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Objective: The aim of the study was to show if pulse rise times (PRTs) extracted from photoplethysmographic (PPG) pulse waves (PWs) have an association with peripheral arterial disease (PAD) or its endovascular treatment, percutanoeus transluminal angioplasty (PTA) of the superficial femoral artery. Methods: Lower and upper limb PPG PWs were recorded and analyzed from 24 patients who suffered from PAD. The measurements were conducted before and after the treatment, and one month later by using transmission-mode PPG-probes placed in the index finger and second toe. Ankle-to-brachial pressure index and toe pressures were used as references in clinical patient measurements. PRTs, i.e., the time from the foot point to the peak point of the PW, were extracted from the PWs and compared bilaterally. The results from the PAD patients were also compared with 31 same-aged and 34 younger control subjects. Results: Statistically significant differences were found between the pretreatment PRTs of the treated limb of the PAD patients and the same-aged control subjects ( $p< 10^{-9}$ , Mann–Whitney U-test). The changes in the PRT of the treated lower limb were observed immediately after the PTA ( $p< 0.001$ , Student's t -test), and after one month ( $p< 0.0005$ ), whereas the PRTs of the non-treated lower limb and upper limb did not indicate changes between different examinations. Conclusion: Results show that a PRT greater than 240 ms indicates PAD-lesions in the lower limb. Significance: This proof-of-concept study suggests that the PRT could be an effective and easy-to-use indicator for PAD and monitoring the effectiveness of its treatment. acceptedVersion

Supplemental material, DS_TECH768710 for A Portable Microscale Cell Culture System with Indirect Temperature Control by Antti-Juhana Mäki, Jarmo Verho, Joose Kreutzer, Tomi Ryynänen, Dhanesh Rajan, Mari Pekkanen-Mattila, Antti Ahola, Jari Hyttinen, Katriina Aalto-Setälä, Jukka Lekkala and Pasi Kallio in SLAS Technology

A device for studying facial pacing for people who suffer from unilateral facial paralysis is presented. The device is able to measure electromyographic (EMG) signals from the healthy side of the face and simultaneously activate the paralysed side with electrical stimulation. Electronics designed for the device are integrated to a single tabletop unit together with a myRIO embedded hardware device by National Instruments (NI). The presented device is designed to fulfil the safety requirements of the Council Directive 93/42/EEC of the European Union concerning medical devices and IEC 60601 standards. The device is powered by a commercial medical grade power source. The custom electronics include isolated measurement and stimulation amplifiers that feed the signals to and from the myRIO. Complex real-time processing can be carried out in the myRIO's FPGA circuit for detecting muscle activations and producing appropriate stimulation signals. The functionality is programmed with NI LabVIEW. The device is controlled wirelessly via a computer interface, and the measured data is logged to the computer. Clinical study with the device is about to be started at the Tampere University Hospital. First trials will determine and compare the required stimulation signal waveform parameters for transcutaneous activation of facial muscles of healthy participants and patients suffering from unilateral facial paralysis. Four measurement and four stimulation channels of the device enable studying different electrode configurations and stimulation patterns for recognizing and reanimating symmetrical facial expressions in the future.

A capacitive facial movement detection method designed for human-computer interaction is presented. Some point-and-click interfaces use facial electromyography for clicking. The presented method provides a contactless alternative. Electrodes with no galvanic coupling to the face are used to form electric fields. Changes in the electric fields due to facial movements are detected by measuring capacitances between the electrodes. A prototype device for measuring a capacitance signal affected by frowning and lifting eyebrows was constructed. A commercial integrated circuit for capacitive touch sensors is used in the measurement. The applied movement detection algorithm uses an adaptive approach to provide operation capability in noisy and dynamic environments. Experimentation with 10 test subjects proved that under controlled circumstances the movements are detected with good efficiency, but characterizing the movements into frowns and eyebrow lifts is more problematic. Integration with a two-dimensional pointing solution and further experiments are still required.