Technology

RESPINOR has developed a break-through medical technology that uses ultrasound to measure liver excursion as a proxy for diaphragm excursion. With RESPINOR DXT (Diaphragm Excursion Technology) we aim at improving clinical decision-making in critically ill patients, with non-invasive technology, measuring the diaphragm movement and providing real-time continuous feedback with an easy to use technology that is operator independent.

The novelty of RESPINOR DXT lies in the usage of a small ultrasound transducer in a highly specialized sensor design that is attached to the skin surface using a patented, disposable, silicone tape solution. RESPINOR DXT is a non-invasive medical device for continuous diaphragm monitoring. The technology has a broad range of potential benefits and represents an enabling technology platform for applications in critical care and other areas of respiratory medicine. RESPINOR DXT will offer accurate and continuous monitoring of diaphragm movement over time in a user-friendly and operator-independent manner to enable correct timing for extubation. It will provide the end-user detailed information on the diaphragm activity, including registration of trends and progression. RESPINOR DXT will improve clinical decision making and the ability to assess patients weaning readiness from MV.

 

Respinor animated sensor with monitor

Medical need

Mechanical ventilation (MV) is one of the most common therapies in the intensive care unit (ICU), and it is a treatment that patients only receive in the most life-critical situations. Every extra day a patient is on MV, the risk of permanent impairment to the breathing ability increases along with treatment costs. Therefore, it is highly important to bring patients off MV and back to spontaneous breathing as quickly as possible. There is currently a lack of accurate and cost-effective solutions to support this process – and the introduction of new technologies is highly warranted. Respiratory problems and respiratory failure after extubation can often be directly linked with diaphragm dysfunction. However, monitoring of the diaphragm is not routinely performed, meaning that diaphragm dysfunction is often under-recognized. The introduction of RESPINOR DXT can represent a paradigm shift.

Patients are put on MV because they are unable to sustain breathing on their own in such a way as to maintain sufficient gas exchange, see Figure 1:Patient on invasive MV in the intensive care unit. MV is a critical, life-sustaining treatment; however, it is also associated with several risks including diaphragm muscle atrophy (shrinkage due to underuse), and muscle fiber damage caused by unloading of the diaphragm as the ventilator assumes control of respiration. Diaphragm impairment has been documented to affect patients as soon as 3-4 days of commencing MV. The diaphragm contributes to 70-75% of the Tidal Volume (VT), and consequently, to avoid extensive damage to the main breathing muscle, the intensive care clinician must balance the need for MV to maintain adequate gas exchange with getting patients off the ventilator as early as possible.

The process of withdrawing ventilatory support for patients is known as weaning and is based on daily observations of clinical parameters to determine whether the underlying cause of respiratory failure has been resolved. When the intensive care clinician has evaluated that the acute phase of the disease has been resolved, a spontaneous breathing trial (SBT) is conducted. The SBT assesses the patient’s ability to breathe while receiving minimal or no ventilator support and typically lasts for 30 minutes. During the SBT, the clinician evaluates various clinical parameters to help predict if the patient can be extubated successfully. For example, the rapid shallow breathing index (RSBI) is the most widely used clinical criterium to predict successful weaning and is the ratio of respiratory rate (RR) to VT. Patients on MV who are not ready to tolerate spontaneous breathing tend to breathe rapidly and shallowly and will, therefore, have a high RSBI. However, the literature presents varying degrees of sensitivity and specificity, questioning the predictive value of the RSBI.

Evaluating parameters such as RR, VT, and blood saturation allow the intensive care clinician to assess the stability of the cardiovascular and metabolic systems, as well as adequate oxygenation and pulmonary function. However, there is no consensus on the criteria for these parameters during the SBT, and the rate of reintubation has been as high as 30% in some studies. The high proportion may be due to undiagnosed diaphragm dysfunction, as the standard of care in weaning does not include direct monitoring of the diaphragm, and monitoring of VT does not uncover diaphragm dysfunction alone. The accessory respiratory muscles can increase their contribution to compensate for any deficiency of the diaphragm during the vast period of the SBT. However, as they do not have the same endurance as the diaphragm, delayed weaning failure and reintubation may occur in patients who have unidentified diaphragm dysfunction but pass an SBT. The risks associated with reintubation are severe, and include increased cardiac and respiratory complications, prolonged length of ICU and hospital stay, prolonged MV support, increased mortality, and higher costs. Direct monitoring of the diaphragm during the weaning process has the potential to optimize extubation timing and thus reduce reintubation rate, improving patient care and outcome, and reducing overall healthcare costs. However, the methods available are invasive and/or require specialist, trained operators. This may change with the introduction of RESPINOR DXT.

Progress

Technical

60%
  • Technical development of RESPINOR DXT prototype completed.
  • Development of first commercial version of RESPINOR DXT in process.

Clinical

50%
  • Verification testing in 30 healthy volunteers, completed and presented at the ERS Congress in Milan 2017.
  • 3 observational studies in critical care patients approved and enrolment ongoing, finalized within 2019.

CE mark

40%
  • RESPINOR has a certified QA system according to ISO 13485:2016.

"I was impressed by your device and your signal. I believe there is a lot to do with your system, to monitor the diaphragm in ICU patients, but also way beyond this application."

Key opinion leader 1