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.

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.

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.

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.

Compression-induced HIF-1 enhances thrombosis and PAI-1 expression in mouse skin.

Pressure ulcers result from tissue hypoxia caused by external forces. Thrombosis due to external forces is considered important, and hypoxia inducible factor-1 (HIF-1) is a master regulator of pressure ulcer development. To date, however, their causal relationship has not been determined. This study therefore investigated the mutual relationship between thrombosis and HIF-1 activation in compressed mouse skin, based on a hypothesis that HIF-1 regulation by plasminogen activator inhibitor-1 (PAI-1) enhances thrombosis. Compression of mouse skin significantly increased the numbers of thrombi and HIF-1α-positive cells compared with control skin. A thrombosis inhibitor significantly reduced the numbers of HIF-1α-positive cells and an HIF-1 inhibitor significantly inhibited thrombosis in compressed skin tissue, suggesting a mutual relationship between thrombosis and HIF-1 activation. Compression of mouse skin also enhanced the level of Pai-1 messenger RNA expression, but this increase was significantly reduced by treatment with an HIF-1 inhibitor, whereas a thrombosis inhibitor had no effect. These results suggested the involvement of PAI-1 in HIF-1-enhanced thrombosis and that an additional factor participates in regulating Pai-1 expression in compressed skin. These findings may suggest new strategies in pressure ulcer management.

Cost-utility analysis of an advanced pressure ulcer management protocol followed by trained wound, ostomy, and continence nurses.

The high prevalence of severe pressure ulcers (PUs) is an important issue that requires to be highlighted in Japan. In a previous study, we devised an advanced PU management protocol to enable early detection of and intervention for deep tissue injury and critical colonization. This protocol was effective for preventing more severe PUs. The present study aimed to compare the cost-effectiveness of the care provided using an advanced PU management protocol, from a medical provider's perspective, implemented by trained wound, ostomy, and continence nurses (WOCNs), with that of conventional care provided by a control group of WOCNs. A Markov model was constructed for a 1-year time horizon to determine the incremental cost-effectiveness ratio of advanced PU management compared with conventional care. The number of quality-adjusted life-years gained, and the cost in Japanese yen (¥) ($US1 = ¥120; 2015) was used as the outcome. Model inputs for clinical probabilities and related costs were based on our previous clinical trial results. Univariate sensitivity analyses were performed. Furthermore, a Bayesian multivariate probability sensitivity analysis was performed using Monte Carlo simulations with advanced PU management. Two different models were created for initial cohort distribution. For both models, the expected effectiveness for the intervention group using advanced PU management techniques was high, with a low expected cost value. The sensitivity analyses suggested that the results were robust. Intervention by WOCNs using advanced PU management techniques was more effective and cost-effective than conventional care.

Prediction of healing progress of pressure ulcers by distribution analysis of protein markers on necrotic tissue: A retrospective cohort study.

Predicting the short-term healing progress of pressure ulcers is important for providing timely and appropriate intervention. Although there are some prediction methods available, these are unsuitable for ulcers with abundant necrotic tissue. We aimed to elucidate the relationship between necrotic tissue alteration and protein distributions on ulcers to establish a new prediction method. Thirty-eight pressure ulcers were retrospectively analyzed. Protein distributions on necrotic tissue were evaluated by the wound blotting at three levels: marker protein positivity, signal patterns (speckled, heterogeneous, or homogeneous), and the occupation of heterogeneous pattern. Peroxidase, alkaline phosphatase, tumor necrosis factor α, and matrix metalloproteinase-2 were used as marker proteins. One-week necrotic tissue alteration was classified as liquefaction or nonliquefaction, and associations with protein distributions were analyzed. The peroxidase positivity was significantly higher in the liquefaction than in the nonliquefaction (p = 0.031). In peroxidase-positive samples, the proportion of nonliquefaction samples was significantly higher in the heterogeneous pattern (p = 0.029). In the heterogeneous-patterned samples, the proportion of samples with an occupation values greater than the median value tended to be higher in the nonliquefaction (p = 0.087). There was no significant relationship between liquefaction and other markers. Peroxidase positivity predicts 1-week liquefaction of necrotic tissue, while a heterogeneous pattern indicates nonliquefaction.

