Thermographic observations in unilateral carpal tunnel syndrome: report of 61 cases

Musculoskeletal disorders prediagnosis by infrared thermography in CNC machinery operators: Regression models approaches

BACKGROUND

Musculoskeletal System Disorders (MSDs) are a group of injuries that represent common occupational diseases and should be evaluated for prevention purposes because an increase has been observed due to the repetitive movements performed in the industry. This research was carried out in a manufacturing industry where metal parts are manufactured, and workers experience back and wrist pain.

OBJECTIVE

To prediagnose Musculoskeletal System Disorders (MSDs) and examine the relationship between temperature, demographic, and physiological factors in workers through predictive models, contributing to MSD prevention.

METHODS

Information from 36 operators was used to obtain vital signs and somatometry data, and thermograms of their hands in the dorsal, palmar, and back areas were collected and analyzed to determine the relationship between temperature and demographic and physiological factors.

RESULTS

The ergonomic evaluations proved that the operators were at high risk owing to repetitive movements and postures adopted during work. Eighty-six percent of cases with injuries were identified using infrared thermograms, proving their high level of effectiveness. When studying the relationship between temperature behavior during recovery from repetitive activities and demographic and physiological factors, it was determined that age, dominant hand, respiratory frequency, and BMI were the most significant.

CONCLUSIONS

Nine regression models were obtained, with coefficients of determination between 0.17 and 0.71. The significant factors for worker injuries were age, dominant hand, respiratory rate, and BMI. However, the sample size and variability in work activities should be extended to generalize the findings.

Infrared thermographic changes after decompression surgery in patients with carpal tunnel syndrome

BACKGROUND

Digital infrared thermal imaging (DITI), which detects infrared rays emitted from body surface to create a body heat map, has been utilized at various musculocutaneous conditions. Notably, DITI can demonstrate autonomic vasomotor activity in the nerve-innervated area, and thus may be of use in carpal tunnel syndrome (CTS). In this study, we compared DITI findings before and after carpal tunnel release (CTR) surgery in patients with unilateral CTS to investigate the corresponding neurophysiological changes.

METHODS

In this retrospective cohort study, DITI parameters such as the temperature differences between the median and ulnar nerve territories and median nerve-innervated digital anisometry were measured. Subjective symptom duration, pain scale, and ultrasonographic findings were also compared before and after CTR. Patients were evaluated before and 6 weeks after CTR, respectively.

RESULTS

A total of 27 patients aged 59.0 ± 11.2 years were finally included. After CTR, median nerve-innervated thermal anisometry was improved (2.55 ± 0.96 °C to 1.64 ± 1.34 °C; p = 0.003). The temperature differences between the median and ulnar nerve territories were not significantly changed. Subjective pain, the Simovic Weinberg Clinical Scale, and palmar bowing of the flexor retinaculum were also significantly improved (p <  0.001 for all comparisons).

CONCLUSIONS

Our results demonstrated that DITI findings could reflect an improvement in autonomic function after CTR. Therefore, DITI can be an objective method to assess pre- and post-operative neurophysiologic changes in CTS.

Temperature Asymmetry Analysis between Left and Right Wrist with Sensory and Infrared Thermography

This article reports a thermal analysis of the wrists to analyze the behavior and recovery of skin temperature after 20 min when performing a highly repetitive movement, and two thermography methods (sensory and infrared) and research groups were compared. The tests were carried out with 44 participants who performed a repetitive task for 10 min and integrated into two groups, of which 22 were trained workers from a maquiladora company and were analyzed with sensory thermography, and the other 22 were in the laboratory with infrared thermography with undergraduate students. The study area is the left and right hand, specifically the wrists. The proposed hypothesis is that people with some musculoskeletal problems have a decrease in temperature when starting repetitive tasks and thermal asymmetries, which measurements were recorded at 0, 10, 15, and 20 min after the task was finished. Findings indicate that the temperatures in both wrists behave similarly. The workers reached higher temperatures, and the centigrade degrees of asymmetry difference were also higher. The variable with influence on the temperature was fractured in the arm. After thermally analyzing the temperature behavior between the wrists of both hands, it is concluded that there is an increase in temperature after finishing a repetitive task, and it does not stabilize after 20 min. Both thermography methods observed that the asymmetries are greater than 0.5 °C, detecting the possible pathology of carpal tunnel syndrome.

