Blood vessel detection using skin impedance tomography and spectroscopy.

Blood vessel detection is an essential method in a non-invasive circulatory monitoring system. However, only using camera-based image processing for finding a vein has many limitations due to the complexity of underneath tissue. Impedance tomography and spectroscopy can collect electrical characteristics map of the biological tissue precisely. The study developed instrumentation to measure the impedance with eight small electrodes, which can observe near vein area and show the conductivity map with small patches using tomographic reconstruction. The study examined the cephalic vein of a healthy human arm to confirm the feasibility of vein location recognition. The system could perform 86.8% pixel accuracy and achieve a mIoU score of 63.7% for vessel location segmentation in 5cm2 area observation. The system could identify a human blood vessel's electrical characteristic and visualize the passage.Clinical Relevance- This approach will support intravascular therapy by identifying the vessel location automatically and providing information to the vessel monitoring system in backend. In addition, the system would allow efficient data entry into the electronic medical record for management of hospitalized patients.

A Small 8-Electrode Electrical Impedance Measurement Device for Urine Volume Estimation in the Bladder.

Urinary incontinence is prevalent among elderly people. Recent studies have demonstrated the effectiveness of continence care based on urine volume measurement for elderly people who maintain their urinary storage function, but have difficulty feeling bladder fullness owing to dementia or neurological disorders. Electrical impedance measurement is a feasible technique that can be adopted in the diaper or underwear for continuous and unobtrusive urine volume measurements. We developed a small sensor device that can measure electrical impedance with a resolution of 0.017 Ω, which is sufficiently small to capture abdominal impedance alterations triggered by urine accumulation. The results obtained from a preliminary feasibility test in a young healthy volunteer suggested that the 8-electrode electrical impedance measurement with linear regression can estimate urine volume in the bladder in humans for the first time.Clinical Relevance-Continence care for elderly people is essential; however, it is a huge burden for nurses and caregivers, because it involves taking patients to the toilet or changing diapers. This study proposes a continuous and unobtrusive measurement device for urine volume in the bladder. Via continuous monitoring and bladder fullness alert, the device will enable nurses and caregivers to provide personalized continence care without hindering their routine care.

Modeling for Change of Daily Nurse Calls After Surgery in an Orthopedics Ward Using Bayesian Statistics.

Nurse call data may be used to evaluate the quality of nursing. However, traditional frequency-based statistics may not easily apply to nurse calls due to the large individual variability and daily call changes. We intended to propose a probabilistic modeling of nurse calls based on Bayesian statistics. We constructed the model including nurse call daily changes, individual variability, and adjustment according to characteristics (age and sex). Nurse call differences after surgery were analyzed based on data from the orthopedic ward from April 2014 to October 2017. Results show that there were differences in nurse calls from day 1 to day 10 after surgery between patients who had undergone orthopedic surgery and those who had undergone other surgeries such as tumor surgery. Furthermore, there were differences in nurse calls from day 1 to day 8 after surgery between patients who used extra pain relief medicine and those who did not. Although the analysis required multiple comparisons regarding daily nurse call changes and fixed data samples per day, our approach using Bayesian statistics could detect the periods and significant differences. This indicates that our nurse call modeling based on Bayesian statistics may be used to analyze nurse call changes.

Prevention of diabetic foot ulcers using a smartphone and mobile thermography: a case study.

OBJECTIVE: Early identification of pre-ulcerative pathology is important to preventing diabetic foot ulcers (DFU), but signs of inflammation are difficult to detect on the feet of patients with diabetic neuropathy due to decreased sensation. However, infrared thermography can objectively identify inflammation. Therefore, a device that allows patients to visualise thermograms of their feet might be an effective way to prevent DFU. We aimed to determine the effects of a novel self-monitoring device to prevent DFU using a thermograph attached to a smartphone. METHOD: A self-monitoring device comprising a mobile thermograph attached to a smartphone on a selfie stick was created, and its effects in two patients with diabetic neuropathy and foot calluses assessed. RESULTS: For one patient, he understood that walking too much increased the temperature in the skin of his feet (a sign of inflammation). The other patient could not detect high-risk findings, because the temperature of his skin did not increase during the study period. CONCLUSION: This device might provide self-care incentives to prevent DFU, although some issues, such as the automatic detection of high-risk thermographic changes, need to be improved.

