WO2009095915A1

WO2009095915A1 - Distal Head Units for Endoscopes

Info

Publication number: WO2009095915A1
Application number: PCT/IL2009/000112
Authority: WO
Inventors: David Nitsan; Shay Dubi
Original assignee: Jetprep Ltd.
Priority date: 2008-01-29
Filing date: 2009-01-29
Publication date: 2009-08-06

Abstract

The present invention is directed to a jet spray head unit suitable for being assembled circumferentially around an elongate medical instrument, comprising a ring-shaped element that is fitted with at least a first set of distally-directed apertures that extend from the distal face to the proximal face of said element, wherein each of said apertures is adapted such that the proximal end thereof may be connected to a source of pressurized irrigation fluid. The present invention further encompasses a method of treatment using said spray head unit.

Description

DISTAL HEAD UNITS FOR ENDOSCOPES

Field of the invention

The present invention relates to spray heads that are constructed such that they may be integrated into standard colonoscopes (or other endoscopes) . The spray heads of the present invention may be used to cleanse the colon and to prepare the bowel for endoscopic procedures. The clearer work space thereby obtained significantly improves the ease and accuracy with which the various diagnostic and/or therapeutic procedures may be performed using the endoscope. The device of the present invention may also be used to spray solutions containing therapeutic agents onto targeted areas within the colon.

Background of the invention

During colonoscopy procedures the physician inserts the colonoscope manually and navigates the device by visualizing the internal path using the integrated camera. Despite the use of various pre-colonoscopy cleansing regimes, in many cases the operator's field of view is severely restricted by fecal debris and other particulate matter that is left behind in the colonic lumen or other body passage.

Various attempts have been made to provide procedures and means for washing the colonic lumen prior to performing a colonoscopic investigation. The diagnostic accuracy and the therapeutic safety of colonoscopy (as well as of other diagnostic/therapeutic procedures such as virtual colonoscopy, sigmoidoscopy and barium enemas) depend, to a large extent, on the quality of the colonic cleansing or preparation. The ideal preparation for colonoscopy would reliably empty the colon of all fecal material in a rapid fashion without causing damage to the colonic tissues. An ideal preparation would also minimize or eliminate any patient discomfort. Common preparations for cleansing include diet in combination with a cathartic agent, polyethylene glycol preparations, gut lavage and phosphate preparations (oral sodium phosphate and tablet form of sodium phosphate) . The use of each of these techniques, however, has significant limitations,

A need therefore exists for a safe, reliable and efficient device and method for cleaning the colonic (or other) lumen prior to, and/or during, endoscopic procedures.

Summary of the invention

The present invention provides a distal head device which is capable of being fitted onto a standard colonoscope (or other endoscopic device) . The distal head is an essentially toroidal or ring-shaped element fitted with a plurality of apertures, some of which are in the form of small-diameter nozzles which are capable of being connected (by means of tubing, for example) to a source of pressurized fluid, thereby producing a cleansing fluid spray, and directing said spray to the desired parts of the body cavity being cleaned. In addition, in most embodiments of the present device, the distal head also possesses larger apertures which are adapted for connection to a suction line, such that they may be used for the removal of fecal debris and other particulate matter from the body cavity being cleaned.

The distal head of the present invention may be formed such that it may readily be fitted over, around or in the distal part of the colonoscope. Alternatively, the spray head may be adapted for integration into other portions of the colonoscope . The assembly of the device may be accomplished prior to the colonoscopy procedure or, alternatively, the device may be fitted onto the proximal part of the colonoscope after the latter has been introduced into the patient, as will be explained in more detail hereinbelow.

It should be noted that the term 'distal' as used throughout this disclosure is taken to refer to the direction away from the operator and into the subject's body. Thus, when used to describe an extremity of a device or instrument (e.g. colonoscope) , the terms "distal portion" and the like refer to those parts of said devices and instruments which will be inserted the furthest into the colon or other body passage. The term 'proximal' thus refers to the opposite direction, orientation or region.

The present invention is primarily directed to a jet spray head unit suitable for being assembled circumferentially around an elongate medical instrument, comprising a ring- shaped element that is fitted with at least a first set of distally-directed apertures that extend from the distal face to the proximal face of said element, wherein each of said apertures is adapted such that the proximal end thereof may be connected to a source of pressurized irrigation fluid.

In one preferred embodiment, the above-disclosed spray head unit further comprises a second set of distally-directed apertures which are adapted such that the proximal end of each said aperture may be connected to a suction line.

