Opportunities of Electronic and Optical Sensors in Autonomous Medical Plasma Technologies

Low temperature plasma technology is proving to be at the frontier of emerging medical technologies with real potential to overcome escalating healthcare challenges including antimicrobial and anticancer resistance. However, significant improvements in efficacy, safety, and reproducibility of plasma treatments need to be addressed to realize the full clinical potential of the technology. To improve plasma treatments recent research has focused on integrating automated feedback control systems into medical plasma technologies to maintain optimal performance and safety. However, more advanced diagnostic systems are still needed to provide data into feedback control systems with sufficient levels of sensitivity, accuracy, and reproducibility. These diagnostic systems need to be compatible with the biological target and to also not perturb the plasma treatment. This paper reviews the state-of-the-art electronic and optical sensors that might be suitable to address this unmet technological need, and the steps needed to integrate these sensors into autonomous plasma systems. Realizing this technological gap could facilitate the development of next-generation medical plasma technologies with strong potential to yield superior healthcare outcomes.

Does task shifting in tuberculosis microscopy services to non-certified technicians in Afghanistan affect quality?

SETTING

Tuberculosis microscopy centres in 30 provinces in Afghanistan.

OBJECTIVE

To compare the quality of sputum smear examinations in microscopy centres with microscopists who are fully certified as laboratory technicians with those performed in centres with technicians who do not have such certification (high school graduates).

DESIGN

Cross-sectional record review of sputum smear microscopy slides examined by technicians and cross-checked by trained assessors as part of routine external quality assurance between July and September 2009.

RESULTS

Of 129 non-certified technicians, 118 (91%) were stationed in rural health centres compared with 217/257 (84%) certified technicians. From 386 microscopy centres, 7313 slides were cross-checked. Of 257 microscopy centres with certified technicians, 42 (16%) had at least one slide with a major error compared to 23 (18%) of 129 microscopy centres staffed with non-certified technicians. The difference was not statistically significant (OR 1.11, 95%CI 0.64-1.94). The number of slides showing major errors was also similar between the centres with both certified and non-certified technicians.

CONCLUSION

This study confirms the deployment of non-certified microscopy technicians to peripheral health centres throughout the country and that their performance with sputum smear microscopy is similar to that of certified technicians with 3 years of training.

High-speed spiral imaging technique for an atomic force microscope using a linear quadratic Gaussian controller

This paper demonstrates a high-speed spiral imaging technique for an atomic force microscope (AFM). As an alternative to traditional raster scanning, an approach of gradient pulsing using a spiral line is implemented and spirals are generated by applying single-frequency cosine and sine waves of slowly varying amplitudes to the X and Y-axes of the AFM's piezoelectric tube scanner (PTS). Due to these single-frequency sinusoidal input signals, the scanning process can be faster than that of conventional raster scanning. A linear quadratic Gaussian controller is designed to track the reference sinusoid and a vibration compensator is combined to damp the resonant mode of the PTS. An internal model of the reference sinusoidal signal is included in the plant model and an integrator for the system error is introduced in the proposed control scheme. As a result, the phase error between the input and output sinusoids from the X and Y-PTSs is reduced. The spirals produced have particularly narrow-band frequency measures which change slowly over time, thereby making it possible for the scanner to achieve improved tracking and continuous high-speed scanning rather than being restricted to the back and forth motion of raster scanning. As part of the post-processing of the experimental data, a fifth-order Butterworth filter is used to filter noises in the signals emanating from the position sensors and a Gaussian image filter is used to filter the images. A comparison of images scanned using the proposed controller (spiral) and the AFM PI controller (raster) shows improvement in the scanning rate using the proposed method.