Influence Of Acoustic Environment Of Ward On Patient And Medical Staff

Due to the improvement of material and spiritual living standards,people have higher requirements for medical treatment and hospitalization environment.The noise problem in hospitals has become a hotspot for complaints from patients and medical staff in recent years.The hospital ward is the main place for inpatients to receive treatment and rehabilitation.Ensuring its quiet and comfortable nursing environment should become one of the core issues of hospital staff and designers.However,due to the lack of research on the acoustic environment of the hospital,the influence of noise on the rehabilitation of hospitalized patients and the efficiency of medical care is not clear,resulting in the blindness of the design and management of the acoustic environment of the ward.Noise issues has not been solved.In order to quantify the comprehensive impact of the sound environment of the ward on the health and comfort of inpatients and medical staff,this research takes the ward of the general hospital as the research object,starting from the experimental determination of the impact of the change of the acoustics on the physiological and psychological indicators of the inpatients,combined with the on-site acoustic measurement.The questionnaire survey and the collection of physiological parameters explore the inherent relationship between the acoustic environment indicators and the subjective evaluation of the users and physiological indicators in a real hospital environment.The research contents of the thesis mainly include:(1)Combining acoustic measurements and questionnaire surveys,it revealed the acoustic environment status of different wards in several departments in a Chinese general hospital,including indoor noise levels,characteristics of noise sources,and subjective evaluations of the acoustic environment by patients and medical staff.The study found that without acoustic treatment,the ward with more beds has a larger average sound absorption coefficient((?))and a lower reverberation time(T₃₀).The day and night noise levels of the measured wards in each department exceeded the standard by 10-15 d BA.The main noise sources of the ICU ward are the working noise and alarm sounds of various medical equipment.The main noise source of the general wards is the"talking"from patients,accompanies and visitors.Noise issue of general wards in general hospitals is more prominent in China.Its daytime noise levels were 12.6 d BA and 8.9 d BA higher than those of similar hospital wards in the USA and UK,and the night-time noise levels were 6.0 d BA and 5.6 d BA higher than the USA and UK ona average.(2)Aiming at the problem of the acoustic environment of the wards,acoustic treatments,including sound insulation and absorption were implemented in the ward,corridor and nurse station of the two departments of the hospital.On the basis of acoustic simulation,the impact of installing different sound-absorbing ceilings of the ward,corridor and nurse station was evaluated.The study found that micro-perforated metal sound-absorbing plate with a noise reduction coefficient(NRC)of 0.5 can effectively reduce the low-frequency(125-250 Hz)reverberation time,but the Speech Transmission Index(STI)was not significantly improved(5%-8%).However,replacing the fiber sound absorption board with noise reduction coefficient NRC>0.7 can effectively reduce the reverberation time of mid-high frequency(500-4k Hz),and improve the STI more significantly(9%-15%).(3)On the basis of the acoustic measurement,the changes of indoor acoustic indicators before and after the treatment were clarified.The study found that the sound field changes in each area were basically consistent with the simulation results.The reverberation time in each area was significantly improved after the sound-absorbing ceiling was installed.The sound absorption ceiling reduces the background noise level and improves the STI,reducing the speaking volume of the medical staff in the nurse station area.Effectively improved the problem of increasing the volume of speech due to excessive background noise before the acoustic treatment.The installation of soundproof doors and windows in the ward effectively reduced the transmission of corridor and outdoor noise.The day and night noise levels in the empty ward were reduced by 14.6d BA(L_eqday=38.5d BA)and 6.1d BA(L_eqnight=31.2d BA),since the noise level of the ward reached the high requirements of the national standard(GB50118-2008).In the normal situation with patients,the sound environment was affected by the activity of the indoor sound sources.The noise level before and after the renovation was not much different during the daytime,but significant difference can be found during the night-time(5.7d BA),which provides a quieter sleep environment for patient.(4)On the basis of the questionnaire survey,the subjective evaluation differences between patients and medical staff under different acoustic environmental conditions(before and after acoustic treatment)were studied.It was found that the proportion of patients'perception of corridor noise sources was significantly reduced after the treatment,and nearly half(48.5%)of the medical staff were aware of the changes in the acoustic environment.Patients and medical staff's subjective evaluation of the acoustic environment of the ward has improved significantly(p<0.01).Compared with patients in the general wards,patients in the silent ward believed that noise had a lower effect on their"sleept"(p<0.05),"emotion"(p<0.05),and"sleep"(p<0.01).Medical staff also believed that the impact of noise on their"talk"(p<0.05)and"work efficiency"(p<0.05)after the treatment was significantly reduced.(5)The differences between the subjective evaluation of the ward acoustic environment and various basic physiological indicators of inpatients under different acoustic environmental conditions were further explored through clinical control experiments,and the quantitative relationship between the acoustic environmental indicators of the ward and the physiological and psychological indicators of the patients was initially established.The study found that the night-time noise level had a greater impact on patients.The patient's rating of the ward noisiness is only significantly positively related to the night-time noise level(L_eqnight)(p<0.01).When the L_eqnightwas lower than 45d BA,the patient would fell that the ward is relative quiet.When the L_eqnightexceeds 50d BA,the patient would fell that the ward was relative noisy.When L_eqnight reached 52d BA,the patients would feel that noise has a greater impact on their"rest"and"emotion".A quieter night-time environment can also improve the patient's sleep quality.Patients in the silent ward have a longer sleep time,with 14 minutes(0.23 hours)longer than patients in the ordinary wards.They also indicated that they have a higher sleep quality(p<0.05),lower noise interference(p<0.01)and the frequency of awakening due to noise during their sleep(p<0.01).Heart rate indicators(total heart rate,average heart rate,minimum heart rate)of patients in the silent ward group was lower than those in the general ward group(p<0.01),and heart rate variability indicators(SDNN)were higher than those in the general ward(p<0.01).The ward noise level was always significantly positively correlated with the patient's heart rate indicators(total heart rate,average heart rate,minimum heart rate)(p<0.01).In general,for every 1d BA increase in L_eq during the daytime,the patient's heart rate will increase by 0.6bpm,and for every 1d BA increase in L_eq during the night-time,the patient's heart rate will increase by 0.7bpm.When the noise level in the ward exceeds 70d BA,the stimulation of the vegetative nerve by the noise will increase.At this time,for every 1d BA increase in L_eq10min,the patient's heart rate will increase by 1.1bpm.This shows that in a relatively quiet hospital environment,the heart's oxygen consumption is lower,and the excitability of the sympathetic and vagus nerves is more balanced,which can reduce unnecessary energy consumption and to a certain extent help the patient's rest and recovery.