医疗器械概论(双语)复习题and答案

填空：

1.The conduction system of the heart consists of the sinoatrial (SA) node,bundle of His,

,atrioventricular(A V)node,the bundle branches and Purkinje fibers.

2.There are two basic forms of piezoresistive strain gauge：bonded and unbonded．

3.The respiratory system includes the mouth；nose；trachea/windpipe；bronchii；

and lungs.

4.The GI(Gastrointestinal)system takes in raw materials in the form of food and

liquids and processes them so that they are absorbed into the body．

5.The nervous system is essential to the functioning of the human organism, which

has been compared to a computer with an electrical communications system．

6.The spinal cord is a complex cable of nerves that connects the brain to most of the

rest of the body.

7.Whereas the CNS is an electrical communications and control system within the

body, the endocrine system is a chemical communications／control system and aids in the regulation of internal body states.

8.Endocrine glands produce hormones, chemical substances released into the

bloodstream to guide such processes as metabolism, growth, and sexual development.

9.Deoxygenated blood enters the right side of the heart at the right atrium．It is then

pumped into the right ventricle and out of the heart to the lungs.

10.Blood is carried away from the heart in arteries and is brought back to the heart in

veins.

11.The upper chambers of the heart are inputs to the pumps and are called atria．The

lower chambers of the heart are called ventricles and are the pump outputs．

12.Blood from the head and arms，as well as the rest of the upper portion of the body,

returns to the heart through the superior vena cava；blood from the lower portion of the body returns through the inferior vena cava.

13.Blood leaves the right atrium through the tricuspid valve to enter the right

ventricle.

14.Blood passes through the mitral valve to the left ventricle, and then back into the

mainstream of the circulatory system via the aortic valve．

15.The coronary arteries supply blood to the heart muscle.

16.The heart is a muscle that is encased in a sac called the pericardium.

17.There are four valves within your heart. They are the mitral, tricuspid, aortic, and

pulmonic valves.

18.The ventricular contraction is known as systole.

19.The ventricular relaxation is known as diastole.

20.The muscle cells of the ventricles are actually excited by the Purkinje fibers. They

are arranged in two bundles, one branch to the left and one to the right.

21.In ventricular fibrillation the major features of the ECG disappear and the

waveform takes on a low amplitude, “jittery” appearance, indicating th at the ventricles are not contracting but only quivering.

22.The delay line in the heart’s electroconduction system is calle d A V node, and the

delay is about 110 ms.

23.Bionelectrodes are a class of sensors that transducer ionic conduction to electronic

conduction so that the signal can be processed in electronic circuits.

24.The microelectrode is an ultrafine device that is used to measure biopotentials at

the cellular level．

25.A strain gauge is a resistive element that produces a change in its resistance

proportional to all applied mechanical strain．

26.Three types of common temperature transducers are thermocouples, thermistors,

and solid-state PN junctions.

27.A thermistoris is a type of resistor with resistance varying according to its

temperature.

28.The colorimeter is a filter photometer that measures the color concentration of a

substance in solution.

29.The flame photometer measures the color intensity of a flame that is supported by

oxygen and a specific substance.

30.The most common cause of movement artifact in ECG recording is electrocde

slippage.

31.The resistance of a strain gauge varies directly as the length and inversely as the

square of the cross-sectional area..

32.The ability to maintain a constant internal environment in the body is called

homeostasis

33.The semipermeable membrane selectively permits materials to pass between the

inside of a cell and its external environment．

34.The three types of muscle cell in the body are cardiac, smooth, and skeletal.

35.The skeletal system consists mostly of bones and some cartilage．

36.The longest and heaviest bone in the body is the femur and the smallest is the

stapes bone in the middle ear.

37.Transducer is a device that will convert some form of energy produced by a

physical stimulus to an another of the stimulus.

38.Transduction is the process of converting the transducible property into an

electrical signal that can be input to an instrument．

39.A passive sensor either provides its own energy or derives its energy from the

phenomenon being measured.

40.Sensor errors include five basic categories:insertion, application, characteristic,

dynamic and environmental errors.

