Effects of sensory combination on crispness and prediction of sensory evaluation value by Gaussian process regression.

Crispness contributes to the pleasantness and enjoyment of eating foods and is popular with people of wide ages in many countries. Hence, a quantitative evaluation method for crispness is required for food companies developing new food products. In this study, the effects of different sensory combinations on crispness were investigated through sensory evaluation, and a Gaussian process regression model was used to predict the evaluation values of crispness. First, four crispness descriptors in Japanese were selected, and sensory evaluations were conducted with ten participants using commercially available snack foods under three different sensory combinations of force, vibration, and sound to confirm the effects of the three senses. An instrumental system also measured force, vibration, and sound for snack foods under the same conditions. The Gaussian process regression model determined the relationship between the sensory and measurement data and predicted the sensory evaluation values from the measurement data. Cross-validation verified that the Gaussian process regression model accurately predicted the food texture evaluation values from the measurement data even in conditions with different sensory components.

Validity of a novel respiratory rate monitor comprising stretchable strain sensors during a 6-min walking test in patients with chronic pulmonary obstructive disease.

BACKGROUND: Breathing frequency is rarely measured during a field walking test since the current monitoring system using a face mask is cumbersome for older adults. For effective clinical application, we aimed to validate the new respiratory monitor using wearable strain sensors during a 6-min walk test (6MWT) in young adults and patients with chronic obstructive pulmonary disease (COPD). METHODS: The study included young adults and patients with stable COPD voluntarily recruited from three hospitals. Breathing frequency during 6MWT were measured by the strain sensor and a nasal capnometer. Total breathing frequencies were measured by the capnometer. The Bland-Altman method was used to estimate the mean limit of agreement for breathing frequency. RESULTS: A total of 23 young adults (age = 23.1 ± 3.7, mean ± SD) and 50 patients with COPD (age = 75.2 ± 7.2, %FEV1 = 59.1 ± 19.7) were analyzed. During the entire test period, the total breathing frequencies were measured based on an average of 252 ± 46 breaths, and the total breathing frequency was higher in patients with COPD than in young adults (mean difference = -3.349, p < 0.0013). The mean difference in breathing frequency between the strain sensors and capnometer was -0.28 (95%CI: 0.75 to 0.20), and the limit of agreement ranged from -4.1 to 3.6. The CI of the limit of agreement included the limit of equivalence (4 counts/min). CONCLUSIONS: The novel respiratory monitor with wearable sensors achieved the target accuracy in both young adults and patients with COPD in the 6MWT.

A Magnetic Food Texture Sensor and Comparison of the Measurement Data of Chicken Nuggets.

Food texture is one of the important quality indicators in foodstuffs, along with appearance and flavor, contributing to taste and odor. This study proposes a novel magnetic food texture sensor that corresponds to the tactile sensory capacity of the human tooth. The sensor primarily consists of a probe, linear slider, spring, and circuit board. The probe has a cylindrical shape and includes a permanent magnet. Both sides of the spring are fixed to the probe and circuit board. The linear slider enables the smooth, single-axis motion of the probe during food compression. Two magnetoresistive elements and one inductor on the circuit board measured the probe's motion. A measurement system then translates the measurement data collected by the magnetoresistive elements into compression force by means of a calibration equation. Fundamental experiments were performed to evaluate the range, resolution, repetitive durability of force, and differences in the frequency responses. Furthermore, the sensor was used to measure seven types of chicken nuggets with different coatings. The difference between the force and vibration measurement data is revealed on the basis of the discrimination rate of the nuggets.

Sum of variance for quantifying the variation of multiple sequential data for the crispness evaluation of chicken nugget.

