brehler, R. & Traupe, H. (2004). Alergic contact dermatitis in children – strategies of prevention and risk management. *Eur J Dermatol* 14: 80-85.

Frequency of contact allergy in children with atopic dermatitis: results of a

cosmetics. Retrospective analysis of 819 patch-tested patients. *Dermatology* 204: 334-

Allergic Contact Dermatitis: A Prospective Study and Review of the Literature.

dermatitis in children: should pattern of dermatitis determinate referral? A retrospective study of 500 children tested between 1995 and 2004 in one U.K.

sesquioleate in children. *Contact Dermatitis* 58: 171-171.

preservatives in children. *Contact Dermatitis* 37: 35-36.

epidemic cosmetic dermatitis. *Lancet* 1: 314-316.

introduction of rhus sensitivity. *Pediatrics* 27: 51-53. Fisher, AA. (1991). Nickel dermatitis in children. *Cutis* 47: 19-21.

Fisher, AA. (1995). Cosmetic dermatitis in childhood. *Cutis* 55: 15-16.

Fisher, AA. (1994). Allergic contact dermatitis in early infancy. *Cutis* 54: 300-302a. Fisher, AA. (1994). Patch testing in children including early infancy. *Cutis* 54: 387-388b.

prospective study of 137 cases. *Contact Dermatitis* 40: 192–195.

*J Dermatol* 125: 573-576.

centre. *Br J Dermatol* 154: 114-117.

*Contact Dermatitis* 22: 273-277.

*Dermatology* 218: 119-125.

*Contact Dermat* 6: 153-156.

186-189.

337.

paper. *Contact Dermatitis* 24: 135-136.

Allergic Contact Dermatitis in Children 125

Rietschel, RL. & Fowler Jr., JF. (2008). Allergic Sensitization to Plants, In: Rietschel, RL. &

Roul, S., Ducombs, G., Léauté-Labrèze, C. & Taïeb, A. (1998). "Lucky Luke" contact dermatitis due to rubber components of diapers. *Contact Dermatitis* 38: 363-364. Roul, S., Ducombs, G., Léauté-Labrèze, C., Labbe, L. & Taïeb, A. (1996). Footwear contact

Rudzki, E. & Rebandel, P. (1996). Contact dermatitis in children. *Contact Dermatitis* 34: 66-67. Rystedt, I. (1985). Contact sensitivity in adults with atopic dermatitis in childhood. *Contact*

Salam, TN. & Fowler Jr., JF. (2001). Balsam-related systemic contact dermatitis*. J Am Acad*

Seidenari, S., Manzini, BM. & Motolese, A. (1992). Contact sensitisation in infants: report of 3

Seidenari, S., Giusti, F., Pepe, P. & Mantovani, L. (2005). Contact Sensitization in 1094 Children Undergoing Patch Testing over 7-Year Period. *Pediatr Dermatol* 22: 1-5. Schnuch, A. & Uter, W. (2003). Decrease in nickel allergy and regulatory interventions.

Schnuch, A., Uter, W. & Reich, K. (2006). Allergic contact dermatitis and atopic eczema, In:

Schnuch, A., Wolter, J., Geier, J. & Uter, W. (2011). Nickel allergy is still frequent in young

Segurado Rodriguez, MA., Ortiz de Frutos, FJ. & Guerra Tapia, A. (2004). Allergic contact

Senff, H., Exner, M., Görtz, J., Goos, M. (1989). Allergic contact dermatitis from Euxyl K400.

Shah, M., Lewis, FM. & Gawkrodger, DJ. (1997). Patch testing in children and adolescents: five years' experience and follow-up. *J Am Acad Dermatol* 37: 964-968. Sosted, H., Hesse, U., Menné, T., Andersen, KE. & Johansen, JD. (2005). Contact dermatitis to

Sosted, H., Johansen, JD., Andersen, KE. & Menné, T. (2006). Severe allergic hair dye

Spann, CT., Tutrone, WD., Weinberg, JM., Scheinfeld, N. & Ross, B. (2003). Topical antibacterial agents for wound care: a primer. *Dermatol Surg* 29: 620-626. Stables, GI., Forsyth, A. & Lever, RS. (1996). Patch testing in children. *Contact Dermatitis* 34:

Thyssen, JP., Johansen, JD., Menné, T., Nielsen, NH. & Linneberg, A. (2009). Nickel allergy in Danish women before and after nickel regulation. *N Engl J Med* 360: 2259-2260. Thyssen, JP., Uter, W., McFadden, J., Menné, T., Spiewak, R., Vigan, M., Gimenez-Arnau, A.

