Drawing Aids and Tools (part 1)

The Drawing Aids and Tools are like the triangles, compasses, and engineering scales of traditional drafting. AutoCAD has similar drawing aids which can help you to draw horizontal and vertical lines on a computer. Most drawing aids can be toggled on or off from the application status bar.

Summary

Things to Remember

The horizontal & vertical lines that we draw on our drawing board are very analogous in AutoCAD drawing aids, which means that the drawing techniques are similar in many respects.
Units and Limits must be set before starting the drawing.
Drawing limits are used to predetermine the size of the drawing area and it is specified before starting drawing. It is the limits where you can perform your drawing efficiently.
AutoCAD allows us to control the direction in which angular units are measured & also the position of the start angle.

MCQs

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Subjective Questions

Q1:

Write short notes on Diabetes:- Insulin.

Type: Short Difficulty: Easy

Show/Hide Answer

Answer: <h4>Diabetes Mellitus</h4>
It is a pathological state or diseases characterized by an evaluation of blood glucose level. It is caused by a relative or absolute deficiency of insulin. It may be occurring either due to:
<ol>
<li>Deficiency or absence of insulin in the body.</li>
<li>Problems related to the transportation or utilization of Insulin.</li>
</ol>
<h4>Features of Diabetes Mellitus</h4>
<table>
<tbody>
<tr>
<td width="163">
Characteristics
</td>
<td width="264">
Type I
</td>
<td width="189">
Type II
</td>
</tr>
<tr>
<td width="163">
Inset (age)
</td>
<td width="264">
Usually 30
</td>
<td width="189">
Usually 40
</td>
</tr>
<tr>
<td width="163">
Type of onset
</td>
<td width="264">
Abrupt
</td>
<td width="189">
Gradual
</td>
</tr>
<tr>
<td width="163">
Nutritional Status
</td>
<td width="264">
Often Thin
</td>
<td width="189">
Often close
</td>
</tr>
<tr>
<td width="163">
Clinical Symptoms
</td>
<td width="264">
Polydipsia, polyuria, polyphagis
</td>
<td width="189">
Often asymptomatic
</td>
</tr>
<tr>
<td width="163">
Ketosis
</td>
<td width="264">
Present
</td>
<td width="189">
Usually absence
</td>
</tr>
<tr>
<td width="163">
Endogenous insulin
</td>
<td width="264">
Absent
</td>
<td width="189">
Variable
</td>
</tr>
<tr>
<td width="163">
Insulin therapy
</td>
<td width="264">
Required
</td>
<td width="189">
Sometimes
</td>
</tr>
<tr>
<td width="163">
Oral hypoglycemic
</td>
<td width="264">
Usually not effective
</td>
<td width="189">
Often effective
</td>
</tr>
<tr>
<td width="163">
Diet
</td>
<td width="264">
Mandatory with insulin
</td>
<td width="189">
Mandatory with or without drugs
</td>
</tr>
</tbody>
</table>
 
<h4>Insulin</h4>
Insulin is peptide hormone produced by beta cells of the pancreas and is central to regulating carbohydrate and fat metabolism in the body. It causes the cells in the liver, skeletal muscle and fat tissue to absorb glucose from the blood. The Diabetes state is characterized by marked differences in all phases of carbohydrate, fat and protein metabolism.
Types
Insulin that is given from exogenous source as a drug can be divided into following categories.
<ul>
<li>Short-acting insulin:This type of insulin is called as soluble insulin. Its duration of action ranges from 6-8 hours. E.g. crystalline zinc insulin and semi Lente insulin.</li>
<li>Insulin injection ( soluble)</li>
</ul>
This is a clear solution of insulin with short duration of actions. It is the only form of insulin that diabetes ketoacidosis and at the time of surgery. In maintenance regimen, it is usually given 15 to 30 minutes before meals. Human insulin many acts faster but have a shorter duration. It is prepared in the injection form. Injection (40units/ml, 80units/ml, 100units/ml in 10ml vial)
 
