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0ПРИБОРОСТРОЕНИЕ, МЕТРОЛОГИЯ И ИНФОРМАЦИОННО-ИЗМЕРИТЕЛЬНЫЕ
ВЕСТНИК ТОГУ. 2021 № 2 (61)
ПРИБОРЫ И СИСТЕМЫ
UDK 681.2.082
©Zhang Chao, 2021
DESIGN OF PRESSURE SENSOR FOR BEDSORE PHYSIOTHERAPEUTIC BED
Zhang Chao - PhD, Assistant Professor, Electronic Information Engineering College, email: 157075018@qq.com (Changchun University, Changchun,, China)
In view of human biomechanics the issues of designing the pressure measuring and automatic regulation module, cleaning and ventilation modules. It is shown that development of the intelligent control system for an intelligent bedsore prevention bed has become the urgent need of hospitals, rehabilitation institutions, nursing centers and patients.
Keywords: pressure measuring, physiotherapeutic bed, physiotherapy module, air-bag method.
Introduction
As a result of the patients with bedsore prevention and treatment of bed can reduce the local stress concentration and increase blood flow, improve skin contact state, so it has good control effect to bedsore, received widespread attention at home and abroad, in 2018 in Hebei university of science and technology Li Jie for bedridden patients, through the mechanical structure design and control system, pneumatic system design and software design, developing a STM32 intelligence turn medical mattress, implemented by the movements of the air mattress rolled over, stand up and bended leg movement, has a certain bedsore prevention role. In 2017 the people's liberation army 161 hospital medical subject Hu Yin, Wang Hengjie designs an alternative to the traditional air compressor of air cushion bed inflatable device, mainly by the main control module, power supply circuit, pressure detection module, liquid crystal display driver module, keys module, real time clock module and alarm circuit and so on, to reduce the noise of the air pump's impact on patients and medical workers.
Although in preventing bedsore bed at home and abroad on the structure and control methods of the related research work, but because the previous lack of human body biomechanical measurement and study of different location of the step-down method, etc, although can play a role in the formation of pressure ulcers, still
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cannot avoid completely bedridden patients with bedsore, cannot achieve when patients lie in bed pressure distribution area of the precision evaluation and analysis of antihypertensive effect, unable to accurately evaluate and predict the extent of the patients with bedsore produce, it is hard to play fully and effectively prevent bedsores, Therefore, in view of human biomechanics, the design of pressure collection and automatic regulation module, the design of cleaning and ventilation module and the design of intelligent control system to develop an intelligent bedsore prevention bed has become the urgent need of hospitals, rehabilitation institutions, nursing centers and patients.
System designing work
When patients in prone position and bed surface evenly partition layout is after six square patch contact pressure, the flexible contact pressure sensor and a good contact with prone position parts of the body, flexible tactile sensor pressure sensor to the change of the contact area pressure, at the same time, the sensor by the data acquisition device through the USB data cable with PC operation terminal (or hand-held operation control terminal) communication, PC receives the packet to its into the unpacking, transformation and calibration calculation, get the pressure value of each sensor and location coordinates, Prone position body pressure comfort evaluation module real-time testing according to each value of the pressure and position coordinates according to the pressure sensor for coloring and positioning, the formation and position of patch one-to-one colour pressure mark figure, at the same time through the pressure data and location weight, mechanical center trajectory, contact area, average speed, the peak pressure, pressure, area of discomfort, comfort index, heart rate, heart rate and breathing of calculation, analysis and evaluation; According to the analysis and evaluation results, biomechanics of realtime intelligent control module will automatically start the automatic adjustment module of intelligent automatic compression and decompression of the adjustment to change the bed surface and the intensive degree of human body prone position interface and biomechanical strength of support, and implement in line with the patient prone position biomechanical characteristics of flat stretch and body pressure equalization, achieve the goal of intelligent bedsore prevention and control.
Hardware device: the box body by the bed, mattress, mattress uniform partition layout the installation of flexible contact pressure sensors are six square pressure acquisition unit, will lead to pressure acquisition unit of lifting up and down automatically adjust the unit, dry cleaning and disinfection and ventilation unit module, intelligent control, physical therapy unit module and a handheld data control terminal and PC terminal operation.
DESIGN OF PRESSURE SENSOR FOR BEDSORE PHYSIOTHERAPEUTIC BED
Fig. 1. Sensor bonded to electronics inside package with side view schematic hardware device and Software intelligent regulation system
A. Research on pressure acquisition and automatic regulation module unit
The pressure acquisition module is located at the upper part of the bed body
(mattress part), which is composed of silica gel head, pressure sensor, waterproof cover, decompression spring, guide bearing rod and linear bearing seat. The silica gel head is located on the upper surface in contact with the human body surface. The silica gel head is made of flexible silica gel material, which forms a better slow pressure effect on the skin of the pressed bone process. The pressure sensor collects the pressure value acted on the silicone block by the human body. The pressure relief spring relives the weight pressure of the human body, forms the physiological bending pressure concave and convex surface of the human spine on the bed surface, and improves the comfort of patients.
