History of radar

Several inventors, scientists, and engineers contributed to the development of radar. The first to use radio waves to detect "the presence of distant metallic objects via radio waves" was Christian Hülsmeyer,[2][3] who in 1904 demonstrated the feasibility of detecting the presence of a ship in dense fog, but not its distance. He received Reichspatent Nr. 165546 for his pre-radar device in April, and patent 169154 on November 11 for a related amendment. He also received a patent (GB13170) in England for his telemobiloscope on September 22, 1904.[2][4]

Nikola Tesla, in August 1917, first established principles regarding frequency and power level for the first primitive radar units[citation needed]. Before the Second World War, developments by the Americans (Dr. Robert M. Page tested the first monopulse radar in 1934),[5] the Germans, the French (French Patent n° 788795 in 1934),[6] and mainly the British who were the first to fully exploit it as a defence against aircraft attack (British Patent GB593017 by Robert Watson-Watt in 1935),[6][7] led to the first real radars. Hungarian Zoltán Bay produced a working model by 1936 at the Tungsram laboratory in the same vein.In 1934, Émile Girardeau, working with the first French radar systems, stated he was building radarsystems "conceived according to the principles stated by Tesla". [1]

The war precipitated research to find better resolution, more portability and more features for the new defence technology. Post-war years have seen the use of radar in fields as diverse as air traffic control, weather monitoring, astrometry and road speed control.

This long-range radar antenna, known as ALTAIR, is used to detect and track space objects in conjunction with ABM testing at the Ronald Reagan Test Site on the Kwajalein atoll.[1]

Radar is a system that uses electromagnetic waves to identify the range, altitude, direction, or speed of both moving and fixed objects such as aircraft, ships, motor vehicles, weather formations, and terrain. A transmitter emits radio waves, which are reflected by the target and detected by a receiver, typically in the same location as the transmitter. Although the radio signal returned is usually very weak, radio signals can easily be amplified. This enables a radar to detect objects at ranges where other emissions, such as sound or visible light, would be too weak to detect. Radar is used in many contexts, including meteorological detection of precipitation, air traffic control, police detection of speeding traffic, and by the military. It was originally called RDF (Radio Direction Finder) in Britain. The term RADAR was coined in 1941 as an acronym for Radio Detection and Ranging. The term has since entered the English language as a standard word, radar, losing the capitalization in the process.

Robot-assisted surgery

Robot-assisted surgery is the latest development in the larger movement of endoscopy, a type of minimally invasive surgery--the idea being that less invasive procedures translate into less trauma and pain for patients. Surgery through smaller incisions typically results in less scarring and faster recovery. It's not that robots are changing the basics of surgery. Surgeons are still cutting and sewing like they have been for decades. Robots represent a new computer-assisted tool that provides another way for surgeons to work.

Rather than cutting patients open, endoscopy allows surgeons to operate through small incisions by using an endoscope. This fiber optic instrument has a small video camera that gives doctors a magnified internal view of a surgical site on a television screen.

In abdominal endoscopy, known as laparoscopy, surgeons thread the fiber optic instrument into the abdomen. First performed in the late 1980s, laparoscopy is now routine for many procedures, such as surgery on the gallbladder and on female organs.

With robotic surgical systems, surgeons don't move endoscopic instruments directly with their hands. Instead, surgeons sit at a console several feet from the operating table and use joysticks similar to those used in video games. They perform surgical tasks by guiding the movement of the robotic arms in a process known as tele-manipulation.

MODERN ROBOTIC SURGERY SYSTEMS

GENERAL LAYOUT OF A ROBOTIC SURGICAL SYSTEM

A General Surgical System consists of the following:

· Surgeon Console

· Image processing Equipment

· Endowrist Instruments

· Surgical Arm Cart

· High Resolution 3D Endoscope

TYPES OF ROBOTIC SYSTEMS

1. AESOP ROBOTIC SYSTEM

AESOP stands for Automated Endoscopic System for Optimal Positioning. Basically, it consists of one robotic arm, which holds the endoscope in position. Foot-pedals or voice activated software allow the physician to control the endoscope as required. This system was developed by Computer motion. AESOP is the first FDA approved robot for operating room assistance (1994).

2. Da VINCI SURGICAL SYSTEM

In July 2000, the FDA cleared da Vinci as an endoscopic instrument control system for use in laparoscopic (abdominal) surgical procedures such as removal of the gallbladder and surgery for severe heartburn. In March 2001, the FDA cleared da Vinci for use in general non-cardiac thoracoscopic (inside the chest) surgical procedures--surgeries involving the lungs, esophagus, and the internal thoracic artery. This is also known as the internal mammary artery, a blood vessel inside the chest cavity. In coronary bypass surgery, surgeons detach the internal mammary artery and reroute it to a coronary artery. In June 2001, the FDA cleared da Vinci for use during laparascopic removal of the prostate (radical prostatectomy).

