Patient Monitoring Systems and Ultrasound Machines Essay Sample

Philips Electronics India Limited is the taking Healthcare Company today. It strives to better the quality of people’s lives by concentrating on their wellness and wellbeing. As a company it is basically divided into Patient Care and Clinical Informatics ( PCCI ) . Imaging and Ultrasound. PCCI as a mode includes patient proctors. diagnostic ECG which features HOLTER. emphasis trial etc. anaesthesia machines. ventilators. telemetry. fetal monitoring systems. and cardiac resuscitation systems ( CRS ) like defibrillators and automatic external defibrillators ( AED ) . Imaging on the other manus can be classified into MRI ( magnetic resonance imagination ) . CT ( computed imaging ) . digital X-rays. cardio-vascular catheterisation ( cath lab ) . atomic medical specialty and ultrasound.

PATIENT MONITORING SYSTEMS

Patient monitoring is critical to care in operating and exigency suites. intensive attention and critical attention units. Additionally. it is priceless for recovery suites. radiology. cath labs. ambulatory. place and sleep-screening applications. Philips has been the innovator in patient proctors. It has three scopes of merchandises in the market viz. IntelliVue. SureSigns and Goldway. IntelliVue Patient Monitor allows a clear position of patient information with its 20 configurable screens and a clinical determination support system ( CDSS ) . It collects and combines physiological informations to supply a clear image of patient position. Its assorted theoretical accounts include MP 2. MP 5. MP 20 Jr. MP 20. MP 30. MP 40. MP 50. MP 60. MP 70. MP 80 and MP 90 etc.

A patient proctor is an instrument that allows real-time monitoring of several parametric quantities of the patient at the same time. These parametric quantities include ECG ( EKG ) . respiration rate. non-invasive blood force per unit area ( NIBP ) . invasive blood force per unit area ( IBP ) . temperature. SP02. cardiac end product ( CO ) . CO2 and much more. It besides has several other particular parametric quantities such as EEG ( EEG ) . BISx ( bi-spectral index ) . PiCCO ( pulse contour invasive uninterrupted cardiac end product ) . spirometry. and EASI 5-lead ECG and pulse- force per unit area fluctuation. Typical proctors alarm in the instance of patient or equipment jobs and offer limited informations storage and retrieval ( swerving ) . All patient proctors interface to the Philips Clinical Network and other equipments.

Apart from supervising a assortment of parametric quantities utile to the physicians. PHILIPS patient proctors are highly user-friendly. They are incorporated with advanced algorithms like ST/AR for arrhythmias. FAST SP02 and 12 Forty readings. Its CDSS provides Neonatal Event Review ( NER ) . OxyCRG. ST map. Horizon View and Advanced Event Surveillance ( AES ) . Its noticeable characteristics include 20 configurable screens. proviso for touch screen. PS/2 trackball. mouse or keyboard.

Components of a patient proctor:

1. Power supply
2. Battery board
3. Main board
4. Recorder board
5. Touch panel
6. I/O board
7. System interface board
8. MMS CPU

Working of patient proctor:
The AC/DC convertor transforms the AC power coming from the power stopper into 14 V/80W DC beginning and isolates the monitoring system from the AC power brinies. The 14V is distributed via power coach and supplies power to all the constituents of the system. The MMS and MMS extension requires 48V DC power which is created by an isolating DC/DC convertor. The CPU is supplied with 3. 3 V and 5 V DC power while the LEDs are supplied with 12V DC power. The multi-measurement waiter ( MMS ) consists of assorted faculties which measure the parametric quantities discussed supra. These faculties are nil but instrumentality amplifiers with station processing circuits wheresoever required. The assorted I/O boards could include PS/2. parallel pressman. USB. remote devices and BISx interface.

I ] Features:

Touchscreen User Interface:
Most scope of IntelliVue proctors now has resistive touch engineering. The protective bed prevents harm from fingernails or crisp objects. This characteristic provides easy entree since the full screen is active. Layers of complicated bill of fares can be avoided. It is highly utile in infection control since it can be operated with a disposable stylus. As a consequence. no bacterium are transferred from baseball mitts to the proctor. Additionally. IntelliVue proctors have no fans or filters unlike other merchandises and therefore no danger of spread of bacteriums. A distant proctor outside the isolation chamber is possible utilizing VGA show and PS/2 accountant so that nurses can see proctor without come ining the cell. These screens can be cleaned with 70 % isopropyl intoxicant. Every patient proctor integrates the show and processing unit into a individual bundle. A proctor with a individual incorporate multi-measurement waiter ( MMS ) can be connected to extra edifice blocks to organize a monitoring system with a big figure of measurings. extra interface capablenesss and slave show. These elements cooperate as a individual incorporate real-time measuring system.