Development of an Electrical Impedance Tomography Spectroscopy for Pressure Ulcer Monitoring Tool: Preliminary study.

This study developed a sensor system that measures electrical impedance with a surrounding electrode array that is located around the wound and estimates the depth and classifies the difference in tissues of small regions in the area using tomography combined with spectroscopy method. The system is designed to integrate into the dressing to reduce unnecessary removal of dressings. In the human trial, moisturizer applied area was detected using Random Forest classifier (94.4% accuracy) and differences between every 10 minutes were significant in moisturizer applied area (p<; 0.05). The study confirmed the proof of concept that the system can monitor the change in human skin without attaching the sensor to the target area and indicate the skin area that had changed.

Bayesian statistic model for nurse call data considering time-series, individual patient variabilities and massive zero-count call data.

Analysis of nurse call data is important to evaluate nursing management, because nurse calls reflect the fundamental demand of patients. However, the nurse call data include time-series properties and individual patient variabilities. In addition, the calls do not necessarily follow the common single distributions such as normal and Poisson distribution. These characteristics of the nurse call data cause the difficulty of applying traditional frequent statistics. To resolve this problem, we introduced Bayesian statistics and proposed a model including three elements: 1) transition, which represents time-series change of nurse calls, 2) random effect, which handles individual patient variabilities, and 3) zero inflated Poisson distribution, which is suitable for nurse call data including massive zero data. To evaluate the model, nurse call dataset containing total 3324 patients in orthopedics ward was used and the differences of nurse calls between the patients who had undergone orthopedics surgery and those who had undergone other surgeries were analyzed. The result in comparing all combinations of elements suggested that our model including all elements was the most fitting model to the dataset. In addition, the model could detect longer duration of nurse call difference existence than the other models. These results indicated that our proposed model based on Bayesian statistics may contribute to analyzing nurse call dataset.

Factors Associated with Callus Formation in the Plantar Region through Gait Measurement in Patients with Diabetic Neuropathy: An Observational Case-Control Study.

Callus has been identified as a risk factor leading to severe diabetic foot ulcer; thus, it is necessary to prevent its formation. Callus formation under the first, second, and fifth metatarsal heads (MTHs) is associated with external forces (pressure and shear stress) during walking. However, the gait factors increasing the external forces remain undetermined. Thus, this study aims to identify the factors increasing the external forces to prevent callus formation. In 59 patients with diabetic neuropathy wearing their usual shoes, the external forces, and the lower extremity joint angles were measured using MEMS force sensors and motion sensors. The external forces and their relationship with the lower extremity joint angles and footwear size were determined. Risk factors causing high external forces on the first MTH included small flexion of the knee joint (p = 0.015) and large ankle pronation motion (p = 0.034) to obtain propulsion. For the second MTH, wearing excessively long footwear was identified (p = 0.026). For the fifth MTH, high external force was related to tight width footwear (p = 0.005). An effective intervention for preventing callus formation for the first MTH would involve assisting the push-off foot motion using rocker-sole footwear or gait training. For the second and fifth MTHs, wearing appropriate size footwear would be effective.

Catheter tips are a possible resource for biological study on catheter failure.

Few studies have investigated the molecular mechanisms of catheter failure (CF). Herein, we performed histological and molecular biological analyses of the catheter tip to demonstrate its potential as a resource for biological investigation. Additionally, we searched for risk factors for the development of inflammation and coagulation, which are pathological conditions clarified by biological analysis. The CF group included 30 failed catheters involving thrombus and subcutaneous edema identified by ultrasonography. The No-CF group included 26 catheters with no complications. The removed catheter tips were fixed for hematoxylin-eosin (HE) staining with the application of a real-time reverse transcriptase polymerase chain reaction for eukaryotic 18S ribosomal RNA (rRNA), interleukin 1ß, tumor necrosis factor α, tissue plasminogen activator, and plasminogen activator inhibitor 1 (SERPINE1). HE staining identified attached nuclear cells on the inner surfaces of both CF and No-CF catheters. The 18S rRNA was amplified in all samples. The expression level of SERPINE1 was significantly higher in the CF group than in the No-CF group (p = 0.01), whereas the expression levels of other genes did not differ between the groups. Symptoms of CF associated with the expression of SERPINE1 were analyzed. The catheter being in contact with blood vessels during placement was a suggested factor related to the high expression of SERPINE1 (p = 0.04). Catheter tips are a potential resource for biological investigation, and expression analysis of the attached cells can reflect the pathological condition of the catheterized tissue. Further studies using catheter tips are required to elucidate the molecular mechanisms of CF.

