Thermal Imaging Revolutionizes Health Care

Revolutionizing Health Care and Machine Vision with Thermal Imaging Technology

Image Source: Cipta/Stock.adobe.com

By David Pike for Mouser Electronics

Published June 27, 2023

The realm of machine vision has traditionally been synonymous with cameras and human-like vision systems. Yet, our perspective is shifting dramatically as we navigate the 21st century. A burgeoning technology, thermal imaging, is now ascending the ranks, promising to redefine our understanding of machine vision and its application in health care. Thermal imaging, or thermography, doesn't merely capture the visible: it unveils the invisible, detecting light-emitting objects outside our typical visual spectrum. Combined with the power of artificial intelligence (AI), it has the potential to overcome the limitations of conventional 2D inspection, offering an immersive and insightful journey into the unseen, and providing a wide range of solutions in medical applications.

Machine Vision

Machine vision, or computer vision, is the name given to a range of technologies enabling computers or machines to see and interpret visual information like humans use sight. It employs cameras to capture still images or video footage and analyzes them for real-time evaluation. Machine vision aims to develop systems that can automate tasks requiring visual perception, recognition, and understanding.

Machine vision systems have been employed across the industrial world. As operators use more autonomous robots in the factory environment, the need for collision avoidance grows. Embedded vision systems will allow factory robots to identify potential hazards and act most appropriately. Machine vision systems also bring benefits to manufacturing. Modern embedded vision systems are being used for manufactured item inspections, collision avoidance, and preventative maintenance.

Seeing Beyond the Visible Spectrum

Machine vision applications use the same wavelengths of light visible to the human eye. Their utility comes from their ability to capture and analyze images far more quickly and accurately than human operators. However, systems using visible light are limited in their ability to analyze three-dimensional objects. Imaging an object using visible light depends on an external light source, as it does not emit radiation. Instead, it reflects light that illuminates its surface. It is, therefore, impossible to create a three-dimensional image of the object using conventional imaging technology.

At its core, thermal imaging operates on the principle that all objects emit infrared radiation. This radiation is captured by thermal cameras, which generate an image by mapping out temperature differences. The resulting image or video sequence provides a vivid portrayal of the environment, independent of lighting conditions, showcasing anomalies in temperature that may signify underlying issues.

The Emergence of Thermal Imaging in Machine Vision

While thermal imaging has seen prominent use in military and surveillance applications, its entry into machine vision and health care is relatively recent. The incorporation of thermal imaging within machine vision opens a plethora of opportunities. Where conventional machine vision can falter in differentiating objects of similar appearance, thermal imaging excels in detecting subtle differences in heat signatures.

Moreover, the conjunction of thermal imaging with AI brings the capability to analyze these thermal variations intelligibly. It allows us to decipher the hidden patterns and correlations in data previously beyond our comprehension. This powerful combination can overcome the limitations of 2D imaging, providing a more nuanced understanding of the environment and the entities within it.

These temperature variations, displayed using advanced imaging systems, can provide valuable insights into an object's thermal patterns and heat distribution. Possibly the most familiar to many will be thermal imaging cameras in humanitarian applications. Handheld cameras with built-in displays have been used repeatedly to provide information to emergency services. This might include the location of victims trapped within collapsed buildings or showing firefighters the source of a fire, allowing them to extinguish it more efficiently.

Thermal imaging has also found many applications across many industries. For example, in building inspections, thermal imaging allows inspectors to identify areas with abnormal temperatures that may indicate poor insulation or where moisture has penetrated structures.

Thermography enables electricians to detect electrical faults such as overloaded circuits, loose connections, and faulty components within systems. It can also identify areas of high resistance within circuits and identify potential fire hazards before they cause significant damage or failure.

Because thermography is a non-contact and non-destructive technology, factory personnel can use it to monitor the condition of machinery without the need to deactivate it for inspection. Engineers can use thermography to remotely create a real-time image of the manufacturing process. The information that thermal imaging provides can be used to identify machines operating inefficiently or components due for replacement.