ST/AR algorithm:

Philips patient proctors identify 22 categories of arrhythmia. ST/AR pacesetter analysis identifies and dismaies on pacesetter failure. This analysis requires merely two active leads ( ECG ) for full truth. It besides facilitates car shift of active leads on lead failure. Neonatal arrhythmia sensing is besides possible with 3 lead ECG. Most other patient proctors in the market necessitate 4 specific ECG leads 1. 2. 3. 5 for full truth. If any of these leads fail. the proctor can non place the arrhythmia decently. Besides. as opposed to 22 categories identified by IntelliVue. most other patient proctors can place merely 14 categories with no dismaying on pacesetter failure.

Horizon View:

This particular characteristic is particularly helpful in the ICU. OR. CCU. ER and the NICU. Horizon View displays real- clip informations. tendencies and intended end of therapy. This helps clinicians see the effectivity or failure of the therapy. in the ER and ICU. Horizon View helps maintain path of the alterations in the status of the patient. It besides allows monitoring of anesthetic position ( BISx ) in the OT along with airing warning and end directed therapy in the ICU.

ST Map:

This characteristic of the PMS is helpful in the ICU. OR. CCU and the ER. ST has 12 Numberss that change every minute. Therefore. ST map shows a simple in writing account of the cardiac status. It is based on Eithoven’s trigon and relavant ST leads are grouped automatically. In the ER. it allows the monitoring of thorax hurting patients. It is utile for thrombolytic therapy in the CCU and for tracking intra-operative ST alterations in the OR. It besides provides monitoring of the effects of stenting in the Cathlab.

Advanced Event Surveillance ( AES ) :

It has particular usage in the ICU. OR. CCU. ER and the NICU. AES looks for altering parametric quantities at the same time. Rules can include rate of alteration of tendencies. events that trigger off dismaies ( xanthous or ruddy position ) . It is utile for the sensing of sepsis. whether therapy marks have been reached. and multiple organ failure etc.

OxyCRG:

Philips invented OxyCRG which stands for Oxy CardioRespiroGram. It shows the bosom rate tendency. O impregnation tendency and tight respiration wave form. It allows neonate diagnosing and differentiate conditions known as cardinal and clogging apnea in prematures. If arterial blood force per unit area ( ABP ) is added. physicians can see if the apnea has caused a bead in blood force per unit area. If the EEG is added. it can give information on whether the apnea was caused by a ictus. To reason. OxyCRG together with NER ( neonatal event reappraisal ) allows the full certification of events.

Neonatal Event Review:

NER provides a snapshot reappraisal of the OxyCRG show whenever a neonatal event occurs like bradycardia. bradypnea and desaturation. IntelliVue MP60 provides storage of upto 50 events while MP50 and below allows 25 event storage. Thus NER provides a count of how many episodes occur and how critical they are.

II ] Faculties:

Non-invasive blood force per unit area:

The conventional method for non-invasive blood force per unit area measuring ( NIBP ) was the Korotkoff method. However. modern twenty-four hours patient supervising systems now use the oscillometric method for measuring.

In the oscillometric method. blood force per unit area is measured as oscillations superimposed on turnup force per unit area. The turnup. inflated around the patient’s limb. senses arterial pulsations as oscillations whose amplitude alterations as the turnup is deflated. The initial oscillations are approximately tantamount to systolic force per unit area ; the larger oscillations represent average force per unit area ; and the diastolic force per unit area is so derived from the average force per unit area.

To take the measuring. the turnup is placed around the patient’s limb and inflated until the arteria is occluded. at a point merely above systolic force per unit area. Blood motion ceases when turnup force per unit area is greater than arterial force per unit area. As cuff deflation commences. blood begins to flux through the arteria at the systolic force per unit area. and the resulting pulsings are detected as oscillations. The turnup continues to deflate. and the amplitude of arterial oscillations increases until it reaches a maximal value. which represents average arterial force per unit area. As cuff deflation continues. arterial force per unit area beads due to reduced opposition from the turnup force per unit area. Diastolic force per unit area is measured when the oscillations begin decreasing quickly.

Three different methods can be used to obtain the measurings: • Manual: For each petition. one measuring of systolic. diastolic. and average force per unit areas is taken. • Car: Repeated measurings of the three values are taken at timed intervals specified by the user. • Stat: Measurements of the three values are taken instantly and repeatedly over a period of five proceedingss. This method uses a faster measurement process but produces a less accurate reading.

