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Author
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Topic: Minute to minute bllod pressure
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pal_karcsi
Member
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posted 09-16-2008 07:23 PM
  
Somebody knows how to get the systolic and diastolic blood pressure from a chart section on a LX 4000 Lafayette polygraph ?
On the caliper statistics there is only a CP mmHG data , that I think refers to the pressure when the cuff valve is close.Thanks guys, ------------------
Attila The Hun ,
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Ted Todd
Member
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posted 09-16-2008 09:32 PM
Pal,I don't know what you are asking for here. There is no polygraph instrument that records both systalic and diastolic blood pressure. Can you clarify your post? Ted IP: Logged |
pal_karcsi
Member
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posted 09-16-2008 09:51 PM
Ted ,
If I understand well, the LX 4000 doesn´t register the electrocardiogram, but the blood pressure. That´s why there is a cuff in the arm and not electrodes on the chest.
The CA channel to my knowledge is a representation of the blood pressure, so there is a systolic and diastolic stroke in the graph. From here the software gets the HR.
However there is no way to get a SBP and a DBP, even though there is a cuff in your arm at constant pressure. That would allow you to get a SBP and DBP reading.Any other input is welcome.
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J.B. McCloughan
Administrator
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posted 09-16-2008 11:23 PM
http://en.wikipedia.org/wiki/Blood_pressure The above link will give you a basic idea of how these measurements can be obtained. We are not applying any of these methods when we collect polygraph data. [This message has been edited by J.B. McCloughan (edited 09-16-2008).] IP: Logged |
skipwebb
Member
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posted 09-18-2008 07:59 AM
pal_karcsi, I think you are misunderstanding the data being collected on the polygraph by the cardio cuff. The pressurized cuff occludes or partially occludes the artery allowing us to see the rise and fall of pressure being exerted by the heart on the vessel. We can extrapolate, based upon our knowledge of the system, the rise is caused by systolic pressure and the fall to be caused by diastolic pressure but we don't derive relative blood pressure from those deductions, only the amount of relative change.Any numbers we obtain are used to graphically demonstrate change in volume and pressure at the artery but do not represent actual blood pressure. This might be a poor analogy but think of it this way. The gasoline gauge on your car probably demonstrates marks on the gauge for full, 3/4 1/2 1/4 and empty. The gauge points to one of those as a result of the float in the tank being held up or allowed to fall by the rise and fall of the gasoline in the tank. We only know what relative percentage of the gas exists in the tank but if we didn't know the size of the tank or the relationship of the tank and float to absolute level, we couldn't know the actual amount of gas in the tank. The gas gauge only allows us to graphically “see” the amount of gas in the tank. It does not tell us the actual amount of gas. Our use of the blood pressure cuff in the manner we use it only shows us graphically the change in relative pressure at the artery it can not tell us the actual pressures.
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pal_karcsi
Member
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posted 09-18-2008 09:36 AM
Thanks for the insight.
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Attila The Hun ,
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