Alexei Katashev

Development of Smart Sock System for Gate Analysis and Foot Pressure Control

In the present paper we describe the wireless system for gate and plantar pressure analysis based on developed Smart socks with embedded knitted pressure sensors. System validation is made by comparative gate analysis of different running and walking modes of asymptomatic and flat foot. Developed system demonstrated potential abilities for gate features detection and therefore it could be used for medical and sport applications.

Effects of Optical Radiation on the Healing of Bone Defect in Rabbits

Hypothesis, that optical radiation is able to alter surface electrochemical potential and due to this affect bone remodeling processes have been proposed. Besides, researches, being done beforehand, in majority used laser radiation of single wavelength; the latter usually does not match well with optical absorption bands of the bone, obtained in a series of in-vitro experiments. The goal of the present work was to evaluate in-vivo influence of the optical light of different wavelength on the bone remodeling / reconstruction process. For this, artificial defect have been made at the mandible bone of female rabbits. During operation and 10 days after surgery operation site was irradiated with optical radiation with either long (550 – 5000 nm) or short (350 – 550) wavelength. Results demonstrated that light treatment suppresses rate of healing of the bone defect for both experimental groups comparing with the control. The suppression effect is more expressed for short-wavelength irradiation.

Development of a New Method to Monitor Shoulder Girdle Motion for Ballerina with Shoulder Impingement Syndrome Based on DAid Smart Shirt Application

Shoulder impingement is the most common cause of shoulder pain. The ability to control the orientation and movement of the scapula is essential for optimal arm function and pain reduction in young adults with shoulder impingement signs. Smart garments find wide range of healthcare applications, including rehabilitation. One of the main parts of smart garment is the sensing system which can include one or several sensing elements for posture and joint motion control. The aim of present research was to verify the possibility of using DAid Smart shirt to capture and monitor shoulder gridle motion during motor control exercises and during training sessions out of laboratory environment for ballerina with shoulder impingement syndrome. Another aim was to develop method of this Smart shirt using in addition to conventional physiotherapy to reduce right side shoulder girdle elevation. As a monitoring tool, specially designed DAid Smart Shirt had been used. Specifically, embodied textile strain sensors gave possibility to capture spatiotemporally motion, but acquisition system provided visual feedback on the screen of remote electronic device. Conclusions: Designed DAid Smart shirt can be objective and convenient tool for shoulder motion monitoring for both: patient and physiotherapist. Thus, it can be used as effective assisting device to conventional physiotherapy for shoulder girdle motion control.

On the Monitoring of Breathing Volume, Using Textile Strain Gauges

Necessity to attach measurement device to the patient mouth makes use of spirometry difficult for continuous breathing volume monitoring in non-hospital applications. There were number of attempts to replace spirometry with measurements of the trunk volume. One of the potential solutions is evaluation of the breathing volume using set of respiratory belts, placed around the chest to measure changes in trunk circumference. Such belts could be made of the highly strain—sensitive knitted resistive fabric, integrated into tight underwear, like T-shirt or compressive body. The objective of the present research was to check usability of the garment—integrated knitted strain gauges for evaluation of the breathing volume. The breathing monitoring garment have been made in a form of T-shirt with seven knitted resistive stretch sensing ribbons, sewn around the T-shirt trunk and calibrated to measure circumference. Circumferences were used to estimate trunk volume of four healthy volunteers (2 male 2 female). Alongside, volunteers breathing volume was measured using commercial spirometer. The results demonstrated that T-shirt, being calibrated irrespectively to measured individual, could evaluates breathing volume with the uncertainty of 0.6 l, given all 7 ribbons are used for calculation of volume. The individual calibration of the T-shirt for particular individual could reduce uncertainty up to 0.3 l.

Detection of Excessive Pronation and Supination for Walking and Running Gait with Smart Socks

Excessive pronation and supination are gait conditions that could lead to such injuries as ankle sprains, shin splints, Achilles tendinitis and others. Early detection of excessive pronation and supination in running and walking gait are important for injury prevention not only for professional athletes but also for the general population. Unfortunately, the typical equipment necessary for detection of these conditions is relatively expensive and therefore is not widely used by non-professionals. Moreover, most of the typical equipment is either designed for operation under laboratory conditions only or is too bulky and consequently affects the performance of the wearer during the performed activity. This study proposes a method for pronation and supination detection by using smart textile socks with integrated pressure sensors and a specific sensor measurement processing algorithm. Each sock has five sensors, one on the heel, two in the middle and two in the front sole area. These sensors are knit from a conductive thread and have a resistivity inversely proportional to the pressure, which allows monitoring of the feet pressure at different parts during a physical activity. A special pressure vector is calculated from the sensor values to characterize the step. The value of this pressure vector give information about the step and allows detection of excessive supination and pronation in the gait. The preliminary tests demonstrated a significant difference between the pressure vector of a normal gait and gait performed with pronation and supination, thus allowing detection of these gait conditions.