41.Error inherent is the difference between the ideal published characteristic transfer

function of the device and the actual characteristic.

42.Bioelectrodes are a class of sensors that transducer ionic conduction to electronic

conduction so that the signal can be processed in electronic circuits.

43.Most such bioelectrical signals are acquired from one of three forms of electrode:

surface microelectrodes, indwelling microelectrodes, microelectrodes.

44.The electrode half-cell potential becomes a serious problem in bioelectric signals

acquisition because of the tremendous difference between the these dc potentials and the biopotentials．

45.The paste-on column electrode is used for longer-term recording or

monitoring-such as continuous monitoring of a hospitalized patient in CCU&ICU.

46.Transducers differ from electrodes in that they use intervening transducible

element to make the measurement, while electrodes directly acquire the signal.

47.Thermistor relies on the change of electrical resistance of some materials

undergoing temperature changes to measure temperature.

48.There are two capacitors in the capsule of Quartz pressure sensors：a pressure

capacitor and a reference capacitor．

49.The capacitance of a parallel plate capacitor varies directly with the plate area and

inversely with the separation between the plates.

50.A thermocouple consists of two dissimilar conductors or semiconductors joined

together at one end.

51.The photoelectric flame photometer is a device for routine determinations the

concentration of Sodium (Na) and Potassium (K) by measurement the color intensity of a flame.

52.The angle of the diffraction grating determines light wavelength if all other

parameters are fixed for spectrophotometer.

53.The autonomic nervous system operates mostly at the subconscious level.

54.The sensory nervous system provides information on the external and internal

environments.

55.The endocrine system is a chemical communications and control system within

the body.

56.The nervous system gathers，assimilates，and integrates data from the outside

world，information on the state of internal organs.

57.The upper and lower chambers of the heart are called atria and ventricles

respectively.

58.The superior and inferior vena cava return blood to the right atrium.

59.The Tricuspid valve is located between the right atrium and the right ventricle.

60.The ventricles are the heart chambers that are subject to the highest pressures.

61.Atrial fibrillation is an arrhythmia in which the upper chambers of the heart quiver

rather than beat.

62.An electrical potential is generated across a cell wall because of a difference in

charge gradient.

63.The SA node is the heart’s pacemaker.

64.Heart block occurs when the internal electro-conduction system of the heart is

interrupted or significantly impeded.

65.When an electrical triggering signal is received, the heart will contract which

starting in the atria.

翻译：

1.The resistance element of unbonded strain gauges is a thin wire of a special alloy

that is stretched taut between two flexible supports. Unbonded strain gauges can be constructed so that they are linear over a wide range of a applied force but are very delicate. The bonded strain gauge, on the other hand, is generally more rugged but is linear over a smaller range of forces. Many biomedical strain gauge transducers are of bonded construction because the linear range is adequate and the extra ruggedness is a desirable feature in medical environments, where people cannot take the kind of precautions that would be required if a more delicate type were used.

无粘结应变仪的电阻元件是一种有2个灵活的支架可以拉长拉紧的特殊合金薄丝。这种合金具有良好的伸展性。无粘结应变仪可以被做到线性度范围大，来测更大范围的应变力，但是十分的精致。从另一方面将，粘结式应变仪应用的更多一些，但是线性度上只能满足小范围的应变。因为粘结式应变仪的线性度足够大，所以许多应用的在生物医学方面的应变仪是粘结式的。

2. A thermocouple consists of two dissimilar conductors or semiconductors joined

together at one end. Because the work functions of the two materials are different,

a potential will be generated when this junction is heated.

一个热电偶温度计的一端包括2个相异的导体和半导体。因为2种材料的工作职能是不同的，所以当交界处被加热时会产生电势。

3.The human heart is located in the upper middle portion of the chest. Although

many people believe that the heart is clearly on the left side of the body, it is actually a little more centered with the lower tip pointed toward the left hip. About one third of the heart lies to the right of the midline of the body; the rest lies to the left. The heart is a muscle that is encased in a sac called the pericardium. This double layer of tissue helps the heart stay in position and protects it from harm.