PiCCO faculty:

PiCCO stands for Pulse Invasive Contour Continuous Cardiac Output. This faculty can be used in the ICU. OR. CCU. NICU etc. It provides round to crush cardiac end product. uninterrupted systemic vascular opposition ( SVR ) . intrathoracic blood volume ( ITBV ) and excess vascular lung H2O ( EVLW ) . By ciphering these values. physicians can place the sum of blood loss and the right volume of fluid. The patient requires a cardinal venous line ideally the internal jugular or subclavian vena. and an arterial catheter with a thermal resistor is placed in one of the larger systemic arterias. e. g. the femoral or brachial arteria. PiCCO system works on the rule that a known volume of thermic index ( ice-cold saline ) is injected into a cardinal vena.

The injectate quickly disperses volumetrically and thermally within the pneumonic and cardiac volumes. This volume of distribution is termed the intrathoracic volume. When the thermic signal reaches the arterial thermal resistor. a temperature difference is detected and a dissipation curve is generated. The country under the curve is reciprocally relative to the cardiac end product. By computations. an estimation of both intrathoracic blood volume ( ITBV ) and EVLW can besides be made. ITBV can be derived from planetary terminal diastolic volume ( GEDV ) determined by thermodilution measuring. PiCCO uses merely CVP line and temporal arteria line and hence is less invasive. These catheters can be used for a period every bit long as 8-14 yearss. It is besides less expensive than other methods of uninterrupted cardiac end product monitoring.

| ITTV = CO * MTtIntra thoracic volume determined from the average theodolite time| | PTV = CO * DstPulmonary Thermal Volume determined from the exponential descent time| | GEDV = ITTV – PTVGlobal end diastolic volume. Can besides be re-arranged as GEDV = CO * ( MTt-DSt ) | | ITBV = 1. 25 * GEDVIntra thoracic blood volume ( entire cardiorespiratory intra vascular fluid volume ) Can besides be re-arranged as ITBV = 1. 25 * CO * ( MTt-DSt ) | | EVLW = ITTV – ITBVExtra vascular Lung Water = Intra thoracic blood volume. Can besides be re-arranged as EVLW = ITTV – 1. 25 * GEDV| Cardiac Output ( CO ) :

The simplest technique of cardiac end product measuring is the thermodilution method. The thermodilution method is based on the rule that the flow rate of an unknown measure of liquid can be determined by adding a known measure of index and mensurating its concentration downstream. Thermodilution involves shooting a cooled solution at a known temperature into the bosom. The injectate solution mixes with and chill the heater environing blood. When the blood leaves the bosom. the temperature as a map of clip indicates the rate of blood flow.

The measuring is taken with a pneumonic arteria ( PA ) Swan Ganz catheter. The catheter is inserted into the bosom. with the proximal lms opening positioned in the right atrium for presenting the injectate. and the thermal resistor. used for monitoring temperature. positioned in the pneumonic arteria. Placement of the catheter is gauged by utilizing force per unit area measurings and X raies of the catheter location. A little sum of thermic index is introduced into the right atrium. The index mixes with the blood in the right ventricle and attacks temperature equilibrium. When the diluted blood reaches the pneumonic arteria. the thermal resistor measures the lessening in blood temperature over clip. The temperature of the injectate solution can be measured either indirectly or straight. Indirectly. the temperature of the chilling bath is measured. Direct measuring uses a flow-through temperature investigation to mensurate the injectate temperature as it is being introduced into the catheter. The investigation is positioned where the syringe injects the index into the proximal lms port. The time/temperature curve ensuing from the measuring resembles a bell-shaped curve. except that it has an exponential decay. The informations are integrated to cipher the country beneath the curve. By convention. the y-axis of the graph shows diminishing temperature.

Stewart Hamilton’s Equation

BISx Module:
BISx stands for bi-spectral index and can be used in the ICU. OR. CCU and the ER. The Bispectral Index ( BIS ) is a uninterrupted processed EEG parametric quantity that provides a step of the province of the encephalon during the disposal of anaesthetics and depressants. BIS was designed to correlate with “hypnotic” clinical end points ( sedation. deficiency of consciousness and memory ) and to track alterations in the effects of anaesthetics on the encephalon. 3rd coevals BIS engineering is presently being used in the OR and ICU. However. most other companies still have the 1st coevals BIS engineering in topographic point.

There are 4 spine electrodes used for this intent. Gel is used to supply good electrical contact with the patient. The 1st is placed at the centre of the brow. The 2nd is placed next to it automatically. 3rd electrode is placed at the same degree as the ciliums midway of the oculus and the hairline. The 4th electrode gets placed between the 2nd and 3rd automatically. These electrodes measure the neuroactivity of the encephalon i. e. EEG signals and convey it to the mainline. This type of monitoring is particularly utile for aged patients or paediatricss with swoon or delicate systems every bit good as during drawn-out surgical processs.

