5100B Arteriosclerosis detection system

Time：2017-06-06

Functions:

Arteriosclerosis detect system includes four kinds of apparatus of arterial detection:

1. Pressure of central carotid artery waveform analysis (PWA)

2. Pulse Wave Velocity, (PWV)

3. Ankle Brachial Pressure Index (ABI)

4. Cardiovascular Disease (CVD) risk assessment

The system provide bundled software coincide with related technical index, and provide vascular aging assessment utility software and information database. This device is integrated with innovation, non-invasive method and multiple parameterized detection and assessment of arterial function.

Characteristic:

1. Pressure of central carotid artery waveform analysis (PWA)

(1) What is central carotid artery pressure?

Central carotid artery pressure is the aortic pressure in its root part. Normally measured by the invasive catheterization. This product applies for the Pulse Wave Analysis (PWA) to measures the central carotid artery pressure by brachial blood pressure, carotid artery waveform and elbow artery waveform.

(2) Why central carotid artery pressure is needed?

Shown from the experiment of ASCOT that different hypotensive drugs will bring different antihypertensive effect on central arterial pressure. The better antihypertensive effect on central arterial pressure, the more effective control on the occurrence of cardiovascular events. Therefore, the examination of central carotid artery pressure is very useful in hypertension treatment of drug effect evaluation and risk assessment.

It was proved that there are significant difference between aorta and brachial arteries in pressure waveform and amplification. The difference of SBP could be 80mmHg during state of motion. Therefore, correct the difference have important meaning.

There was evidence that CAP and other related index have closer relation with cardiovascular risk middle indexes than traditional brachial blood pressure, which may better predict cardiovascular and cerebrovascular events, especially atherosclerosis. According to the research data, among the population of young people who do not have obvious arteriosclerosis symptom or atherosclerosis, their peripheral arterial pressure are much greater than central arterial pressure. While among the population of aging people who have obvious arteriosclerosis or atherosclerosis symptom, their peripheral arterial pressure are close to the central arterial pressure, or the central arterial pressure is even higher than the peripheral arterial pressure.

l Compared with peripheral arterial pressure, the central arterial pressure has more direct effect on splanchnic perfusion and pressure load.

l Related research shows that central arterial pressure is more useful to be applied for the prediction of cardiovascular events than peripheral arterial pressure.

l The peripheral arterial pressure may be overestimated or underestimated compared with central arterial pressure. Those influence factors include peripheral amplification, some medication, or physical stimulation.

l The analysis of central arterial pressure waveform may produce indicator of Ventricular coupling and arterial blood flow dynamics.

The analysis of carotid arterial pressure waveform includes central arterial pressure, wave reflection, blood pressure pulsation, the vigor rate of endocardium and pulsation flow dynamics technical indicator. This analysis can reflect arterial function and arterial coupling effect, which can be applied for the clinical pathology examination and assessment of cardiovascular, and can provide informational parameter for the risk classification of the patient with hypertension, effect of treatment and strategy of prevention and detection for the vascular disease in early stage.

(3) Normal range of non-invasive CASP of normal people

The normal range non-invasive CASP of normal people has linear relation with gender or age. When considering gender and age at the same time, it will have greater correlation with non-invasive CASP. The non-invasive CASP will increase around 1.9 mmHg after 10 years of age for each growth. The average non-invasive CASP of male is 2.5 mmHg higher than female.

The normal range of non-invasive CASP of male: 91.60～132.04mmHg; female: 81.72～131.59mmHg.

The non-invasive CASP is lower than brachial artery systolic blood pressure (SBP), but the difference value between brachial arterial SBP and non-invasive CASP is independent of age.

(4)Augmentation Index

a. Explanation of nouns

When pressure wave conducts along the periphery of arterial walls, it will produce reflective wave on the different blood vessels (normally small resistance arteries) of organization structure.

The reflective wave antidromic conducts to the near heart artery in same speed. The pressure wave of antidromic conduction and anterior conduction will overlap. The point of reflection is called “Pi”. Peripheral artery is 80 cm far from heart in average. When the speed of pressure wave conduction is normal, adults reflective wave is overlap with forward reflective wave in the period of systole, while the situation of children are more in period of diastole. If PWV became faster or resistance increases in peripheral region, it will bring forward the reflective point, which lead to the overlap happening in the early stage of systole.