<ul>
<li>Intermediate insulin: The duration of action of this type of insulin ranges from11-16 hrs. Examples include neutral protamine Hagedorn insulin, insulin zinc lente etc.</li>
<li>Isophane insulin</li>
</ul>
This is neutral insulin of intermediated action. Its duration of action is less than protamine zinc insulin.it will not give control of diabetes throughout the 24 hours by itself but it is of value when to combine with soluble insulin.
<ul>
<li>Insulin zinc suspension</li>
</ul>
The amorphous form has a relatively quick action and the crystalline form has a slow action. When these two preparation are mixed in different proportion, a wide range of action can be obtained.
<ul>
<li>Long-acting insulin: This insulin has got the long duration of action. Its duration is 24 hours. E.g. protamine zinc insulin etc.</li>
<li>Protamine zinc insulin (ultralente)</li>
</ul>
This is a long-acting form of insulin. It was designed as to produce a “one shot a day” form to treatment. However, the delay in the commencement of its action and the prolongation of its action to more than 30 hours make it unsuitable for this.
Mechanism of Action
Insulin stimulates carbohydrates metabolism in skeletal and cardiac muscles and adipose tissue by facilitating transport of glucose into these cells. Nerve cells, erythrocytes, and cells of the intestine, liver and kidney tubules do not require insulin also has a direct effect on fat and protein metabolism. The hormone stimulates lipogenesis and protein synthesis. Insulin also promotes an intracellular shift of potassium and magnesium and thereby temporary decreased blood concentration of these ions. insulin prepared is mainly three types:
<ol>
<li>Short duration with relatively rapid action; e.g. regular insulin, semilente insulin.</li>
<li>Intermediate duration of action; e.g. isophane insulin injection and insulin zinc suspension.</li>
<li>Those which actions are slow onset and last for a long period; e.g. protamine zinc insulin and insulin zinc suspension.</li>
</ol>
Indications
<ul>
<li>Insulin is the mainstay of the treatment of type-I diabetes mellitus. It can also-also used in treated in severe cases type-II diabetes.</li>
<li>Type-I diabetes: a body is unable to produce insulin. It has to be given from the exogenous source. Insulin obtained from different sources is available.</li>
<li>As insulin is of protein in nature. It cannot be given by oral route and has to be given in an injectable form either by intravenous or subcutaneous route.</li>
</ul>
Preparation
It is available in form of injections;
<table width="826">
<tbody>
<tr>
<td width="129">
Type
</td>
<td width="106">
Appearance
</td>
<td width="112">
Sources
</td>
<td width="149">
Can be mixed with
</td>
<td width="66">
Onset (hr)
</td>
<td width="81">
Peak(hr)
</td>
<td width="183">
Duration (hr)
</td>
</tr>
<tr>
<td width="129">
Rapid acting
Soluble regular insulin
</td>
<td width="106">
 
Clear
</td>
<td width="112">
 
Human, beef, pork
</td>
<td width="149">
 
All preparations
</td>
<td width="66">
 
0.5-1
</td>
<td width="81">
 
2-4
</td>
<td width="183">
 
6-8
</td>
</tr>
<tr>
<td width="129">
Insulin zinc suspension
</td>
<td width="106">
Cloudy
</td>
<td width="112">
Beef, pork
</td>
<td width="149">
Regular, lente preparations
</td>
<td width="66">
1
</td>
<td width="81">
3-6
</td>
<td width="183">
12-16
</td>
</tr>
<tr>
<td width="129">
Intermediated action
Isophane insulin
</td>
<td width="106">
 
 
Cloudy
</td>
<td width="112">
 
 
Human, beef, pork
</td>
<td width="149">
 
 
Regular
</td>
<td width="66">
 
 
1-2
</td>
<td width="81">
 
 
8-12
</td>
<td width="183">
 
 
18-24
</td>
</tr>
<tr>
<td width="129">
Insulin zinc suspension
</td>
<td width="106">
Cloudy
</td>
<td width="112">
Human, beef, pork
</td>
<td width="149">
Regular, semilente
</td>
<td width="66">
1-2
</td>
<td width="81">
8-12
</td>
<td width="183">
18-24
</td>
</tr>
<tr>
<td width="129">
Long acting
Protamine zinc insulin
</td>
<td width="106">
 