Crispness is one of the words most frequently used to describe the texture of fried or dried food in addition to being a key to the determination of freshness for many non-fried foods. In this study, a new feature value called the sum of variance was assessed for its contribution to the estimation of crispness. Dynamic time warping and its averaging algorithms were employed to determine the sum of variance from a set of sequential force data measured using an instrument. The sum of variance is a feature value that expresses the variance of multiple sequential data. In an experiment, seven chicken nugget samples were prepared, and five panels evaluated their texture according to six Japanese word descriptors. An instrument experiment determined the six feature values, including the sum of variance from the measurement data, whereas multiple linear regression was applied to determine the relationship between the sensory values and feature values. For three of the six textures, the sum of variance reduced the error between the sensory values and their estimated values by up to 50%, confirming that this feature contributes to the textural estimation of food crispness.

Development of Band-shaped Device and Detection Algorithm of Laryngeal Elevation.

This study concerns a measurement device and an algorithm of the laryngeal elevation for the Mendelsohn maneuver. The measurement device is band-shaped and measures the change of the circumferential length of the neck by stretchable strain sensors. The device is lightweight of 35 g. The algorithm detects the onset and offset points in time of the laryngeal elevation by the first-order difference and the dynamic time warping distance. Twelve elderly people participated in an experiment to validate the effectiveness of the device. A clustering method separated the measurement data into two groups based on their waveforms. We defined template data from the measurement data. The algorithm detected the onset and offset time by using the template data. Although the offset time of a group had an error of about 4 s, the onset and offset time points of the other group were errors within 1 s.

Measurement of laryngeal elevation time using a flexible surface stretch sensor.

BACKGROUND: Dysphagia is a growing health problem in aging societies. An observational cohort study targeting community-dwelling populations revealed that 16% of elderly subjects present with dysphagia. There is a need in elderly communities for systematic dysphagia assessment. OBJECTIVE: This study aimed to verify whether laryngeal elevation in the pharyngeal phase could be measured from the body surface using thin and flexible stretch sensors. METHODS: Thirty-two elderly subjects (17 males, 15 females; mean age ± SD: 89.2 ± 6.2 years) with suspected dysphagia underwent a swallowing contrast examination in which seven stretch sensors were attached to the front of the neck. The elongation of the sensors was measured and compared to the laryngeal elevation time values obtained using videofluorography. The sensor signal detected the laryngeal elevation start time, conclusion of the descent of the larynx, and the laryngeal elevation time. The respective laryngeal elevation times obtained using videofluorography and using the sensor were compared using the Bland-Altman method. RESULTS: The laryngeal elevation time was 1.34 ± 0.46 s with the stretch sensor and 1.49 ± 0.56 s with videofluorography. There was a significant positive correlation between the duration obtained by both methods (r = .69, P < .0001). A negative additional significant bias of -0.15 s (95% confidence interval -0.30 to -0.03, P = .046) was noted in the laryngeal elevation time from the videofluorography measurement. CONCLUSION: Laryngeal elevation time can be measured non-invasively from the neck surface using stretch sensors.

Monitoring respiratory rates with a wearable system using a stretchable strain sensor during moderate exercise.

Respiratory rate, a sensitive indicator of respiratory status, is rarely measured during the field walking test. Our objective was to develop and validate a non-invasive, wearable monitoring system using stretchable strain sensors and an accompanying algorithm capable of providing real-time measurements of respiration during exercise. Twenty-four healthy volunteers wore stretchable sensors during a walking test protocol that included standing, sitting, walking, and walking with a stick. Sensors were placed on the ribcage and abdomen. The Bland-Altman method was used to assess the accuracy and precision of breath counts; total respiration time and inspiration time ratio were determined by custom algorithms and compared with measurements obtained with the standard flow sensor. The output signal from the stretchable sensor was highly synchronized with flow signals. The limits of agreement were within 3 breaths/min throughout the test protocol. Differences between sensors for total respiration time and inspiration time ratio were less than 14% and 26%, respectively. The agreement was maintained regardless of respiratory rate or volume. The wearable respiratory monitoring system yielded accurate and precise breath counts and total duration of respiratory cycle during moderate exercise in healthy young individuals, suggesting that it might be useful in clinical practice. Graphical abstract.

Method for measuring tri-axial lumbar motion angles using wearable sheet stretch sensors.

