Intravascular Arterial Monitoring System

High blood pressure is an important risk factor for vascular diseases (arteriosclerosis), renal and heart insufficiency. Blood pressure is the force in the arteries when the heart beats (systolic pressure) and when the heart is at rest (diastolic pressure). It is measured in millimeters of mercury (mm Hg). High blood pressure is defined in an adult as a blood pressure greater than or equal to 140 mm Hg systolic pressure or greater than or equal to 90 mm Hg diastolic pressure.
Fraunhofer Institute for Microelectronic Circuits and Systems have recently reported that they have designed an intravascular arterial pressure monitoring device which has a diameter of about one millimeter including its casing and it measures the patient’s blood pressure 30 times per second.

Presently, there are different systems available for non-invasive blood pressure measurement. Using such systems the blood pressure can be measured indirectly and quickly by means of an inflatable sleeve on the arm or leg or even over 24 hours long term blood pressure measurement. These extra corporal systems are cumbersome and uncomfortable for patients. Especially overnight, this method of measurement is stressful for the patient. A further disadvantage is the low data acquisition rate. Other systems exhibit sensors (TIP-catheter), which are inserted by means of a catheter into a forearm artery. Considering these systems, drift and inadequate dynamical behavior may generate faulty pressure data. Another possibility deals with blood pressure measurement by means of fluid-filled catheters. In this case drifts and inaccuracies in the pressure measurement may also occur. Additionally, the risk of inflammatory infection increases.

Owing to the size of the device made by the Fraunhofer Institute, it will fit right into one of the arteries in the body and will make it easier to monitor the patient’s blood pressure and get a precise data almost at anytime of the day without any hassle. “A doctor introduces the pressure sensor directly into the femoral artery in the groin,” explains head of department Dr. Hoc Khiem Trieu of the Fraunhofer Institute for Microelectronic Circuits and Systems IMS in Duisburg. It is connected via a flexible micro-cable to a transponder unit, which is likewise implanted in the groin under the skin. This unit digitizes and encodes the data coming from the micro-sensor and transmits them to an external reading device that patients can wear like a cell phone on their belt. From there, the readings can be forwarded to a monitoring station and analyzed by the doctor.” Because the researchers use special components in CMOS technology, the system requires little energy. The micro-implants can be supplied with electricity wirelessly via coils.



Implantable pressure sensors are also suitable for other applications, such as monitoring patients suffering from cardiac insufficiency. The researchers are currently performing the first clinical trials.

Since we are learning the cardiovascular physiology right now, I think this device is interesting and good to know about.

http://www.sciencedaily.com/releases/2009/01/090119081512.htm

Mithil Chokshi
VTPP 435 - 501