Tomar, J., Jain, VK., Aggarwal, K., Dayal, S. & Gupta, S. (2005). Contact allergies to

protection against nickel allergy. *Contact Dermatitis* 64: 121-125.

& Lidén, C. (2011). The EU Nickel Directive revisited – future steps towards better

cosmetics: testing with 52 cosmetic ingredients and personal products. *J Dermatol*

Ring, J., Przybilla, B., Ruzicka, T. (Eds.), *Handbook of Atopic Eczema,* 2nd ed.,

German females – probably due to insufficient protection from nickel-releasing

hair dyes in an adult Danish population – an interview based study. *Br J Dermatol*

dermatitis in children. *Contact Dermatitis* 35: 334-336.

453b.

*Dermatitis* 13: 1-8.

153: 132-135.

341–344.

32: 951-955.

*Dermatol* 45: 377-381.

cases. *Contact Dermatitis* 27: 319-320.

Springer-Verlag, Berlin, pp. 178-201.

objects. *Contact Dermatitis* 64: 142-150.

dermatitis. *An Pediatr (Barc)* 60: 599-601.

*Contact Dermatitis* 20: 381-382, 0105-1873

reactions in 8 children. *Contact Dermatitis* 54: 87-91.

*Contact Dermatitis* 49: 107-108.

Fowler Jr., JF, *Fisher's Contact Dermatitis,* 6th ed., BC Decker Inc, Hamilton, pp. 405-

Marghescu, S. (1985). Patch test reactions in atopic patients. *Acta Derm Venereol (Stockh)*

Menezes de Pádua, CA., Schnuch, A., Lessmann, H., Geier, J., Pfahlberg, A. & Uter, W.

Milingou, M., Tagka, A., Armenaka, M., Kimpouri, K., Kouimintzis, D. & Katsarou, A.

Militello, G., Jacob, SE. & Crawford, GH. (2006). Allergic contact dermatitis in children. *Curr*

Möller, H. (1997). Merthiolate allergy: a nation-wide iatrogenic sensitisation. *Acta Derm*

Mortz, CG. & Andersen, KE. (1999). Allergic contact dermatitis in children and adolescents.

Mortz, CG., Lauritsen, JM., Bindslev-Jensen, C. & Andersen, KE. (2001). Prevalence of atopic

Motolese, A., Manzini, BM. & Donini, M. (1995). Patch tests in infants. *Am J Contact Dermatol*

Neri, I., Guareshi, E., Savoia, F. & Patrizi, A. (2002). Childhood allergic contact dermatitis

Nielsen, NH., Linneberg, A., Menné T., Madsen F., Frølund L., Dirksen A. & Jørgensen T.

Novák, M., Kvíčalová, E. & Friedländerová, B. (1986). Reactions to merthiolate in infants.

Onder, M., Atahan, CA., Oztas, P. & Oztas, MO. (2001). Temporary henna tattoo reactions in

Onder, M. & Adisen, E. (2008). Patch test results in a Turkish paediatric population. *Contact*

Osawa, J., Kitamura, K. & Ikezawa, Z. (1991). A probable role for vaccines containing thimerosal in thimerosal hypersensitivity. *Contact Dermatitis* 24: 178-182. Pambor, M., Winkler, S. & Bloch, Y. (1991). Allergic contact dermatitis in children. *Contact*

Pevny, I., Brennenstuhl, M. & Razinskas, G. (1984). Patch testing in children (I). Collective test results; skin testability in children*. Contact Dermatitis* 11: 201-206. Pevny, I., Brennenstuhl, M. & Razinskas, G. (1984). Patch testing in children (II). Results and

Rademaker, M. & Forsyth, A. (1989). Contact dermatitis in children. *Contact Dermatitis* 20:

Rastogi, SC., Johansen, JD., Menné, T., Frosch, P., Bruze, M., Andersen, KE., Lepoittevin, JP.,

Rietschel, RL. & Fowler Jr., JF. (2008). Pathogenesis of Allergic Contact Hypersensitivity, In:

Wakelin, S. & White, IR. (1999). Contents of fragrance allergens in children's

Rietschel, RL. & Fowler Jr., JF., *Fisher's Contact Dermatitis,* 6th ed., BC Decker Inc,

dermatitis, asthma, allergic rhinitis, and hand and contact dermatitis in adolescents. The Odense Adolescence Cohort Study on Atopic Diseases and Dermatitis. *Br J*

(2001). Persistence of contact allergy among Danish adults: an 8-year follow-up

(2005). Contact Allergy to neomycin sulfate: results of a multifactorial analysis.