The formula of  augmentation index is: AI=ΔP/PP. There are two points of view in former literature which illustrate this formula. Firstly, ΔP is the difference value between highest point of blood pressure and blood pressure in return point. PP is the pulse pressure difference (the difference value between systolic pressure and diastolic pressure). Secondly, when applying echo-tracking technique, ΔP is the difference value between highest point of pressure wave in systole and the overlapping point of outgoing pulse wave and reversal reflective wave. PP is the overall amplitude of the pulse wave. The second view is commonly accepted.

b. clinical significance

the worse vessel compliance, the faster of reflective wave, and the longer distance between the position of outgoing pulse wave and reversal reflective wave, which causes a biggerΔP, at the same time, the vascular elasticity reducing leads to the decrease of overall amplitude of the pulse wave. Hence, the value of PP reduce, and AI will increase accordingly. Therefore, the Ai value can quantitatively reflect the overall elasticity of the arterial system, and sensitively show the situation of pressure wave reflection and the change of arterial diameter by referring to the elasticity change of main artery and arteriole. Based on the special value that reflect the arterial elasticity, AI value has been widely applied clinically in every field.

2. Pulse Wave Velocity (PWV)

1. Pules Wave Velocity:

(1)PWV calculated formula and clinic assessment standard:

PWV = distance/time difference(Δt) 

(2)Clinical significance

The reduction of arterial elasticity is the composite reaction of early vascular wall damage that is caused by various cardiovascular risk factors. It not only the early vascular pathological markers with high specificity and sensitivity, but a king of high risk factor, which take part in the evolution and occurrence of cardiovascular disease. Therefore, the non-invasive measurement of the Artery elastic functional system examination has been a popular research topic. The pulse wave velocity measurement is regular indicator of the non-invasive measurement of the Artery elastic functional system examination. PWV, as a non-invasive measurement, can early detect dysfunctions of the artery, and synthetically reflect various risk factors of vascular damage.  

(3)The range of normal and abnormal PWV value

The value of PWV increases with the increase of age, its reference Value is 1400cm/s.

According to assessment of American College of Cardiology medical scientific report (1993):

l PWV<1400cm/s: normal value.

l 1400cm/s ≤ PWV ≤ 1800cm/s: mild peripheral arteriosclerosis.

3.Ankle Brachial Pressure Index (ABI)

(1)ABI = 

(2)Clinical significance

The use of ABI can help to non-invasively assess the open of lower limb arterial blood vessels, and can predict a variety of cardiovascular and cerebrovascular events, it is more accurate and more objective to measure arteriosclerosis than applying a single PWV value. This is because, if the arterial is stenosis or occlusion, the pulse wave will be blocked in the occlusion site, so the pulse wave transmission will slow down. At this time, regardless of the extent of arteriosclerosis, PWV sometimes may always show a normal or lower value, which mislead the diagnosis of disease. While the ABI will be significantly reduced. From the value of ABI, we can find the occlusion of lower extremity arteries. Therefore, the ABI index can be used as a complement to PWV, which provide more comprehensive prediction of arteriosclerosis. In normal situation, ABI≥1. If ABI＜1, lower extremity artery may have stenosis occlusive lesions. If ABI＜0.5, lower extremities have severe ischemia. If conditions permit, lower extremity blood supply should be reconstructed in time.

(3)Normal ABI range is 0.9 - 1.4

Cardiovascular Disease (CVD) risk prediction

(1) Cardiovascular Risk Reclassification

Based on the FRS model stratification and subclinical vascular disease technical indicators to reclassify cardiovascular risk.

Assessment standard:

a. Any value of PWVa-f, AI, and ABI reaching sub-clinical vascular disease threshold level will be high-risk (+).

b. FRS >20 means high-risk (+); if less than 20, including low risk, medium risk in vascular age, need reclassification according to degree of vascular lesions (see table 1).

Table 1 reclassification of cardiovascular disease risk

(2)Clinical application

1. Healthy or community-based populations need to be further stratified for cardiovascular risk, assess vascular aging and screen high-risk groups after a general physical examination, and assess vascular aging, which provide the evidence for individualized decision-making of comprehensive prevention and control, and ultimately delay or reverse the early vascular aging.

2. Bring forward the condition judgment of vascular aging related disease (Hypertension, atherosclerosis, metabolic syndrome, diabetes and chronic kidney disease), decision-making treatment, prognosis and curative effect evaluation.

3. To provide subclinical vascular disease monitoring indicators for the rehabilitation of medical and clinical research.

4. To provide the vascular disease monitoring, risk assessment and individualized prevention and treatment for the cardiovascular health and rehabilitation of the population with special needs, in order to delay the early blood vessel aging.

PACKING LIST

TYPE BX-5100 ARTERIOSCLEROSIS DETECTING SYSTEM