Biotechnology And Medical Science - Proceedings Of The 2016 International Conference

Proceedings of the 216 International Conference on Biotechnology and Medical Science

Yong Zhang

• Publisher: WSPC
• Year: 2016
• eBook ISBN: 9789813145887
• Topic: Medicine
• Subtopic: Biotechnology in Medicine

This book is an all-embracing review of biotechnology, biomedical engineering, bioinformatics, pharmacy and medicinal chemistry, and biopharmaceutical technology. Existing theories and the latest findings are discussed. Researchers, engineers, academic

Session 1

Biotechnology

STUDY ON THE OCULAR BLOOD PRESSURE BASED ON HARMONIC ANALYSIS

Jintao Yu^a, Fang Feng, and Zhiping Yang

School of Computer and Information Engineering, Harbin University of Commerce, Harbin,
150028, China

E-mail: ^a[email protected]

Lots of researches have shown that ocular blood pressure (OBP) of healthy volunteers is much different from glaucoma patients. Increased OBP is the most well-known risk factor for the induction of glaucoma. What’s more, our results indicated that the calculations of the first through fifth harmonics of the OBP pulse are superior in distinguishing between healthy people and glaucoma patients. This paper mainly studies on the relationship between the OBP and Age based on the harmonic content of envelope waveform aimed at the healthy volunteers (age: 41.5±12.5years), here we randomly choose 27 (SBP: 115.9±8.6, DBP: 66.0±7.9) without the history of eye disease. A laser speckle flowgraphy (LSFG, NAVI LSFG system, Soft-care, Japan) device is utilized to estimate the BF in the ONH. OBP is recorded around one of the fingers by a noninvasive blood recorded at 200Hz sampling rate (Finometer Pro®, Holland). Then, calculated the Frequency Coefficient (FC: 0.45±0.447) and Frequency Index (FI: 0.05±0.032).The results indicated that age in the healthy body has great influence on FC and FI (P<0.001). We considered that the FC of the first five harmonics is less suitable for calculations independent from age, FI is not related to the blood pressure, which changes with aging. So FI is used to be an indictor to assess ocular cycle in the healthy volunteers. This study has important significance for the diagnosis in clinical ophthalmology.

1.INTRODUCTION

Glaucoma is the second most cause of blindness in the world. Although the pathogenesis of glaucoma remains unclear, some references indicated that increased OBP is the most risk factor [1]. Nowdays, majority of studies have shown that abnormal ocular blood flow (OBF) will cause some physiological disease [2-4]. OBP has obvious difference along with the slight changes caused by each heartbeat in Pulsation cycle. The pulse waveform of OBP has been used to be a method for assessing the vascular status of glaucoma [5-7]. The present study indicated that it’s so important for glaucoma patients to decrease the amplitude of OBP, compared to the healthy volunteers.

In the circulation of system, the pulse waveform of ocular blood pressure has entered into a more detailed research stage. Many studies have focused on the ocular blood pressure pulse based on fast Fourier transform (FFT). In short, the analysis principle of FFT is also used in the periodic function [8-10], e.g. arterial pressure pulse, which composed of sine wave that the amplitude and phase change repeatedly [11]. Fourier analysis, which decomposes the signal into the sum of different frequency sine wave functions [12], Compared to the time-domain waveform, the former technologies are considered to be on behalf of the frequency. The frequency domain waveform contains the highest power spectral components and the frequency of the arterial pressure has direct relationship with the heartbeat [13-15]. The result of the waveform analysis is that the spectrum component part lower than the fundamental frequency, which relates to respiratory system and cardiovascular system [16].

Some studies have shown that the higher harmonic of the arterial pressure represents the stronger vascular resistance [17]. The vascular resistance is effected by size, elastic, physical properties of the blood flow and wave reflection from distal arterial tree part. What’s more, the risk of vascular, which is defined by the resistance of the oscillation system [18-20], have great relationship with vascular resistance. The resistance is defined by the non-oscillatory or stable movement, so it is regarded as a risk factor in zero frequency [21].

Although the pulses derived from blood vessel originally, it relies mainly on vascular quantitative change, the size of the eye, eye external elastic, rather than the changes of their eyes’ OBF [22]. This research ignores the effect caused by other factors, e.g. height, weight, blood type and so on.

From the perspective of OBP, if the harmonic components of OBP have relationship with some other ocular measures, waveform analysis of FFT will provide a new method for the eye state of its own blood vessels. Therefore, the purpose of this research is to analyze the harmonic components of OBP waveform based on FFT for the healthy volunteers, to achieve the relationship between OBP and age.

2.RESEARCH METHOD OF THE RELATIONSHIP BETWEEN OBP AND AGE

2.1.Data Collection

Participants (age: 41.5±12.5 years, n=27) that just take account of the healthy which are randomly selected from society. We collect the data in the Devers Eye Institute United States. The participants have a normal ocular blood pressure (systolic ocular blood pressure [SBP]:≤130mmHg and diastolic ocular blood pressure [DBP]:≤80mmHg). Before the collection of data, all of the participants received a questionnaire, including age, gender, height, known cardiovascular risk factors (e.g. arterial hypertension, diabetes, and smoking history), atherosclerosis and so on. Then, the study is conducted in accordance with the Declaration of Helsinki on Biomedical Research Involving Human Subjects [23-25]. What’s more, the participants sign informed consent. They must remain at least 20min rest in an ambient temperature at 23°C, pupil expansion without drug. OBP and BF data are recorded for 2 minutes during spontaneous respiration. LSFG-NAVI is a updated model, the special area sensor is replaced by the ordinary charge-coupled device camera, to describe a more clear spatial resolution, and the measurement has good reproducibility. LSFG is used to collect BF data of the ONH, utilizing the laser speckle phenomenon. Finometer is used to achieve the OBP data at the same time as shown in Fig. 1.

Fig. 1. LSFG and Finometer pictorial diagram of the system: Universal serial bus, PC, LCD.

The heartbeat is estimated by home visit. The method takes the instrument to collect the data of OBP and BF for 2 minitues. Since the rapple waveform frequency is 1Hz, the frequency of the rapple has direct relationship with the pulse of OBP. In order to meet the sampling theorem, the data sampling frequency is larger than 2Hz, and then the data collection is considered to be feasible.

2.2.Cubic Spline Interpolation

Since collecting the data of the OBP, some data lost during blinking (eg. Fig.2) In order to reduce error in the process of calculation, this method adopts cubic spline interpolation. Cubic spline interpolation is very simple in the calculation, stable enough and good convergence. What’s more,...

Table of contents

• Cover
• Halftitle
• Title
• Copyright
• Preface
• Committees
• Contents
• Session 1: Biotechnology
• Session 2: Medical Science
• Session 3: Food Hygiene, Environment and Human Health