Cloudy
</td>
<td width="112">
 
Beef, pork
</td>
<td width="149">
 
Regular, semilente
</td>
<td width="66">
 
4-6
</td>
<td width="81">
 
8-16
</td>
<td width="183">
 
24-36
</td>
</tr>
<tr>
<td width="129">
Insulin zinc suspension
</td>
<td width="106">
Cloudy
</td>
<td width="112">
Beef
</td>
<td width="149">
Regular
</td>
<td width="66">
4-6
</td>
<td width="81">
8-16
</td>
<td width="183">
24-36
</td>
</tr>
</tbody>
</table>
 
Doses
<ol>
<li>The dose is variable depending on the condition and blood glucose level of the patient. IDDM( insulin depending diabetes mellitus) patients normally require. 0.4-0.8IU/Kg/day</li>
<li>Insulin requirement should be increased if you are taking the medication as contraceptives, corticosteroid, or thyroid replacement therapy whereas insulin requirement may be reduced if you are taking salicylates, sulpha antibiotics</li>
</ol>
Contraindication
<ul>
<li>Severe allergic reaction</li>
<li>Hypoglycemia</li>
</ul>
Adverse effect
<ul>
<li>Hypoglycemia and insulin shock</li>
<li>Urticaria, skin rashes</li>
<li>Infection at site of injection</li>
<li>Insulin allergy</li>
<li>Obesity</li>
</ul>
Nursing consideration
<ul>
<li>Insulin should be stored at a cold temperature of 2-8degree Celsius. The cold chain should be maintained.</li>
<li>Read labels carefully as there are different types of insulin.</li>
<li>Give required dose 15-30 minutes before meals.</li>
<li>The vial should not be used if it looks different from normal appearances.</li>
<li>Insulin must be measured in insulin syringe with 40 units/ml. it cannot be estimated in ordinary syringes.</li>
<li>Encourage patient to take foods at an exact time to prevent hypoglycemic reactions.</li>
<li>After insulin injections, the site should not be massaged, only press at the injection site.</li>
<li>If possible use disposable syringes to prevent contamination.</li>
<li>Instruct patients to have an identification card.</li>
<li>Teach patient about the proper use of injection technique. Inform patient to rotate the site of injection. Similarly, inform the patient to use a sterile needle only.</li>
<li>Remains caution that some patients may develop insulin resistance and require high doses to control the symptoms of a disease.</li>
</ul>

Videos

Diabetes Patient Education Types of insulin

Drawing Aids and Tools (part 1)

4. Drawing Aids and Tools

AutoCAD drawing is just like drawing on a drawing board. Most of the beginners to CAD think that they should learn how to draw the drawing objects all over again. Actually, almost all of the drawing aids that AutoCAD provides are similar to the traditional drafting. The horizontal & vertical lines that we draw on our drawing board are very analogous in AutoCAD drawing aids, which means that the drawing techniques are similar in many respects. So, if you get stuck while drawing, then just think about the way you would do the same task on a drawing board & then, seek for the same way to do it with AutoCAD.

4.1 Setting up Units and Limits

Intro:

Among the most essential concepts for newcomers to AutoCAD, drawing scale & drawing units are also included. Unless you are familiar with the units, scale & the commands to control them, then you can't create sensible drawings with AutoCAD. Here, we discuss about these concepts, starting with the most commonly asked questions in this part.

At what scale should I start the drawings?

- As a simple rule, everything that you draw with AutoCAD will be drawn in full size. This is quite a surprise to those who are newbie to AutoCAD & have spent a couple of years working on a drawing board. Actually, when you start your drawing, you don't have to think about scaling as you do in drawing board. When you are drawing on a paper, then you often need to decide the scale like 1:15 or 1:100 depending upon the size of the drawing object so that the drawing will be OK on the drawing sheet. But there is no need to think about a drawing scale in AutoCAD until it comes to print the drawing. So, simply you can make drawings at a scale of 1:1, as the scaling of drawing takes place at the stage of printing.

Am I drawing in meters or millimeters?

