| 1. |
- Pigot, Henry, et al.
(författare)
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A novel nonlinear afterload for ex vivo heart evaluation: Porcine experimental results
- 2022
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Ingår i: Artificial Organs. - : Wiley. - 0160-564X .- 1525-1594. ; 46:9, s. 1794-1803
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Tidskriftsartikel (refereegranskat)abstract
- Background: Existing working heart models for ex vivo functional evaluation of donor hearts often use cardiac afterloads made up of discrete resistive and compliant elements. This approach limits the practicality of independently controlling systolic and diastolic aortic pressure to safely test the heart under multiple loading conditions. We present and investigate a novel afterload concept designed to enable such control. Methods: Six ∼70 kg pig hearts were evaluated in vivo, then ex vivo in left-ventricular working mode using the presented afterload. Both in vivo and ex vivo, the hearts were evaluated at two exertion levels: at rest and following a 20 μg adrenaline bolus, while measuring aortic pressure and flow, left ventricular pressure and volume, and left atrial pressure. Results: The afterload gave aortic pressure waveforms that matched the general shape of the in vivo measurements. A wide range of physiological systolic pressures (93 to 160 mm Hg) and diastolic pressures (73 to 113 mm Hg) were generated by the afterload. Conclusions: With the presented afterload concept, multiple physiological loading conditions could be tested ex vivo, and compared with the corresponding in vivo data. An additional control loop from the set pressure limits to the measured systolic and diastolic aortic pressure is proposed to address discrepancies observed between the set limits and the measured pressures.
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| 2. |
- Pigot, Henry
(författare)
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A Self-Sustaining Model for Peer-to-Peer Engineering Education Among Children in Low Resource Environments
- 2018
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Ingår i: 10:e Pedagogiska Inspirationskonferensen 2018. - 2003-3761 .- 2003-377X. ; 10
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Engineering education among children has the potential to spark their interest in technical subjects, overcome gender imbalances within the field, and empower young people with the tools to make positive changes in their communities. However, it can be difficult to integrate into existing school curricula, especially when resources are constrained.Here I present a one-year case study conducted in Nepal where I formed a student-led electronics and programming club for children aged 10-16. The club model uses hands-on peer-to-peer teaching and open-source activity documentation. This approach allows the club to sustain itself and scale up without the need for ongoing teacher involvement. The documented club activities are low-cost, further lowering barriers for implementation. In total, over 100 hours of activities were conducted. Today, the students independently run 3 hours of activities each week, teaching their peers basic programming, electronics, and engineering design concepts.This model for student-driven hands-on learning could also be used in higher education to increase student motivation and interest in course material. As student led initiatives, the activities would require minimal guidance from teaching staff after setup, while effectively complimenting typical lecture/lab course structures.
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| 3. |
- Pigot, Henry, et al.
(författare)
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Ventilator for Improved Cardiopulmonary Resuscitation
- 2018
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Konferensbidrag (refereegranskat)abstract
- Sudden cardiac arrest is the second most common cause of death in Sweden, following tumors. Annually, 10 000 people are subject to sudden cardiac arrest outside of hospital in the country.Following sudden cardiac arrest, blood circulation in the body ceases, and the brain is subject to irreversible damage within minutes. The treatment consists mainly of mechanical chest compressions to circulate blood, combined with artificial gas exchange in the lungs to ventilate carbon dioxide and deliver oxygen.It is possible to achieve improved circulation and increased coronary perfusion pressure when the gas flow to the patient's lungs is automatically controlled using the phase of the chest compression cycle. We have developed this idea into a mobile ventilator prototype, specifically intended to be used in cardiopulmonary resuscitation.In this talk, we show how our phase-controlled ventilator compares to continuous insufflation of oxygen when combined with chest compressions to treat sudden cardiac arrest in healthy pigs.The main result is a statistically significant improvement in coronary perfusion pressure, facilitating increased coronary perfusion, which is known to be correlated with the return of spontaneous circulation upon defibrillation and ultimately patient survival.
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| 4. |
- Soltesz, Kristian, et al.
(författare)
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Phase-controlled intermittent intratracheal insufflation of oxygen during chest compression-active decompression mCPR improves coronary perfusion pressure over continuous insufflation
- 2019
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Ingår i: Resuscitation. - : Elsevier BV. - 1873-1570 .- 0300-9572. ; 138, s. 215-221
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Tidskriftsartikel (refereegranskat)abstract
- Purpose: It has previously been shown that continuous intratracheal insufflation of oxygen (CIO) is superior to intermittent positive pressure ventilation (IPPV) regarding gas exchange and haemodynamics. The purpose of this study was to investigate gas exchanged and haemodynamics with a new technique of phase-controlled intermittent insufflation of oxygen (PIIO) compared to CIO. Method: Twenty (20) pigs were used, stratified into two groups (CIO, PIIO), with 10 animals each. Upon induction of ventricular fibrillation, standard ventilator support was replaced by either of CIO or PIIO ventilation. Chest compressions were delivered by the LUCAS I mCPR device. Following 20 min of CPR in normothermia, defibrillation was attempted. Results: Return of spontaneous circulation (ROSC) occurrence was not significantly higher (P<0.16) in the PIIO (9/10) than in the CIO (6/10) group. During the decompression phase the PIIO group showed significant increases in mean (P<0.01), maximal (P<0.02) and end-decompression (P<0.01) coronary perfusion pressure (CPP), compared to the CIO group. PIIO resulted in increased compression phase aortic pressure (P<0.03). Intratracheal pressure was 5–30 cmH2O within both groups during mCPR, with a significantly lower (P<0.02) mean for the PIIO group. Arterial and venous blood gas analysis showed comparable results between the groups, when taking base line values into account. An exception was that PIIO resulted in significantly higher (P<0.05) oxygen partial pressure during mCPR, and lower (P<0.05) arterial lactate following ROSC. Conclusion: PIIO results in significantly higher CPP and compression phase aortic pressure during mCPR in a porcine population. Further studies are needed to validate these findings in humans.
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