Components OF ANAESTHESIA

Spo2 Faculty:
This faculty is by and large used in the ICU. OR. CCU. ER and NICU. It is used for monitoring shunt flow ( blending of blood between the aorta and the pneumonic arteria ) . observing sphacelus ( by supervising the impregnation and perfusion in a damaged limb versus baseline ) and in supervising the impregnation and perfusion in a re-attached or transplanted limb. It uses FAST algorithm. is motion cogent evidence and low perfusion capable. The faculty is a stopper and drama with no anterior apparatus demands and enables uninterrupted show. Measurement of Spo2 is done utilizing pulse oximetry. Pulse oximetry is based on the rule that red blood cells absorb different sums of light depending on the sum of O they contain.

When visible radiation is transmitted through organic structure tissue such as a finger. it is absorbed otherwise by skin pigments. tissue. gristle. bone. arterial blood. and venous blood. Most of these substances absorb visible radiation at a changeless rate. The blood in the arterias and arteriolas. nevertheless. is pulsatile. As the blood vass expand and contract. the length of the light way is altered. impacting its soaking up. Because the lone important variable is due to pulsating blood. the ratio of HbO2 to Hb can be measured in the pulsatile portion of the signal to uncover the O impregnation of the arterial flow. The measuring is derived utilizing two wavelengths of light — one in the ruddy part and one in the infrared – to mensurate maximal and minimal soaking up differences between the two molecules. This is done by the aid of a investigation. normally attached to a ?nger or the ear lobe.

The SpO2 measuring is taken by agencies of an optical turnup that is placed on the patient’s fingertip. From the conveying side of the transducer. ruddy and infrared visible radiation is scattered through the capillary bed and detected by a photo-diode on the receiving side. The measuring is independent of skin pigmentation. tissue soaking up. and other invariables. The resulting measuring is plotted as a plethysmogram. The wave form is relative to the blood volume alterations. the pulse rate. and the comparative perfusion of the tegument and transducer.

The technique is undependable if peripheral perfusion is hapless and may bring forth erroneous consequences in the presence of nail gloss. inordinate motion or high ambient visible radiation. In general. arterial oxygenation is satisfactory if SpO2is greater than 95 % .

Temperature Measurement:
The temperature measuring used by Philips’ patient monitoring systems is based on a thermal resistor whose opposition is reciprocally relative to its temperature. By mensurating the thermistor’s opposition. its temperature can be calculated. The opposition of the thermal resistor is measured by go throughing a current through it and mensurating the electromotive force developed across it.

The delta temperature measuring reflects two different temperature pro bevalues and calculates the difference in temperature between the two measurings. A temperature delta from different sites can be diagnostic of an altered physiologic province. Temperature can be measured by a assortment of temperature investigations designed for usage with different anatomic sites. The pick of site is determined by the type of information needed by the clinician.

Invasive blood force per unit area measuring:

This measuring is particularly utile in the ICU and the OT. When mensurating invasive blood force per unit area. the force of motion of the blood in the patient’s systemic arterial system is transported by a unstable column in the force per unit area line to the transducer. This force per unit area causes an electrical signal to be generated which is so amplified to expose the force per unit area moving ridge and the numerics for the systolic. diastolic. and average force per unit area values.

An invasive blood force per unit area measuring is collected through a force per unit area transducer that is connected to a force per unit area line by agencies of a catheter which is invasively placed in the patient’s blood watercourse. Blood force per unit area is depicted as a force per unit area moving ridge with the numerics for systolic. diastolic. and average force per unit area values. The blood force per unit area shows the rhythms of contraction and release within the bosom and the attendant force per unit area that is generated to travel the blood through the vass.

Pulse Pressure Variation:
It is by and large used in the ICU. OR and the CCU. It helps physicians decide whether unstable disposal is executable when the patient has low blood force per unit area or cardiac end product. Measurement of these indexs can foretell an addition in cardiac end product induced by volume enlargement before volume enlargement is really performed. It is calculated utilizing fluctuations in the arterial blood force per unit area ( ABP ) during airing. This faculty is once more a stopper and play device and can be used whenever any arterial force per unit area is available ( ABP. ART. VAP ) . Hence a PiCCO catheter is non required. Capnography:

Capnography is a simple method of supervising the concentration or partial force per unit area of C dioxide ( CO2 ) in the respiratory gases. This method of supervising straight shows the riddance of CO2 by the lungs and indirectly reflects the production of CO2 by tissues and CO2 circulatory conveyance to the lungs. It is a non-invasive and accurate method. Several processs are available for supervising airway CO2. The first process is by utilizing a side watercourse sample measured through a quickly reacting infrared CO2 analyzer or measured through a mass spectrometer. The 2nd process is direct measuring of CO2 values through an infrared analyzer at the terminal of the endotracheal tubing.