Application of Garment—Embedded Textile Electrodes for EIT Based Respiratory Monitoring

Electrical Impedance Tomography (EIT) is a technology capable of supplementing spirometry in a number of applications due to the ability to evaluate regional changes in lung volume. EIT measurements require an array of conventional bio-potential electrodes attached to the patient’s chest. Replacement of conventional electrodes with knitted conductive textile electrodes integrated in a patient’s undershirt could increase the area of EIT applications such as daily respiratory monitoring in hospitals, at home, during physical activity, etc. The goal of the present paper was to demonstrate the usability of textile electrodes for EIT measurements. The conductive textile was integrated in the chest of a long sleeves thermal undershirt to form three rows of 16 circumferential electrodes that can be connected to a commercially available EIT monitoring system. Two healthy male volunteers aged 45–50 performed tidal breathing, deep breathing, and FRC maneuvers. The breathing volumes and FRC were measured using a body plethysmograph. The course of measurements demonstrated that contact between skin and textile electrodes are not tight enough to operate with the EIT device. Applying additional pressure to the electrodes and the use of electrolyte spray reduced the impedance of the textile electrodes to adequate values. Under such conditions, there were no differences in correlation coefficients between spirometry volumes and EIT volumes obtained using either conventional or textile electrodes.

Application of Smart Sock System for Testing of Shoe Cushioning Properties

Appropriate choice of shoes with required cushioning characteristics is rather an urgent problem for people from very different groups, such as sportsmen, elderly people, people with foot disorders and locomotion problems. Present research is devoted to further development of wireless DAids™ Pressure Sock System and its application for shoe cushioning estimation. In particular, a new version of pressure sensors with improved sensitivity and working range is designed and tested. Based on above-mentioned developments, the possibility of shoe cushioning testing using DAid™ Pressure Sock System was studied. For this purpose, gait records of several test subjects who used sets of shoes with different cushioning properties, as well as bare walking, were made. Data analysis showed that the developed system gives the possibility to recognize different shoe cushioning. Several approaches to data processing to increase the sensitivity of such recognition are discussed. The comparison showed the potential ability of the developed system to test wirelessly shoe cushioning in real outdoor conditions. Such ability also provides the possibility to monitor and estimate degradation of cushioning quality of shoes under deterioration and environment.

A comparison between the commercially available gamma criteria evolution software and new modified algorithm for field-in-field technique

new gamma evaluation algorithm was created to improve ability of gamma criterion to determine, whenever field – in field plan two dose distributions are acceptable for further therapy. New parameter, dose gradient, was introduced to differentiate high dose gradient regions from low and use only those with high dose gradient. The aim of this article is to determine whether the new gamma criterion algorithm evaluation principle is suitable for FIF plans verification. For this study a 17 x 12 cm rectangular 6MV photon beam was used. Rectangular fields, sized 5 x 12, 6 x 8,5 and 3 x 4,3 cm were added as segments for each 17 x 12 cm base field in center. Dose distribution was calculated using treatment-planning system (TPS) to be used as a starting point to make distorted plans with segments displaced in superior, inferior, lateral left and lateral right directions to simulate patient movement or positioning errors during irradiation. Dose distributions for the distorted plans were measured using pixel ionization chambers detector array. The resulting dose distributions were compared to the reference one provided by TPS using gamma criterion. For acceptance criteria ΔDM=3% dose-difference, ΔdM=3 mm distance-to-agreement (DTA) and dose gradient 5% were used and 95% of all pixels should be within this criterion. For all the plans, considered in the present paper, 95% threshold was exceeded before the displacement reached clinically significant values of 3 mm. New algorithm show steep decrease of “pass” pixels at 3 mm even for segments with 3 x 4, 3 cm size. One has to conclude, that created algorithm should be investigated at comparison of dose distribution plans of clinical field in field conformal radiotherapy.

A comparison of the accuracy of the smart sock system to force platform and optical system for measurement of temporal parameters of locomotion

The aim of the study was to present a new DAid R ©Pressure Sock System for feet locomotion monitoring and to verify it’s temporal characteristics by data comparison with the same obtained by two other widely used methods as reference. Designed system is based on sensors which can be knitted directly in the garment or hosiery items. DAid R ©Pressure Sock System was created for sport and medical applications. Comparison of temporal characteristics of different types of locomotion, obtained using designed system and reference devises, showed good agreement between data.

Application of Gamma Criteria for FIF Therapy for Wide Breast Size Range

Evolution of complex planning techniques, such as IMRT and VMAT, has set high requirements for labor intensive quality assurance procedures. For the evaluation of intensity modulated radiotherapy plan, gamma evaluation method is widely used for accurate quantitative comparison of measured dose distribution and desired dose distribution from treatment planning system (TPS). Field – in – field (FIF) 3D conformal planning technique, widely used now in breast cancer treatment. FIF is the forward planning technique, where one or more subfields are introduced to achieve higher dose homogeneity in treatment volume. Since FIF is based on the same intensity modulation principles as IMRT, it is possible to use gamma evaluation method for FIF breast fields. The aim of the present paper is to determine whether gamma criteria pass/fail rate is treatment volume dependent. For this study, four patients with different breast volumes (1115.4 cc, 1716.46 cc, 2531.65 cc and 3276.27 cc) were examined. Calculation was performed using treatment planning system XiO, where reference fields were exported to phantom and artificial shifts of the field in step of 1 mm were introduced. The maximum shift for one direction (lateral or longitudinal) does not exceeded 1 cm. The FIF segments were shifted relative to base fields in eight directions: lateral “+”, lateral “-”, longitudinal “+”, longitudinal “-”. All uncertainties related to LINAC and MLC were excluded because of TPS versus TPS comparison method. For acceptance criteria ⇆DM=3% dose-difference and ⇆dM=3 mm distance-to-agreement (DTA) were used and 95% of all pixels should be within this criterion. Results demonstrates, that, independently on the breast size, gamma criterion failed to detect internal field displacement up to 5 mm