HANDHELD BATTERY OPERATED LAPAROSCOPIC ULTRASOUND DOPPLER STETHOSCOPE
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BACKGROUND OF THE INVENTION
Field of the Invention
The present invention relates to laparoscopic surgical apparatus and ultrasound doppler stethoscopes 10 in general and in particular to a handheld battery operated laparoscopic ultrasound doppler stethoscope.
Description of Prior Art
Laparoscopic and endoscopic surgical apparatus are similar in that both comprise elongated tubular
15 members which are used in various types of surgical procedures.
A conventional flexible fiberoptic endoscope comprises an assembly of an elongated flexible fiberoptic cable and an adjacent flexible surgical
20 instrument receiving channel, often referred to as a biopsy channel. In a typical surgical procedure using the endoscope, a flexible surgical instrument is inserted in the biopsy channel for performing the surgery, e.g. a biopsy, on internal organs and tissues
25 as in an intestinal tract.
In the performance of the surgical procedure, the fiberoptic cable is used to illuminate and view the surgical area and the operative end of the surgical instrument at the surgical site. Because the
3Q fiberoptic cable and the surgical instrument are both flexible and intimately coupled in the endoscope, it is not possible to move or otherwise manipulate the surgical instrument without affecting the field of view of the surgeon. Such changes in the field of view of a surgeon during a surgical procedure tends to restrict the use of the endoscope to certain procedures and generally increases the difficulty of the procedures in which it is used.
An ultrasound doppler apparatus comprises electronics and a probe tip for transmitting an ultrasound signal at a predetermined frequency and detecting the echo thereof from a body. The body may be a solid body or one which comprises any combination of fluids and gases which provides a discontinuity in the acoustic impedance at the gas-fluid interface. If the body from which the transmitted signal is reflected is moving, the frequency of the reflected signal is shifted from the frequency of the transmitted signal as a function of the direction and velocity of the moving body. For example, if the direction of the moving body is away from the probe tip, the frequency of the detected signal is shifted downward from the transmitted frequency. On the other hand, if the direction of the moving body is toward the probe tip, the frequency of the detected signal is shifted upward from the transmitted frequency. In either case, the magnitude of the shift in frequency is a function of the velocity of the moving body.
Ultrasound doppler apparatus as described above has been used for many years as a simple noninvasive aid in the assessment of arterial and venous blood flow. In these applications, the probe tip is applied to the exterior of a body part, e.g. arm, leg, head. etc. , and, with appropriate frequencies and range gating techniques employed, information concerning the •> arterial and/or venous blood flow is obtained. More recently, within the past five years,
? 5 experiments have been carried out in which a flexible doppler probe has been used in place of a surgical instrument in the biopsy channel of a flexible fiberoptic endoscope to obtain information about the underlying vascular supply of interior organs and 10 tissues such as, for example, the intestinal wall of the upper gastrointestinal tract. In one of these experiments, as reported in the article, AN ENDOSCOPIC DOPPLER PROBE FOR ASSESSING INTESTINAL VASCULATURE BY R. . Martin et al. , Ultrasound in Medicine and 15 Biology, Volume 11, Number 1, January/February 1985, particular attention was directed to arterial structures which clinically pose a risk of bleeding when performing endoscopic papillotomy, a therapeutic technique in which the papilla of Vater is cut to 20 release bile duct stones.
In σholosystectomies which involve the removal of a gall bladder, splanchnic nerve surgery which involves the severing of stomach nerves to reduce acid production in the treatment of ulcers, bowel 25 resections and other types of surgery, it is just as necessary to identify and distinguish arteries, veins, ducts and nerves. Unfortunately, however, these organs are not located in the same place in every body. For example, it is well known that the gall 30 bladder artery and the gall duct have as many as six different locations in as many bodies and that they are normally buried in fatty tissue which makes their identification difficult. Similarly, it is very difficult to identify the arteries and veins in bowel resections because they are normally embedded in membranes and because much of the bowel's blood supply is provided by veins from the liver. Because conventional fiberoptic endoscopes with doppler probes as described above are flexible and intimately coupled such that, as the probe is moved, the surgeon's field of view changes, their use in identifying embedded vascular structures in laparotomic surgeries, such as cholosystectomy, splanchnic nerve, bowel resection and similar surgeries is severly limited and open abdominal surgery in such cases is usually necessary. Needless to say, open abdominal surgery is far more risky to the patient, much more expensive, and generally requires a much longer period of recuperation than endoscopic surgery.