The pericardium creates a lubricating fluid on its inside surface so that the friction between it and the heart walls is reduced, allowing the heart to beat freely within the walls of the sac.

人的心脏位于胸腔上部的中间部分。尽管许多人相信心脏明显是在身体的左侧，但是它实际上更靠近指向左髋关节的较低的尖端部。大约三分之一的心脏位于身体中线的左侧，其余的位于左侧。心脏是心包包囊下的肌肉。这种双层组织可以帮助心脏保持在正确的位置，并保护心脏免受伤害。心包内具有润滑液，可以使心脏与心壁的摩擦减少，从而使心脏跳动自如。

4.The column electrode does fairly well in overcoming the motion artifact, but even

so it is often necessary for the medical staff conducting the test to clean and gently abrade the skin at the site where the electrode is attached.

柱状电极很好的克服了运动伪影。尽管如此，进行测试的医务人员同样需要对解除电极的皮肤进行清洁和按摩。

5.Surface electrodes are those that are placed in contact with the skin of the

subject．Also in this category are certain needle electrodes of a size that prevents their being inserted inside a single cell which a microelectrode is. Surface electrodes(other than needle electrodes) vary in diameter from 0.3 to 5cm, with most being in the 1-cm range. Human skin tends to have a very high impedance compared with other voltage sources. In any event, one must treat surface electrodes as a very high impedance voltage source - a fact that seriously influences the design of biopotentials amplifier input circuit.

表明电极

6.The colorimeter is a filter photometer that measures the color concentration of a

substance in solution. This is accomplished electronically by detecting the color light intensity passing through a sample containing the reaction products of the original substance and a reagent. A yellow urine sample, for example, passes yellow light and absorbs blue and green. For this reason, and to obtain purity in measurement, optical color filters are used to select a narrow wavelength spread((bandwidth) of light that shines on the photodetectors. Laser light-emitting diodes are also used and are preferred if the wavelength is suitable.

7.Thermistors are resistors that are designed to change value in a predictable manner

with changes in temperature. A positive temperature coefficient (PTC) device increases resistance with increases in temperature, while a negative temperature coefficient (NTC) device decreases resistance with increases in temperature.

热敏电阻是电阻是一种电阻值岁温度变化而变化的电阻。正我温度系数（PTC）电阻随温度的升高而变大。而负温度系数（NTC）器件电阻值随温度升高而减少。

8.By international scientific agreement, the zero reference point when making

half-cell potential measurements is the hydrogen-hydrogen(H-H) electrode, which is assigned a half-cell potential of zero volts by convention. All other electrode half-cell potentials are measured against the H-H zero reference. The half-cell potentials cited for any given electrode are the differential potential between the actual electrode and the H-H reference electrode. The electrode offset potential will be zero when the two electrodes are made of identical materials, which is the usual case in bioelectric sensing.

通过国际科学协议，按照国际惯例，在进行半电池电位测量时，零参考点是氢—氢电极。所有其他的电极半电池电位的零点以氢—氢电极为参考。该半电池电极电位为

9.The ventricular contraction commences immediately after the R wave on the ECG.

The ventricular pressure increases to a level greater than atrial pressure, forcing shut the tricuspid and mitral valves. These valve closures give rise to the first heart sound. The ventricles will begin to relax following the peak of systole, and the ventricular pressure will begin to drop. When the ventricular pressure is less

than the pressure in the arteries, the respective valves will close. During this period of pressure reversal, blood attempts to flow back into the ventricles. The valve closure and blood flow dynamics at this time give rise to the second heart sound.

10.It would not be desirable for the ventricles to contract in response to an action

potential before the atrial are empty of their contents. A delay is needed, therefore, to prevent such an occurrence; this is the function of the A V node. At 45cm/s the action potential will reach the A V node 30 to 50ms after the SA node discharges, but another 110ms will pass before the pulse is transmitted form the A V node. The

A V node, then, operates like a delay line to retard the advance of the action

potential along the internal electroconduction system toward the ventricles.