(2010). Patch tests in children: a review of 13 years of experience in comparison

114(Suppl.): 113-116.

*Opin Pediatr* 18: 385-390.

*Contact Dermatitis* 41: 121-30.

*Venereol* 50: 509-517.

*Dermatol* 144: 523-532.

6: 153-156.

*Pharmacoepidemiol Drug Saf* 14: 725-733.

with previous data. *Pediatr Dermatol* 27: 255-259.

from henna tattoo. *Pediatr Dermatol* 19: 503-505.

study. *Contact Dermatitis* 45: 350-353.

children. *Int J Dermatol* 40: 577-579.

case reports. *Contact Dermatitis* 11: 302-310.

cosmetics and cosmetic-toys. *Contact Dermatitis* 41: 84-88.

*Contact Dermatitis* 15: 309-310.

*Dermatitis* 58: 63-65.

*Dermatitis* 24: 72-74.

Hamilton, pp. 1-10a.

104-107.

**1. Introduction**

patch testing will be discussed.

relevance of positive patch test results.

**2.1 Prevalence in infants and young children**

**2. Epidemiology**

**8**

*USA*

**Contact Dermatitis in Children**

*Boston University, Department of Dermatology*

Laurel M. Morton and Katherine Szyfelbein Masterpol

Allergic contact dermatitis is increasingly being recognized as a disease that affects children in addition to adults. Historically, irritant contact dermatitis such as 'diaper dermatitis' was a frequent diagnosis made in children, while allergic contact dermatitis was not considered a significant disease in this age group. Clinicians may have attributed this to children's lack of exposure to allergens or to the belief that pediatric immunity was not vigorous enough to result in sensitization. Some suspect that the infrequent diagnosis of this condition was due to scarce patch testing in this age group. It is true that contact allergy has not been studied as intensely in children as in adults and data from adult studies may not always reflect results in children. By means of many reports and epidemiological studies in the literature, it has become clear that allergic contact dermatitis is a significant diagnosis to consider in

This chapter was written as a review of the current literature. Background regarding allergic contact dermatitis will be provided with a discussion of its prevalence in children. The most common allergens that affect children will be reviewed, and important pearls regarding

Recent studies suggest that allergic contact dermatitis remains more common in adults than in children (Kwangsukstith & Maibach, 1995) affecting approximately 10% of the adult population (Marks, 1997) and accounting for just over 4% of all dermatologic consultations (Mendenhall et al., 1973). Though the condition is increasingly being recognized in the pediatric population, most epidemiologic studies have been completed retrospectively and investigate the occurrence of positive patch tests in symptomatic patients only. Generally, standard series are used. For example, the European Standard Series is commonly utilized in European studies. Yet, some variation in tested allergens exists and studies often evaluate specific pediatric populations, making it difficult to compare studies. The exact rates of incidence and prevalence remain less clear, potentially due to only recent interest in studying this condition in children. Furthermore, only a minority of studies report on the

A common explanation for low rates of allergic contact dermatitis in children was their lack of a robust immune system. Early studies seemed to support this theory. For instance, Straus

young children, and even infants, with eczematous disease.


**5. Conclusions and final comments**

The use of solar radiation to catalyze Fenton-like processes has been proven to be effective to deactivate waterborne pathogens. Experimental results and reported deactivation parameters suggest that these processes could be an interesting alternative to conventional chlorine disinfection for developing countries. Furthermore, solar-driven Fenton-like processes is a more efficient alternative when compared to conventional solar disinfection (SODIS), since the required exposure times for both are significantly different and much lower for the photocatalytic arrangement. Nevertheless, it is well documented that for solar photocatalysis to perform at optimum conditions, a primary treatment of raw water might be needed in order to decrease the concentrations of interfering compounds such as natural organic matter. When considering the necessity to provide a disinfectant residual in order to protect water treated with AOPs, sequential disinfection using AOPs as a primary process coupled with secondary free chlorine also represents an interesting alternative for developing countries. Similar to the synergistic effects produced by ozone on secondary free chlorine deactivation of strong microorganisms such as *C. parvum* oocysts, preliminary studies conducted with AOPs used as primary disinfectant –instead of ozone- have reported to generate similar synergistic effects on the deactivation of conservative surrogates such as *B. subtilis* spores and helminth eggs. More comprehensive work needs to be conducted in order to fully characterize the magnitude and occurrence of this synergism under a wide range of experimental conditions of interest for drinking water treatment such as water pH and temperature. Finally, in order to fully understand the effectiveness of solar-driven Fenton-like processes when used for disinfection purposes, it is clear that more studies are required in order to elucidate the actual mechanism of cell deactivation when using such processes.