Vibration inhibits deterioration in rat deep-tissue injury through HIF1-MMP axis.

Deep-tissue injury (DTI) is a unique type of pressure ulcer (PU) in which deep-tissue damage expands outwards to the superficial skin. DTI progresses rapidly into a severe PU, despite initially appearing as only a bruise or darkened tissue in the superficial skin. Although some DTI detection methods are available, there is currently no strategy for treating deteriorating DTI. This study investigated the efficacy of vibration therapy for preventing DTI deterioration through down-regulation of the hypoxia-inducible factor-1 matrix metalloproteinase (MMP) axis in rats. We prepared a conventional PU rat model (PU group) and a DTI deterioration rat model (DTI group). The DTI group was further divided into two groups subjected to vibration and control treatments, respectively. Macroscopic and histological features, hypoxia, oxidative stress, apoptosis, and MMP2 and MMP9 activities in compressed skin were analyzed. Hypoxia, oxidative stress, and MMP activity were enhanced in the DTI group compared with the PU group. Vibration remarkably inhibited DTI deterioration, hypoxia, and the expression/activities of MMP2 and MMP9. These results suggest that vibration therapy can effectively attenuate deterioration of DTI. This report provides the first evidence for a therapeutic treatment for deteriorating DTI.

Effects on interface pressure and tissue oxygenation under ischial tuberosities during the application of an alternating cushion.

Pressure ulcers are hazardous to people with diminished sensory and motor functions who remain in the same position for a long time. An important reason for the occurrence of pressure ulcers is the inability of wheelchair users to make postural changes by themselves with no appropriate method of pressure release. In this study, we researched the effects of applying an air cell inflate-deflate alternating sequence cushion prototype to relieve pressure from tissue loaded areas. Moreover, the hypothesis that the alternating sequence could stimulate blood reperfusion in loaded tissues and redistribute interface pressure on support area was also tested. Ten healthy volunteers were recruited to try the prototype cushion for 65 min of continuous loading; 5 min on static mode and 60 min on alternating mode. This study was conducted on healthy people because their sensitivity allowed them to state clearly and in detail, in a feedback questionnaire, any discomfort experienced with the use of our cushion. In order to address our hypothesis, interface pressure, and bilateral ischial oxygenated and deoxygenated hemoglobin were measured. After applying the alternating cushion, the interface pressure was redistributed over a larger contact area. Besides, blood perfusion was improved according to increments in oxygenated hemoglobin and decrements in deoxygenated hemoglobin of ischial regions during loaded condition. Feedback questionnaire showed that the participants did not feel pain or discomfort using the alternating cushion. The overall results showed positive effects on healthy tissue which has encouraged us to design a study involving subjects who use wheelchairs for mobility.

Establishment of a novel rat model for deep tissue injury deterioration.

Deep tissue injuries (DTIs) can become significant problems because of their rapid deterioration into deep pressure ulcers. Presently, no animal model of DTI deterioration has been developed. By concentrating pressure and shear stress in deep tissues while minimising pressure and shear stress in the overlying skin, we produced an effective rat model of DTI deterioration. Two-dimensional finite element method (FEM) simulated the distribution of pressure and shear stress under several pressure-loading conditions. FEM showed that concentrated shear stress in deep tissue with minimum shear stress in the overlying skin could be created by using a prominence and a cushion, respectively. On the basis of the results of FEM analysis, we selected suitable conditions for testing the rat DTI deterioration model. The compressed area was macroscopically observed until day 13, and histopathologic analysis via haematoxylin and eosin (H&E) staining was performed on days 3, 7 and 13. H&E staining showed that the distribution of tissue damage was similar to the predicted FEM results. Deep ulceration and tissue damage extending from deep tissues to the overlying skin and surrounding tissues were observed in the DTI deterioration model, which are similar to the clinical manifestations of DTI deterioration. In conclusion, a representative DTI deterioration model was established by concentrating high shear stress in deep tissues while minimising shear stress in the overlying skin. This model will allow a better understanding of the mechanisms behind DTI deterioration and the development of preventative strategies.

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.

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.

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.

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.

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.

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.