Revolutionizing Health Care with Thermal Imaging

The characteristics of thermal imaging and its ability to provide helpful information make it a highly desirable tool for assisting medical professionals to identify and diagnose many conditions. However, thermography is not a standalone diagnostic tool and should be used with other clinical evaluations and tests.

Passive Diagnostics

Many uses of thermal imaging are entirely passive—that is, they do not depend on subjecting the patient to potentially harmful radiation, in contrast to technologies such as X-ray or MRI. While thermography cannot entirely replace these diagnostic tools, it can be used to monitor a patient's condition in real time without the risks associated with long-term radiation exposure.

The technology's non-invasive nature is also instrumental in reducing the need for exploratory surgery. Any surgical procedure includes the risk of infection or other complications. However, in certain situations, health care workers can use thermal imaging to provide a more accurate diagnosis, thus avoiding unnecessary surgery and better focusing treatment to improve clinical outcomes for patients.

Thermography is also an ideal tool in the battle to reduce or eliminate the spread of infectious diseases, allowing medical personnel to monitor or diagnose patients from a distance, without needing to dispose of or sterilize equipment. Additionally, it's an ideal technology for applications that require many patients to be screened quickly, such as protocols during the COVID-19 pandemic.

Moreover, thermography can be used as a screening tool for breast cancer, detecting abnormal temperature patterns, which may indicate the presence of tumors or other abnormalities that cannot yet be seen in different ways, allowing for early treatment. The technology is also particularly suitable for imaging blood flow because its high resolution means it can detect temperature variations with great precision. This is highly beneficial in the diagnosis of vascular disorders, as thermal imaging can be used to identify abnormalities in a patient's blood flow and to help detect conditions such as deep vein thrombosis, peripheral vascular disease, and vasculitis.

The sensitive nature of thermal imaging equipment can provide remarkably accurate information about the source of increased temperature within affected tissue, allowing medical professionals to decide on specific treatment strategies. The same technology can be used to evaluate pain conditions by visualizing temperature changes in the affected areas. It can help identify sources of pain, assess nerve function, and can be used to monitor the effectiveness of treatments in real time.

Fluorescence Imaging

Medical thermal imaging does not need to rely solely on passively detecting radiation emitted by the patient. Thermography is being developed to function as part of immunotherapy, which stimulates the immune system to fight cancer cells.

During immunotherapy, medical practitioners monitor immune cells using a technique called fluorescence imaging. The patient receives an injection of a chemical agent, which has the characteristic of concentrating around tumor cells. The agent fluoresces (i.e., glows) when exposed to near-infrared (NIR) light, so the limits of the cancerous cells can be detected with great precision. 

The use of NIR is safe for both the patient and medical practitioner and can penetrate below the skin's surface to create an image of deeper tissue structures. Using this technique, doctors can access an accurate understanding of the effects of immunotherapy, offering great hope for cancer patients.

Wellness Applications

Thermal imaging is finding applications beyond traditional medical care. For example, extreme exercise, such as that practiced by professional athletes, can send temperatures in certain body parts above 37°C (98.6°F), especially in the joints and muscles. Thermal imaging allows sports medicine providers to examine these temperature variations in greater detail to help improve recovery times and future performance while reducing the risk of tissue damage.

Conclusion

Leveraging cutting-edge image processing technology, thermal imaging brings many advantages to the medical arena. This non-contact, non-invasive method can take center stage in diagnosing chronic and acute conditions. Complementing other diagnostic techniques, it enables swift monitoring and delivers real-time analysis capabilities. The integration of this technique with advanced image analysis and recognition software forms a formidable arsenal for early diagnosis. This timely intervention empowers physicians to initiate prompt treatment protocols, maximizing the potential for optimal patient outcomes.

The development of miniaturized electronics is creating exciting opportunities for thermal management. With a camera already installed in every smartphone, could thermal imaging be the key to future health care? The ability to detect and diagnose conditions in their earliest stages, which is so often key to effective treatment, makes thermal imaging an indispensable tool for the medical industry. Could this become the next development that rivals antibiotics or gene therapy in its potential?