In another preferred embodiment, the distal opening of each of the second set apertures is larger than the distal opening of each of the first set apertures. In a further preferred embodiment, the spray head unit according to the present invention may further comprise a plurality of apertures located on the external circumferential surface of said unit.

Although the device of the present invention may be constructed in a number of different ways, in one preferred embodiment the spray head unit comprises a proximal ring, a distal ring and a separating ring that intervenes between said proximal and distal rings.

In some embodiments of the device of the present invention, the aforementioned apertures may be distributed around the distal face of the spray head unit in an essentially even manner. In other embodiments, however, the apertures are arranged around the distal face of the head unit in an asymmetric, eccentric manner with respect to the imaginary longitudinal (axis passing through the center of said unit, such that the width of the distal face of said unit is nonuniform, and such that there are more apertures concentrated in one region of the distal face than in another region. This particular configuration has the advantage that it permits larger spray and suction apertures to be incorporated into the distal face of the device. In one version of this embodiment, the distal face of the head unit is crescent- shaped.

In another aspect, the spray head unit comprises three or more concentric rings or tubes, such that the distally- directed apertures are provided in the form of annular passages between adjacent rings or tubes.

In one preferred version of the embodiment described immediately hereinabove, the inner diameter of the inner ring or tube is less than the external diameter of the elongate medical device around which the device will be fitted. Furthermore, said inner ring or tube is constructed from an elastic material that permits radial expansion thereof.

In another preferred version of this embodiment, one or more of the annular passages is provided with one or more deflectors at the distal opening thereof, wherein said deflectors are capable of altering the exit angle of fluid flowing distally through said passage (s).

All of the embodiments of the distal head unit disclosed above may be constructed such that they are suitable for use together with any elongate medical instrument, such as an endoscope or catheter. In one particularly preferred embodiment, the head unit is suitable for being assembled around an endoscope such as (but not limited to) a colonoscope, sigmoidoscope, duodenoscope, bronchoscope etc. Most preferably, the endoscope is a colonoscope.

The present invention is also directed to a jet spray head unit comprising at least a first set of distally-directed apertures that extend from the distal face of an endoscope, wherein said distal end has been adapted to accommodate said apertures, and wherein each of said apertures is adapted such that the proximal end thereof may be connected to a source of pressurized irrigation fluid.

In one embodiment of this aspect of the invention, the apertures are disposed around the distal face of the endoscope in an essentially annular distribution. In another embodiment, the distal region of the endoscope has a larger diameter than the body of said endoscope, such that there is room to accommodate the distally-directed apertures. In one alternative embodiment of this version of the device, the distal region is capable of being inflated as a result of the internal fluid pressure of washing fluid introduced therethrough .

In one preferred version of this aspect of the invention, the distal head unit is incorporated into an endoscope such as a colonoscope, sigmoidoscope, duodenoscope, bronchoscope, and so on.

In another aspect, the present invention is further directed to a stand-alone jet spray head unit suitable for passage through the working channel of an endoscope, wherein said head unit has a narrow proximal part suitable for connecting said unit with one or more conduits and a broader distal part, the external surface of which is pierced by one or more of the following sets of apertures:

a) Forward-pointing jets; b) Jet nozzles directed at an angle other than 90 degrees to the distal face of the device; c) Radially outward-pointing jets; d) A rotatable ring that is capable propel liquids introduced into said head unit radially; e) Backward-pointing jets.

In this embodiment of the device of the invention, the various nozzles, apertures and rings are in fluid contact with channels that open into the narrow proximal portion of the device, to which may be connected one or more conduits supplying irrigation fluid to said device. In one version of this embodiment, the device is also fitted with suction apertures that are in fluid contact with a further set of channels that may be connected at their proximal end to a suction line attached to the narrow, proximal portion of the device.

The present invention also provides methods for cleaning a body cavity and/or for producing a spray of fluid (e.g. containing a therapeutic or diagnostic agent) into a body cavity, using the above-disclosed devices. These methods will be described in more detail hereinbelow.

In another aspect, the present invention is also directed to a system for spraying fluid into a body cavity and/or for aspirating fluid therefrom, comprising: a) a jet spray head unit suitable for being assembled circumferentially around an elongate medical instrument, as disclosed hereinabove; b) a reservoir containing the fluid to be sprayed; c) a pumping device connected to said reservoir d) one or more conduits for transporting said fluid to a first set of apertures or nozzles on said jet spray head unit; and optionally further comprising: e) one or more conduits connected at their proximal ends to a negative pressure source and at their distal ends to a second set of apertures on said jet spray head unit; and f) a control unit for controlling the distally-directed flow of fluid to be sprayed through said first set of apertures or nozzles and/or the proximally-directed flow of fluid aspirated through said second set of apertures.