As indicated above, laparoscopic surgery is similar to endoscopic surgery in that the surgical instrument used comprises an elongated tubular member. Like endoscopic surgery, it is far less risky, less costly, and generally requires a much shorter period for recuperation than open abdominal surgery. The two types of surgery differ, however, in that in laparoscopic surgery, now popularly known as band-aid surgery, a plurality of small surgical incisions are required to provide a passageway into a body cavity through which small diameter rigid tubes are passed to the surgical site. In a first one of the tubes, a fiberoptic cable is provided for illuminating and viewing the surgical site. In a second one of the tubes a surgical instrument is provided for use in performing surgery at the site. .An advantage of laparoscopic surgery over endoscopic surgery is that in endoscopic surgery, as the surgeon moves the surgical instrument during a surgical procedure, the field of view moves, while in laparoscopic surgery, as the surgeon moves the surgical instrument during a surgical procedure, the field of view remains stationary.
While laparoscopic surgery has many advantages as discussed above, its use has been prevented or severely restricted in cases in which inadvertent perforation of an artery or vein would significantly place at risk the health and safety of a patient. This is. because, heretofore, there has been no apparatus or method for readily locating and identifying embedded vascular structures within a body cavity, thus necessitating open abdominal surgery.
SUM.MARY OF THE INVENTION In view of the foregoing, a principal object of the present invention is a handheld battery operated laparoscopic ultrasound doppler stethoscope.
In accordance with the above object, there is provided an ultrasound doppler stethoscope comprising a body member and an elongated rigid doppler probe.
The body member comprises conventional electronic circuits used for generating and transmitting ultrasound signals at a predetermined frequency, conventional electronic circuits for processing doppler shifted return signals, one or more electrical jacks for coupling the electronic circuits to a speaker, headphones and/or other signal indicating apparatus and a female probe jack for removably attaching the doppler probe to the electronics in the body member.
The doppler probe comprises an elongated removable rigid tubular member. The tubular member has an outside diameter small enough to permit the tubular member to be freely, but snugly, inserted into a laparoscopic tube which corresponds to those normally used for receiving surgical instruments in a laparoscopic surgical apparatus. On one end of the tubular member in the doppler probe there is fitted a male probe jack which is adapted to removably mate with the female probe jack in the body member. At the opposite end of the tubular member in the doppler probe, there is fitted an ultrasound transmitting and receiving transducer. The transducer and the male probe jack are interconnected by means of a coaxial cable.
In one embodiment of the present invention the doppler probe comprises stainless steel and other materials which can be repeatedly sterilized as by an autoclave.
In another embodiment of the present invention the doppler probe is disposable and comprises relatively inexpensive materials which can be discarded after a single use.
In practice, the ultrasound doppler stethoscope of the present invention is used in the same manner as a conventional laparoscopic surgical instrument in that once the probe of the stethoscope has been inserted in a properly positioned laparoscopic tube, it can be manipulated and moved about the surgical site without disturbing the field of view estabished by the fiberoptics of the laparoscope. The principal value of the ultrasound doppler stethoscope of the present invention is that there is now available an apparatus which can be used to locate and identify embedded vascular and duct structures 5 during laparoscopic surgery and thereby extend the use of conventional laparoscopic surgery to include surgeries which heretofore were not possible without undue risk to the health and safety of a patient.
Brief Description of the Drawings 10 The above and other objects, features and advantages of the present invention will become apparent from the following detailed description of the accompany drawings in which:
Fig. 1 is a side view of a handheld battery 15 operated laparoscopic ultrasound doppler stethoscope according to the present invention; and
Fig. 2 is an enlarged view of the doppler probe of the stethoscope of Fig. 1.
Detailed Description of the Drawings
20 Referring to Figs. 1 and 2, there is provided in accordance with the present invention a handheld battery operated laparoscopic ultrasound doppler stethoscope designated generally as 1. In the stethoscope 1 there is provided a main body member 2
25 and an elongated rigid doppler probe 3.
