Change of bilateral difference in radial artery pulse morphology with one-side arm movement

Previous studies have demonstrated that the compliance of peripheral artery changes with arm movement. This study aimed to quantify the bilateral difference in radial artery pulse morphology with one-side arm movement. Twenty-four healthy subjects were recruited. Radial artery pulses were synchronously recorded from both arms, with one arm (left or right) at five different positions (90°, 45°, 0°, −45° and −90°) and the other arm at horizontal level (0°) as reference. Two types of indices of arterial pulse morphology were derived from the normalized arterial pulse signals: the waveform width corresponding to the 50%, 60% and 70% pulse amplitude (W50, W60, W70) and the total area of normalized pulse waveform (Apulse). No matter whether the moving arm was left or right arm, when compared with the other side reference arm, all the waveform widths decreased with arm moving from 90°, 45°, 0°, −45°, and −90°. The bilateral difference of W50, W60 and W70 with the moving arm (either left or right) at 90°, 45° were significantly positive (both p < 0.01) and significantly negative at −90° (both p < 0.05). Meanwhile, no matter whether the moving arm is left or right, Apulse decreased with arm moving from 90°, 45°, 0°, −45°, and −90°. The bilateral difference of Apulse with the left moving arm were significantly positive at 45°, 90° (both p < 0.05). Meanwhile, the bilateral difference of Apulse from the moving right arm was significantly positive at 90° and significantly negative at −45° and −90° (all p < 0.05). In summary, this study quantified the bilateral arterial pulse morphology between arteries with different compliances induced by a simple arm positioning procedure

Open-source automated external defibrillator

The Automated External Defibrillator (AED) is a medical device that analyzes a patient's electrocardiogram in order to establish whether he/she is suffering from the fatal condition of Sudden Cardiac Arrest (SCA), and subsequently allows the release of a therapeutic dose of electrical energy (i.e. defibrillation). SCA is responsible for over 300,000 deaths per year both in Europe and in USA, and immediate clinical assistance through defibrillation is fundamental for recovery. In this context, an open-source approach can easily lead in improvements to the distribution and efficiency of AEDs. The proposed Open-Source AED (OAED) is composed of two separate electric boards: a high voltage board (HV-B), which contains the circuitry required to perform defibrillation and a control board (C-B), which detects SCA in the patient and controls the HV-B. Computer simulations and preliminary tests show that the OAED can release a 200 J biphasic defibrillation in about 12 s and detects SCA with sensitivity higher than 90% and specificity of about 99%. The OAED was also conceived as a template and teaching tool in the framework of UBORA, a platform for design and sharing medical devices compliant to international standards