In one preferred embodiment of the system of the present invention, the control unit is capable of separately controlling the distally-directed flow of fluid to some or all of the first set apertures or nozzles. In this way, fluid spray may be selectively directed to certain chosen areas of the body cavity being treated. In addition to the components listed above, the system may also further comprise an endoscope upon which is assembled the jet spray head unit. The endoscope may be of any type commonly used in medical practice including (but not limited to) a colonoscope, bronchoscope, duodenoscope and sigmoidoscope .

The fluid to be sprayed by the above-defined system may be of many different types including (but not limited to) irrigation fluid or cleansing fluid (such as saline) , solutions or suspensions of therapeutic agents (such as chemotherapy agents; for example Xeloda, Oxaliplatin and CPT and biologic solutions such as Erbitux and Avastin) , and solutions or suspensions of diagnostic agents (such as iodine or barium-containing substances).

Suitable pumps that may be used for the purposes of pumping the fluid to be sprayed within the body cavity include (but are not limited to) simple water pumps, centrifugal, and peristaltic pumps. Similarly, suction pressure may be generated with water pumps and vacuum pumps, as are well know to the skilled artisan in the field.

Brief description of the figures

Figs. IA - ID depict a typical device of the invention constructed from three separate ring-like elements.

Figs. 2A - 2F show an alternate embodiment of the device of the present invention, in which the apertures are distributed in an asymmetrical manner around a crescent-shaped distal face. Fig. 3 depicts a stand-alone version of the distal spray head unit of the present invention.

Figs. 4A - 4F depict an embodiment of the present invention in which the spray and aspiration apertures are formed within the distal face of a colonoscope. In Fig. 4E, the spray and aspiration apertures are formed within an expanded-diameter distal portion of said colonoscope.

Figs. 5A - 5C show an alternative embodiment of the distal spray unit of the present invention, in which said spray unit is constructed of a series of concentrically arranged tubes.

Fig. 6 depicts one particular arrangement of the spray nozzles that may be used in conjunction with the various embodiments of the present invention.

Fig. 7 depicts alternative versions of the first, second and fifth embodiments of the device of the present invention, in which the generally circular cross-sectional from thereof is incomplete, thereby leaving an aperture or gap in the various components from which the device is constructed.

Detailed description of the preferred embodiments

Various exemplary, non-limitative embodiments of the present invention will now be described, with reference to the accompanying figures.

First Embodiment:

The first embodiment of the distal head of the present invention is a symmetrical design with small holes or nozzles on the distal face of the device; the holes have a small diameter (e.g. 0.3 to 1.2 mm), such that when provided with a fluid source, they are able to permit the high pressure exit of fluid jets therefrom. In addition to the aforementioned small diameter apertures, larger holes (having diameters in the range of, for example, 1 to 8 mm) suitable for use as aspiration channels may also be present. One or more tubes may connect the nozzles and suction apertures to a water pump and vacuum pump respectively, in such a way that the liquid and vacuum compartments are isolated from each other. Alternatively, or additionally, nozzles may also be present on the external circumferential surface of the device. The various components that form one particular example of this embodiment of the invention are illustrated in Figs. IA -ID.

Fig. IA shows an exploded view of the component parts of a device of this embodiment of the invention, generally indicated as 10. The figure depicts the various components of the device from their proximal ends. The device is essentially constructed of three sections: a front part 12, a rear part 14, and a separating ring 16 that intervenes between said front and rear parts.

Fig. IB is a view from the proximal aspect of the same device as illustrated in Fig. IA, following assembly of the three sections .

Fig. 1C is an exploded view of the component parts of the same device of this embodiment of the invention as shown in Fig. IA, from the distal aspect.

Fig. ID depicts the two abovementioned sets of apertures that open onto the distal surface of front part 12, namely the small diameter flow nozzles 20, (through which the washing fluid spray passes) and the larger diameter suction ports 18. Returning now to Fig. IA, it may be seen that the proximal surface of rear part 14 is fitted with a series of vacuum line connectors 22 (three such connectors are shown in the figure) for the purpose of connecting the device to a suction source (e.g. a hospital aspiration line). In addition, rear plate 14 is also fitted with wash line connectors 24 (three in number in Fig. IA), for the purpose of connecting device 10 to a pumping device.