The ETCO2 ( End Tidal Carbon Dioxide ) measuring for Carbon Dioxide uses a technique based on the soaking up of infrared radiation by certain gases. Infrared visible radiation is absorbed by C02. The sum of soaking up varies harmonizing to the CO2 concentration in the gas mixture. By utilizing an infrared sensor to mensurate the soaking up. the CO2 concentration in a gas can be derived. CO2 respiratory gas measurings are evaluated as gas base on ballss through the air passage arranger on the patient’s cannulation system. Respiratory CO2 gas readings are depicted as a real-time CO2 wave form together with numerics for ETCO2. Airway Respiration Rate ( AWRR ) . and Inspired Minimum Carbon Dioxide ( IMCO2 ) . During standardization. the value for instantaneous CO2 is besides obtained.

Electroencephalogram:

The EEG ( EEG ) is the measuring of the electrical activity of the encephalon. This activity creates an electrical signal that. depending on the person’s province of consciousness or wellbeing. produces characteristic wave forms. The moving ridges seen are generated from electrical potencies located on the surface of the encephalon. These potencies are recorded by puting electrodes on the scalp.

It gives us information sing the blood flow to the encephalon during cardiac and vascular surgery. It besides enables coma monitoring and forecast. EEG allows one to supervise the effects of barbiturate depressants on epileptics and
is utile for sensing ictuss in newborns.

Percentage of entire power in each frequence set:
• Alpha – Alpha waves represent the EEG in a normal awake grownup. Their frequence is defined as 8-13 Hz. • Beta – Beta waves represent the EEG during periods of witting attempt. Their frequence is defined as 13 to 30 Hz • Theta – Theta moving ridges are normally seen in the presence of pathology. Their frequence is defined as 4 to 8 Hz • Delta – Delta moving ridges are seen in the presence of pathology. coma and certain phases of anaesthesia. Their frequence is defined as 0. 5 to 4 Hz.

The International 10/20 System of Electrode Placement is a process for the mensural location of every bit spaced electrodes on the scalp. This system is based on the relationship between the cortical countries of the encephalon and the location of the EEG electrodes that reside straight above them.

Traditionally there are 21 electrode locations in the 10/20 system. All of these are needed for diagnostic recordings ; nevertheless in EEG supervising a sub-set of these electrodes may be used to find the neurological position of the patient. Each location is marked with a alone letter/number combination. The letters correspond to the cortical countries of the encephalon where they are located. The Numberss are uneven for the left places. even for the right places. and increase as they move off from the midplane ( which is designated as Z for nothing ) . When utilizing an EEG proctor turn uping the proper topographic point for electrodes can be simplified. The electrode brace can be marked utilizing landmarks on the caput such as the hairline. ears and top of the caput to come close the 10/20 locations. A form of electrodes on the caput and the channels they are connected to is called a collage. There are many different combinations of electrode braces.

Electrocardiogram:

The skin surface EKG ( ECG ) measures the electrical activity of the patient’s bosom. or myocardium. This information indicates the status of the heart’s electrical conductivity system. The electrical cells of the bosom generate. behavior. and coordinate electrical urges that cause the heart’s mechanical cells to contract. As these urges move through the assorted parts of the heart’s conductivity system. little electrical currents besides move toward the body’s surface. The measuring represents the altering electrical potencies and their patterned advance through the bosom. The electrical signals are detected by electrodes placed on assorted countries of the patient’s bole and limbs. The information carried by the signals varies harmonizing to where and how the electrodes are placed.

An ECG is recorded utilizing lead overseas telegrams connected to a monitoring device. ECG leads are individual electrodes. or arrays of electrodes. placed at specific anatomical places that detect the electrical electromotive force of a specific cardiac vector. Each lead monitors the heart’s electrical activity from a different position. Unipolar leads detect signals traveling from the bosom to the skin’s surface ; bipolar leads detect the surface electrical activity traveling from one electrode to another. The EASI 12-lead ECG uses a particular lead placement that detects electrical activity. which does non match straight to the standard ECG vectors. but from which all 12 of the standard vectors can be derived.

Lead overseas telegram sets are available with assorted Numberss of lead wires ; common types are three. five. and 12 lead sets. The terminal of each wire is attached to an electrode and is color-coded to ease anatomical arrangement. Electrodes can be placed in many different agreements. depending on factors such as clinical application. type of patient. and suspected diagnosing.

Limb Leads Three bipolar limb leads are called leads I. II. and III. Electrodes are placed on the patient’s right arm. left arm. and left leg. organizing a form known as Einthoven’s trigon. For convenience. the electrodes can besides be placed on the patient’s bole near the shoulders and hip. The unipolar leads are called aVR. aVL. and aVF ; they can be monitored by the same three electrodes. When selected on the proctor. these leads measure the current from the bosom out to the specified limb.