Unintentional body movement parameters and pulse rate variability parameters are associated with the desire to void.

Urinary incontinence is highly prevalent in elderly populations with physical and cognitive impairment. For the assessment and care of urinary incontinence, the desire to void is important. We have developed a bed sensor system that non-invasively and unconstrainedly measures the parameter changes of unintentional body movements. This study is aimed to evaluate the validity of measurement by the sensor system and parameters in healthy adults. We conducted experiments on 29 healthy adult volunteers. The parameters were unintentional body movement derived from changes in center of gravity and pulse rate variability (PRV) based on pulse wave measurements using a finger probe; further the relationship between the desire to void and measured parameters were examined. The body movement parameters at the buttock and thigh were associated with the desire to void (p < 0.050). All the PRV parameters trended significantly with desire to void as well (p < 0.050). The parameters achieved sensitivities of 0.18-0.88 in estimating strong desire to void, and 7 among 14 sensitivity measurements included in the receiver operating characteristic analysis exceeded 0.70. The body movement parameters and PRV parameters were useful in the estimation of the desire to void in healthy adults. To achieve accurate estimation, a combination of the PRV parameters and body movement parameters is required.

Pattern detection from seating pressure distribution during wheelchair motion using deep embedded clustering.

To minimize the occurrence of ulcers in high-risk mobile individuals such as wheelchair users, it is necessary to detect all typical distribution patterns and to indentify the patterns that may be associated with pressure ulcers. However, pattern detection is difficult because the pressure distribution during motion includes a variety of patterns compared to those of static postures. Thus, the establishment of a method to detect typical patterns based on distribution patterns is important. We utilized deep embedded clustering for identification purposes. This clustering technique extracts features using auto-encoder and simultaneously optimizes data points into the clusters, which might realize good clustering performance due to the detected optimal features. We used a pressure distribution dataset that was pre-labeled by nursing experts. The dataset consisted of a total of 26944 distribution images with ten class annotations. The clustering method including traditional approaches (k-means and principal component analysis plus k-means) were compared with deep embedded clustering while the threshold to noise reduction was changing. The deep embedded clustering with 80 mmHg threshold achieved the best performance. This approach also tended to be less dependent on the threshold values.

Bed Sensor System with Multiple Weight Sensor Units for Urine Accumulation Measurement in Bladder.

Urinary incontinence is highly prevalent in elderly populations. Some elderly people with dementia cannot feel or express the desire to urinate, which makes continence care difficult in elderly people with dementia. Therefore, a system to estimate the proper timing for urination is needed. Because bladder volume is associated with the desire to void, it can be employed to estimate the proper timing. In this study, we developed a new bed sensor system that non-invasively and unconstrainedly measures urine accumulation in the bladder. To capture the slight weight change due to body alignment changes caused by body sinking in bed mattress, the system takes measurements in five body areas (head, torso, buttock, thigh, and lower limb) with five separate sensor units. We measured weight change during bladder voiding and urine accumulation in a human subject. Interestingly, the weight around head as well as buttock measured by the newly developed sensor system gradually increased when urine accumulated in the bladder, which suggested that the weight changes might reflect urine accumulation.

Examination of the Effect of Suitable Size of Shoes under the Second Metatarsal Head and Width of Shoes under the Fifth Metatarsal Head for the Prevention of Callus Formation in Healthy Young Women.

