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This paper presents a general embedded processing system implemented in a field-programmable gate array providing high frame rate and high accuracy for a laser Doppler blood flow imaging system. The proposed system can achieve a basic frame rate of flow images at 1 frame/second for 256 x 256 images with 1024 fast Fourier transform (FFT) points used in the processing algorithm. Mixed fixed-floating point calculations are utilized to achieve high accuracy but with a reasonable resource usage. The implementation has a root mean square deviation of the relative difference in flow values below 0.1% when compared with a double-precision floating point implementation. The system can contain from one or more processing units to obtain the required frame rate and accuracy. The performance of the system is significantly higher than other methods reported to date. Furthermore, a dedicated field-programmable gate array (FPGA) board has been designed to test the proposed processing system. The board is linked with a laser line scanning system, which uses a 64 x 1 photodetector array. Test results with various operating parameters show that the performance of the new system is better, in terms of noise and imaging speed, than has been previously achieved.

Primary Objective: The prime rationale of this research is to investigate the possible occurrence of previously unrecognized episodes of desaturation apparent in preterm infants with chronic lung disease as they freely move around a non-artificial environment., Research Design: The study comprises 58 hours of telemetric recordings of SpO2, heart rate, body movement and temperature, along with full ECG and photoplethysmographic waveforms for eight preterm subjects in their home environment. MAIN OUTCOME/RESULTS: The data is analysed for remarkable events, more particularly periods of spontaneous desaturation. Statistical results for all case studies are collated into a table along with examples of graphical analysis., Conclusions: This study has shown that some patients are prone to episodes of hypoxemia during the course of normal daily activity or daytime sleep that would usually go unrecognized and that more effective management of supplemental oxygen treatment may be possible with continual unobtrusive monitoring.

Primary Objective: This communication describes the initial stage of a research project concerning the monitoring of SpO2 in infants prone to periods of spontaneous oxygen desaturation whilst freely moving around their home environment. The primary aim was to determine an appropriate probe type and site together with an assessment of the suitability of two commercially available oximeter units., Research Design: The study comprised 19 comparative tests, totalling 162 hours of recordings at resolution one sample every four seconds. Comparisons are drawn between probes, probe sites and pulse oximeters. MAIN OUTCOMES/RESULTS: The bias and precision is presented with respect to the probe and measurement site. Also, correlation between the trial and reference recordings is considered., Conclusions: It is concluded that ambulatory recording of SpO2 in infants utilizing equipment suitable for home monitoring can produce diagnostic data equivalent to that of the Ohmeda 3700 biox, but that an indication of movement artefact may be required for confirmation of accuracy. It became apparent that 'wrap around' probes, used on the index finger or big toe are the most suitable.

Field Programmable Gate Arrays (FPGAs) allow digital circuitry to be integrated on to a single device without the long time penalty incurred with mask programmable Application Specific Integrated Circuits (ASICs). This makes FPGA technology an attractive option to engineer involved in designing digital circuitry where space is at a premium. Furthermore, the relatively low cost of FPGAs at low volume, compared to mask programmable ASICs make them an excellent prototyping option for designers who are considering low cost volume production with mask programmable ASICs. There are several different types of FPGAs available which thus creates confusion for prospective users uncertain of their relative benefits. This paper serves as an introduction to FPGA technology and the stages involved in implementing a design, via the application of an Actel FPGA to the development of an ambulatory long term electrocardiogram (ECG) based RR interval recorder.