Heart Sounds
Devin Nickol, M.D.
1. This is a recording of a normal heart. Listen carefully to distinguish
S1 and S2. Note that the period of time between S1 and S2 (systole) is shorter
than the period of time between S2 and the next S1 (diastole). This is helpful
in distinguishing systolic from diastolic murmurs. Unfortunately, in a tachycardic
patient diastole shortens and is often more difficult to distinguish from
systole. It may help to remember that S1 is usually louder than S2. In any
case, whenever you listen to heart sounds you should first try to clearly
identify S1 and S2 in order to &get your bearings&.
2. Here the mitral and tricuspid components of S1 have become
separated enough to be distinguished as two separate sounds. The result
is a split S1. This can be difficult to distinguish from an S4 (see below).
3. In this case, the aortic and pulmonic components of S2
have become separated enough to be distinguished as two separate sounds.
This happens normally during inspiration, and in that case it is referred
to as a &physiologically split& S2. An S2 that remains split during
both inspiration and expiration is referred to as a &fixed split&
4. In addition to the &normal& components of the
cardiac cycle (S1 and S2), occasionally &extra& sounds will be
present. These are named according to their location in the cardiac cycle,
and the nature of the sound they make. An S3 is a sound occuring shortly
after S2 (makes sense....), and can be difficult to distinguish from a split
S2. In most cases, an S3 will occur later than the second component of a
split S2, which can be helpful in telling them apart. Compare this recording
to the recording of the split S2 above. Hear the difference?
5. While an S3 is located shortly after S2, an S4 occurs later
in the cardiac cycle. So much later, in fact, that it occurs shortly before
the next S1. Distinguishing an S3 from an S4 can be challenging. The rhythm
of the sounds may be helpful - since an S3 occurs close to S2, the cardiac
cycle sounds something like the word &Kentucky&, with the last
two syllables coming in rapid succession. Try saying it a few times out
loud to get the feeling. Ignore those people staring at you....they're just
in awe of your rapidly developing auscultation skills. An S4, on the other
hand, makes the cardiac cycle sound more like the word &Tennessee&,
with the first two sounds occurring close together. In a tachycardic patient
with both an S3 and S4, diastole may shorten enough to cause a &summation
gallop& - the S3 and S4 fuse to form one sound.
6. In addition to the sounds we've discussed so far, there
are several other &extra& sounds that may wind up in the cardiac
cycle for various reasons. These include clicks (often as a result of abnormalities
in valve movement), rubs (perhaps from irritation of the pericardium), and
even &plops& (such as from an atrial myxoma flopping around).
Mitral valve prolapse is a common condition which may produce systolic clicks
and/or murmurs. The first recording below demonstrates a late systolic click
with no murmur. Listen until you are convinced that the click occurs before
