The technology of tongue and hard palate contact detection: a review.

The tongue and hard palate play an essential role in the production of sound during continuous speech. Appropriate tongue and hard palate contacts will ensure proper sound production. Electropalatography, also known as EPG, is a device that can be used to identify the location of the tongue and hard palate contact. It can also be used by a speech therapist to help patients who have a speech disorder. Among the group with the disease are cleft palate, Down syndrome, glossectomy, and autism patients. Besides identifying the contact location, EPG is a useful medical device that has been continuously developed based on the patient's needs and treatment advancement. This article reviews the technology of electropalatography since the early introduction of the device. It also discusses the development process and the drawbacks of the previous EPG systems, resulting in the EPG's upgraded system and technology. This review suggests additional features that can be useful for the future development of the EPG. The latest technology can be incorporated into the EPG system to provide a more convenient method. There are some elements to be considered in the development of EPG's new technology that were discussed in this study. The elements are essential to provide more convenience for the patient during speech therapy. New technology can accelerate the growth of medical devices, particularly on the development of speech therapy equipment that should be based on the latest technological advancements available. Thus, the advanced EPG system suggested in this article may expand the usage of the EPG and serve as a tool to provide speech therapy treatment services and not limited to monitoring only.

Laser-induced changes of in vitro erythrocyte sedimentation rate.

The study of the effects of low-level laser (LLL) radiation on blood is important for elucidating the mechanisms behind the interaction of LLL radiation and biologic tissues. Different therapy methods that involve blood irradiation have been developed and used for clinical purposes with beneficial effects. The aim of this study was to compare the effects of different irradiation protocols using a diode-pumped solid-state LLL (λ = 405 nm) on samples of human blood by measuring the erythrocyte sedimentation rate (ESR). Human blood samples were obtained through venipuncture into tubes containing EDTA as an anticoagulant. Every sample was divided into two equal aliquots to be used as an irradiated sample and a non-irradiated control sample. The irradiated aliquot was subjected to a laser beam with a wavelength of 405 nm and an energy density of 72 J/cm2. The radiation source had a fixed irradiance of 30 mW/cm2. The ESR change was observed for three different experimental protocols: irradiated whole blood, irradiated red blood cells (RBCs) samples re-suspended in non-irradiated blood plasma, and non-irradiated RBCs re-suspended in irradiated blood plasma. The ESR values were measured after laser irradiation and compared with the non-irradiated control samples. Irradiated blood plasma in which non-radiated RBCs were re-suspended was found to result in the largest ESR decrease for healthy human RBCs, 51%, when compared with RBCs re-suspended in non-irradiated blood plasma. The decrease in ESR induced by LLL irradiation of the plasma alone was likely related to changes in the plasma composition and an increase in the erythrocyte zeta potential upon re-suspension of the RBCs in the irradiated blood plasma.

Effects of low-level laser irradiation on human blood lymphocytes in vitro.

Low-level laser irradiation (LLLI) has various effects on cultured human lymphocytes in vitro, but little is known about such effects in whole blood. This study investigated whether LLLI affected lymphocyte count in human whole blood in vitro. A total number of 130 blood samples were collected from apparently healthy adult patients through venipuncture into tubes containing EDTA. Each sample was divided into two equal aliquots to be used as a non-irradiated control sample and an irradiated sample. The irradiated aliquot was subjected to laser wavelengths of 405, 589, and 780 nm with different fluences of 36, 54, 72, and 90 J/cm2, at a fixed irradiance of 30 mW/cm2. A paired student t test was used to compare between non-irradiated and irradiated samples. The lymphocyte counts were measured using a computerized hematology analyzer and showed a significant (P < 0.02) maximum increase (1.6%) at a fluence of 72 J/cm2 when compared with non-irradiated samples. This increase in lymphocyte count upon irradiation was confirmed by flow cytometry. At a wavelength of 589 nm and fluence of 72 J/cm2, irradiation of whole blood samples showed a significant increase in CD45 lymphocytes and natural killer (NK) (CD16, CD56) cells, but no significant changes in CD3 T lymphocytes, T-suppressor (CD3, CD8) cells, T-helper (CD3, CD4) cells, and CD19 B lymphocytes when compared with their non-irradiated counterparts. Our results clearly demonstrate that NK cell count is altered by irradiation, which ultimately affects the whole lymphocyte count significantly.