In the main body member 2 there is provided conventional electronics for generating ultrasound signals having a predetermined frequency, e.g. 8 MHz and conventional electronics for processing doppler
30. frequency shifted return signals, two 2.5 mm jacks for one or two headsets, or one headset and a tape recorder, or a speaker amplifier apparatus, a volume control and pushbutton power switch. The electronics, jacks, volume control and pushbutton power switches are conventional components which need not be described in detail herein but are commercially available and are used in the ultrasonic stethoscope, Model BF5A, manufactured by Medasonics of Fremont, California.
In the doppler probe 3 there is provided an elongated rigid tubular member 5. At the left end of the tubular member 5 there is provided an ultrasound signal transducer 6. Transducer 6 comprises a piezoelectric crystal. The piezoelectric crystal changes shape slightly when a voltage is applied to it. When the voltage oscillates at any frequency, the crystal vibrates at the same frequency, thus generating a sound wave of very low power. The sound wave is directed through the tissue of a patient and is reflected from the tissue interfaces, such as the surface of a blood vessel or the red blood cells within the vessel. A reflection from the moving blood cells is shifted slightly in frequency? higher if the cells are moving toward the crystal, lower if they are moving away. The reflected sound wave arriving at the same crystal that generated the original wave sets up tiny vibrations within the crystal which thereby generates a corresponding alternating voltage, the reverse of the process that generated the wave. This voltage differs slightly in frequency from the original generating voltage if the reflecting interface (blood cells) is moving. Reflections from stationary surfaces are unchanged in frequency and ignored by the instrument. The reflected signal is separated from the original voltage in a process similar to the operation of a transistor radio (AM band) , and the difference between the two frequencies is amplified. This difference is converted into an audible sound that indicates blood flow which can be monitored using the headphones, speaker or other indicating apparatus coupled to the electronics in the body member.
At the opposite end of the tubular member 5 and the narrow end of the body member 2 there is provided an attaching jack assembly 7 for removably attaching the doppler probe 3 to the body member 2 and the electronics therein. The jack assembly 7 comprises a conventional 3 mm stereophone jack assembly comprising a male and female plug connector. In a preferred embodiment of the present invention, the female connector 8 is permanently mounted in the body member 2 and the male connector 9 is permanently mounted in the end of the tubular member 5. The transducer 6 is connected to the male connecting member 9 by means of a coaxial cable 10.
The stethoscope 1 is intended to be used in connection with laparoscopic surgery and therefore the outside diameter of the tubular member 5 is chosen so that the tubular member 5 can be inserted in a conventional laparoscopic tube having a typical inner diameter of 11 mm. Of course, larger or smaller diameters may be used depending on the size of the laparoscopic tube. Likewise, typical laparoscopic tubes are approximately 6 inches in length. In a preferred embodiment of the present invention the length of the tubular member 5 is 12 inches, although shorter or longer lengths may be used in a particular application.
The doppler probe 3 comprises stainless steel and other materials which are suitable for repeated sterilization as by an autoclave. Alternatively, inexpensive plastic materials, or the like, which are compatible with human tissue and fluids may be used in a disposable version of the doppler probe 3.
The stethoscope of the present invention is intended to be used in conventional laparoscopic surgery in which a first laparoscopic fiberoptic tube is inserted in a body cavity along with a laparoscopic surgical instrument which will be used for performing the surgery. To use the stethoscope in the laparoscopic surgery, a laparoscopic trocar and tube assembly is inserted in the body cavity in the same manner as the two previously described tubular members. After the trocar is removed, the probe 3 of the stethoscope 1 is inserted through the laparoscopic tube. Since the probe 3 is separate from the fiberoptic tube, manipulation of the probe 3 at the surgical site will not disturb the field of view of the surgeon. This is the principal advantage of the present invention and allows for an extension of conventional laparoscopic surgery to include surgeries which heretofore had been too risky to perform due to the surgeon's inability to identify the location of arteries, veins and ducts with certainty.
While preferred embodiments of the present invention are described above, it is contemplated that various modifications may be made thereto without departing from the spirit and scope of the present invention. Accordingly, it is intended that the embodiments described be considered only as illustrative of the present invention and that the scope thereof should not be limited thereto but be determined by reference to the claims hereinafter provided and their equivalents.