BACKGROUND: Body movements, such as trunk flexion and rotation, are risk factors for low back pain in occupational settings, especially in healthcare workers. Wearable motion capture systems are potentially useful to monitor lower back movement in healthcare workers to help avoid the risk factors. In this study, we propose a novel system using sheet stretch sensors and investigate the system validity for estimating lower back movement. METHODS: Six volunteers (female:male = 1:1, mean age: 24.8 ± 4.0 years, height 166.7 ± 5.6 cm, weight 56.3 ± 7.6 kg) participated in test protocols that involved executing seven types of movements. The movements were three uniaxial trunk movements (i.e., trunk flexion-extension, trunk side-bending, and trunk rotation) and four multiaxial trunk movements (i.e., flexion + rotation, flexion + side-bending, side-bending + rotation, and moving around the cranial-caudal axis). Each trial lasted for approximately 30 s. Four stretch sensors were attached to each participant's lower back. The lumbar motion angles were estimated using simple linear regression analysis based on the stretch sensor outputs and compared with those obtained by the optical motion capture system. RESULTS: The estimated lumbar motion angles showed a good correlation with the actual angles, with correlation values of r = 0.68 (SD = 0.35), r = 0.60 (SD = 0.19), and r = 0.72 (SD = 0.18) for the flexion-extension, side bending, and rotation movements, respectively (all P < 0.05). The estimation errors in all three directions were less than 3°. CONCLUSION: The stretch sensors mounted on the back provided reasonable estimates of the lumbar motion angles. The novel motion capture system provided three directional angles without capture space limits. The wearable system possessed great potential to monitor the lower back movement in healthcare workers and helping prevent low back pain.

Effects of oral administration of fucoidan extracted from Cladosiphon okamuranus on tumor growth and survival time in a tumor-bearing mouse model.

We evaluated the anti-tumor activities of the oral administration of fucoidan extracted from Cladosiphon okamuranus using a tumor (colon 26)-bearing mouse model. The materials used included low-molecular-weight fucoidan (LMWF: 6.5-40 kDa), intermediate-molecular-weight fucoidan (IMWF: 110-138 kDa) and high-molecular-weight fucoidan (HMWF: 300-330 kDa). The IMWF group showed significantly suppressed tumor growth. The LMWF and HMWF groups showed significantly increased survival times compared with that observed in the control group (mice fed a fucoidan-free diet). The median survival times in the control, LMWF, IMWF and HMWF groups were 23, 46, 40 and 43 days, respectively. It was also found that oral administration of fucoidan increased the population of natural killer cells in the spleen. Furthermore, from the results of the experiment using Myd-88 knockout mice, it was found that these effects are related to gut immunity. These results suggest that fucoidan is a candidate anti-tumor functional food.

Refractoriness to platelet transfusion following partial hepatectomy for hepatocellular carcinoma: report of two cases.

Refractoriness to platelet transfusion indicates a condition in which an expected increase in platelet count is not attained after platelet transfusion. We report herein two cases of refractoriness to platelet transfusion that were caused by the presence of antibodies against the human leukocyte antigen following partial hepatectomy for hepatocellular carcinoma. Due to low postoperative platelet counts in the first case, the patient was transfused with 75 units of platelet concentrate for 3 days after surgery, but was unable to gain a significant increase in the platelet count because of platelet transfusion refractoriness due to anti-human leukocyte antigen antibodies. This case was not complicated and had a favorable clinical course. Despite being transfused with 60 units of platelet concentrate during the 2 days after surgery, the patient's platelet count in the second case did not increase because of the presence of anti-human leukocyte antigen antibodies. Bleeding from the cut surface of the liver into the intraperitoneal cavity was found on the second postoperative day because of a decrease in platelet count. On postoperative day 5, disseminated intravascular coagulation occurred. Perioperative refractoriness to platelet transfusion is an intractable complication since no efficient treatment is available. Preoperative examinations for anti-platelet antibodies should be performed in patients undergoing hepatectomy for hepatocellular carcinoma. This is especially true in cases of decreased platelet counts due to preceding liver cirrhosis and when the prediction for postoperative platelet transfusions is necessary.