Chest Leads Chest leads. besides called precordial leads. are unipolar. Leads labelled V with a figure or missive appellation can be placed around the full perimeter of the thorax. every bit good as the dorsum. The most common clinical aim in fiting V leads is ischemia sensing.

Modified Chest Lead ( MCL1 ) is a bipolar thorax lead in which two electrodes are placed over the thorax

Five-Electrode Placements:
Electrodes for five-lead sets can be placed in assorted places. The right leg ( RL ) lead serves as a land.

ULTRASOUND SYSTEM

Diagnostic echography ( echography ) is an ultrasound-based diagnostic imagination technique used to visualise hypodermic organic structure structures including sinews. musculuss. articulations. vass and internal variety meats for possible pathology or lesions. Obstetric echography is normally used during gestation and is widely recognized by the populace.

In natural philosophies. the term “ultrasound” applies to all acoustic energy ( longitudinal. mechanical moving ridge ) with a frequence above the hearable scope of human hearing. The hearable scope of sound is 20 hertz-20 kHz. Ultrasound is frequency greater than 20 kHz.

Diagnostic applications:

Typical diagnostic sonographic scanners operate in the frequence scope of 2 to 18 MHz. It requires a medium for transmittal and travels at a velocity of 1540 m/s in blood or tissues. The pick of frequence is a tradeoff between spacial declaration of the image and imaging deepness: lower frequences produce less declaration but image deeper into the organic structure.

It is possible to execute both diagnosing and curative processs. utilizing ultrasound to steer interventional processs ( for case biopsies or
drainage of unstable aggregations ) . Sonographers are medical professionals who perform scans for diagnostic intents.

Sonography is effectual for imaging soft tissues of the organic structure. Superficial constructions such as musculuss. sinews. testicles. chest and the neonatal encephalon are imaged at a higher frequence ( 7-18 MHz ) . which provides better axial and sidelong declaration. Deeper structures such as liver and kidney are imaged at a lower frequence 1-6 MHz with lower axial and sidelong declaration but greater incursion.

Basic Principle:
The Doppler Effect ( or Doppler displacement ) . is a alteration in frequence of a moving ridge ( or other periodic event ) for an perceiver traveling comparative to its beginning. The standard frequence is higher during the attack. it is indistinguishable at the blink of an eye of passing by. and it is lower during the recession. When the beginning of the moving ridges is traveling toward the perceiver. each consecutive moving ridge crest is emitted from a place closer to the perceiver than the old moving ridge. Therefore the clip between the reachings of consecutive moving ridge crests at the perceiver is reduced. doing an addition in the frequence. Conversely. if the beginning of moving ridges is traveling off from the perceiver. each moving ridge is emitted from a place further from the perceiver than the old moving ridge. so the arrival clip between consecutive moving ridges is increased. cut downing the frequence. Ths Doppler displacement is given by the equation:

Where
Ft=transmitted Doppler frequence
V=velocity of blood flow
Theta=angle between flow of blood and ultrasound beam
C= velocity of sound in tissue

Sonography employs the Doppler Effect to measure whether blood is traveling towards or off from the investigation. and its comparative speed. By ciphering the frequence displacement of a peculiar sample volume. for illustration flow in an arteria or a jet of blood flow over a bosom valve. its velocity and way can be determined and visualised. This is peculiarly utile in cardiovascular surveies ( echography of the vascular system and bosom ) and indispensable in many countries such as finding contrary blood flow in the liver vasculature in portal high blood pressure. The Doppler information is displayed diagrammatically utilizing spectral Doppler. or as an image utilizing colour Doppler ( directional Doppler ) or power Doppler ( non-directional Doppler ) .

Types:
The two chief types of Doppler echocardiographic system differ in transducer design and operating characteristics. signal processing processs and in the types of information provided. 1. CONTINUOUS DOPPLER:

Continuous moving ridge ( CW ) Doppler is the older and electronically simpler of the two sorts. As the name implies. CW Doppler involves uninterrupted coevals of ultrasound moving ridges coupled with uninterrupted ultrasound response. A two crystal transducer accomplishes this double map with one crystal devoted to each map. The chief advantage of CW Doppler is its ability to mensurate high blood speeds accurately. CW Doppler can accurately enter the highest speeds in any valvular and inborn bosom disease. It is besides of considerable importance for the quantitative rating of unnatural flows.

The chief disadvantage of CW Doppler is its deficiency of selectivity or deepness favoritism. Since CW Doppler is invariably conveying and having from two different transducer caputs ( crystals ) there is no proviso for imaging or run gating to let selective placing of a given Doppler sample volume in infinite. The absence of anatomic information during CW scrutiny may take to interpretative troubles. peculiarly if more than one bosom chamber or blood vas lies in the way of the ultrasound beam.

