scholarly journals The Effect of Periocular Negative Pressure Application on Intraocular and Retrobulbar Pressure in Human Cadaver Eyes

2021 ◽  
Author(s):  
Brian Shafer ◽  
Tanner J. Ferguson ◽  
Nathan Chu ◽  
Enrico Brambilla ◽  
Paul Yoo
Keyword(s):  
Negative Pressure ◽  
Human Cadaver ◽  
Pressure Application

Effect of posture, route of respiration, and negative pressure on palatal muscle activity in humans

1995 ◽  
Vol 79 (2) ◽  
pp. 448-454 ◽  
Author(s):  
I. L. Mortimore ◽  
R. Mathur ◽  
N. J. Douglas
Keyword(s):  
Negative Pressure ◽  
Muscle Activity ◽  
Respiratory Activity ◽  
Maximum Activity ◽  
Electromyographic Activity ◽  
Airway Narrowing ◽  
Pressure Application ◽  
Supine Posture ◽  
Inspiratory Activity ◽  
Male Subjects

Sleep apnea is worse in the supine posture and is associated with retropalatal airway narrowing or occlusion. We have, therefore, examined the effects of posture, negative pressure, and route of respiration on palatal muscle activity in 13 nonsnoring awake male subjects by using electromyography. Electromyographic activity of the levator palatini and palatoglossus was expressed as a percentage of maximum activity. Both the levator palatini (P = 0.002) and palatoglossus (P = 0.002) exhibited phasic inspiratory activity. Overall, posture did not affect the levator palatini (F = 1.58; P = 0.23) or palatoglossus (F = 0.98; P = 0.34) activity, but analysis by route of respiration showed the palatoglossus to be more active when the subjects were nose breathing supine (F = 6.64; P = 0.02). Levator palatini activity was lower when nose breathing was compared with mouth breathing in both the erect and supine postures (F = 6.67; P < 0.02). Nose breathing with the mouth held open caused an increase in palatoglossal activity (P = 0.04). Negative-pressure application (0 to -12.5 cmH2O) caused significant increases in levator palatini (P < 0.001) and palatoglossus (P < 0.001) activity, 100 ms after pressure stimulus, irrespective of route. However, the palatoglossus required significantly greater negative pressures to cause activation when applied via the nose compared with the mouth (P < 0.05). These observations indicate that the levator palatini and palatglossus have respiratory activity and are reflexly activated by negative pressure.

scholarly journals Cardiac Arrest after Connecting Negative Pressure to the Subgaleal Drain during Craniotomy Closure

2014 ◽  
Vol 2014 ◽  
pp. 1-3 ◽  
Author(s):  
Monu Yadav ◽  
Sapna A. Nikhar ◽  
Dilip Kumar Kulkarni ◽  
R. Gopinath
Keyword(s):  
Cardiac Arrest ◽  
Negative Pressure ◽  
Surgical Procedure ◽  
Vacuum System ◽  
Suction Drain ◽  
Pressure Application ◽  
Neurosurgical Patients ◽  
One Year ◽  
Pressure Suction ◽  
Subgaleal Space

A one-year-old child operated on for arachnoid cyst in right frontoparietotemporal region had sudden bradycardia followed by cardiac arrest leading to death after connecting negative pressure to the subgaleal drain during craniotomy closure. The surgical procedure was uneventful. It is a common practice to place epidural or subgaleal drains connected to a vacuum system towards the end of craniotomy to prevent accumulation of intracranial and extracranial blood. The phenomenon of bradycardia with hypotension is known to occur following negative pressure application to the epidural, epicranial, or subgaleal space after craniotomy closure. However cardiac arrest as a complication of negative pressure suction drain in neurosurgical patients is not described in the literature.

Microvascular effects of therapeutic topical negative pressure application (TNPA)

2007 ◽  
Vol 21 (5) ◽  
Author(s):  
Maxwell Langfitt ◽  
Lawrence Webb ◽  
Thomas L Smith
Keyword(s):  
Negative Pressure ◽  
Topical Negative Pressure ◽  
Pressure Application

scholarly journals Vacuum-Actuated Bending for Grasping

Robotics ◽  
2018 ◽  
Vol 7 (4) ◽  
pp. 73
Author(s):  
Jay Miller ◽  
Nathan Wicks
Keyword(s):  
Negative Pressure ◽  
Atmospheric Pressure ◽  
Ambient Pressure ◽  
Positive Pressure ◽  
Cellular Solids ◽  
Pressure Application ◽  
Bending Actuator ◽  
Robotic Devices ◽  
Good Agreement

Soft robotic devices typically are actuated with the application of a positive pressure (compared to ambient pressure), but some exciting work has been done with negative pressure application, with advantages for safety and robustness. Here, we present a negative pressure bending actuator inspired by previous work by Yang et al., fabricated using rapid prototyping techniques and elastomeric polymers. We describe the mechanical behavior of the system from a cellular solids perspective, showing the steps needed for the analysis and characterization of future similar systems. We find good agreement between experimentally measured values of displacement and force generated in atmospheric pressure conditions.

Effects of Cutaneous Negative Pressure Application on Perforator Artery Flow in Healthy Volunteers: A Preliminary Study

2018 ◽  
Vol 35 (03) ◽  
pp. 189-193 ◽  
Author(s):  
Marco Innocenti ◽  
Mariella Santini ◽  
Emanuela Dreassi ◽  
Robin Martin ◽  
Dario Melita ◽  
...  
Keyword(s):  
Negative Pressure ◽  
Color Doppler ◽  
Skin Surface ◽  
Control Group ◽  
Study Group ◽  
Pressure System ◽  
Pressure Application ◽  
Muscle Fascia ◽  
Deep Inferior Epigastric Artery ◽  
Preliminary Study

Background The creation of skin flaps based on small perforator vessels is an increasingly popular procedure nowadays; the optimization of their blood supply enhances surgical success. This study evaluates the effects on the flowmetries of 7 days' negative pressure application on the skin surface overlying the muscle fascia emergence of periumbilical perforators of the deep inferior epigastric artery (DIEA). Methods Ten volunteer participants were enrolled. In each subject, one periumbilical perforator of the DIEA was identified on each side of the abdomen using an eco-color-Doppler. One of them was used as the control group, while the other (the study group) underwent 80 mm Hg negative pressure for 7 days. The flowmetries of both perforators were measured before and after the application of negative pressure wound therapy. Results After the application of negative pressure, randomly applied on the skin surface over one of the two selected periumbilical perforators, an increase in the flowmetries was observed in both groups of perforators (2.74 cm/s; p < 0.0001). The relative flowmetry increase in the control group was 9.55% (2.735 cm/s), while in the study group it was 44.03% (8.748 cm/s). Conclusion The application of negative pressure system on the skin surface over the muscle fascia emergence of the selected periumbilical perforators showed an increase in flowmetry. Although this is a preliminary study, this simple and economical procedure before surgery could be usefully employed to increase the rate of success in microsurgical procedures.

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