**4. Usage of IR-based technologies in forensic sciences**

*3.8.4. Usage for body temperature monitoring*

106 Forensic Analysis - From Death to Justice

*3.8.5. Usage for diagnosis of skin diseases*

method for the diagnosis of skin diseases [38].

*3.8.6. Usage for diagnosis of rheumatic diseases*

*3.8.7. Usage for diagnosis of ocular diseases*

*3.8.8. Usage for diagnosis of pain*

syndrome [38, 41].

of trauma.

Methods based on IRT have been used for body temperature screening of a population in public spaces, such as airports and bus terminals, to prevent the spread of epidemics, such as

In general, skin diseases have an inflammatory origin. One of the diagnostic signs of these diseases is a temperature increase in the skin surface. Thus, IRT has been accepted as a reliable

IRT has been defined as a reliable diagnostic method of diseases characterized by local temperature increases, such as rheumatoid arthritis, inflammatory arthritis, gut, tennis elbow, fibromyalgia, acute muscle injuries and spasms, enthesopathies and complex regional pain

In medical studies using IRT, an ocular temperature increase was determined in patients with ocular diseases, such as anterior uveitis, hyperemic bulbar conjunctiva, post-herpetic neural‐

IRT is also used to determine the body's painful point. Gratt et al. classified temperature differences in patients with oropharynx pain following their 6-year clinical assessment. They reported that "patients with 'hot' thermograms had the clinical diagnoses of sympathetically maintained pain, peripheral nerve-mediated pain, temporomandibular joint arthropathy, and maxillary sinusitis. Subjects with 'cold' thermograms were demonstrated to have the clinical diagnoses of peripheral nerve-mediated pain and sympathetically independent pain. Subjects with 'normal' thermograms were demonstrated to have the clinical diagnosis of cracked tooth syndrome, trigeminal neuralgia, pretrigeminal neuralgia, or psychogenic facial pain" [44]. Furthermore, the linear-polarized near-infrared light irradiation (LPNIR), a non-invasive method, was defined as a relief treatment for patients with chronic pain from frozen shoulder,

osteoarthritis, rheumatoid arthritis, post-herpetic neuralgia and other disorders [45].

The medical applications of IR-based technologies may help forensic scientists in medical malpractice claims, provide a preliminary diagnosis of the cause of death and detect the signs

gia, Graves' ophthalmopathy, glaucoma and dry eye syndrome [42, 43].

severe acute respiratory syndrome (SARS), avian influenza and swine influenza [38].

Fast, accurate and complete application in forensic analysis are of substantial importance for the delivery of a right to the justified person, as well as the fast, accurate and complete manifestation of justice. In this context, many forensic analysis methods have been improved and implemented in the previous century. Spectrophotometric methods were developed in parallel to the developments in optics and microscopy. Since the end of the twentieth century, the use of technologies based on IRT and IR spectrophotometry has been an important cornerstone [36]. Physical evidence obtained by IR photography provides critical clues for investigators in crime scene investigations. One advantage of this evidence is that it is suitable for re-examination after a long time [16]. IR imaging has been defined as two categories, including passive IR imaging and active IR imaging. Passive IR imaging may be used to detect non-contact radiation, without an external energy source. In this method, heat traces left by humans and objects may be investigated. Active IR imaging requires external heating or cooling of objects prior to imaging. While the external heat or cool source may be a component of the system in some applications, they profit by heat of a human body, domestic heating or air-conditioning system in some applications [46]. Currently, IR spectrophotometry has been used to analyse general polymers and materials, such as fibers, coatings, tapes and adhesives [36]. Chemical imaging, including visible-near IR chemical imaging, macroscope, in addition to the visible chemical imaging macroscope, visible chemical imaging microscope and light sources and liquid tuneable filter specification techniques have been defined as methods with substantial potential for the forensic analysis of materials, including paints, tapes and adhe‐ sives, inks and firearm propellants [47].

In this section, the use of several technologies based on IRT and IR spectrophotometry in forensic science is described.