2. PULSED WAVE DOPPLER:
Most modern sonographic machines use pulsed Doppler to mensurate speed. Pulsed wave machines transmit and receive series of pulsations. The frequence displacement of each pulsation is ignored ; nevertheless the comparative stage alterations of the pulsations are used to obtain the frequence displacement ( since frequence is the rate of alteration of stage ) . The major advantages of pulsed Doppler over uninterrupted moving ridge is that distance information is obtained ( the clip between the familial and standard pulsations can be converted into a distance with cognition of the velocity of sound ) and gain rectification is applied. The disadvantage of pulsed Doppler is that the measurings can endure from aliasing.

When pulsations are transmitted at a given sampling frequence ( known as the pulse repeat frequence ) . the maximal Doppler frequence that can be measured unequivocally is half the pulse repeat frequence. If the blood speed and beam/flow angle being measured combine to give a frequence value greater than half of the pulse repeat frequence. ambiguity in the Doppler signal occurs. This ambiguity is known as aliasing. Low pulse repeat frequences are employed to analyze low speeds ( e. g. venous flow ) . Aliasing will happen if low pulse repeat frequences or speed graduated tables are used and high speeds are encountered. Conversely. if a high pulsation repeat frequence is used to analyze high speeds. low speeds may non be identified.

SYSTEM Components:

Transducers:

Ultrasound transducers convert electric signals into ultrasound energy that is transmitted into tissues and the reflected ultrasound energy back into an electric signal. Ultrasound transducers consist of the followers:

1. Piezoelectric crystal
2. Live electrode
3. Land electrode
4. Backing block
5. Acoustic dielectric
6. Plastic lodging
7. Insulated screen

The most of import constituent is a thin piezoelectric crystal component located near the face of the transducer. The forepart and back faces of the crystal are coated with a thin conducting movie to guarantee good contact with the two electrodes that will provide the electric field used to strive the crystal i. e. malformation caused in the crystal when a electromotive force is applied to it. The surfaces of the electrodes are coated with gold or Ag electrodes. The outside electrode is grounded to protect the patient from electrical daze and its outside surface is coated with a watertight electrical dielectric. The inside electrode abuts against a thick backup block that absorbs sound moving ridges that travel back into the transducer. The lodging is normally a strong plastic. An acoustic dielectric of gum elastic or cork prevents the sound waves from go throughing into the lodging. Strong. short electrical pulsations from the ultrasound machine make the transducer ring at the coveted frequence. The sound is focused either by the form of the transducer. a lens in forepart of the transducer. or a complex set of control pulsations from the ultrasound scanner machine. This concentrating produces an arc-shaped sound moving ridge from the face of the transducer. The moving ridge travels into the organic structure and comes into focal point at a coveted deepness.

New engineering transducers use phased array techniques to enable the sonographic machine to alter the way and deepness of focal point. Materials on the face of the transducer enable the sound to be transmitted expeditiously into the organic structure ( normally looking to be a rubbery coating. a signifier of electric resistance matching ) . In add-on. a water-based gel is placed between the patient’s tegument and the investigation to guarantee good electrical contact.

The sound moving ridge is partly reflected from the beds between different tissues. Specifically. sound is reflected anyplace there are denseness alterations in the organic structure: e. g. blood cells in blood plasma. little constructions in variety meats. etc. Some of the contemplations return to the transducer.

The return of the sound moving ridge to the transducer consequences in the same procedure that it took to direct the sound moving ridge. except in contrary. The return sound wave vibrates the transducer ; the transducer turns the quivers into electrical pulsations that travel to the supersonic scanner where they are processed and transformed into a digital image.

Probes:

1. Linear array investigation: Used in abdominal variety meats ( extrathoracic ) . superficial constructions ( tegument. mammary secretory organs ) .

2. Curved array investigation: Used in abdominal echography and gestation diagnosing.

3. Sector array investigation: Used in echocardiography. intra pelvic and intra thoracic variety meats. encephalons. eyes.

Manner:

1. A-mode: A-mode is the simplest type of ultrasound. A individual transducer scans a line through the organic structure with the reverberations plotted on screen as a map of deepness. Curative ultrasound aimed at a specific tumour or concretion is besides A-mode. to let for pinpoint accurate focal point of the destructive moving ridge energy.

2. B-mode: In B-mode ultrasound. a additive array of transducers at the same time scans a plane through the organic structure that can be viewed as a planar image on screen.

3. M-mode: M stands for gesture. In m-mode a rapid sequence of B-mode scans whose images follow each other in sequence on screen enables physicians to see and mensurate scope of gesture. as the organ boundaries that produce contemplations move relation to the investigation.