The pressure automatic regulation module is located below the pressure acquisition module and consists of a linear gear set and a DC motor. The pressure automatic adjustment module is connected with the pressure acquisition module by connecting the protective sleeve and the traction head. The linear moving axis pulls the pressure acquisition module downward to reduce the contact pressure between the contact surface of the human body and the module. The upward traction pressure acquisition module moves upward to increase the supporting force of the module on the human body. The analysis of the moving structure of pressure collection is shown in Fig. 2.
B. Study on cleaning, disinfection and drying and ventilation modules
The spray duct is a set of straight stainless steel tubes with uniformly distributed nozzle holes, located between the silica gel head and the upper support plate. During the cleaning and spraying operation, the solenoid directional valve connects the nozzle to the water tank, and the cleaning fluid pressurized by the pump sprays to clean the patient's excrement left on the bed. During dry ventilation operation, the electromagnetic directional valve connects the nozzle with the air pump, and the pressurized air of the air pump is blown into the bed body to play the role of
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ventilation and drying, and can be blown to the patient's body surface from the gap of the silica gel block, so as to keep the skin on the body surface dry and cool, and reduce the occurrence of bedsores.
C. Study on the intelligent control physiotherapy module The intelligent control physiotherapy module can carry out fast control without delay on the multi-area pressure collection linear motion module unit at the same time. According to the physiotherapy plan formulated by the doctor, the reasonable physiotherapy action can be prepared, the movement module can be controlled to carry out up and down orderly movement, and massage physiotherapy can be carried out on the patient's muscle group.
The intelligent control physiotherapy module is composed of a five-core single-chip microcomputer system, in which four single systems are respectively responsible for the collection of pressure data of shoulders, waist, buttocks and legs and the control of movement stroke; One main system is used for summarizing the collected data and uploading it to the LCD display interface through data transmission, as well as the network cloud system. Doctors and guardians can carry out real-time monitoring through mobile phones and other terminal devices.
pressure sensor silicone head
Intelligent control physiotherapy module unit
According to the biomechanical characteristics of human lying posture and the physiological bending characteristics of human spine, the mechanical self-adaptive
DESIGN OF PRESSURE SENSOR FOR BEDSORE PHYSIOTHERAPEUTIC BED
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adjustment of the degree of convexity and concavity of the control motion module is realized. At the same time, the movement module can be controlled to carry out up and down orderly movement, and massage physiotherapy can be performed on the patient's muscle group. Sleep quality, heart rate, respiration and other physiological parameters can also be monitored by lying posture.
The sleep physiological parameter monitoring module can monitor the sleep quality, heart rate, respiration and other biological parameters through the body pressure in the lying position, and can be used to display, record and alarm the comfort index, heart rate, heartbeat, respiration and other data in the sleep process.
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Fig. 3. Local module arrangement diagram
The comfort index refers to the data obtained by first calculating the mean value and standard deviation according to body weight, mechanical center trajectory, contact area, pressure peak value, and pressure mean value and the number of discomfort areas, and then calculating the correlation of indicators. The specific method is as follows:
- the weight, mechanical center trajectory, contact area, pressure peak, pressure mean and the number of discomfort areas were averaged in time order respectively (x) , standard deviation (s), measured value (x);
- finding the index value of the above indexes;
- the comfort index can be obtained by averaging the index values of the above indexes;
- the maximum value of the comfort index is 10.
- the greater the comfort index, the better the comfort of the mattress. The smaller the comfort index, the worse the comfort of the mattress.
Acknowledgements
This work is partially supported by Education department of Jilin province, the grant No. is JJKH20200569KJ.And Innovation Team Project by Science and Technology department of Jilin province.
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Заглавие: Конструкция датчика давления для противопролежневой физиотерапевтической кровати
Авторы:
Чжан Чао - Чанчуньский университет, Чанчунь, КНР
Введение: Рассматриваются вопросы проектирование модулей измерения давления, автоматического регулирования, очистки и вентиляции с учетом биомеханики человека. Показано, что разработка интеллектуальной системы управления кроватью для предотвращения пролежней стала насущной потребностью больниц, реабилитационных учреждений, центров ухода за больными и пациентами.
Ключевые слова: измерение давления, противолежневая кровать, модуль физиотерапии, метод воздушной подушки.
