An implantable optical blood pressure sensor based on pulse transit time.
Jens Fiala1, Philipp Bingger, Dominic Ruh
1Department of Microsystems Engineering (IMTEK), Laboratory for Micro-Optics, University of Freiburg, Georges-Koehler-Allee 102, Freiburg, 79110, Germany. jens.fiala@imtek.uni-freiburg.de
Biomedical Microdevices
|October 12, 2012
Summary
This study presents an implantable sensor for long-term blood pressure monitoring using pulse transit time. The system, utilizing microelectromechanical systems (MEMS) and optical methods, shows promise in animal models for accurate measurement.
Area of Science:
- Biomedical Engineering
- Medical Devices
- Sensor Technology
Background:
- Continuous blood pressure monitoring is crucial for managing cardiovascular health.
- Existing methods for long-term blood pressure monitoring have limitations.
- Pulse transit time (PTT) offers a non-invasive correlation with blood pressure.
Purpose of the Study:
- To develop and validate an implantable sensor system for long-term blood pressure monitoring.
- To leverage the correlation between PTT and blood pressure for accurate measurements.
- To integrate advanced technologies for a highly-resolved and reliable sensor.
Main Methods:
- Fabrication of a highly integrated implantable sensor module using MEMS technologies.
- Utilizing 8 light-emitting diodes (LEDs) and a photodetector for extravascular measurement.
- Application of spectrophotometric approaches for hemoglobin derivative analysis.
- Implementation and calibration of the sensor system in animal models.
Main Results:
- Successful development of an implantable sensor system for long-term blood pressure monitoring.
- Demonstrated extravascular measurement of highly-resolved photoplethysmograms.
- Validation of the sensor system's calibration in animal models.
- Potential for simultaneous measurement of hemoglobin derivatives.
Conclusions:
- The developed implantable sensor system effectively monitors blood pressure long-term by utilizing PTT.
- MEMS and optical technologies enable a compact and highly functional sensor.
- The system shows feasibility and accuracy in preclinical animal studies.
- This technology holds potential for improved cardiovascular health management.
Related Concept Videos
01:30Equipments Used To Measure Blood Pressure
Direct Method
This invasive approach involves cannulating a peripheral artery. During each cardiac contraction, pressure generates mechanical motion within the catheter, transmitted through rigid, fluid-filled tubing to a transducer. This transducer converts mechanical motion into electrical signals displayed as waveforms on a monitor. An automatic flushing system prevents blood backflow. Due to the potential risk of unexpected arterial blood loss, this method is primarily used in intensive...
This invasive approach involves cannulating a peripheral artery. During each cardiac contraction, pressure generates mechanical motion within the catheter, transmitted through rigid, fluid-filled tubing to a transducer. This transducer converts mechanical motion into electrical signals displayed as waveforms on a monitor. An automatic flushing system prevents blood backflow. Due to the potential risk of unexpected arterial blood loss, this method is primarily used in intensive...
01:30Pulse rhythm
Pulse rhythm refers to the pattern of pulsations within specific intervals, offering valuable insights into the regularity or irregularity of the heart's beats as observed through the pattern of pulsation within specific intervals. A regular pulse exhibits a consistent heart rate with uniform waveforms and pulsation force, variations of which can be classified as normal, weak, or bounding.
Conversely, an irregular pulse pattern is termed dysrhythmia, stemming from disruptions in cardiac muscle...
Conversely, an irregular pulse pattern is termed dysrhythmia, stemming from disruptions in cardiac muscle...
01:19Assessing Blood pressure using a doppler ultrasound
To obtain accurate blood pressure measurements in clinical settings, especially when traditional methods are insufficient, healthcare professionals utilize the Doppler ultrasound technique. This method uses high-frequency sound waves to detect blood flow within the arteries, which is crucial for patients with conditions that complicate circulatory system assessment.
Pre-Procedural Guidelines for Doppler Ultrasound Blood Pressure Assessment:
Preparation of Equipment:
Pre-Procedural Guidelines for Doppler Ultrasound Blood Pressure Assessment:
Preparation of Equipment:
01:17Measurement of Blood Pressure
Assessing blood pressure is a standard procedure executed in virtually all medical environments. The method utilized today was established over a hundred years ago by an innovative Russian doctor, Dr. Nikolai Korotkoff. The soft ticking noise, known as Korotkoff sounds, heard while taking blood pressure readings results from turbulent blood flow within the vessels. The apparatus required for this procedure includes a sphygmomanometer, a blood pressure cuff attached to a gauge, and a stethoscope.
01:16Pulse
When the heart pumps blood out, arterial elastic fibers play a crucial role in sustaining a high-pressure gradient. They expand to accommodate the received blood and then recoil - a process known as the pulse that can be either manually palpated or electronically quantified. Despite a reduction in its effect with increased distance from the heart, elements of the pulse's systolic and diastolic components persist, observable even at the arteriole level.
The pulse serves as a clinical indicator...
The pulse serves as a clinical indicator...
01:24Pulse Oximetry
Pulse oximetry, or SpO2, is a non-invasive method for continuously monitoring arterial oxygen saturation (SaO2). This procedure involves attaching a probe or sensor to the patient's fingertip, forehead, earlobe, or nose bridge. The sensor works by detecting changes in oxygen saturation levels through light signals generated by the oximeter and reflected by the pulsing blood under the probe.
Purpose
Average SpO2 values are greater than 95%. If the readings fall below 90%, it indicates that...
Purpose
Average SpO2 values are greater than 95%. If the readings fall below 90%, it indicates that...