Application Status of Infrarde Thermography in the Evaluation of Curative Effect of Traditional Chinese Medicine

DONG Fan (董 凡), ZHANG Hui (张 慧), FAN Xin-rong (樊新荣), HUANG Bo-ming (黄博明)

1. Shaanxi University of Chinese Medicine, Xianyang 712000, China

2. China Academy of Chinese Medical Sciences, Beijing 100700, China

3. Zhonghe Sub Health Service Center, Beijing 100700, China

ABSTRACT Infrarde thermography is a kind of functional imaging technology to detect the surface temperature of human body. To a certain extent, it provides a scientific basis for the datamation,visualization and objectification of traditional Chinese medicine (TCM). It has the characteristics of noninvasive, accuracy and predictability. In this paper, infrarde thermography was applied, and summed up its advantages and disadvantages, so as to play a more important role in the field of TCM infrarde thermography.

KEYWORDS Infrarde thermography; Ttraditional Chinese medicine; Curative effects

Infrarde thermography is a functional imaging technology that detects the surface temperature of the human body. The human body continuously emits infrared radiation that is invisible to the naked eye. The infrarde thermography uses an infrared detector with a light sensitive element to detect the infrared of the target. The radiant energy is reflected to the optical imaging objective lens to obtain different infrared heat maps of different parts of the human body[1]. Due to the differences in tissue metabolism and blood circulation in various parts of the body, the temperature expressed is also different, which will form different thermal imaging on the infrared device. Under normal circumstances, the body is in a state of thermal equilibrium. When this state is destroyed, the temperature of the body surface is increased or decreased, and the image shows a high temperature area or a low temperature area. The heat radiation of normal tissues and abnormal tissues is different, and the location and scope of the lesion can be judged through the detection of infrarde thermography[2]. In recent years, the application of infrarde thermography in the field of TCM has become more and more extensive. With the help of infrarde thermography, the heat map conditions before and after TCM intervention can be detected, so that it can provide clinicians with objective support to observe the prognosis of the disease and adjust the treatment plan in time.

INFRARDE THERMOGRAPHY TO EVALUATE THE EFFECTIVENESS OF TCM

Infrarde Thermography to Evaluate the Efficacy of Chinese Materia Medica Preparations

NI JL[3]et al. divided 80 patients with perimenopausal insomnia with heart-kidney incompatibility into 2 groups randomly. The treatment group took self-made Yishen Ningshen(益肾宁神) Decoction (Semen Coicis,Fructus Tritici Levis,Bulbus Lilii,Yerbadetajo Herb,Rhizoma Alismatis,Radix Cyathulae,Flos Sophorae,Poria cocos Schw,Radix Rehmanniae Recens,Radix Paeoniae Alba,Rhizoma Atractylodis Macrocephalae,Semen Cuscutae,Fructus Ligustri Lucidi,Radix Dipsaci,Rhizoma Cibotii,Pericarpium Citri Reticulatae). The control group took vitamin E soft capsule and oryzanol. The total effective rate (95.0%) in the treatment group was higher than 77.5% in the control group. The infrared thermal imaging patterns of the 2 groups changed:① Before treatment: The thermal imaging centered on the forehead and chest was red or more red than yellow. The cold image centered on the kidney area, uterus, and bladder area is blue or blue with purple and green. It showed that the thermal image of the internal organs of the upper Jiao (上焦) tend to be hot, and the thermal image of the internal organs of the lower Jiao (下焦) tend to cool. ② After treatment: Compared with before treatment, in the control group, there was no obvious cooling area in the forehead, or there may be patchy areas where the temperature decreases, and the temperature of the trunk was not obviously changed. The thermal image in the treatment group with the forehead and chest as the center, the temperature of each part was more uniform, showing more yellow or less red or yellow, and the hot area was smaller than before treatment. The cold image centered on the kidney area, uterus, and bladder area was green or green with yellow, and the cold area was smaller than before, with mainly cool areas. The above research used infrarde thermography to compare the changes of the patient's images before and after treatment, which can provide clinicians with a visual judgment basis for the diagnosis and treatment of the disease.