S2. Realize that the very first sound you hear in this recording is actually an
S2 - as mentioned above, it's always a good idea to spend several seconds just listening
to S1 and S2 until you are sure you know which is which. The second recording below
demonstrates a mid-systolic click followed by
a murmur that continues through the rest of systole. It is difficult to distinguish
the click from the beginning of the murmur.
&&&&&&&&&&
7. Many people find diastolic murmurs more difficult to hear
than systolic murmurs. This may be due to the fact that they are often low
pitched, and therefore it is important to always listen with both the diaphragm
and bell. Below is a recording of a murmur which starts immediately
following S2, continues through most of diastole, but clearly ends before
the next S1. The murmur actually obscures S2 almost completely. Remember
to identify S1 and S2 when you first begin listening.电机的S1工作制、S2工作制、S3工作制等分别是指什么意思？哪里有定义？_百度知道
电机的S1工作制、S2工作制、S3工作制等分别是指什么意思？哪里有定义？
我有更好的答案
每个周期包括一段恒定负载运行时间、包括一段停机和断能时间。此外。S2工作制指短时工作制：按周期循环运行。S3工作制指断续周期工作制。下一次启动前，电机需冷却至与冷却介质温度之差在2K以内：在恒定负载下按给定的时间运行，电机在改时间内不足以达到热稳定，随之停机断能S1工作制指连续工作制：保持在恒定负载下运行到热稳定状态，还有S4~S10工作制
采纳率：87%
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我们会通过消息、邮箱等方式尽快将举报结果通知您。intel对S1、S2、S3、S4、S5的定义？_百度知道
intel对S1、S2、S3、S4、S5的定义？
求以上定义，S5是关机，S3是休眠其他是什么？具体的带电情况是什么？
我有更好的答案
也称为STD（Suspend to Disk，挂起到硬盘）、所有应用程序和被打开的文档等等的状态都是保存在主存储器中，用户可以把工作恢复到正好上次他们保持的状态-计算机从S3状态回来时主存储器的内容和它进入S3状态时候的内容是相同象的，保护操作系统当前的状态简言之：S0，无论是G3 Mechanical Off还是G2都得运行启动程序来启动操作系统：最耗电的睡眠模式。处理器的所有寄存器被刷新，CPU和硬盘、DVD驱动器等等这些的设备可以一再的进入和从低能源状态回来，叫做C0-Cn和D0-D3。(例如膝上型计算机，当使用电池运行的时候通常关掉所有当前未使用的设备;，虽然ACPI规范仅仅提到术语&S3&和&quot；　　S2：将CPU关闭：一个比S1更深的睡眠状态，不过已经不给CPU供电了，将运行中的数据写入内存后关闭硬盘；　　S4。在这个状态下，主存储器(RAM)仍然有电源供给，但其余的硬件设备仍然运转；　　S3：通常称为STR（Suspend to RAM，挂起到内存）; G1 睡眠细分为从S1到S4这四种状态。系统从这几种状态被唤醒到G0运行（唤醒等待时间）所需的时间最短的是S1，较短的是S2和S3，不太短的是S4。S1，和Soft Off都是相同的叫法。G2和G3Mechanical Off几乎是相同的，但有些部件仍然带电，使计算机仍然可以被键盘、时钟。这种模式通常指上电待机或者简单叫做POS，特别在BIOS设置界面上；然而，通常这种模式并不被采用。S3 ：在BIOS中叫做&挂到内存& (Suspend to RAM&#47、modem（电话唤醒）；　　S5：所有硬件设备（包括电源）全部都关闭，也就是关机。　　(S0)正常工作状态，内存信息写入硬盘，然后所有部件停止工作；计算机恢复的过程比重启要快。(规范中提到了S3和S2是相当类似的，只有更多的组件在S3状态下会被关掉电源。) 相比较S4来说S3有两个好处：计算机的正常工作状态-操作系统和应用程序都在运行。CPU(s)执行指令，所有主存储器的内容被储存在非挥发性存储器，例如硬盘，包括所有应用程序,打开的文档等，除了把主存储器中的内容移进移出所消耗的时间以外.S4和其他的S状态有很大不同,事实上更类似G2Soft Off状态和G3 Mechanical Off状态,而不是S1-S3.在S4状态下的系统同样可进入G3(Mechanical Off)状态;睡眠(Sleep)&。在启动系统从G2恢复到G0正常工作模式的过程中， 在Windows Vista和Mac OS X则叫做&睡眠(Sleep)&quot。在这个状态下(即没有进入G1睡眠)，并且CPU停止执行指令；一些桌面型计算机也这么做来减少噪声，第二，如果任何正在运行的应用程序(被打开的文档等等)有私有信息在里面，这些信息是不会被写到硬盘上的。S4： 在Windows中叫休眠， 在Mac OS X中叫作安全睡眠，也称为挂到硬盘，虽然ACPI规范中只提到了一个术语S4（main article,并且保留S4时候的状态信息。)&#8226.所以它可以恢复到以前的运行状态在关掉电源之后. G2（S5）Soft Off--G2，S5。CPU和内存的电源一直维持着，一些设备如果没有被使用那么就会被停止供电，尽管它也是几乎唯一的有电源供给的原件。因为操作系统.这意味着从S4恢复后，用户可以恢复到原本的工作状态、LAN（网络唤醒）还有USB设备所唤醒。一些新式的计算机不再支持S1；老式的电脑对S1支持可能要比S3好。S2;STR)，在Windows XP以后的Windows版本和一些Linux发行版中叫做&quot；　　S1：也称为POS（Power on Suspend，CPU停止工作）。然而，在系统不能被唤醒比如遇到了电源故障的时候，高速缓冲存储器可能会被flushed来防止数据毁坏;待机(Standby)&，采用的方法和S3是一样的。S4和S3 之间的差异是，其他的硬件设备仍然正常工作,包括所有的没有保存的文档,而在S4状态下则没有影响：电脑正常工作，所有硬件设备全部处于打开或正常工作的状态:Hibernate(OS feature))。在这个状态下,在S3状态下的时候如果一旦停电了,所有主存储器上的数据就会丢失
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