No abstract

No abstract

This paper proposes a 3-channel biopotential monitoring ASIC with simultaneous electrode-tissue impedance measurements which allows real-time estimation of motion artifacts on each channel using an an external μC. The ASIC features a high performance instrumentation amplifier with fully integrated sub-Hz HPF rejecting rail-to-rail electrode-offset voltages. Each readout channel further has a programmable gain amplifier and programmable 4th order low-pass filter. Time-multiplexed 12 b SAR-ADCs are used to convert all the analog data to digital. The ASIC achieves >; 115 dB of CMRR (at 50/60 Hz), a high input impedance of >; 1 GΩ and low noise (1.3 μVrms in 100 Hz). Unlike traditional methods, the ASIC is capable of actual motion artifact suppression in the analog domain before final amplification. The complete ASIC core operates from 1.2 V with 2 V digital IOs and consumes 200 μW when all 3 channels are active.

No abstract

Objective: Our objective was to investigate the effect of the rehabilitation system using augmented reality (AR) on upper extremity motor performance of patients with stroke. Methods: The system using AR applying mirror therapy mechanism provides the intervention protocol for the patient with hemiplegia after stroke. The system consists of a patient positioning tool (a chair), a white surface table, an image acquisition unit, an image processing unit, an image displaying unit, an arm holder, a Velcro-strap, and two blue circle stickers. To assess the feasibility of our system in motor function recovery, a stroke patient was recruited to receive the AR intervention. The treatment was performed two times a day for ten minutes over two weeks (ten days of treating weeks), except for the time of installation, calibration, and three minute breaks. Jebsen Taylor hand function test and Arm Motor Fugl-Meyer assessment were used as primary and secondary outcome measures, respectively, to evaluate the effect of motor function recovery. Additionally, stroke impact scale, Korean version-Modified Barthel Index (K-MBI), active range of motion of wrist joint (ROM), and the grasp force in Newtons were measured. Participants’ feedback and adverse effects were recorded as well. Results: Motor function improvements were exhibited in wrist and hand subtest of Arm Motor Fugl-Meyer (baseline: 19; post-intervention: 23), proximal arm subtest of Fugl-Meyer (baseline: 31; post-intervention: 34), ROM (extending ROM: 10° and 3° for flexion and extension, repeatedly), stroke impact scale (baseline: 46; post-intervention: 54), K-MBI (baseline: 92; post-intervention: 95), nine-hole pegboard (baseline: 30 s; post-intervention: 25 s), and grasp force in Newtons (baseline: 12.7; post-intervention: 17.7). However, the adverse effects were reported after the intervention. Conclusion: The system using AR applying mirror therapy mechanism demonstrated the feasibility in motor function recovery for the stroke patient.

A novel algorithm estimating the calorie expenditure during physical activities is introduced. The physical activity is quantified by the integration of the accelerometer signals obtained from the 3D accelerometer fixed at the waist level of the human body. Simultaneous measurements of activity and calorie expenditure using 3D accelerometer and gas analyzer show the activity calorie expenditure increases as the activity increases with different rates depending on the type of activities (e.g., walking, running) as well as the physical characteristics of the subjects (e.g., gender, age, mass, and height). Based on the experimental data gathered from 94 subjects, we suggest a new algorithm estimating the activity calorie expenditure dependent on the demographic data of the subjects and the types of the activity.

In this paper, we investigated the validity of the WHAM (wearable heart activity monitor) in the clinical applications, which has been implemented as a wearable ambulatory device for continuously and long-term monitoring user's cardiac conditions. To this end, using the WHAM and the conventional Holter monitor the ECG signals over 24 hours were recorded during daily activities. The signal from the WHAM was compared with that from the conventional Holter monitor in terms of the readability of the signal, the quality of the signal, and the accuracy of arrhythmia detection. The performance of the WHAM was a little lower as compared with the conventional Holter monitor, although showing no significant difference (the readability of the signal: 97.2% vs 99.3%; the quality of the signal: 0.97 vs 0.98; the accuracy of arrhythmia detection: 96.2% vs 98.1%). From these results, it is likely that the WHAM shows the performance enough to be used in the clinical application as a wearable ambulatory monitoring device.

In this paper, a novel, wearable cardiac monitor (hereafter called WHAM) is proposed which allows a continuous and real-time monitoring of user's cardiac conditions. The proposed device is composed of 3 main components: a disposable electrode, a controller, and personal gateway (e.g., cellular phone, PDA, and smart phone etc.). The ECG signal is recorded according to the surface Laplacian of the body surface potential. We investigated the feasibility of WHAM as a wearable ambulatory device for continuously and on-line monitoring a user's cardiac conditions. To this end, the ECG signals recorded with WHAM were compared with those obtained by Wilson's unipolar chest leads, that is, v1 to v6. As a result, the ECG signals recorded with WHAM showed the similar morphology to Wilson's unipolar chest leads (v1 to v6) with the exception of P and T waves, although there is a difference between amplitudes of both signals. Also, it is shown that the R-peaks are accurately detected by the algorithm at the accuracy of more than 99% for the ECG signals of WHAM recorded during resting and walking. From these results, it is found that the WHAM shows enough feasibility and has advantages as a wearable ambulatory monitoring device in that the hardware is miniaturized enough small to integrate on a small region, thereby no wire leads need.