As mentioned above, front part 12 and rear part 14 are separated by an intervening separating ring 16, the purpose of said ring being to provide complete functional separation between the aspiration and positive-pressure wash channels. It may be seen from Fig. IA that said ring 16 contains (in this example) three suction ports 18, which are positioned such that upon assembly of the three parts of the device, said ports become inserted into the corresponding vacuum line connectors 22.

A fully assembled device according to this embodiment is shown attached to the distal end of a standard colonoscope in Fig. IE. In this figure, the arrows indicate the direction of the fluid spray, which is directed in both forward and lateral directions.

In the case of blockage of the suction channels (e.g. with fecal debris or other particulate matter) , it is possible to reverse the flow and to cause flow at high pressure through the suction channel (i.e. in a proximal to distal direction) in order to clean it. Additionally, in some embodiments these channels may also be used, alternately, for both rinsing the colon and aspirating the fluid and loosened particulate matter. Second Embodiment:

The second embodiment of the present invention differs from the above-described first embodiment by virtue of the eccentric arrangement of the spray nozzles with respect to the imaginary longitudinal (i.e. proximal-distal) axis passing through the center of the device. In common with the first embodiment, this embodiment of the present invention has a series of small diameter holes on the front side of the device. These small holes act as nozzles with a diameter of around 0.3mm to 1.2mm. In addition, larger holes (having diameters in the range of, for example, 1 to 20 mm) , for use as aspiration apertures are also provided. One or more tubes connect the nozzles and suction apertures to a water pump and vacuum pump respectively. The liquids and vacuum compartment are isolated from each other. Alternatively or additionally further nozzles may be disposed on the external circumference surface of the device. The various component parts of this embodiment of the invention are illustrated in Figs. 2A - 2E. Figs. 2D and 2E illustrate the positioning of the small-sized flow nozzles 20 and the larger diameter suction ports 18. In Fig. 2D, the suction ports 18 are present as a series of discrete apertures, the device shown in Fig. 2E has a single, large crescent-shaped port 18' for maximum aspiration efficiency. Fig. 2F depicts a device of this embodiment that has been attached around the distal end of a colonoscope. The eccentric arrangement of the small diameter flow nozzles 20 in relation to the central axis of the device may be readily seen in this figure. A key advantage of this arrangement is that it permits larger suction apertures 18 to be incorporated into the device. Third Embodiment:

The third embodiment of the present invention is a standalone device which may be introduced through the working channel of the endoscope. Various different configurations of nozzles/holes for fluid jets and suction ports are possible. The following non-limitative list provides some examples:

A. Forward-pointing jets to cleanse the colonic lumen (or other body cavity) distal to the leading edge of the device

B. Jet nozzles directed at an angle other than 90 degrees to the distal face of the device (e.g. angled out toward the colonic wall) .

C. Radially outward-pointing jets.

D. The force of the water provides sufficient force to cause a ring to rotate and thus propel the washing liquids radially.

E. Backward-pointing jets either for device advancement or for breaking up fecal material just before it is aspirated through the working channel.

An example of this embodiment of the invention is shown in Fig. 3, wherein the letters in the figure correspond to the letters that identify the various jet/nozzle configurations in the preceding list. In addition, dedicated suction apertures (not shown) may also be present. A further alternative is to utilize the longitudinal gap that is present between wall of the working channel and the conduit that is connected to the device as a functional suction channel .

The present invention also provides a variant of this embodiment, wherein the distal head of the device has all of the features shown in Fig. 3, but wherein said head is constructed as an inflatable element. In this case, the device will be introduced into the working channel of the endoscope in its deflated state, in order to facilitate its insertion and passage to the distal end of said channel. Then, after the device has passed out of the working channel at its distal end, it is inflated, thereby becoming in closer contact with the internal walls of the colon (or other body cavity) . Using the jet nozzles, the inflated device can then be caused to slide and hover in an essentially frictionless manner through the body cavity lumen, but in close contact with the walls thereof, thereby increasing the efficiency of the cleansing procedure.

Fourth Embodiment :

Most modern colonoscopes possess an integrated single nozzle through which fluid may be propelled for the purpose of local cleansing. This nozzle, together with other standard features of colonoscopes that may be used in conjunction with the present invention, is illustrated in Fig. 4A. The elements indicated by lower case letters in the figure are listed below:

Current colonoscope configuration: a. illumination lights b. single nozzle for liquid introduction c. working channel (single or dual) d. camera and light source e. camera cleansing spray nozzle f . colonoscope

The fourth embodiment of the present invention comprises a standard distal extremity of a conventional colonoscope that has been adapted to provide an increased washing capability by virtue of the multiple washing-jet nozzles that penetrate the distal face. The nozzles may be located on the front surface of the colonoscope and direct jets forward, with an expanding angle or focusing angle. The latter possibility is illustrated in Fig. 4D. In either case, the advantage of the nozzle configuration is to provide a larger cleansing area. These multiple nozzles are indicated by the letter ¹G' in Fig. 4B.

