1. School of Biomedical Engineering, Science & Health Systems WWW.BIOMED.DREXEL.EDU/ResearchPortfolio/ V 2.0 SD [020204] Impedance Cardiography for Non-invasive Monitoring of Hemodynamics BIOMEDICAL SIGNALS & SYSTEMS RESEARCH PROGRAM OVERVIEWPROGRAM OVERVIEW Gastroscope Non-invasive Monitoring of Gastric Contractility Impedance cardiography (ICG) is a safe, affordable, non-intrusive, and non-invasive technology that has special significance in its application to monitoring of the heart. As a cardiac diagnostic tool, this technology measures continuously any electrical impedance changes that occur throughout the thorax in response to changes in blood flow resulting from each and every heartbeat. The Gastroscope is proposed as the only non-invasive system for measuring and monitoring the myoelectrical activity of the stomach. This will be achieved by placing electrodes on the abdominal surface and recording the signals preceding gastric activity. The Gastroscope is designed specific to this task and will incorporate electronic components for extracting and manipulating pre-determined frequency components of importance. The system will be programmed for signal processing techniques and mathematical computations for revealing specific information visually to a medical professional operating the device. Faculty: Dr. Hun H. Sun, Ph.D., Drexel University; Dr. Han C. Ryoo, Ph.D., Drexel University. Collaborating Researchers: Dr. Ata Akin, Ph.D., Drexel University. 3.3 cpm 12 dB fEGG= 27 dB POWERMENU E

2. School of Biomedical Engineering, Science & Health Systems WWW.BIOMED.DREXEL.EDU/ResearchPortfolio/ V 2.0 SD [020204] IMPEDANCE CARDIOGRAPHY FOR NON-INVASIVE MONITORING OF HEMODYNAMICS PROJECTONEPAGERPROJECTONEPAGER Faculty/Contact: Dr. Hun H. Sun, Ph.D., Drexel University; Dr. Han C. Ryoo, Ph.D., Drexel University. E-mail: Hun.H.Sun@drexel.edu; HanRyoo@drexel.edu Collaborating Researchers: Dr. Ata Akin, Ph.D., Drexel University. Funding: Wantagh, Inc. Laboratorie: Biomedical Information Technology Laboratory (BITLab). Impedance cardiography (ICG) is a safe, affordable, non-intrusive, and non-invasive technology that has special significance in its application to monitoring of the heart. As a cardiac diagnostic tool, this technology measures continuously any electrical impedance changes that occur throughout the thorax in response to changes in blood flow resulting from each and every heartbeat. An ICG measures the heart’s mechanical activity in a way similar to how an ECG measures the heart’s electrical activity. Measurement of the heart’s mechanical activity is indicated by a change in impedance over time that results from the heartbeat-induced changes in blood flow. The change in impedance over time is indicated as dZ/dt in Figure 3. Cardiac events are marked as points A, B, C, X, and O on the impedance signals in Figure 3. By using advanced signal processing techniques, these points are localized and integrated into system models (such as Kubicek or Sramek) to obtain hemodynamic information that can be used to show cardiac performance. Figure 1 - Electrode configuration Figure 2 - Monitor-displayed impedance signals Figure 3 - ECG phonocardiograph and impedance signals showing cardiac events In Patient  Critical Care  Surgery / Anesthesia  Emergency Care Clinical Applications Out Patient  Chronic Heart Failure  Hypertension  Pacemaker  Dialysis Figure 1 shows two pairs of disposable impedance electrodes positioned on a patient’s neck and thorax, as well as to an ECG lead array. The other end of the electrodes are connected to a monitor, which displays the heartbeat-induced impedance signals, as seen in Figure 2. Continuous measurement of these impedance signals makes it possible to measure, calculate, and monitor the complete cardiac cycle, including stroke volume, cardiac output, contractility parameters, and total thoracic fluid status. The phonocardiograph signal in Figure 3 indicates the opening and closing of the heart valve, but is not used in the signal processing.

3. School of Biomedical Engineering, Science & Health Systems WWW.BIOMED.DREXEL.EDU/ResearchPortfolio/ V 2.0 SD [020204] GASTROSCOPE NON-INVASIVE MONITORING OF GASTRIC CONTRACTILITY PROJECTONEPAGERPROJECTONEPAGER Faculty/Contact: Dr. Ata Akin, Ph.D., Drexel University. E-mail: akin@drexel.edu Funding: Drexel University, Sanhill, Inc. Laboratorie: Biomedical Information Technology Laboratory (BITLab). manipulating pre-determined frequency components of importance. The system will be programmed for signal processing techniques and mathematical computations for revealing specific information visually to a medical professional operating the device. The Gastroscope is proposed as the only non-invasive system for measuring and monitoring the myoelectrical activity of the stomach. This will be achieved by placing electrodes on the abdominal surface and recording the signals preceding gastric activity. The Gastroscope is designed specific to this task and will incorporate electronic components for extracting and Design of a portable handheld NIR Breast Cancer Imager 3.3 cpm 12 dB fEGG= 27 dB POWERMENU E Problem Statement:  A need for non-invasive monitoring of stomach activity  Ambulatory recording is required  Cost of diagnosing gastric motility disorders is high  Follow-up tests are uncomfortable to patients Components of Gastroscope:  High gain low noise amplifier  Low pass filter  Analog Digital Converter  Digital Signal Processor  Memory  Display  Ports for data transfer Solution = Gastroscope Signal Processing of fEGG:  The acquisition of myoelectrical signals of the stomach are called the Electrogastrogram (EGG). EGG signals have a dynamic range of 0.01 Hz to 2 Hz (1-120 cycles per minute, cpm). The frequency component within 2-5 cpm is called the primary/dominant signal while the high frequency components at the 50-80 cpm are called the fast EGG (fEGG)  fEGG signals are correlated with the peristaltic contractions; hence the motility.  fEGG signals can be extracted by using a bandpass filter with appropriate bandwidth EGG Signal Fast Fourier Transform Peak Detection and Corresponding Frequency Butterworth Filter Power Average Power Data Windowing (1 minute) Display and Memory Primary Signal 3 cpm Secondary Signal 50 - 80 cpm