Erythrocyte sedimentation rate of human blood exposed to low-level laser.

This study is designed to investigate in vitro low-level laser (LLL) effects on rheological parameter, erythrocyte sedimentation rate (ESR), of human blood. The interaction mechanism between LLL radiation and blood is unclear. Therefore, research addresses the effects of LLL irradiation on human blood and this is essential to understanding how laser radiation interacts with biological cells and tissues. The blood samples were collected through venipuncture into EDTA-containing tubes as an anticoagulant. Each sample was divided into two equal aliquots to be used as a non-irradiated sample (control) and an irradiated sample. The aliquot was subjected to doses of 36, 54, 72 and 90 J/cm(2) with wavelengths of 405, 589 and 780 nm, with a radiation source at a fixed power density of 30 mW/cm(2). The ESR and red blood cell count and volume are measured after laser irradiation and compared with the non-irradiated samples. The maximum reduction in ESR is observed with radiation dose 72 J/cm(2) delivered with a 405-nm wavelength laser beam. Moreover, no hemolysis is observed under these irradiation conditions. In a separate protocol, ESR of separated RBCs re-suspended in irradiated plasma (7.6 ± 2.3 mm/h) is found to be significantly lower (by 51 %) than their counterpart re-suspended in non-irradiated plasma (15.0 ± 3.7 mm/h). These results indicate that ESR reduction is mainly due to the effects of LLL on the plasma composition that ultimately affect whole blood ESR.

Surface modifications of human tooth using Nd:YAG laser for dental applications.

Ablation using Nd:YAG laser has potential in resulting a rough effect on tooth surfaces. The objective of this study is to perform a comparative evaluation of the roughness structure of enamel using the Cynosure Cynergy Nd:YAG laser and 37% phosphoric acid. The results obtained for laser-etched with a pulse width of 300ms show roughed and porous surface with greater depth. Both show remarkable graininess on the surface and fewer indentations. Comparison of the elemental compositions demonstrated that calcium has higher composition when exposed to laser-etch compared to acid-etch. The atomic percentages of calcium in sample A for acid-etched and laser-etched are 5.08 and 9.61, respectively. While acid-etched and laser-etched for sample B are 3.98 and 12.84, respectively. Other elements are not profoundly affected by the technique used in this study. However, carbon and oxygen show inconsistent results for both of the samples. Thus, Nd:YAG laser provides significant effects on the tooth surface but does not primarily modify the element compositions of the tooth. Therefore, Nd:YAG laser can potentially be implemented for etching procedure as a replacement of acid etching technique.

Peripheral venous blood oxygen saturation can be non-invasively estimated using photoplethysmography.

Measurement of peripheral venous oxygen saturation (SvO2) is currently performed using invasive catheters or direct blood draw. The purpose of this study was to non-invasively determine SvO2 using a variation of pulse oximetry techniques. Artificial respiration-like modulations applied to the peripheral vascular system were used to infer regional SvO2 using photoplethysmography (PPG) sensors. To achieve this modulation, an artificial pulse generating system (APG) was developed to generate controlled, superficial perturbations on the finger using a pneumatic digit cuff. These low pressure and low frequency modulations affect blood volumes in veins to a much greater extent than arteries due to significant arterial-venous compliance differences. Ten healthy human volunteers were recruited for proof-ofconcept testing. The APG was set at a modulation frequency of 0.2 Hz (12 bpm) and 45-50 mmHg compression pressure. Initial analysis showed that induced blood volume changes in the venous compartment could be detected by PPG. Estimated arterial oxygen saturation (97% [IQR=96.1%-97.4%]) matches published values (95%-99%). Estimated venous oxygen saturation (93.2% [IQR=91.-93.9%]) agrees with reported ranges (92%-95%) measured in peripheral regions. The median difference between the two saturations was 3.6%, while the difference between paired measurements in each subject was statistically significant (p=0.002). These results demonstrate the feasibility of this method for real-time, low cost, non-invasive estimation of SvO2. Further validation of this method is warranted.

A model-based control protocol for transition from ICU to HDU: Robustness analysis.

The robustness of a model-based control protocol as a less intensive TGC protocol using insulin Glargine for provision of basal insulin is simulated in this study. To quantify the performance and robustness of the protocol to errors, namely physiological variability and sensor errors, an in-silico Monte Carlo analysis is performed. Actual patient data from Christchurch Hospital, New Zealand were used as virtual trial patients.