Application of digital infrared thermography for carpal tunnel syndrome evaluation

We investigated the thermographic findings of carpal tunnel syndrome (CTS). We enrolled 304 hands with electrodiagnostically identified CTS and 88 control hands. CTS hands were assigned to duration groups (D1, < 3 months; D2, 3‒6 months; D3, 6‒12 months; D4, ≥ 12 months) and severity groups (S1, very mild; S2, mild; S3, moderate; S4, severe). The temperature difference between the median and ulnar nerve territories (ΔM-U territories) decreased as CTS duration and severity increased. Significant differences in ΔM-U territories between the D1 and D3, D1 and D4, D2 and D4, and S1 and S4 groups (P = 0.003, 0.001, 0.001, and < 0.001, respectively) were observed. Thermal anisometry increased as CTS duration and severity increased. Significant differences in thermal anisometry between the D1 and D4 as well as the D2 and D4 groups (P = 0.005 and 0.04, respectively) were noted. Thermal anisometry was higher in the S4 group than in the S1, S2, and S3 groups (P = 0.009, < 0.001, and 0.003, respectively). As CTS progresses, skin temperature tends to decrease and thermal variation tends to increase in the median nerve-innervated area. Thermographic findings reflect the physiological changes of the entrapped median nerve.

Infrared thermal imaging monitoring on hands when performing repetitive tasks: An experimental study

The monitoring of infrared thermal images is reported to analyze changes in skin temperature in the hand fingers when repetitive work is performed to know which finger has a greater risk of injury, besides, the recovery time is analyzed regarding the initial temperature and its relationship with age, sex, weight, height if practice sports, and Body Mass Index (BMI) per individual. For the above, an experimental test was carried out for 10 minutes on a repetitive operation that takes place in the telecommunications industry and 39 subjects participated in which an infrared thermal image of the dorsal and palmar part of both hands was taken in periods of 5 minutes after the 10-minute test has elapsed. The results show that none of the participants recovered their initial temperature after 10 minutes of the experimental test. In addition, it was found that there is a relationship between skin temperature and sex, and that age influences the recovery of temperature. On the other hand, the thumb, index, and middle fingers have a higher risk of injury in the analyzed task. It is concluded that performing repetitive work with all the fingers of the hand does not show that all they have the same risk of injury, besides that, not all the variables studied affect the recovery of temperature and its behavior.

Quantitative Models for Prediction of Cumulative Trauma Disorders Applied to the Maquiladora Industry

Temperature gradient changes on the surface of the skin or in the middle of the body are signs of a disease. The aim of this study is to develop quantitative models for the prediction of cumulative trauma disorders (CTDs) arising from highly repetitive activities, considering risk factors, such as age, gender, body mass index (BMI), blood pressure (BP), respiratory rate (RR), and heart rate, to prevent injuries in manufacturing factory operators. This research involved 19 individuals from the area of sanding and 14 individuals from the area of tolex in manufacturing factories who had their vital signs and somatometry taken, as well as thermal images of their hands in the dorsal and palmar areas; an evaluation by the OCRA method was also applied. Factors such as BP and heart rate were determined to significantly influence the injuries, but no strong association with BMI was found. Quadratic regression models were developed, the estimates of which were adequately adjusted to the variable (R² and R² adjusted > 0.70). When integrating the factors of the OCRA method to the generated models, a better fit was obtained (R² and adjusted R² > 0.80). In conclusion, the participants who present levels out of the normal range in at least one of the factors have high probabilities of developing injuries in their wrists.

