Biothermal Modeling of Post-Cryoplasty Atheroscelerosis in Restenotic Patients

Estimating Scalp Moisture in a Hat Using Wearable Sensors

Hair quality is easily affected by the scalp moisture content, and hair loss and dandruff will occur when the scalp surface becomes dry. Therefore, it is essential to monitor scalp moisture content constantly. In this study, we developed a hat-shaped device equipped with wearable sensors that can continuously collect scalp data in daily life for estimating scalp moisture with machine learning. We established four machine learning models, two based on learning with non-time-series data and two based on learning with time-series data collected by the hat-shaped device. Learning data were obtained in a specially designed space with a controlled environmental temperature and humidity. The inter-subject evaluation showed a Mean Absolute Error (MAE) of 8.50 using Support Vector Machine (SVM) with 5-fold cross-validation with 15 subjects. Moreover, the intra-subject evaluation showed an average MAE of 3.29 in all subjects using Random Forest (RF). The achievement of this study is using a hat-shaped device with cheap wearable sensors attached to estimate scalp moisture content, which avoids the purchase of a high-priced moisture meter or a professional scalp analyzer for individuals.

Effect of Ambient Temperature Changes on Blood Flow in Anterior Cerebral Artery of Patients with Skull Prosthesis

BACKGROUND

In many cases, an injury to the head leads to the replacement of a part of the skull with materials such as titanium and polyether ether ketone.

METHODS

Three-dimensional heads model of 15 healthy individuals and 13 patients were prepared. The models were simulated using thermal fluid structure interaction analysis to evaluate the effects of cold (5°C) and hot (55°C) temperatures of the skull on the conditions of blood flow in the anterior cerebral artery.

RESULTS

The results showed negligible changes (<3%) in wall shear stress (WSS) vessel and von Mises stress between the healthy individuals and patients both at 25°C and 55°C. However, at 5°C, the values of these 2 parameters in the patients were 2.1 and 2.5 times those in healthy individuals, respectively. The value of WSS in healthy individuals and the patients in cold temperature was 1.2 and 2.9 times those at normal temperature. The corresponding values for von Mises stress were 1.1 and 2.2, respectively. Accordingly, the stress changes between cold and hot ambient temperatures were found to be negligible in all samples.

CONCLUSIONS

The changes in stress were significant only for the patients when exposed to cold ambient temperature, and only in patients, exposure to a cold ambient temperature significantly increased the risks of vascular aneurysm and damage to the brain tissue surrounding the blood vessels. These risks were found to be negligible for both healthy individuals and patients when exposed to hot ambient temperature and also for healthy individuals exposed to cold ambient temperature.

PolarCath cryoplasty enhances smooth muscle cell apoptosis in a rabbit iliac artery model: an experimental in vivo controlled study

PURPOSE

To in vivo investigate the histological response after single and double cryoplasty therapy in a rabbit iliac artery model.

MATERIALS AND METHODS

In total, 40 New Zealand White rabbits underwent percutaneous transluminal angioplasty of the iliac artery using either PolarCath balloon or a conventional angioplasty balloon of equal diameter. Arterial injury, inflammatory response and smooth muscle cells (SMC) apoptosis with the TUNEL (Terminal deoxynucleotidyl transferase dUTP Nick End Labeling) immunohistochemical assay were analyzed. Rabbits were divided between single or double balloon inflation and histological results were compared between cryoplasty and control angioplasty both at 30 min and 72 h.

RESULTS

Arterial injury and wall inflammation scores were low and similar between cryoplasty and control groups after single and double balloon inflation. Compared to conventional balloon angioplasty, Polarcath cryoplasty demonstrated superior SMC apoptosis after single inflation at 30 min [12.0±1.2 cells/(0.025 mm)2 vs 7.0±1.5 cells/(0.025 mm)(2), p=0.002], single inflation at 72 h [9.0±1.0 cells/(0.025 mm)(2) vs 5.4±1.4 cells/(0.025 mm)(2), p=0.001], double inflation at 30 min [11.6±1.5 cells/(0.025 mm)(2) vs 6.8±1.4 cells/(0.025 mm)(2), p=0.001] and double inflation at 72h [9.2±0.8 cells/(0.025 mm)(2) vs 5.0±0.7 cells/(0.025 mm)(2), p=0.001]. There were no significant differences in apoptosis between single and double cryoplasty application at 30 min and 72 h.

CONCLUSION

Cryoplasty demonstrated superior rates of SMC apoptosis at 30 min and 72 h and was associated to relatively low arterial injury and inflammation scores. An immediate second PolarCath inflation did not achieve superior apoptosis.

Cryoplasty versus conventional balloon angioplasty of the femoropopliteal artery in diabetic patients: long-term results from a prospective randomized single-center controlled trial

The purpose of this study was to investigate the immediate and long-term results of cryoplasty versus conventional balloon angioplasty in the femoropopliteal artery of diabetic patients. Fifty diabetic patients (41 men, mean age 68 years) were randomized to cryoplasty (group CRYO; 24 patients with 31 lesions) or conventional balloon angioplasty (group COBA; 26 patients with 34 lesions) of the femoropopliteal artery. Technical success was defined as <30% residual stenosis without any adjunctive stenting. Primary end points included technical success, primary patency, binary in-lesion restenosis (>50%), and freedom from target lesion recanalization. Cox proportional hazards regression analysis was performed to adjust for confounding factors of heterogeneity. In total, 61.3% (19 of 31) in group CRYO and 52.9% (18 of 34) in group COBA were de novo lesions. More than 70% of the lesions were Transatlantic Inter-Society Consensus (TASC) B and C in both groups, and 41.4% of the patients in group CRYO and 38.7% in group COBA suffered from critical limb ischemia. Immediate technical success rate was 58.0% in group CRYO versus 64.0% in group COBA (p = 0.29). According to 3-year Kaplan-Meier estimates, there were no significant differences with regard to patient survival (86.8% in group CRYO vs. 87.0% in group COBA, p = 0.54) and limb salvage (95.8 vs. 92.1% in groups CRYO and COBA, respectively, p = 0.60). There was a nonsignificant trend of increased binary restenosis in group CRYO (hazard ratio [HR] 1.3; 95% CI 0.6-2.6, p = 0.45). Primary patency was significantly lower in group CRYO compared with group COBA (HR 2.2; 95% CI 1.1-4.3, p = 0.02). Significantly more repeat intervention events because of recurrent symptoms were required in group CRYO (HR 2.5; 95% CI 1.2-5.3, p = 0.01). Cryoplasty was associated with lower primary patency and more clinically driven repeat procedures after long-term follow-up compared with conventional balloon angioplasty.