Parameters Extracted From Arterial Pulse Waves as Markers of Atherosclerotic Changes: Performance and Repeatability

Abstract

Arterial diseases are significant and increasing cause of mortality and morbidity. In this study, we analyze and compare the discrimination capability of different arterial pulse wave (PW) based indices, both earlier proposed and novel ones, for describing the vascular health. The repeatability of the indices is also evaluated. Both volume PWs and dynamic pressure PWs are recorded by using photoplethysmographic and electromechanical film (EMFi) sensors connected to a wireless body sensor network. The study population consists of 82 subjects, 30 atherosclerotic patients, and 52 control subjects. In addition, day-to-day variability of the derived indices is studied with ten test subjects examined on three different days. The results are evaluated in terms of statistical tests and receiver operating characteristic (ROC) curves as well as coefficient of variation (CV) and intraclass correlation coefficient (ICC). Altogether 24 out of the evaluated 40 PW parameters showed statistical differences ( or less) between controls and atherosclerotic patients. Maximum area under curve was 0.88. Most of the indices had ICCs higher than 0.8 and average CVs less than 0.1. The study shows that the amplitude ratios and time intervals between different PW peaks could be a useful additional tool for the detection of atherosclerosis. The results encourage us for further studies in this field. Up to our knowledge, the performance and the repeatability of different PW derived indices have previously not been studied and compared with each other this extensively. Our findings also provide evidence for the utility of PW measurements for the detection of atherosclerotic changes.

Lower Limb Pulse Rise Time as a Marker of Peripheral Arterial Disease

“…The stiffening of the arteries increases the pulse wave velocity which makes the heart-beat induced wave and first reflected wave more and more overlapping, causing delayed temporal location of the peak value compared with the healthy arteries having more distinct waves. Differences in other upper limb PWderived features, such as augmentation index and reflection index, between healthy controls and atherosclerotic patients have also been observed in an earlier study [19].…”

“…In the case of non-treated lower limb or upper limb, no consistent changes were observed in the PRT. Based on the present and previous studies, lower limb PW-derived features [8], [9], [12], [16], [19] could add to diagnostics especially in patients presenting with stenoses and mediasclerotic changes of the lower limb arteries. Despite the promising results, further studies with higher sample sizes should confirm and validate the results.…”

“…In such patients, normal or too high ABI readings are expected, despite the stenoses, since the stiffening of the lower limb arteries prevents the compression of the arteries with a cuff used in the ABI measurement. Lower limb PRT or other lower limb PW-derived markers [8], [9], [11], [16], [19] could play an additional diagnostic role along with conventional screening tools such as ABI and toe pressure measurement especially in patients having stenoses and mediasclerotic changes concomitantly present in the lower limbs. As the PRT is not significantly disturbed from the inserted endovascular instrumentation, it could be suitable even for peri-operative monitoring to check the patient's response to the treatment.…”

Evaluation of Printed P(VDF-TrFE) Pressure Sensor Signal Quality in Arterial Pulse Wave Measurement

“…Especially the piezoelectric polymer poly(vinylidenefluoride-co-trifluoroethylene) (P(VDF-TrFE)) has high potential for meeting the aforementioned requirements due to its solution processability, which enables affordable fabrication with additive printing methods, and ability to form thin films for unobtrusive user-experience [9][10] [11]. In this contribution, we study the accuracy and reliability of additively fabricated piezoelectric P(VDF-TrFE) PW sensor signal quality by comparing it to a PW signal obtained concurrently with a reference sensor made of electromechanical film (EMFi) electret material, which has been used earlier in several clinical studies for collecting PW data [21] [22]. Furthermore, 22 test subjects are examined which enables statistical comparison between the proposed P(VDF-TrFE) sensor and the reference sensor.…”

The effect of percutaneous transluminal angioplasty of superficial femoral artery on pulse wave features

“…Systolic toe pressures or toe-to-brachial pressure index (TBI) have also been suggested as an alternative to ABI especially to diabetic patients, but also they have problems with the reliability [6]. Many studies have suggested pulse wave (PW) measurement and analysis for finding vascular abnormalities or abnormal vascular aging [7,8,9,10,11,12].…”