Stimulated infrared thermography applied to differentiate scar tissue from peri-scar tissue: a preliminary study

Every human injury leads to a scar formation. The healing process leads to the formation of new tissue: the scar, which is different from the original tissue. This process is influenced by mechanical strength and the local vasculature is modified. The purpose of this study is to show that there are various temperatures between the scar and the peri-scar area associated with the healing process that can be estimated using the thermal infrared camera. In the study, 12 scars were stimulated by cold. Several changes of temperature were observed between scar and peri-scar area for 10 min. Scars appeared significantly colder with a Wilcoxon test (p = 0.01). Results showed that stimulated infrared thermography can be used to monitor the temperature difference between the scar and peri-scar tissue.

Clinical applications of dynamic infrared thermography in plastic surgery: a systematic review

BACKGROUND

Infrared thermography (IRT) has become an increasingly utilized adjunct to more expensive and/or invasive investigations in a range of surgical fields, no more so than in plastic surgery. The combination of functional assessment, flow characteristics and anatomical localization has led to increasing applications of this technology. This article aims to perform a systematic review of the clinical applications of IRT in plastic surgery.

METHODS

A systematic literature search using the keywords 'IRT' and 'dynamic infrared thermography (DIRT)' has been accomplished. A total of 147 papers were extracted from various medical databases, of which 34 articles were subjected to a full read by two independent reviewers, to ensure the papers satisfied the inclusion and exclusion criteria. Studies focusing on the use of IRT in breast cancer diagnosis were excluded.

RESULTS

A systematic review of 29 publications demonstrated the clinical applications of IRT in plastic surgery today. They include preoperative planning of perforators for free flaps, post operative monitoring of free flaps, use of IRT as an adjunct in burns depth analysis, in assessment of response to treatment in hemangioma and as a diagnostic test for cutaneous melanoma and carpal tunnel syndrome (CTS).

CONCLUSIONS

Modern infrared imaging technology with improved standardization protocols is now a credible, useful non-invasive tool in clinical practice.

Changes in Body Temperature in Incomplete Spinal Cord Injury by Digital Infrared Thermographic Imaging

Objective

To investigate changes in the core temperature and body surface temperature in patients with incomplete spinal cord injuries (SCI). In incomplete SCI, the temperature change is difficult to see compared with complete spinal cord injuries. The goal of this study was to better understand thermal regulation in patients with incomplete SCI.

Methods

Fifty-six SCI patients were enrolled, and the control group consisted of 20 healthy persons. The spinal cord injuries were classified according to International Standards for Neurological Classification of Spinal Cord Injury. The patients were classified into two groups: upper (neurological injury level T6 or above) and lower (neurological injury level T7 or below) SCIs. Body core temperature was measured using an oral thermometer, and body surface temperature was measured using digital infrared thermographic imaging.

Results

Twenty-nine patients had upper spinal cord injuries, 27 patients had lower SCIs, and 20 persons served as the normal healthy persons. Comparing the skin temperatures of the three groups, the temperatures at the lower abdomen, anterior thigh and anterior tibia in the patients with upper SCIs were lower than those of the normal healthy persons and the patients with lower SCIs. No significant temperature differences were observed between the normal healthy persons and the patients with lower SCIs.

Conclusion

In our study, we found thermal dysregulation in patients with incomplete SCI. In particular, body surface temperature regulation was worse in upper SCIs than in lower injuries. Moreover, cord injury severity affected body surface temperature regulation in SCI patients.

Application of infrared thermography in computer aided diagnosis

The invention of thermography, in the 1950s, posed a formidable problem to the research community: What is the relationship between disease and heat radiation captured with Infrared (IR) cameras? The research community responded with a continuous effort to find this crucial relationship. This effort was aided by advances in processing techniques, improved sensitivity and spatial resolution of thermal sensors. However, despite this progress fundamental issues with this imaging modality still remain. The main problem is that the link between disease and heat radiation is complex and in many cases even non-linear. Furthermore, the change in heat radiation as well as the change in radiation pattern, which indicate disease, is minute. On a technical level, this poses high requirements on image capturing and processing. On a more abstract level, these problems lead to inter-observer variability and on an even more abstract level they lead to a lack of trust in this imaging modality. In this review, we adopt the position that these problems can only be solved through a strict application of scientific principles and objective performance assessment. Computing machinery is inherently objective; this helps us to apply scientific principles in a transparent way and to assess the performance results. As a consequence, we aim to promote thermography based Computer-Aided Diagnosis (CAD) systems. Another benefit of CAD systems comes from the fact that the diagnostic accuracy is linked to the capability of the computing machinery and, in general, computers become ever more potent. We predict that a pervasive application of computers and networking technology in medicine will help us to overcome the shortcomings of any single imaging modality and this will pave the way for integrated health care systems which maximize the quality of patient care.