XU GM[4]et al. used conventional treatments(antibiotics, analgesia, oral celecoxib capsules,functional exercises, etc.) in the control group of patients after unicondylar replacement of the knee joint, and the patients in the treatment group were added with the Taohong Siwu Decoction (桃红四物汤) more. A medical infrared thermal imager was used to detect the skin temperature of the patients 2 days before the operation and the 3rd, 7th, and 10thday after the operation. The results showed that the skin temperature of patients after the operation was increased than that before the operation. The skin temperature of patients in the treatment group was decreased compared with the control group.The VAS score showed that on the 3rd, 7th, and 10thday after operation, the patients in both groups increased compared with that before the operation.Compared the 2 groups after operation, the VAS scores in the treatment group was lower than the control group. The data analysis of the infrared heat map was consistent with the VAS score, indicating that the infrared thermal imaging device detects the changes in skin temperature before and after operation, and after administration of medication,which can effectively reflect the curative effect of Taohong Siwu Decoction (桃红四物汤), so as to guide the clinic.

YU JF[5]et al. selected 82 patients with hepatitis B and liver cirrhosis in the compensatory stage, and randomly divided them into the treatment group of 42 patients who were treated with the Lizhong Decoction (理中汤) with Entecavir Dispersible tablets, and 40 patients in the control group who were only treated with Entecavir Dispersible tablets. 40 healthy people were selected as the healthy control group without any treatment. The infrared heat map showed that the skin temperature in the healthy control group was uniform, and the infrared track of the Governor Vessel showed continuous. In patients with hepatitis B and liver cirrhosis, the gastric cavity and periumbilical skin temperature were low, and the infrared track of the Governor Vessel was roughly continuous, but often interrupted. The average temperature of the spleen and stomach meridian of the patients with hepatitis B liver cirrhosis and the original acupoint temperature of the two meridians before treatment were significantly lower than the healthy control group. After 3 months of treatment,the spleen and stomach meridians in the treatment group and the control group were both lower than the healthy control group, but the average temperature of the spleen and stomach meridian in the treatment group was significantly improved compared with the control group. At the same time,the clinical symptom scores, liver function, and KPA test results of the patients in the treatment group were better than those in the control group.It can be seen that the change of infrared thermal imaging temperature was consistent with the above results. Infrarde thermography is used as one of the tools to evaluate the efficacy of Chinese materia medica.

ZHOU FM[6]used infrared thermal imaging to detect and observe the syndrome differentiation of 24 cases of cervical spondylosis with arthralgia type. The scanning parts included the head,neck, back and upper limbs on both sides. Each patient was scanned once before and after treatment. The general treatment used traction of the mandibular occipital band in the sitting position. For the wind-cold syndrome, modified Guizhi Fuzi Decoction (桂枝附子汤) was used.For the deficiency-cold syndrome, modified Huangqi Guizhi Wuwu Decoction (黄芪桂枝五物汤) was used. For the wind-dampness syndrome,modified Qianghuo Shengshi Decoction (羌活胜湿汤) was used. Infrared heat map showed that before treatment, for the wind-cold syndrome, the affected side's shoulder, back, upper limbs showed low temperature changes, showing characteristics of low temperature in front and back. For the deficiency-cold syndrome, the affected side of the shoulder and back and the posterior and outer sides of the upper limbs showed low temperature changes. Regardless of the patient's syndrome, the pain points on the shoulder, back, and upper limbs of the affected side often show high temperature changes. After treatment, for the wind-cold syndrome, the lowest temperature on the affected side was (0.4±0.4) ℃ lower than the healthy side,with an average lower of 0.1 ℃. For the deficiencycold syndrome, the lowest temperature on the affected side was (0.3±0.3) ℃ lower than the healthy side, with an average lower of 0.15 ℃.For the wind-dampness syndrome, the highest temperature on the affected side was (0.2 ±0.1) ℃higher on the healthy side, with an average lower of 0.1 ℃. In cases without recovery, regardless of the type of syndrome, the thermal imaging images at the pain points were mostly high temperature changes. Infrared thermal imaging images before and after treatment showed that the three syndrome cases had a clear tendency to recover to normal temperature. Infrared thermal imaging showed that the temperature recovery was consistent with the treatment results, which can indicate that infrared thermal imaging can be considered as an objective indicator for syndrome differentiation and treatment and efficacy evaluation to a certain extent.