Excessive pressure and shear stress while walking cause a risk of callus formation, which eventually causes foot ulcers in patients with diabetes mellitus. Callus under the second metatarsal head (MTH) has been associated with increased shear stress/pressure ratios (SPR). Callus under the fifth MTH has been associated with increased peak shear stress (PSS). The purpose of this study is to examine whether the effect of the suitable size and width of shoes prevents diabetic foot ulcers under the second and fifth MTH. We measured the pressure and shear stress by testing three kinds of sizes and two types of width of shoes. Significant difference was not observed in the SPR under the second MTH among different sizes of shoes. However, the pressure and shear stress were significantly lower when putting on shoes of fit size compared with larger sizes. The PSS under the fifth MTH was significantly smaller when putting on shoes of fit width compared with those of narrow width. Wearing shoes of fit size and width has the potential to prevent callus formation by reducing the pressure and shear stress constituting SPR under the second MTH and PSS under the fifth MTH.

Evaluation of comfort associated with the use of a robotic mattress with an interface pressure mapping system and automatic inner air-cell pressure adjustment function in healthy volunteers.

AIM OF THE STUDY: A robotic mattress equipped with an interface pressure mapping system and an automatic inner air-cell pressure adjustment function had been developed to aid in the management of pressure ulcers, but its effects on comfort remained unclear. The present study aimed to investigate whether use of the mattress with continuous, automatic, interface pressure mapping-based regulation of inner air-cell pressure (i.e., robotic mattress) improves comfort over that provided by body weight-based pressure regulation (traditional approach) in healthy volunteers. MATERIALS AND METHODS: A robotic mattress was used with two settings (i.e., interface pressure-vs. body weight-based regulation). First, 20 healthy volunteers were recruited, and the level of comfort, interface pressure distribution, body immersion, and tissue oxygenation were measured and compared between the two settings. RESULTS: The level of comfort (20.5 vs 47.5, p = 0.014), contact area (2263.9 vs 2145.2 cm2, p = 0.002), and body immersion for healthy participants were significantly larger when using the interface pressure-based setting. CONCLUSION: The robotic mattress provided improved comfort, which might be caused by increased contact area, and improved body immersion. The robotic mattress is expected to be effective both for managing pressure ulcers and increasing comfort.

Development of Personalized Fitting Device With 3-Dimensional Solution for Prevention of NIV Oronasal Mask-Related Pressure Ulcers.

BACKGROUND: Pressure ulcers related to oronasal masks used with noninvasive ventilation (NIV), along with patient discomfort, occur due to improper fit of the mask. We developed a personalized fitting device using a 3-dimensional (3D) scanning solution to prevent the formation of NIV mask-related pressure ulcers. This study aimed to evaluate the effectiveness of the proposed personalized fitting device. METHODS: We conducted a randomized crossover experimental study of 20 healthy participants to study the use of this personalized fitting device between the face and an NIV mask designed with 3D solutions. The fitting device was not used under the NIV mask for the control. The outcome measures were the presence of blanchable erythema, standardized redness intensity, discomfort level, and contact pressure. RESULTS: The incidence of blanchable erythema and standardized redness intensity values were significantly lower for subjects who used the fitting device when worn for 30 min (P < .001). The discomfort levels at the forehead, nasal bridge, and both cheeks, as well as leakage, were significantly reduced as well (P = .008, P < .001, P = .001, P = .002, P = .001, P = .02, P < .001, P < .001, P < .001). Contact pressure at the nasal bridge, where pressure ulcers most frequently develop, was significantly decreased with the fitting device (P < .001). CONCLUSIONS: Personalized fitting devices that incorporate 3D scanning solutions may contribute to the prevention of NIV mask-related pressure ulcers and the reduction of discomfort.

A Randomized Controlled Trial to Investigate the Effectiveness of the Prevention of Aspiration Pneumonia Using Recommendations for Swallowing Care Guided by Ultrasound Examination.

Prevention for aspiration pneumonia requires assessment of aspiration and adequate swallowing care. This randomized controlled trial aimed to investigate the effectiveness of ultrasound examination and recommendations for swallowing care for the reduction of aspiration and pharyngeal post-swallow residue as compared with standard swallowing care. Twenty-three participants were randomized to the intervention group and 23 to the control group. The intervention consisted of four ultrasound examinations during mealtimes and recommendations for swallowing care every 2 weeks during an 8 week period. No recommendations concerning swallowing care based on ultrasound examinations were provided to the control group. The frequency of aspiration or residue was defined as x/y × 100% when aspiration or residue were detected x times from y times concerning the total ultrasound measurements. The proportion of the residents with reduced frequency of aspiration which was detected by ultrasonography at eight weeks were 4.3% in the intervention group and 0% in the control group. The median reduction in the frequency of aspiration and residue in the intervention group was 31%, and that in the control group was 11%. In conclusion, swallowing care guided by frequent ultrasound examinations during mealtimes had a trend of reducing the frequency of aspiration and residue during an 8-week period in individuals relative to standard swallowing care alone.