Real-time infrared thermography for ureter detection during hysterectomy

BACKGROUND

Recognition of different anatomic structures might be difficult in the presence of diseases such as neoplasm or endometriosis that can subvert the anatomy. This can be a challenge for young surgeons approaching gynecologic surgery. The aim of the present study was to evaluate the effectiveness of infrared thermocamera to identify the anatomic structures in gynecologic surgery.

MATERIALS AND METHODS

From February 2010 to May 2011, consecutive patients who required abdominal hysterectomy were considered for eligibility. During a procedure for benign disease, we evaluated the temperature difference between the ureter and infundibulopelvic vessel (experiment A). In patients with gynecologic cancer, the thermal gradient was determined between the iliac vessels and the ureter (experiment B).

RESULTS

The data from 21 patients were recorded, 12 for experiment A and 9 for experiment B. We found a statistically significant difference between the ureter and vessels in both experiments (31.675°C ± 0.673°C for the ureter and 33.332°C ± 0.828°C for the infundibulopelvic vessel, P < 0.0001; 31.706°C ± 0.751°C for the ureter, 33.787°C ± 0.63°C for the iliac vein, and 33.784°C ± 0.639°C for the iliac artery, P < 0.0001).

CONCLUSIONS

Infrared imaging allowed us to identify the anatomic structures in laparotomy, providing preliminary data for its application in laparoscopy.

Adaptação à prótese híbrida de extremidade superior: estudo termográfico de um caso

O objetivo do estudo foi verificar, por meio de termografia, a adaptação à prótese híbrida de extremidade superior de um sujeito do sexo masculino, 42 anos, amputado proximal de braço esquerdo. Imagens termográficas foram captadas por uma câmara de infravermelho imediatamente após a retirada da prótese, que vinha sendo usada por 8 horas ininterruptas, e 20 minutos de repouso mais tarde, quando foi alcançado equilíbrio térmico em ambiente a 21°C. As imagens foram adquiridas nos planos frontal anterior, sagital direito e esquerdo, tendo sido definidas e analisadas regiões de interesse em cada uma. Os resultados mostram que as temperaturas das regiões avaliadas reduziram-se em média 0,79°C (p<0,05) após a estabilização térmica. Na região do tórax e na axila contralateral ao coto, por onde passa o tirante de fixação da prótese, constataram-se elevadas temperaturas, coincidindo com queixa de desconforto do sujeito e indicando atrito; temperatura mais alta no ombro anterior homolateral à amputação caracterizou sobrecarga; e baixa temperatura no segmento residual à amputação indicou pouca circulação, assinalando dificuldade de adaptação. Os resultados sugerem que a avaliação termográfica pode contribuir para identificar desconforto de amputados com prótese de membro superior e ser utilizada no acompanhamento de sua reabilitaçao; no caso, sugere-se ainda o desenvolvimento de materiais de modo a aumentar o conforto na fixação das próteses de extremidade superior.

Infrared thermography based on artificial intelligence as a screening method for carpal tunnel syndrome diagnosis

This study further evaluated a computer-based infrared thermography (IRT) system, which employs artificial neural networks for the diagnosis of carpal tunnel syndrome (CTS) using a large database of 502 thermal images of the dorsal and palmar side of 132 healthy and 119 pathological hands. It confirmed the hypothesis that the dorsal side of the hand is of greater importance than the palmar side when diagnosing CTS thermographically. Using this method it was possible correctly to classify 72.2% of all hands (healthy and pathological) based on dorsal images and > 80% of hands when only severely affected and healthy hands were considered. Compared with the gold standard electromyographic diagnosis of CTS, IRT cannot be recommended as an adequate diagnostic tool when exact severity level diagnosis is required, however we conclude that IRT could be used as a screening tool for severe cases in populations with high ergonomic risk factors of CTS.

