An ultra low energy biomedical signal processing system operating at near-threshold.

This paper presents a voltage-scalable digital signal processing system designed for the use in a wireless sensor node (WSN) for ambulatory monitoring of biomedical signals. To fulfill the requirements of ambulatory monitoring, power consumption, which directly translates to the WSN battery lifetime and size, must be kept as low as possible. The proposed processing platform is an event-driven system with resources to run applications with different degrees of complexity in an energy-aware way. The architecture uses effective system partitioning to enable duty cycling, single instruction multiple data (SIMD) instructions, power gating, voltage scaling, multiple clock domains, multiple voltage domains, and extensive clock gating. It provides an alternative processing platform where the power and performance can be scaled to adapt to the application need. A case study on a continuous wavelet transform (CWT)-based heart-beat detection shows that the platform not only preserves the sensitivity and positive predictivity of the algorithm but also achieves the lowest energy/sample for ElectroCardioGram (ECG) heart-beat detection publicly reported today.

Tc-99m HMPAO leukocyte and Tc-99m nanocolloid scintigraphy in posttraumatic bone infection.

Posttraumatic osteomyelitis was investigated in 23 patients using nuclear medicine techniques. Tc-99m hexamethylpropilene amine oxime (HMPAO)-labeled leukocyte scintigraphy was performed in 11 patients, and Tc-99m nanocolloid scanning was performed in the other 12 patients. The scintigraphic findings were compared with clinical, laboratory, radiologic, and bacteriologic results. The findings on leukocyte imaging were consistent with the clinical symptoms in 7 of 11 patients, with the laboratory pattern in 7 of 10 patients, with the radiologic findings in 7 of 11 patients, and with the results of bacteriology in 6 of 7 patients. The findings on nanocolloid scintigraphy corresponded with the clinical symptoms in 9 of 12 patients, with the laboratory pattern in 8 of 10 patients, with the radiologic findings in 8 of 12 patients, and with the bacteriology in 4 of 5 patients. The results suggest that both methods were of similar value for the detection of chronic posttraumatic osteomyelitis regardless of whether the process was active. Conversely, on the basis of semiquantitative analysis of the images, leukocyte scintigraphy seemed to characterize the grade of inflammation better than did nanocolloid scintigraphy.