ZHANG LJ[7]et al. gave basic treatments to diabetic foot patients in the control group (oral hypoglycemic drugs, anti-infection, vasodilation,local treatment, etc.). The treatment group was additionally given Xuefu Zhuyu Decoction (血府逐瘀汤) on this basis. The infrared thermal imaging equipment was used to observe the foot temperature between the 2 groups of patients before treatment and showing no significant difference. After taking Xuefu Zhuyu Decoction,the difference in limb temperature between the treatment group and the control group was increased (0.27±0.26) ℃, which was significantly decreased than before treatment (t=6.13,P＜0.001).The infrared heat map can directly reflect that the temperature of the heat map of early diabetic foot patients was lower, and the clinical effect can be determined earlier than the clinical manifestations.After 4 weeks of treatment with Chinese materia medica, the temperature of the foot can be observed through the infrared heat map, and compared with before treatment, there was good improvement of the peripheral circulation, indicating that the infrarde thermography can provide guidance and affirmation for clinicians' medication.

Infrarde Thermography to Evaluate the Efficacy of Acupuncture

LUO DQ[8]performed warm acupuncture an T4-7 Jiaji point on 32 patients with sub-healthy chest arthritis in the experiment group, and 32 patients in the control group received TCM health training and nursing education. The medical infrarde thermography was used to take images before and after the intervention. The results showed that the improvement rate of the average temperature of the left anterior area of patients with sub-healthy chest palsy was 77.4%, indicating that the average temperature of the left anterior area of patients with sub-healthy chest palsy could be increased after intervention. Comparing the infrared heat maps in the experimental group and the control group, the results showed that the average temperature of the left precordial area between the 2 groups after intervention showed statistically significant difference (P=0.000,P＜0.05), which showed that the warm acupuncture treatment at T4-7 Jiaji points (夹脊穴) can improve the hypothermia of the left anterior area of patients with sub-healthy chest pain. In addition, the analysis and processing of the scale scores of patients with sub-healthy chest arthritis showed that it was consistent with the improvement of the average temperature of the left precordial area on the infrared heat map, which indicates that infrared heat map could be one of the indicators of curative effect in patients with arthralgia.

CHEN SH[9]et al. used infrarde thermography to observe the effect of liver and kidney conservation acupuncture on insomnia (40 cases). The control group (40 cases) took estazolam tablets. The study proved that the temperature of the forehead in the experiment group and the control group after treatment was lower than that in the same group before treatment (P＜0.01). After treatment, the temperature in the experiment group was lower than that in the control group (P＜0.05). The temperature of the forehead of the insomnia patients in the experiment group dropped uniformly, while the control group showed sporadic changes. Thus, by observing the temperature change of the infrared heat map, the effectiveness of the liver and kidney conservation acupuncture method in the treatment of patients with insomnia can be verified. At the same time, the difference of PSQI scores between the experiment group and the control group after treatment was statistically significant (P＜0.05),indicating that infrarde thermography can be used as a TCM treatment of insomnia to provide a visual evidence and another perspective to evaluate the efficacy standard.

SONG J[10]et al. randomly divided 150 patients with knee osteoarthritis into the meridian acupoint group, the meridian and tendon syndrome differentiation group and the combination group.The treatment method was acupuncture at the traditional meridian acupoints, Ashi points (阿是穴) along the meridian, and a combination of the two. Infrarde thermography was used to analyze and observe the curative effect, and it is found that the irregular temperature area around the affected knee in the infrared thermal image was reduced or disappeared compared with before the intervention.The common acupoints on the infrared thermal image and the regularity of Ashi points along the meridians were analyzed. The temperature of each observation point of knee osteoarthritis patients in the 3 groups decreased to different degrees after treatment, specifically: ① The body surface temperature change in part of observation points in the meridian acupoint group and the meridian and tendon syndrome differentiation group was significantly lower than the combination group(P＜0.05). ② The body surface temperature of some observation points in the meridian acupoint group was lower than the meridian and tendon syndrome differentiation group (P＜0.05). Acupuncture at the acupoints along the meridian and tendon plus Ashi points in combination with meridians was better than monotherapy in treating knee osteoarthritis patients. Infrarde thermography can evaluate the efficacy of knee osteoarthritis within a certain range.

Infrarde Thermography to Evaluate the Efficacy of Tuina

DONG N[11]used infrarde thermography to explore the effects of abdominal Tuina (推拿) on patients with primary insomnia of heart and spleen deficiency syndrome, and the results showed that the average temperature of the abdomen of patients with heart and spleen deficiency insomnia after massage treatment increased compared with before intervention. The average temperature of the forehead was decreased. The total effective rate of abdominal massage treatment was 93.3%.It showed that infrared thermal imaging can be used as an index for clinical observation of curative effect.

