Magnetic electrophrenic nerve stimulation to produce inspiration.
Magnetic electrophrenic nerve stimulation to produce inspiration.
复制标题
磁电膈神经刺激产生灵感。
DOI：
10.1007/bf02368471
复制
发表时间：
1991
影响因子：
3.8
通讯作者：
Nyenhuis,JA
中科院分区：
文献类型：
--
作者：
Mouchawar,GA;Bourland,JD;Geddes,LA;Nyenhuis,JA
In a previous paper (1) we reported hemidiaphragm stimulation which produced an inspiration in the dog using a pancake coil applied to the lower right chest. In the present paper we report bilateral phrenic nerve stimulation in the dog with a chestencircling coil which produced inspiration without cardiac stimulation. A 21 kg, barbiturate-anesthetized (30 mg/kg) dog was placed on its back inside an 18-turn, 34-cm diam., 3-cm-wide coil wound with two layers of 10-gauge copper wire. The inductance was 210 tzH and the resistance 69 milliohms. The energy source consisted of a 682/~ f capacitor bank that could be charged up to 10,000 volts. An ignitron was used as a switch to discharge the capacitor bank into the coil. The current in the coil was measured with a current probe and the time from the onset of the current to the peak current was typically 560/zsec. This duration is equal to that of the pulse of current induced in the tissue. Four locations were selected for the coil: at the level of the xiphoid process, 5, 9, and 14 cm headward to the xiphoid. Blood pressure and the ECG (manubrium xiphoid) were recorded continuously. Tracheal air flow was measured with a Fleisch pneumotachograph. The pulsed magnetic field was delivered between spontaneous breaths. The volume of air inspired due to delivery of the pulsed magnetic field (which stimulated the phrenic nerves and contracted the diaphragm), was determined by integrating the inspiratory (pneumotachogram) air-flow velocity record.With the coil at the level of the xiphoid, only expiratory movements were obtained. Figure 1 illustrates the location of the dog in the coil (lower) and a typical record of the ECG, pneumotachogram, blood pressure, and the magnetic stimulus marker. The magnetically induced breath is identified by M. Note the rapid inspiratory air flow coincident with delivery of a pulse of 5,400 amps to the coil surrounding the chest. Note also the absence of cardiac stimulation as evidenced by no alteration in the blood-pressure record. On the ECG can be seen the magnetic stimulus artifact (A).