The da Vinci is intended to assist in the control of several endoscopic instruments, including rigid endoscopes, blunt and sharp dissectors, scissors, scalpels, and forceps. The system is cleared by the FDA to manipulate tissue by grasping, cutting, dissecting and suturing.

In use, a surgeon sits at a console several feet away from the operating table and manipulates the robot's surgical instruments. The robot has three hands attached to a free-standing cart. One arm holds a camera (endoscope) that has been passed into the patient through small openings. The surgeon operates the other two hands by inserting fingers into rings.

The arms use a technology called EndoWrist--flexible wrists that surgeons can bend and twist like human wrists. The surgeon uses hand movements and foot pedals to control the camera, adjust focus, and reposition the robotic arms. The da Vinci has a three-dimensional lens system, which magnifies the surgical field up to 15 times. Another surgeon stays beside the patient, adjusting the camera and instruments if needed.

3. ZEUS SURGICAL SYSTEM

The most exciting product to date from Computer Motion is the Zeus minimal invasive surgical robot system. It is also the one making regular headlines in the second half of 1999 and early in 2000.

Minimal invasive surgery (MIS) has been around for over a decade now. About 4 million procedures are carried out annually around the world by surgeons using long slender devices to probe, cut and repair patient tissues and organs. While MIS has led to faster recovery time for patients, surgeons find the technique physically challenging because it limits precision and dexterity, and brings on fatigue more rapidly.

In introducing the AESOP robot, Computer Motion has already improved one element of MIS, namely support and positioning of endoscopic cameras. With the Zeus system, all the instruments are robotic. The surgeon, as seen above, can sit comfortably at a master console and control the slave robotic instruments using a pair of master manipulators. The following advantages are achieved:

The fatigue factor is substantially reduced as the surgeon is seated and does not have to constantly hold onto the instruments.

T

he robotic instruments follow the surgeon's motion while filtering out tremors. With motion scaling, they can also execute micro-movements which may be humanly impossible.

With robotic instruments, the incisions needed are even smaller than with previous MIS instruments, leading to fewer traumas on the patients and hence shorter recovery times.

Zeus has a similar setup to the Da Vinci system. It includes the following:

· A computer workstation

· A video display

· Hand controls to move table mounted with Surgical Instruments

· Endoscope inserted into patient

· A set of Working Robotic Arms

Using the Zeus system, surgeons have achieved the following remarkable milestones:

In France, a series of operations have been performed on infants to repair a condition known as patent ductus arteriosis. Using the Zeus robotic system, a surgeon was able to close an open artery with only 3 incisions of 0.2" diameter each on the patient's body, in contrast to the 4-5" opening and rib cage separation which were previously necessary.

In Canada, a surgeon using the Zeus system was able to perform a bypass procedure on a beating heart, again with small incisions only rather than a split chest. The patient was able to return home the day after the operation

FUTURE SCOPE

1. TELESURGERY

Telesurgery is basically Robotic Surgery that is done across long distances. This means that the surgeon and the patient are at two different places while the surgery is carried out.

World's First Telesurgery :

On September 7, 2001 a doctor in New York removed the diseased gallbladder of a 68-year-old patient in Strasbourg, France. The surgeon used a computer with a high-speed network connection to move robotic tools in the French operating room.

Someday doctors may be able to use this technology to operate on patients in dangerous or inaccessible locations.

2. THE HEALING TOUCH

Research is being done to allow robots experience ‘Robotic Feeling’ of the patients body tissues. Sensors are being developed to send three-dimensional information of organs to tiny pins on the surgeon’s fingertips. The doctor can then feel changes in texture or the strength of his grip. This technology may be used to detect lung tumors or to work on delicate tissues.

3. VOICE CONTROLLED SURGERY

The microphone and headset that a surgeon is wearing while Voice Controlled surgery allows him to control robotic surgical instruments and cameras, as well as room lighting and other equipment, with voice commands. This frees the other operating room personnel from adjusting equipment. Voice Command is the basic tool for HERMES robotic system.

4. ROBOTIC BRAIN SURGERY

Robotic surgical tools give the doctor finer control over delicate movements and more accurate pinpointing of the diseased area in the Brain. This allows the surgery to be performed without fitting patients with a painful, cumbersome immobilizing frame that is needed for traditional brain surgery.

5. PRACTICE MAKES PERFECT

Doctors at the Surgical Planning Lab in UK can use 3D images of their patients to see the shapes of tumors and to practice surgeries. This technology is also used to track changes in the body over time, either for disease sufferers or for aging patients.

NASA is developing a robotic probe to detect the shape of brain tumors. The robot’s precise movements and the probe’s thin wires cause less damage to the brain than traditional surgery.

REFERENCES

1. Science and Technology Review, June 1998.

2. en.wikipedia.org

3. www.o-keating.com

4. SEMINAR TOPIC FROM ::