Test & measurement Accurate and calibrated real-time recordings of


the inhalation flow profile provide the information above, from which it can be determined whether the patient carried out the inhalation correctly and achieved a high lung deposition during inhalation. Other parameters of interest include the inspired vital capacity (IVC) and peak inspired flow rate (PIF), along with the full inhalation airflow


characteristic as shown in Figure 3. Subsets of parameters such as forced inspired


volume during the first second of inhalation (FIV1) or the airway resistance (RAW) can also be determined from the inhalation airflow profile. The derivation of the latter is shown in Figure 4. Some parameters such as airway resistance (RAW) can be of special interest for patients


with chronic obstructive pulmonary diseases (COPD) as it may relate directly to the condition of the disease. As the inhaler is now being utilised as a spirometer-like device, all parameters are derived upon use of the inhaler without any additional effort or time-related burden to the patient. Besides monitoring every inhalation through the inhaler for its quality and the correct use of the inhaler, the above parameters monitored over time can additionally provide feedback on the effectiveness of the medication, the course of the disease and alert the healthcare professional or be motivational for the patient and increase adherence. Cohero Health already provides patients with


Figure 2. Schematic illustration of drug deposition when the drug is released in the optimal timing window (left side) and when the drug is released too late (right side).


an additional spirometer for exactly this reason, i.e. to allow the patients to routinely measure their lung function over the course of the treatment. The benefit of providing direct disease management and sharing this data with medical professionals helps patients and clinicians to assess treatment progress and also enables payment-by- results rather than pay-per-dose. This same development can be observed in the insulin or sleep apnea industry where it has led to growing market shares for companies offering connected devices in recent years and simultaneously brought down treatment costs and improved patient outcomes. Most importantly, this combination of drug delivery and diagnostic unit in a single device is a powerful tool in improving patient outcomes. Figure 6 shows the schematic behavior of PIF,


IVC and RAW versus time. It visualises the positive effect of starting the treatment, the stable treatment phase during regular dosage and the negative effect of interrupting the treatment. By adding the capability of measuring flow to


the drug delivery inhaler device, not only can patient compliance and correct use of the inhaler be monitored, but also the effectiveness of the medication and course of the disease over time can be observed by utilising the spirometer-like lung function recordings. Next generation inhalers - natively


Figure 3. Parameters derived from the inhalation airflow characteristic: inspired vital capacity (IVC) and peak inspired flow rate (PIF).


incorporating airflow measurements in their design - will facilitate automatic dose release at the optimal point in time, individually tailored to the patient and their specific condition.


How to Measure tHe InHalatIon Flow ProFIle


Figure 4. Besides the peak inspired airflow (PIF), the airway resistance (RAW) can be determined from calibrated inhalation airflow characteristics recorded with a sufficient high temporal and flow resolution.


Instrumentation Monthly March 2022


Before inhalers natively include electronics and connectivity features by design, existing inhalers and inhaler platforms can be enhanced with the required electronics to achieve connectivity and the required sensing functionality. This is already being done today by companies such as Propeller Health, Adherium and others that have designed a variety of clip-ons for existing inhalers to add connectivity by monitoring parameters such as date and time of usage as well as evaluating signals from additional sensors such as accelerometers, GPS and many more. In the past, accurate measurement of the flow through the inhaler was challenging due to the lack of sufficiently robust and yet sensitive devices capable of measuring the smallest flows. In order to avoid revalidation of the inhaler with the FDA and maintain approval, the


Continued on page 60... 59


Page 1  |  Page 2  |  Page 3  |  Page 4  |  Page 5  |  Page 6  |  Page 7  |  Page 8  |  Page 9  |  Page 10  |  Page 11  |  Page 12  |  Page 13  |  Page 14  |  Page 15  |  Page 16  |  Page 17  |  Page 18  |  Page 19  |  Page 20  |  Page 21  |  Page 22  |  Page 23  |  Page 24  |  Page 25  |  Page 26  |  Page 27  |  Page 28  |  Page 29  |  Page 30  |  Page 31  |  Page 32  |  Page 33  |  Page 34  |  Page 35  |  Page 36  |  Page 37  |  Page 38  |  Page 39  |  Page 40  |  Page 41  |  Page 42  |  Page 43  |  Page 44  |  Page 45  |  Page 46  |  Page 47  |  Page 48  |  Page 49  |  Page 50  |  Page 51  |  Page 52  |  Page 53  |  Page 54  |  Page 55  |  Page 56  |  Page 57  |  Page 58  |  Page 59  |  Page 60  |  Page 61  |  Page 62  |  Page 63  |  Page 64  |  Page 65  |  Page 66  |  Page 67  |  Page 68  |  Page 69  |  Page 70  |  Page 71  |  Page 72  |  Page 73  |  Page 74