### **6. References**

lower for the photocatalytic arrangement. Nevertheless, it is well documented that for solar photocatalysis to perform at optimum conditions, a primary treatment of raw water might be needed in order to decrease the concentrations of interfering compounds such as natural organic matter. When considering the necessity to provide a disinfectant residual in order to protect water treated with AOPs, sequential disinfection using AOPs as a primary process coupled with secondary free chlorine also represents an interesting alternative for developing countries. Similar to the synergistic effects produced by ozone on secondary free chlorine deactivation of strong microorganisms such as *C. parvum* oocysts, preliminary studies conducted with AOPs used as primary disinfectant –instead of ozone- have reported to generate similar synergistic effects on the deactivation of conservative surrogates such as *B. subtilis* spores and helminth eggs. More comprehensive work needs to be conducted in order to fully characterize the magnitude and occurrence of this synergism under a wide range of experimental conditions of interest for drinking water treatment such as water pH and temperature. Finally, in order to fully understand the effectiveness of solar-driven Fenton-like processes when used for disinfection purposes, it is clear that more studies are required in order to elucidate the actual mechanism of cell deactivation when using such

Alrousan, D.M.A., Dunlop, P.S.M., McMurray, T.A., Byrne, A. Photocatalytic inactivation of

Anipsitakis G.P., Dionysiou D.D. 2004. Transition metal/UV-based advanced oxidation

Bandala E.R., Pelaez M.A., Dionysiou D.D., Gelover S., García A.J., Macías D. 2007.

Bandala E.R., Estrada C. 2007. Comparison of solar collection geometries for application to

Bandala E.R., Pelaez M.A., Garcia-Lopez J., Salgado M.J., Moeller G. 2008. Photocatalytic

Bandala E.R., Corona-Vasquez B., Guisar R., Uscanga M. 2009. Deactivation of highly

Bandala E.R., González L., de la Hoz F., Pelaez M.A., Dionysiou D.D., Dunlop P.S.M., Byrne

Bandala E.R., Gonzalez L., Sanchez-Salas J.L., Castillo J.H. 2011b. Inactivation of Ascaris

azo dyes. Chemical Engineering and Processing 47, 169–176.

International Journal of Chemical Reactor Engineering 7, A7.

Photochemistry and Photobiology A: Chemistry 218, 185-191.

*E. coli* in surface water using immobilised nanoparticle TiO2 films. Water research

technologies for water decontamination. Applied Catalysis B: Environmental, 54,

Degradation of 2,4-dichlorophenoxyacetic acid (2,4-D) using cobaltperoximonosulfate in Fenton-like process. Journal of Photochemistry and

photocatalytic degradation of organic contaminants. Journal of Solar Energy

decolourization of synthetic and real textile wastewater containing benzidine-based

resistant microorganisms in water using solar driven photocatalytic processes.

J.A., Sanchez J.L. 2011a. Application of azo dyes as dosimetric indicators for enhanced photocatalytic solar disinfection (ENPHOSODIS). Journal of

eggs in water using sequential solar driven photo-Fenton and free chlorine. Journal

processes.

**6. References**

43 (2009) 47-54.

Engineering 129, 22–26.

of Water and Health, (In press).

Photobiology A: Chemistry 186, 357–363.

155-163.


