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Regular monitoring of blood flow and pressure in vascular reconstructions or grafts would provide early warning of graft failure and improve salvage procedures. Based on biocompatible materials, we have developed a new type of thin, flexible pulsation sensor (FPS) which is wrapped around a graft to monitor blood pressure and flow. The FPS used carbon black (CB) nanoparticles dispersed in polydimethylsiloxane (PDMS) as a piezoresistive sensor layer, which was encapsulated within structural PDMS layers and connected to stainless steel interconnect leads. Because the FPS is more flexible than natural arteries, veins, and synthetic vascular grafts, it can be wrapped around target conduits at the time of surgery and remain implanted for long-term monitoring. In this study, we analyze strain transduction from a blood vessel and characterize the electrical and mechanical response of CB-PDMS from 0-50% strain. An optimum concentration of 14 wt% CB-PDMS was used to fabricate 300-μm thick FPS devices with elastic modulus under 500 kPa, strain range of over 50%, and gauge factor greater than 5. Sensors were tested in vitro on vascular grafts with flows of 0-1,100 mL/min. In vitro testing showed linear output to pulsatile flows and pressures. Cyclic testing demonstrated robust operation over hundreds of cardiac cycles, with ±2.6 mmHg variation in pressure readout. CB-PDMS composite material showed excellent potential in biologic strain sensing applications where a flexible sensor with large maximum strain range is needed.
This article was published in the following journal.
Name: IEEE transactions on biomedical circuits and systems
Comparative study of pressure (ankle-brachial pressure index) and flow (strain gauge plethysmography and reactive hyperaemia) measurements in diagnosis of peripheral arterial disease in patients with severe aortic stenosis.
The measurement of the ankle-brachial pressure index is a straightforward method for the detection of peripheral disease in the lower limbs. Only a few old studies with small numbers of patients have ...
Implantable neural probes are widely used to record and stimulate neural activities. These probes should be stiff enough for insertion. However, it should also be flexible to minimize tissue damage af...
Polydimethylsiloxane (PDMS) is one of the most preferred material in microfluidic device/biomedical applications because of its unique properties. However, improvement in surface wettability of PDMS i...
We report on a novel graphene/P(VDF-TrFE) heterostructure based highly sensitive, flexible and biocompatible pressure/strain sensor developed through a facile and low-cost fabrication technique. The h...
Approximately 800 000 coronary angiography procedures are per- formed in Germany each year, mainly in order to identify coronary artery stenoses. As a rule, revascularization is indicated only when co...
The aim of this study is to investigate diagnostic accuracy of median nerve strain and applied pressure measurement . Idiopathic carpal tunnel syndrome patients and healthy controls will b...
In order to identify the responding patients with vascular filling test, this research aims to compare the performance of the increased flow in the femoral artery to the performance of the...
Autoregulation is the ability of a vascular bed to maintain blood flow despite changes in perfusion pressure. For a long time it had been assumed that the choroid is a strictly passive vas...
Anesthesia reduces blood pressure and cerebral blood flow is normally considered to be maintained despite marked changes in blood pressure. Vascular surgical patients are often elderly, ha...
Continuous measurement of intratracheal pressure in mechanically ventilated infants using a fibreoptic pressure transducer in the endotracheal tube (ETT). Based on the findings, tracheal p...
The force that opposes the flow of BLOOD through a vascular bed. It is equal to the difference in BLOOD PRESSURE across the vascular bed divided by the CARDIAC OUTPUT.
Obstruction of the flow in the SPLANCHNIC CIRCULATION by ATHEROSCLEROSIS; EMBOLISM; THROMBOSIS; STENOSIS; TRAUMA; and compression or intrinsic pressure from adjacent tumors. Rare causes are drugs, intestinal parasites, and vascular immunoinflammatory diseases such as PERIARTERITIS NODOSA and THROMBOANGIITIS OBLITERANS. (From Juergens et al., Peripheral Vascular Diseases, 5th ed, pp295-6)
A value equal to the total volume flow divided by the cross-sectional area of the vascular bed.
Obstruction of flow in biological or prosthetic vascular grafts.
The ratio of maximum blood flow to the MYOCARDIUM with CORONARY STENOSIS present, to the maximum equivalent blood flow without stenosis. The measurement is commonly used to verify borderline stenosis of CORONARY ARTERIES.
Vascular relates to blood vessels (Oxford Medical Dictionary) and can be used to describe the supply of blood, a disease affecting the blood vessels or molecules associated with these structures. For example, <!--LGfEGNT2Lhm-->atherosclerosis ...
Blood is a specialized bodily fluid that delivers necessary substances to the body's cells (in animals) – such as nutrients and oxygen – and transports waste products away from those same cells. In vertebrates, it is composed of blo...