- Generally, people use decimal drawing units while drawing in AutoCAD. You need to make decision what units you will be taking before you start the drawing. There are different drawing units like cm, m, km, furlong, mile and so on. It's entirely up to you which one to choose. However, almost in every places people use either meters or millimeters. Now which of these 2 units you would choose to create your drawing. It depends upon the type of drawing your are creating. In other words, it depends upon the work field you choose. For instance, Architects will almost always use the unit mm. (millimeters). On the other hand, Landscape Architects & Civil Engineers usually use the unit m. (meters).

In order to change the unit type, you need to use the 'Drawing Units' dialog box.

Units:

Before starting drawing, you should set up the drawing units. For stating the AutoCAD command UNITS:

Type UNITS (in the command line)

Command: Units

Hit ENTER (A dialog box appears)

Now, you can select appreciable units of measurement (length, angle, precision and so on) for the objects that you are drawing.

As you can see the dialog box is divided into 4 main sections. The upper 2 are 'Length', which refers to linear units & 'Angles', refers to angular units. You can set up the linear units & angular units independently. And, in each one of them you can control the type & precision. Whereas, the Angle section also allows you to provide the direction in which angles are to be measured.

Moreover, the third section includes the Insertion scale/ Drawing units. It allows you to give a specific unit to the drawing you are going to do. And the last section is Sample Output, which gives you a preview of the drawing units. Simply they will be displayed using the recent settings.

Angular Units:

You can see in the dialog box again that there are also 5 types of angular units. Decimal degrees is the default option, but there are other options as well. The table below shows the different types of unit with its description.

Type of Unit	Description
Decimal Degrees	Metric units
Deg/Min/Sec	Degrees, Minutes & Seconds
Grads	400 grads= 360 degrees
Radians	2 Pi radians= 360 degrees
Surveyor	Compass bearings

AutoCAD allows us to control the direction in which angular units are measured & also the position of the start angle. The 0 angle at the 3 o'clock position (i.e. East) with angles increasing in a counter-clockwise direction is the default value. This default value is suitable in many condition but there are also certain situations where it is suitable to have the 0 angle at the North position and the angles increasing in clockwise direction.

In order to alter the start angle, click on the 'Direction' button on the 'Drawing Units' dialog box. Then, a Direction Control dialog box will appear. You can specify the base angle by clicking on the appropriate radio button or, you can also set it to a certain angle of your choice with the 'other' option.

Unit precision:

You can set up the precision of linear & angular units using the Drawing Units dialog box. AutoCAD sets the precision of linear unit to 4 places of decimal (default value), so it appears in the form 0.0000. The precision of Angular Unit is set to the whole degrees only.

Generally, the default setting of 4 decimal places is suitable for linear units. However, it is often necessary to alter the angular units precision. Even so, you don't need to alter the default setting of either of the units unless there is a specific reason for doing it.

If you think that changing the unit precision makes your drawing more accurate, then you are wrong. It just means that the coordinate display on the status bar & results from the different inquiry commands will be displayed with a greater degree of precision.

Limits:

Drawing limits are used to predetermine the size of the drawing area and it is specified before starting drawing. It is the limits where you can perform your drawing efficiently. Actually, it represents the coordinates of the lower left and the upper right corners of a rectangle in terms of x & y coordinates.

In order to set the drawing limits, you can follow the following procedure,

Type LIMITS (in the command line)

Command: LIMITS

Press ENTER ( to set the default coordinates i.e. (0,0) or, if you want to put other coordinates then you can specify it as x,y

Specify lower left corner or [ON/OFF] <0.0000,0.0000>: (Enter)

Type the upper right coordinate limits as x, y

Specify upper right corner <12.0000,9.0000>: x, y (say: 300, 300)

Press ENTER

You may not see the entire drawing limits on your graphics screen even so after setting it. So, for this

Type ZOOM at the command prompt

Command: ZOOM or Z

Type ALL to see the entire drawing area
Press ENTER

A sample of limited drawing area is shown below with the Grid mode made ON. If the Grid mode is off then you cannot see the limits that you have entered, so you need to activate the Grid mode ON.

Lesson

4. Drawing Aids and Tools

Subject

Mechanical Engineering

Grade

Engineering

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