Advanced Energy Conversion

Chapter 2

Abstract

and Muhammad Aziz

system modeling, power to gas

1. Introduction

11

Chemical Looping Combustion

Renewable energy provides a quick win solution for global warming, but it comes with drawbacks. Renewable sources such as solar and wind are not available for continuous use; thus, intermittency of electric power generation is an issue. Fluctuation of electricity production could damage the grid. Throughout the years, researchers have come up with solutions to solve this problem by storing the excess electricity via an energy storage system. One of the most efficient options is through solid oxide electrolysis cell (SOEC) to produce H2. In itself, H2 contains a lot of energy and can be converted to electricity via combustion or fuel cell. Therefore, storing electricity in the form of H2 could prove to be effective. Energy storage systems such as power-to-gas may provide a clean and efficient way to store the overproduced electricity. In this work, a power-to-gas system coupled with a chemical looping combustion combined-cycle system is proposed to provide base and intermediate load power from the unused electricity from the grid. Enhanced process integration was employed to achieve optimal heat and exergy recovery. This chapter focuses on the design of a system consisting of a power-to-gas conversion method and a H2-powered chemical looping combustion power generation system.

Keywords: chemical looping combustion, solid oxide electrolysis cell,

Combustion of fossil energy sources for industrial processes around the world contributes massively to the creation of greenhouse gases (GHG) and mainly CO2. This has been a major problem worldwide as it directly increases the pollution level and the likelihood of the earth's increase in temperature. This led the international community to investigate ways to prevent this phenomenon [1]. Besides, fossil fuels are inevitably bound to be depleted in the future [2]. As of right now, as much as 84% of the world energy consumption is still fossil fuel driven, less than what the previous year had (85%); even so, it is still very high. Without a radical transformation, fossil fuel will still be the majority of energy source in the foreseeable future. This condition necessitates scientists and engineers to provide a sound solution. Efforts to reduce the fossil fuel usage and transition to sustainable energy

Power Generation System

for a Power‐to‐Gas Scheme

Muhammad W. Ajiwibowo, Arif Darmawan

#### Chapter 2


**1. Introduction**

In terms of comfort and exuberant use, cotton fibre is considered the most classical fibre in garment technology. Versatility of cotton fibres ranging from very finer to very courser and structure of cotton yarns such as single to ply are considered as decisive factors of selection regarding their use in apparel production. On the other hand, the comfort property, being one of the prime features of woven fabric used as a garment, is greatly influenced by the structure of constituent yarns in that particular fabric. Comfort evaluation includes mainly vapour and liquid transmission properties of yarn and fabric at constant atmospheric conditions and constraints. Liquid transmission includes water absorbency and wicking [1, 2].

Absorbency is used to describe the ability of a fabric to take in moisture—an important feature that influences a variety of other factors such as skin comfort, static build-up, shrinkage, water repellency and wrinkle recovery. One of the most common occurrences in the manufacturing and usage of textile materials is liquid flow. Wicking is the spontaneous transfer of a liquid into a porous structure caused by capillary forces. Therefore, study of capillary flow in textile media is very important. When the free energy of the solid-gas interface surpasses that of the solid-liquid interface, capillary phenomena occur. A liquid that does not wet fibres cannot wick into a fabric, and wicking can only take place when fibres are assembled with capillary spaces. But the objective of this is to present an overview only in wicking property of textiles.

Study of wicking in textile material is of great interest for two main reasons. Firstly, it allows a better understanding of liquid-fibre contact in order to characterise any liquid flow of spin finishes, dyeing or coating of either fabrics or yarns. Secondly, it enables the characterisation of textile structures, their porosity resulting from the capillaries formed by the inter-filament spaces in which the liquid flows [3]. Moisture absorption is intimately linked to the comfort of garments made from cellulosic fibres. The term wetting is usually used to describe the displacement of solid-air interface with solid liquid interface. Wetting behaviour is commonly characterised by the value of the contact angle within the liquid [4]. The wetting and wicking behaviour of the fibrous structure is a critical aspect of performance of products such as sports clothes, hygiene disposable materials and medical products. Clothing comfort is influenced by the wetting and wicking processes that occur during wear.

Therefore, a thorough understanding of liquid transmission behaviour inside various intermediate forms of textiles is obviously needed through absorbency and wicking phenomena of yarns and fabrics. As the yarns are composed of fibres with a structured arrangement, any change of this arrangement by twisting and plying creates different sort of wicking behaviour on them and in turn, the fabrics made out of these yarns along with its varying weave forms and directions must exhibit different nature of wicking effects. The findings that are interlinking between fabric wicking and corresponding yarn wicking are always a matter of interest to study the nature of absorbency specially for textiles made out of natural fibres and hence, are elaborated progressively in this chapter.