Diaphragm (optics) photographic lens is called an iris diaphragm. In the early years of photography, a lens could be fitted with one of a set of interchangeable diaphragms , often as brass strips known as Waterhouse stops or Waterhouse diaphragms. The iris diaphragm in most modern still and video cameras is adjusted by movable blades, simulating the iris of the eye. The diaphragm has two to twenty blades (with most lenses today featuring between five and ten blades), depending on price and quality of the device in which it is used. Straight blades result in polygon shape of the diaphragm opening, while
Diaphragm pacing Diaphragm pacing Diaphragm pacing, (and even earlier as electrophrenic respiration), is the rhythmic application of electrical impulses to the diaphragm to provide ventilatory support for respiratory failure or sleep apnea. Historically, this has been accomplished through the electrical stimulation of a phrenic nerve by an implanted receiver/electrode, though today an alternative option of attaching percutaneous wires to the diaphragm exists. The idea of stimulating the diaphragm through the phrenic nerve was first firmly postulated by German physician Christoph Wilhelm Hufeland, who in 1783 proposed that such a technique could be applied as a treatment for asphyxia. French neurologist Duchenne de