Sympathetic pathology evidenced by hand thermal anomalies in carpal tunnel syndrome

OBJECTIVE

To clarify sympathetic pathology in carpal tunnel syndrome and the usefulness of digital infrared thermography as a diagnostic aid.

MATERIAL AND METHODS

38 clinically diagnosed carpal tunnel syndrome hands from 30 patients (confirmed by the standard nerve conduction studies) and 41 hands from 22 healthy volunteers (the hands having current finger inflammation were excluded) were studied. A series of hand infrared photos of each subject were taken and stored by using the technique of digital infrared thermography. We studied the infrared pictures and measured the temperatures of finger tips from digit 1 (D1) to digit 5 (D5), the center point of thenar (Th) and hypothenar eminences (Ht), then we calculated the temperature differences (absolute values) between each two of the 7 points, and median index (MI): (D1-D2)+(D2-D3)+(D1-D3). The means of D2 and Th (MD2+Th), D5 and Ht (MD5+Ht) were also calculated.

RESULTS

The results showed that the temperatures of median nerve distribution area in the hands were highly significantly different (Th-Ht, p < 0.001, MI, p < 0.001) between carpal tunnel syndrome (CTS) and the control group. The differences between the median and ulnar nerve distribution area were also highly significantly different in CTS hands (MD2+Th compared to MD5+Ht, p < 0.01). The sensitivity and specificity of digital infrared thermography were 84 and 91%, respectively.

CONCLUSION

Digital infrared thermography suggests sympathetic neural pathology in carpal tunnel syndrome. It may also be useful as an additional non-invasive tool in the diagnosis of CTS especially in the early stage.

Laparoscopic infrared imaging

BACKGROUND

As an adjunct to direct visual imaging, an infrared endoscope was developed to assist in the identification of various anatomic structures and to assess tissue viability during laparoscopic procedures. A camera sensitive to emitted energy in the mid-infrared range (3 to 5 microm) was incorporated into a two-channel visible-light laparoscope.

METHODS AND MATERIALS

Laparoscopic procedures were performed in a porcine model, inexperienced laparoscopists being asked to localize and differentiate structures before dissection using the visible-light system and then the infrared system. To determine clinical utility, nine laparoscopic urologic procedures were performed with the assistance of the infrared system.

RESULTS

In the clinical evaluation, infrared imaging proved to be useful in differentiating between blood vessels and other anatomic structures. In contrast to the experience with the conventional endoscope, vessel identification, assessment of organ perfusion, and transperitoneal localization of the ureter was successful in all instances using the infrared system. In the porcine model, this system also permitted assessment of bowel perfusion during laparoscopic occlusion of mesenteric vessels and distinguished between the cystic duct and artery.

CONCLUSION

Infrared imaging is a potentially powerful adjunct to laparoscopic surgery. It may improve the differentiation and localization of anatomic structures and allow assessment of physiologic features, such as perfusion, not previously attainable with laparoscopic techniques.

Clinical trials among worker populations: the value and significance of anamnestic findings and clinical and instrumental tests for diagnosing work-related musculoskeletal disorders of the upper limbs (WMSDs)

The authors discuss the value and significance of symptoms in WMSDs, in view of the fact that the anamnestic threshold proposed in epidemiological investigations cannot be used as clinical and diagnosing criteria. Some useful clinical procedures are suggested for cases where there is a suspicion of musculoskeletal disorders of the cervical spine and upper limbs, bearing in mind that they are to be applied within the framework of health surveillance programmes undertaken by health care practitioners who are not specialists in orthopaedics, physiatrics or neurology. The recommendations for instrumental tests and specialist referrals are also discussed for the various disorders. The authors also provide flow charts for the diagnostic procedures pertaining to WMSDs. The appendix shows a sample patient chart illustrating the proposed procedures; it also permits the findings to be encoded so that they can be stored in a dedicated database. The codes for diagnosing WMSDs are also reported for the same epidemiological purposes.