4. Doppler manner: This manner makes usage of the Doppler Effect in mensurating and visualising blood flow. a. Color Doppler: Speed information is presented as a colour coded sheathing on top of a B-mode image

B. Continuous Doppler: Doppler information is sampled along a line through the organic structure. and all speeds detected at each clip point is presented ( on a clip line ) .

c. Pulsed moving ridge ( PW ) Doppler: Doppler information is sampled from merely a little sample volume ( defined in 2Dimage ) . and presented on a timeline.

d. Duplex: a common name for the coincident presentation of 2D and ( normally ) PW Doppler information. ( Using modern ultrasound machines colour Doppler is about ever besides used. hence the alternate name Triplex.

CONTROL PANEL:

The system control panel contains the undermentioned keys. rotary controls. and slide controls:

2D: To go out the current imagination manner or application and return to 2D Mode.

2D Addition: To set the addition. or overall brightness. of a 2D or MMode image.

Acquire: In unrecorded imagination. Stress Echocardiography. and Quick Review playback. it is used to get down and halt the acquisition of a cringle. When an image is frozen it is used to get a frame.

Angio: To come in Color Power Angio or to add angio information to the mention image in PW Doppler or CW Doppler.

Angle: In PW Doppler. an pointer. called the angle-to-flow pointer. appears on the imaging screen along with the Doppler pointer line to place the angle-to-flow pointer analogue to and in the same way as the blood flow.

Baseline: In PW and CW Doppler. used to set the zero baseline place in the Doppler spectral hint.

Body Mark: To expose the organic structure marker soft keys and take a organic structure marker to put on the imagination screen.

Color: To come in Color Mode or to add colour information to the mention image in PW Doppler. CW Doppler. or MMode.

CW: In a cardiac preset. used to expose the CW spectral hint. In a noncardiac preset. it is used to place the CW mention line.

Del: To cancel a selected label. If no label is selected. all of the labels are deleted. Besides used to cancel a selected measuring. If no measurementis selected. all of the measurings are deleted.

Depth: To increase or diminish the distance from the face of the transducer to the deepest point in the displayed image.

Doppler Addition: In PW and CW Doppler. it is used to set the brightness of the spectral show.

Enter: To snap an point or take a bill of fare option.

Focus: To travel the location of the focal zone or focal zones. the country or countries where the image is most clearly focused.

Freeze: To stop dead a unrecorded image and originate Quick Review. which allows you to scroll through the frames utilizing the trackball.

Fusion: To rhythm through merger frequence scenes available for the selected transducer and the manner.

Keyboard: To type information into Fieldss and to type labels. rubrics.

Label: To expose the Label soft keys and take a label to put on the imagination screen.

Left: In unrecorded imagination. it is used to come in Dual Imaging. The unrecorded image is on the left. and the frozen image appears on the right.

LGCs: Traveling the slide controls up or down adjusts the elaboration of a returning 2D signal.

Measure: To expose the measuring soft keys and to get down an unlabeled measuring. A caliper appears on the image.

Mic: To turn the mike on and off when entering a voice note during a VCR recording.

MMode: In a cardiac preset. it is used to expose the MMode hint. In a non-cardiac preset. it is used to come in MMode Preview.

Option Keys ( 1. 2. 3. and 4 ) : The option keys are labeled 1. 2. 3. and 4. Before utilizing 3D Mode. Panoramic Imaging. Stress Echocardiography. or Tissue Doppler. you need to delegate one of the option keys to the manner or application in the Options apparatus window.

Patient: To open the Patient Identification window in which you can make a new patient survey. edit information about the current patient. or re-start a patient survey that was started before the same twenty-four hours.

Power: To change the acoustic power transmitted for the current manner.

Probe: To trip the following affiliated transducer traveling from top to bottom. The name of the current transducer appears on the right side of the imagination screen.

PW: To come in PW Doppler Preview. so that you can place the Doppler sample volume gate.

Report: To open the study for the current survey.

Reappraisal: To open Image Review for the current survey.

Right: In unrecorded imagination. it is used to come in Dual Imaging. The unrecorded image is on the right. and the frozen image appears on the left.

Scale: In Color Power Angio. Color Mode. or CW or PW Spectral Doppler. it is used to expose higher or lower speeds and frequencies The Scale scene changes the pulse repeat frequence ( PRF ) .

Spectral: In CW Preview or PW Preview. it is used to expose the CW or the PW Doppler spectral hint. severally.

TGCs: Traveling the TGC ( Time Gain Compensation ) slide controls to the right or left adjusts the elaboration of the returning 2D signals at a specific image deepness.

THI: To come in Tissue Harmonic Imaging.

Volume: To set the volume of the talker for CW and PW Doppler and for VCR playback.

Rapid climb: To put a rapid climb box on an image and amplify the country in the rapid climb box.