11.The different parts of the ECG waveform are designated by letters. The P-wave

indicates atrial contraction; ventricular systole occurs immediately following the QRS complex, and a refractory period is indicated by the T-wave.

12.Insertion errors occurs during the act of inserting the sensor into the system being

measured．This is a general problem with electronic measurements，indeed，with all measurements．For example, when measuring the voltage in a circuit, one must be certain that the inherent impedance of the voltmeter is much larger than the circuit impedance; otherwise circuit loading will occur, and the reading will be in significant error. Possible sources of this form of error include using a transducer that is too large for the system(e.g., pressures)，one that is too sluggish for the dynamics of the system，or one that self-heats to the extent that excessive thermal energy is added to the system.

13.When the muscle fibers of the myocardium is in contraction, the volume of the

ventricular chamber is less, so blood is squeezed out. The contraction of so many muscle cells at one time creates a mass electrical signal that can be detected by electrodes placed on the surface of the patient’s chest or the patient’s extremities.

This electrical discharge can be mechanically plotted as a function of time, and the resultant waveform is called an electrocardiogram (ECG). An electrocardiogram (ECG) measures changes in electrical potential across the heart, and can detect the contraction pulses that pass over the surface of the heart.

14.Imagine a metallic electrode immersed in an electrolytic solution．Almost

immediately after immersion，the electrode will begin to discharge some metallic ions into the solution，while some of the ions in the solution start combining with the metallic electrodes．After a short while，a charge gradient builds up，creating

a potential difference，or electrode potential , or halfcell potential.

想象一下一个金属电极浸泡在电解液中。几乎在浸泡同时，电极立即开始排出一些金属离子进入溶液，而这些离子中有些开始和金属电极结合。过了一会，电荷梯度开始聚集，造成了电势差，或者电极电位，或者半电池电位。

简答：

1.List the major system of the body.

Nervous system, Endocrine system, circulatory system, musculoskeletal system, respiratory system, gastrointestinal system

2.Describe several symptoms of cardiac arrhythmias detailed in your own words.

Conditions under this classification include extremes in heart rate, premature contractions, heart block, and fibrillation.

3.Describe the dynamics of blood flow.

上、下腔静脉和冠状静脉窦→右心房→右房室口（三尖瓣开放）→右心室→肺动脉口（肺动肺瓣开放）→肺动脉→肺（经肺泡壁周围的毛细血管进行气体交换）→肺静脉→左心房→左房室口（二尖瓣开放）→左心室→主动脉口（主动瓣开放）→主动脉（通过各级动脉分布至全身）。

4.List three techniques that might be used to overcome the effects of electrode offset

potentials.

1)Sometimes adhesive tape is used to hold the electrode in place, and while this approach will work for a while, the electrodes inevitably（不可避免地）become loose. In an hour or two the problem returns.

2)Another popular solution involves the use of a rough (prickly多刺的) surface electrode that digs in be low the scaly（有鳞的，劣等的）outer layer of skin. But these electrodes are often uncomfortable for the patient, and they fail to solve the problem completely.

3)The column electrode does fairly well in overcoming the motion artifact, but even so it is often necessary for the medical staff conducting the test to clean and gently abrade（摩擦）the skin at the site where the electrode is attached.

5.Finish the following diagram, fill in the name in the blank.

6.What is the definition of cardiac output (CO) ?

Cardiac output (CO) is defined as the product of heart rate in beats per minute and the volume of blood ejected from the ventricles during systole（心脏收缩）.

CO=heart rate (beats/min) ×stroke volume (L/beat)

7.What is the difference of transducers and electrodes?

Transducers（传感器）differ from electrodes（电极）in that they use some intervening transducible element to make the measurement, while electrodes directly acquire the signal.

8.What are the advantages of the quartz transducer?

very low levels of hysteresis（滞后）

very low levels of slippage（滑移）of the metals and alloys with respect to the crystal very low levels of temperature sensitivity

highly elastic properties

ruggedness