Luciole Medical, a medtech company based in Switzerland, has developed near-infrared sensors that can assess levels of tissue oxygenation as well as cerebral blood flow by measuring oxygenated and deoxygenated hemoglobin. The sensors include a skin patch, which measures brain blood flow and oxygen saturation in patients undergoing surgery, and a minimally invasive probe that monitors patients with severe brain injuries or brain hemorrhage.
Brain blood flow and oxygenation are both crucial for normal brain function. Reduced brain oxygenation can have significant effects, such as paralysis, speech impairment, cognitive impairment and death. It is important to monitor these parameters in vulnerable patients, such as those who have suffered a brain injury or those who are anesthetized. Rapidly obtaining such clinical data can help doctors in diagnosing and treating a variety of issues.
To address this, Luciole Medical has used near-infrared technology in two different types of sensor. The system is based on the principle that hemoglobin, which carries oxygen in the blood, will absorb near-infrared light. The light can penetrate biological tissues, and is then absorbed by oxygenated and deoxygenated hemoglobin, allowing the sensor to calculate their concentrations in the tissue.
Medgadget asked Philippe Dro, Luciole Medical CEO some questions about the concept.
Conn Hastings, Medgadget: Please give us an overview of the clinical problems caused by poor brain oxygenation and blood flow.
Phillipe Dro, Luciole Medical: The brain is well known as a very sensitive organ which can barely cope with oxygen depletion. Under certain circumstances, the oxygen supply may be impaired and clinicians need to be able to detect this supply impairment in a timely manner in order to take suitable corrective or therapeutic action. Until recently, the physiological impact of this event was not really understood. Today, an increased body of publications shows the role of oxygen shortage in several cognitive syndromes.
Medgadget: What systems currently exist to monitor brain blood flow and oxygenation?
Phillipe Dro: Several systems using various technologies were developed over recent decades in order to gain knowledge of the very complex physiology of this unique organ. Methods used to monitor cerebral oxygenation in real time include jugular venous oximetry, brain tissue oxygen tension and near-infrared spectroscopy. The innovation from these methods comes from the understanding of brain physiology and the application of new signal treatment algorithms.
Medgadget: So, how can near-infrared light be used to measure these parameters?
Phillipe Dro: The physical principle is well-known and is called spectrometry. It is a method used to measure how much a chemical substance absorbs light that passes through it and is based on the principle that each substance absorbs or transmits light over a certain range of wavelengths. Human tissues contain different substances whose absorption spectra at near-infrared wavelengths (650–1000 nm) are well defined. A component of blood, hemoglobin, absorbs light in the near-infrared range depending on the degree of oxygen that binds to it. Moreover, in contrast to visible light, near-infrared light has the ability to be detected through as much as 80 mm of tissue.
Medgadget: Please give us an overview of the two sensors offered by Luciole Medical, and their different applications.
Phillipe Dro: The Luciole platform consists of two main clinical tools: RheoProbe, which is a minimally invasive device, is implanted in the brain matter for patients in a coma following brain haemorrage or traumatic brain injuries. The probe measures cerebral blood flow, intracranial pressure, temperature and oxygenation parameters.
The RheoPatch is an adhesive patch that is applied to the skull (frontal). The patch can be used to complement the probe but can also be used to monitor cerebral oxygenation and cerebral blood flow during events where the brain is at risk of desaturation. The primary application is during surgery (especially heavy surgery such as cardiac surgery) and for patients having a specific risk profile, such as elderly patients.
Medgadget: Can measuring these parameters help clinicians in diagnosing the source of a problem, or monitor how effective a treatment is?
Phillipe Dro: Measuring these parameters in real time can help clinicians to understand the oxygenation situation of the brain, which helps them make informed and speedy decisions on a variety of head traumas from traumatic brain injury to stroke. Our platform monitors cerebral blood flow allowing doctors to rapidly identify ischemia, which is the condition caused by insufficient blood flow to the brain. This can help doctors to design and implement the best treatment plan for patients and potentially save lives.
Medgadget: Luciole Medical just recently raised 4.7 million Euro to commercialize these sensors. When do you envisage that these products will be available commercially?
Phillipe Dro: The Rheoprobe has got marketing authorization in Europe and will be commercialized in the near future. The Rheopatch is under development, has already been tested in the clinic and is expected to be approved in late 2019.