Simulation models in respiratory research are increasingly used for medical product development and testing, especially because in-vivo models are coupled with a high degree of complexity and ethical concerns. This work introduces a respiratory simulation system, which is bridging the gap between the complex, real anatomical environment and the safe, cost-effective simulation methods. The presented electro-mechanical lung simulator, xPULM, combines in-silico, ex-vivo and mechanical respiratory approaches by realistically replicating an actively breathing human lung. The reproducibility of sinusoidal breathing simulations with xPULM was verified for selected breathing frequencies (10–18 bpm) and tidal volumes (400–600 ml) physiologically occurring during human breathing at rest. Human lung anatomy was modelled using latex bags and primed porcine lungs. High reproducibility of flow and pressure characteristics was shown by evaluating breathing cycles (n_Total = 3273) with highest standard deviation |3σ| for both, simplified lung equivalents ( $${{\boldsymbol{\mu }}}_{\dot{{\bf{V}}}}$$µV̇ = 23.98 ± 1.04 l/min, μ_P = −0.78 ± 0.63 hPa) and primed porcine lungs ( $${{\boldsymbol{\mu }}}_{\dot{{\bf{V}}}}$$µV̇ = 18.87 ± 2.49 l/min, μ_P = −21.13 ± 1.47 hPa). The adaptability of the breathing simulation parameters, coupled with the use of porcine lungs salvaged from a slaughterhouse process, represents an advancement towards anatomically and physiologically realistic modelling of human respiration.

The majority of stroke patients experience deficits in motoric functions, especially in gait and mobility. They need rehabilitation to regain walking independence, which is a major goal of rehabilitation after stroke. To document and assess the rehabilitation progress, instrumented motion analysis and clinical assessments are commonly used. In a clinical pilot study the applicability of an instrumented insole system in stroke rehabilitation is evaluated. Motion parameter of 35 stroke patients were gathered with the system while completing 90 s level walking and Timed Up & Go test at the beginning and end of four weeks inpatient rehabilitation. For level walking the motion parameter were gathered with the clinical reference system simultaneously. The mean stride time for level walking decreased from 1.20 s to 1.16 s (clinical system), or from 1.19 s to 1.12 s (insole system), respectively. Focusing on individual comparison of each patient's progress, 9 gait parameters are extracted for level walking, 6 sub-phases of Timed Up & Go test are detected and analyzed, as well as progress of Center of Pressure in the sub-phases is examined. Although the overall data show wide distribution, the system proofed to be applicable in clinical stroke rehabilitation routine. As the system is location-independent, and has the advantage of assessing additional parameters of the Timed Up & Go test, it is additionally suitable for integration in a tele-or home rehabilitation system.

Dry powder inhalers are used by a large number of patients worldwide to treat respiratory diseases. The objective of this work is to experimentally investigate changes in aerosol particle diameter and particle number concentration of pharmaceutical aerosols generated by four dry powder inhalers under realistic inhalation and exhalation conditions. To simulate patients undergoing inhalation therapy, the active respiratory system model (xPULM™) was used. A mechanical upper airway model was developed, manufactured, and introduced as a part of the xPULM™ to represent the human upper respiratory tract with high fidelity. Integration of optical aerosol spectrometry technique into the setup allowed for evaluation of pharmaceutical aerosols. The results show that there is a significant difference (p < 0.05) in mean particle diameter between inhaled and exhaled particles with the majority of the particles depositing in the lung, while particles with the size of (>0.5 μm) are least influenced by deposition mechanisms. The fraction of exhaled particles ranges from 2.13% (HandiHaler^®) over 2.94% (BreezHaler^®), and 6.22% (Turbohaler^®) to 10.24% (Ellipta^®). These values are comparable to previously published studies. Furthermore, the mechanical upper airway model increases the resistance of the overall system and acts as a filter for larger particles (>3 μm). In conclusion, the xPULM™ active respiratory system model is a viable option for studying interactions of pharmaceutical aerosols and the respiratory tract regarding applicable deposition mechanisms. The model strives to support the reduction of animal experimentation in aerosol research and provides an alternative to experiments with human subjects.