2018年10月4日 星期四

Continuous Non Invasive Blood Pressure Research Platform (ECG and PPG) Pulse Arrival Time Based

This project is cuffless cNIBP research platform with ECG(two-electrode) and PPG

In cuffless non-invasive blood pressure monitor field, we with the accurate calibration of PAT to BP, beat-to-beat BP can be estimated from PAT. On the basis of the theoretical relationship between PAT and BP and their experimental or empirical relationship, various models that correlate PAT with BP have been established.

PAT and BP with Regression:

Pulse transit time (PTT) is the time it takes for the pressure or flow wave to propagate between two arterial sites. PTT measured as the time delay between invasive proximal and distal blood pressure or flow, and PTT(propagate time) can be converted to Pulse Wave Velocity(PWV is speed unit).
the most used is the R-wave(QRS Complex) in the electrocardiogram (ECG) and combine pulsemeter(piezo or PPG), leading to the so called pulse arrival time (PAT). PAT is not exactly the PTT, as it includes the time interval between ventricular depolarization and the opening of the aortic valve which is known as pre-ejection period (PEP) and it varies beat-to-beat.

Most efforts have employed the time delay between ECG and finger photoplethysmography (PPG) waveforms as a convenient surrogate of PTT.

However, these conventional pulse arrival time (PAT) measurements include the pre-ejection period (PEP) and the time delay through small, muscular arteries and may thus be an unreliable marker of BP.

Shortcoming is that PAT includes the pre-ejection period (PEP) in addition to PTT. Since the PEP component depends on the electromechanical functioning of the heart, it can change independently of PTT and thus BP.

Because the ECG QRS-Complex is not the starting point for blood to actually enter the radial artery, it is a biopotential to depolarization of the sinus node

This project only for research

Reference : 
[1] Continuous Blood Pressure Measurement from Invasive to Unobtrusive: Celebration of 200th Birth Anniversary of Carl Ludwig
[2] Cuff-Less and Continuous Blood Pressure Monitoring: A Methodological Review

2018年9月21日 星期五

Xcode 10.0 update problem of wxWidgets (g++)

ld: warning: /System/Library/Frameworks//...

try dylib to TBD files:

if the problem remains unsolved:

1. sudo mv /Library/Developer/CommandLineTools /Library/Developer/CommandLineTools.old
2. sudo rm -rf /Library/Developer/CommandLineTools.old
3. Download Command Line Tools from AppleDeveloper :
4. Double Click *.dmg (e.g. Command_Line_Tools_macOS_10.13_for_Xcode_9.2.dmg) install
5. Rebuild your wxWidgets project with g++

2018年9月9日 星期日


wxNixieClock is time sync tool for Nixie Clock project.(Only MAC-OS-X)

g++ -o2 -o wxnixieclock.cpp serialport.cpp connectargsdlg.cpp `wx-config --cxxflags --libs` -m64

1. Pair BT of MAC and Nixie Clock.
2. Open to select tools -> Connect Device -> cu.BT device driver
3. Click SyncTime button
4. Done!

Install wxWidgets dependency in terminal

1. user$ /usr/bin/ruby -e "$(curl -fsSL" 
2. brew install wxwidgets 

Reference : Nixie Clock

2018年9月7日 星期五

STM32F407-MG996R and MAC OS X GUI tester

STM32F407 with PWM to control MG996R, and GUI tester for MAX OS X

make STM32F407 project, and burn to board.(0.5ms~2.5ms)
build GUI
g++ -o2 -o wxservotester.cpp serialport.cpp connectargsdlg.cpp `wx-config --cxxflags --libs`
3. -> Tools -> ConnectDevice
Test your servo motor!

2018年7月8日 星期日

Real-Time wxSignalProcess with Serial Port(VCP) for MAC OS X

一個C++ MAC OS X的範例從/dev/tty.* or /dev/cu.* device driver取得Virtual COM Port的資料並且顯示在GUI,Framework用wxWidgets 3.0以及MRPT修改版的wxMathPlot 0.1.2,和修改以前Linux POSIX API的Class組合,多增加ioctl讀取,以及一個STM32F4的DMA+ADC的Example可供測試。