LIU GK12]et al. divided 100 patients with knee osteoarthritis into the control group (50 cases) and observation group (50 cases) through envelope grouping. The control group received acupuncture,and the observation group received massage.The infrarde thermography was used to observe the effect. The results showed that the VAS score in the observation group was significantly lower than that in the control group, and the knee joint function score was also significantly lower than the control group. The infrared heat map showed significant differences from the control group except for observation point 1, observation point 7, and observation point 11. Massage treatment of knee osteoarthritis can alleviate the pain symptoms of patients and improve the function of the knee joint.The application of infrarde thermography is helpful for clinicians to judge the patient's treatment status and establish an objective standardized system for Tuina treatment of diseases.

CHEN Y[13]et al. gave massage to 166 patients with lumbar disc herniation. The infrarde thermography was used to observe the changes of infrared thermal image before and after massage treatment. Before treatment, the infrared thermal image of the patient showed abnormal heat in the lumbosacral region. The temperature range of the abnormal hot zone was higher than normal,and the temperature in the center of the abnormal hot zone was more than 4 ℃ different from the surrounding temperature. After treatment, 109 patients with lumbar disc herniation had normal or improved thermal image, and 104 patients had normal or improved thermal image after treatment.After the treatment, the infrared thermal image showed that the range of the hot zone was reduced compared with before, and the center temperature of the abnormal hot zone was also reduced. The local blood circulation of the patients with effective treatment was improved or normal, while the thermal image of the patients with no treatment was basically unchanged. The thermal imaging examination has high application value in judging the curative effect of tuina treatment of lumbar intervertebral disc herniation.

Infrarde Thermography to Evaluate the Efficacy of Moxibustion

ZHANG YM[14]et al. carried out moxibustion on sub-healthy people with yang-deficiency constitution. The treatment effect was observed through infrared thermal image characteristics. The three Jiao (三焦) infrared heat map characteristics of sub-healthy yang-deficiency people were characterized by the highest upper Jiao (上焦)temperature and the second in middle Jiao (中焦)temperature. Among them, the lower Jiao (下焦)temperature was the lowest, with typical "cold"characteristics, concentrated in the chest and abdomen functional areas; after moxibustion treatment, there was no significant difference in the comparison of the infrared thermal image of the subhealthy yang-deficiency physique subjects and that of the normal physique subjects (P>0.05), which indicates that infrared thermal imaging detection technology can provide a visual basis for guiding the efficacy of TCM.

ZHANG XY[15]used infrarde thermography to observe the efficacy on chest apoplexy with cold-congelation syndrome in heart meridian by moxbusiton group [(warm moxibustion at Danzhong (RN17), Juque (RN14), Xinshu (BL15),Jueyinshu (BL14), Geshu (BL17)] and drug group (oral or sublingual compound Danshen dripping pills). Before and after treatment in the moxibustion group, the temperature changes in the precordial area and four acupoints [Shenmen(HT7), Shaohai (HT3), Neiguan (PC6), Quze(PC3)] were statistically significant (P＜0.05).Before and after treatment in the drug group,difference in the temperature was not statistically significant (P>0.05). The total effective rate in moxibustion group was 78.79%, and that in drug group was 72.73%. After moxibustion intervenes in chest apoplexy with syndrome of cold congelation in heart meridian, clinical symptoms,precordial temperature, and acupoint temperature changes were correlated, indicating that infrarde thermography has certain reference value in evaluating the efficacy of moxibustion.

LU GK[16]randomly divided patients with cervical spondylotic radiculopathy into the treatment group (30 cases) which applied moxibustion moxibustion to the affected side of the neck Jiaji(EX-B2), Daqiao, Gaoyu, and Tianzong, and the control group (30 cases) which received mild moxibustion at the above acupoints. The infrared heat map showed that the temperature difference between the healthy side and the affected side of the 2 groups was reduced to different degrees before and after the treatment (P＜0.05). After the treatment, the temperature difference between the healthy side and the affected side in the 2 groups was significantly different (P＜0.05), which proves that infrarde thermography can be used as an objective indicator of curative effect evaluation to a certain extent.