The external force associated with callus formation under the first metatarsal head is reduced by wearing rocker sole shoes.

INTRODUCTION: Callus is one of the main causes of diabetic foot ulcers. Therefore, preventing callus formation is very important. In a previous study, it was clarified that callus formation under the first metatarsal head (MTH) is associated with high shear stress time integral/pressure time integral (SPR-i). another study, it was clarified that rocker sole shoes are effective in reducing peak pressure under the first MTH. Therefore, we hypothesized that rocker sole shoes reduce SPR-i under the first MTH. This study aimed to clarify the effect of rocker sole shoes for external forces and leg motions in comparison with that of the normal sole shoes. METHODS: In-shoe external forces and leg motions were measured during walking wearing the normal sole shoes or the rocker sole shoes in healthy participants. As the external forces, the peak plantar pressure (PP), pressure time integral (PI), peak shear stress (PSS), and shear stress integral (SSI) of each gait cycle were calculated. Additionally, shear stress-pressure ratios (SPR) were calculated by dividing shear stress by pressure; concretely, peak values (SPR-p) and time integral values (SPR-i). As the leg motion, hip and knee joint motions were analyzed for the axis of flexion- extension. Three axes of ankle joint motion (inversion-eversion, plantar flexion-dorsiflexion, and adduction-abduction) were analyzed. RESULTS AND DISCUSSION: Six participants attended, and twelve feet were analyzed. When wearing the rocker sole shoes, the SPR-i under the first MTH was significantly smaller than when wearing the normal sole shoes. The SPR-i higher than 0.60 is associated with callus formation under the first MTH. In three of five feet with callus, SPR-i exceeded 0.60 in the normal sole shoes. The SPR-i of all three feet became smaller than 0.60 when wearing the rocker sole shoes. Although the knee (flexion-extension) and ankle (plantar flexion-dorsiflexion) joint motion became smaller when wearing the rocker sole shoes, there was no significant difference in walking speed. It is considered that propulsion was maintained by the push-off support provided by rocker sole shoes. CONCLUSION: It was suggested that rocker sole shoes are effective preventing callus formation under the first MTH.

Development of a Plantar Load Estimation Algorithm for Evaluation of Forefoot Load of Diabetic Patients during Daily Walks Using a Foot Motion Sensor.

Forefoot load (FL) contributes to callus formation, which is one of the pathways to diabetic foot ulcers (DFU). In this study, we hypothesized that excessive FL, which cannot be detected by plantar load measurements within laboratory settings, occurs in daily walks. To demonstrate this, we created a FL estimation algorithm using foot motion data. Acceleration and angular velocity data were obtained from a motion sensor attached to each shoe of the subjects. The accuracy of the estimated FL was validated by correlation with the FL measured by force sensors on the metatarsal heads, which was assessed using the Pearson correlation coefficient. The mean of correlation coefficients of all the subjects was 0.63 at a level corridor, while it showed an intersubject difference at a slope and stairs. We conducted daily walk measurements in two diabetic patients, and additionally, we verified the safety of daily walk measurement using a wearable motion sensor attached to each shoe. We found that excessive FL occurred during their daily walks for approximately three hours in total, when any adverse event was not observed. This study indicated that FL evaluation method using wearable motion sensors was one of the promising ways to prevent DFUs.

Detecting pharyngeal post-swallow residue by ultrasound examination: a case series.

