Non-contact Milk Goat Respiration Monitoring System Based On Ultrasound

The milk goat industry is an important part of animal husbandry in China,and the health of the milk goat is the guarantee of its stable and high yield.However,the high incidence of diseases in milk goat breeding has brought great economic losses to farmers.The breathing of sick milk goats at rest is faster or slower than normal individuals.Therefore,real-time respiration monitoring of milk goats can be used as an effective means to detect diseased individuals in time,and then it can prevent infection and reduce mortality by the way of isolation and treatment.Aiming at the respiration monitoring of livestock,the traditional wearable equipment about monitoring respiration is easily damaged.Moreover,it interferes with the natural state of livestock.In addition,although the technology based on visible light image processing can solve the problem of interference,it is easily affected by light conditions so that it is not suitable for milk goats and other livestock with pure hair.Namely,the existing respiration monitoring methods for milk goats are difficult to promote and apply in actual breeding.Thus,ultrasonic sensing method was used to replace the traditional wearable and video monitoring methods to realize non-contact respiratory monitoring in the natural resting state of milk goats.Specifically,the main research content and results of my study are as follows:(1)The design of a broadband synchronous ultrasonic transceiver.In order to facilitate the development of research and avoid noise interference in the audible frequency during the resting state of milk goats,we design and implement a set of ultrasound transceiver with broadband and synchronization.The design content mainly includes a USB sound card and a broadband ultrasound transmitter.First of all,with the core of STM32 microcontroller,the connection relationship between it and digital MEMS microphones was designed to receive broadband ultrasound and other electronic components,so that a prototype of the hardware part of the USB sound card was achieved.Secondly,in order to realize the function of USB sound card and meet the requirements of 96 k Hz high sampling rate and high synchronization of receiving and sending,we proposed a complete design scheme about some firmware program and methods of synchronizing audio stream.In particular,we proposed an audio stream architecture that could guarantee the real-time and integrity of the USB sound card audio stream,and next we designed an efficient audio stream program based on the abovementioned audio stream architecture in the first step.Then we use a reverse design method to accurately calculate the clock system distribution of peripherals about transceiver so that the USB sound card could keep a synchronous state between sending and receiving.Further,in order to realize the synchronization of the system between sending and receiving,we design some methods about synchronization in the audio stream program.For another part of the design,we design a broadband ultrasound transmitter based on a general speaker frame so as to transmit broadband ultrasound with the controllable power.In the end,we tested and verified the performance of the transceiver.The results show that this transceiver has the following traits: wideband(20 ～42k Hz)and high sampling rate(96 k Hz),high degree of synchronization between sending and receiving,convenience and controllability.It provides a fundamental tool for a resting milk goat about research of respiration monitoring to design this transceiver.(2)Design of a respiration monitoring algorithm based on acoustic SFR.In order to avoid the problem of monitoring blind spots caused by the unfixed resting position and posture of the milk goat,a new robust respiration monitoring algorithm that has nothing to do with the position of the measured object was designed based on non-contact ultrasound.In this paper,we utilized the physical phenomenon of multipath effects in indoor to build echo models firstly.Then we summarized the theory of the influence on the effective signal of the chest movements accompanied with breathing in the echo.Based on the above-mentioned theory,we construct a mathematical model that could stably express chest movement information.At the meantime,the precise acquisition method of SFR was designed in detail.Further,we design a method that could dynamically extract some effective SFR time series that could reflect chest movement information.Finally,based on the extracted effective SFR time series,a method which can recover the continuous respiratory waveform was designed.The algorithm solved the problem of position sensitivity of existing methods to the measured object in principle,and provided a method support for the research of resting respiration monitoring of milk goats.(3)The construction and experiment of non-contact respiration monitoring system for a resting milk goat.With the ultrasonic transceiver as the supporting tool and the respiration monitoring algorithm as the method,we construct a respiration monitoring system,and the experiments were set to monitor the respiration of milk goats respectively.The results showed that the respiration monitoring system would not interfere with the milk goat’s resting state.Meanwhile,this system can solve the problem that the existing wireless signal-based respiration monitoring methods are sensitive to position and orientation of the measured object effectively.In addition,it was not affected by the position,body size,age and posture of the resting milk goat.The analysis of the test data showed that the maximum respiration rate error of this system was only 0.4 breaths/min,and the average respiration rate error was about 0.15 breaths/min.Therefore,this system can be applied to monitor the respiration of a resting milk goat accurately by the way of a non-contact ultrasound.