WANG LL[17]et al. administered moxibustion to Zusanli (ST36) in 15 patients with infantile spasm,and 10 healthy children in the control group did not receive any treatment. The infrared heat map showed that the temperature distribution on both sides of the head and face of the control group was balanced and the symmetry was good. The patient's bilateral temperature symmetry was poor in the spasm group, and the temperature on the right side was lower than that on the left side. Then the infantile spasm patients with moxibustion in Zusanli (ST36) were taken for comparison before and after intervention. The infrared thermal images before and after 15 minutes in the resting state were used as the blank group and the treatment group respectively. The results showed that the temperature difference of the facial thermal image before and after 15 minutes in the resting state did not change significantly. The temperature difference between the two sides of the face before and after 15 minutes of moxibustion was significantly reduced,and the temperature on both sides tend to be symmetrical. Studies have shown that by observing the infrared heat map, it can be objectively understood that moxibustion at Zusanli (ST36) can improve the blood circulation of the head and face of infantile spasms to a certain extent, reflecting the role of infrarde thermography in evaluating curative effects.

Infrarde Thermography to Evaluate the Efficacy of Other Aspects

HE YC[18]used infrarde thermography to observe the 15-type intervention of TCM guided metabolism during low-intensity aerobic exercises.Infrared thermograms of 26 patients with type 2 diabetes were taken. Self-control before and after intervention was performed to observe the role of guiding exercise for temperature in the body surface area. The infrared heat map showed that the temperature of the kidney meridians, liver meridians, and gall bladder meridians decreased on both sides. The difference between the maximum temperature and the minimum temperature in the middle and lower Jiao (下焦) increased, which made the temperature of the middle and lower Jiao tend to be inconsistent. The temperature of Geshu (BL17)on left and Dazhu on right side increased, and that of Yanglingquan (GB34) on the left and Xuanzhong(GB39) on the left and right sides decreased. The temperature of the eyes and mouth tended to be inconsistent. There was consistency for the changes of infrared heat map data and the changes of laboratory data, TCM syndromes, emotional state,and sleep state from a theoretical perspective of TCM.

ZHAO MY[19]treated patients with knee osteoarthritis with the TCM "Xi Tong Ning" (息痛宁)fumigation and washing prescription with traditional therapy. Before and after the treatment, infrared thermal imager was used to detect the temperature of the knee joint area, and the results showed the temperature of the infrared heat map before and after treatment when compared with the WOMAC score and the VAS score, the scatter plot showed a straight line trend, and the abnormal points were not obvious. The temperature of the infrared heat map before and after treatment was positively correlated with both, indicating that infrarde thermography can be used as an objective basis for evaluating the clinical efficacy of fumigation treatment of knee bone arthritis.

TANG YH[20]treated 34 cases of sub-healthy with phlegm and dampness by cupping therapy,and 34 cases in the control group did not undergo any intervention. The temperature of the 2 groups was detected by infrarde thermography, and the collected temperature was statistically analyzed.The results showed that the temperature changes of the upper abdomen and back in the experiment group before and after the intervention showed statistically significant difference (P＜0.05), while the temperature changes in the control group showed no statistically significant difference(P>0.05). For scale score analysis after the intervention, the physical fitness score and SF-36 quality of life scale score in the experiment group and the control group were compared. ThePvalues were 0.043 and 0.000, respectively. There were significant differences between the 2 groups after the intervention. The effective rate of the scale evaluation was 87.1%, which was higher than the 61.29% evaluated by the infrared heat map. The above visible infrared heat map can be used as a tool for evaluating the effect of the cupping method in regulating phlegm and dampness, but the sensitivity is not as good as the score evaluation of the scale.

THINKING AND PROSPECT

Infrarde thermography has unique advantages in evaluating the effectiveness of traditional Chinese medicine. As a visual detection method, it can also digitize human body temperature. It can be called "TCM CT", which can effectively evaluate the effects of TCM on diseases, which can provide clinicians with reliable support for follow-up disease treatment.

The progress of infrarde thermography in the evaluation of medical efficacy is as described above, but there are still many problems:① Infrared equipment lacks uniform production standards, and various manufacturers have different technical parameters and detection rules.② Infrared detection is more sensitive to temperature. Therefore, it is easily affected by environmental factors. ③ The operation level of clinicians is uneven, and most doctors still have empirical and subjective judgments, do not have perfect comprehensive judgment ability. ④ Lack of unified scientific research ideas, and the rationality of the results needs further discussion. ⑤ The sample size in the research process is small, which is only personal empirical research with small sample.⑥ Lack of automated analysis software, manual data processing is cumbersome and with large errors.With the continuous research and improvement of infrarde thermography, it believed that it will play a pivotal role in evaluating the efficacy of TCM in the future, making the traditional medicine of the motherland objective, visualized, and digitalized.