AIMS: Prevention of aspiration pneumonia is a great concern in the era of global aging. The assessment of pharyngeal post-swallow residue is important because remaining food and liquid in the pharyngeal area has a possibility of flowing into the lower airway which can cause aspiration pneumonia. Ultrasound examination has been recently used to assess swallowing disorders because of its noninvasiveness. The aim of this study was to investigate the performance for detecting pharyngeal post-swallow residue using an ultrasound examination by comparing with those using a fiberoptic endoscopic evaluation of a swallowing study as a reference. MATERIAL AND METHODS: A linear array transducer attached to the thyroid cartilage to visualize the vocal folds in the sagittal plane. The pharyngeal post-swallow residue in the ultrasound movie was interpreted as a misty hyperechoic area above the vocal folds that remained after swallowing. Nineteen ultrasound images simultaneously obtained with fiberoptic endoscopic evaluation of swallowing study images from nine participants (eight men) with a median age of 70 years at a dysphagia outpatient clinic were analyzed by the montage of swallowing examinations. RESULTS: Misty hyperechoic areas above the vocal folds that remained after swallowing were detected in 10 ultrasound images. Eight US images out of ten correctly detected pharyngeal post-swallow residue. The sensitivity for detecting pharyngeal post-swallow residue of 19 images from nine participants by US examination was 62%, and the specificity was 67%. CONCLUSIONS: The proposed detection method of pharyngeal post-swallow residue by ultrasound examination enabled the real-time assessment for swallowing of people with dysphagia. Ultrasound assessment-based daily swallowing care which detects pharyngeal residue will be useful for preventing aspiration pneumonia.

Topical Administration of Acylated Homoserine Lactone Improves Epithelialization of Cutaneous Wounds in Hyperglycaemic Rats.

Clinicians often experience delayed epithelialization in diabetic patients, for which a high glucose condition is one of the causes. However, the mechanisms underlying delayed wound closure have not been fully elucidated, and effective treatments to enhance epithelialization in patients with hyperglycaemia have not been established. Here we propose a new reagent, acylated homoserine lactone (AHL), to improve the delayed epithelialization due to the disordered formation of a basement membrane of epidermis in hyperglycaemic rats. Acute hyperglycaemia was induced by streptozotocin injection in this experiment. Full thickness wounds were created on the flanks of hyperglycaemic or control rats. Histochemical and immunohistochemical analyses were performed to identify hyperglycaemia-specific abnormalities in epidermal regeneration by comparison between groups. We then examined the effects of AHL on delayed epithelialization in hyperglycaemic rats. Histological analysis showed the significantly shorter epithelializing tissue (P < 0.05), abnormal structure of basement membrane (fragmentation and immaturity), and hypo- and hyperproliferation of basal keratinocytes in hyperglycaemic rats. Treating the wound with AHL resulted in the decreased abnormalities of basement membrane, normal distribution of proliferating epidermal keratinocytes, and significantly promoted epithelialization (P < 0.05) in hyperglycemic rats, suggesting the improving effects of AHL on abnormal epithelialization due to hyperglycemia.

Factors Associated With Callus in Patients with Diabetes, Focused on Plantar Shear Stress During Gait.

BACKGROUND: The aim of this study is to identify whether plantar shear stress in neuropathic patients with diabetes with callus is increased compared with those without callus. METHOD: The differences in foot deformity, limited joint mobility, repetitive stress of walking, and ill-fitting shoes between patients with callus and those without callus were also determined. Subjects were recruited from the Diabetic Foot Outpatient Clinic. A newly developed in-shoe measurement system, which has flexible and thin insoles, enabled measurement of both plantar pressure and shear stress simultaneously when subjects walked as usual on a 10 m walkway. RESULTS: It was found that plantar shear stress adjusted for weight during the push-off phase was increased by 1.32 times in patients with callus compared with those without callus (mean ± SD: 0.0500 ± 0.0160 vs 0.0380 ± 0.0144, P = .031). Moreover, hallux valgus deformity, reduction in dorsiflexion of the ankle joint and increase in plantar flexion were showed in feet with callus. Increased plantar shear stress may be caused by gait change that patients having callus push off with the metatarsal head instead of the toe as a result of foot deformity and limited joint mobility. CONCLUSIONS: It was found that plantar shear stress adjusted for weight during the push-off phase was increased in patients with callus compared with those without callus by using the newly developed measurement system. These results suggest that reduction of plantar shear stress during the push-off phase can prevent callus formation in neuropathic patients with diabetes.