The multiple nozzles of this embodiment of the present invention are either incorporated within the distal face of a standard colonoscope, or alternatively, incorporated within a custom-built expanded diameter distal head region.

The nozzles may be provided with the cleansing fluid through a series of internal cross linked channels, where one or more of said channels permit the forward flow of said fluid toward the nozzles. This movement of fluid through internal channels is schematically illustrated in Fig. 4C.

In an additional version of this embodiment of the invention, the integral distal head piece may be constructed as a flexible device that is capable of being inflated as a result of the internal fluid pressure of the washing fluid introduced therein. An example of this version is shown in Fig. 4E.

Supply tubes for suction and washing fluid (e.g. water or saline) can be assembled on the exterior surface of the colonoscope and attached thereto by a variety of means, including (but not limited to) a rubber sheath and tie-wraps (as illustrated in Fig. 4F) . Fifth Embodiment:

In an alternative embodiment, a flexible configuration is used in order to provide better compatibility with the body lumen. An example of this embodiment prior to attachment to the distal end of colonoscope is shown in Fig. 5A. The inner diameter of the device is assembled on the endoscope outer diameter. The free tension inner diameter is smaller than the endoscope diameter, and so when assembled the device stretches and enables a fast & fixed assembly. Fig. 5B depicts an example of this embodiment following assembly around the distal end of a colonoscope. Once the endoscope is assembled the "flow" lumen is tightened, thus creating a very narrow nozzle, wherein said nozzle is capable of providing a 360° fluid spray, which may be used either to provide a rinsing or cleansing fluid, or to administer liquid therapeutic agents to the colonic (or other body cavity) wall .

The outer lumen of this embodiment is intended to be used as a suction lumen for debris, liquids and fecal remains from the colon. This lumen may optionally contain one or more reinforcing structures which may assist said lumen to remain open in the face of the negative pressure (i.e. suction) forces .

A reflector is designed to cause deviation of the flow at a certain, pre-determined angle, utilizing surface tension forces. Fig. 5C schematically illustrates, in side view, the relationship between the suction ports 18" and the flow nozzles 20". The enlarged view in the central part of the figure shows reflector 28 located within flow nozzle 20". As shown in the figure, said reflector 28 serves to change the direction of the fluid flow such that it exits flow nozzle 20" at a fixed, predetermined angle. Nozzle design:

Various different types of nozzle structure may be used in order to optimize flow and to reduce turbulent flow, as well as to determine the desired shape and size of the fluid droplets and exit angle of the spray that leaves the nozzle. For example, the fluid may be directed such that it exits the nozzle as a fine, pointed linear jet. Alternatively, the nozzle may be designed such that the fluid spray leaving therefrom may be conical in shape, with predetermined opening angles, for example 60, 90 or (fully opened) 360 degrees. Both the linear jet and the conical sprays are illustrated in the lower part of Fig. 6. Two of the nozzle geometry considerations (i.e. size of nozzle aperture, and the use of a pre-constriction taper in order to reduce turbulent flow) that are important in determining the shape and size of the fluid spray are shown in the upper part of Fig. 6. Clearly, the size and shape of the fluid jets leaving the nozzles may have a large impact on the type of washing forces that may be exerted on the colonic wall. For example, a very fine jet, leaving the nozzle under high pressure will be very effective at dislodging stubbornly-attached, hard fecal matter, albeit over a relatively small surface area.

Materials and construction of the device:

In most of the embodiments of the present invention, the distal spray/suction head is constructed from biocompatible materials that are well known to the skilled artisan, including, but not limited to, bio-compatible plastics, metal, silicone and rubber resins. The device may be constructed from these materials by means of standard manufacturing techniques such as injection molding, machining, extrusion, and so on. Following their manufacture, the devices of the present invention may be sterilized by means of autoclaving, or by treatment with alcohols and/or detergents. The distal head devices of the present invention are intended for use with standard colonoscopes and therefore will be manufactured such that the internal and external dimensions thereof are appropriate for the assembly of said devices on, in or around the distal portion of such colonoscopes.

The distal head device of the present invention is typically used in conjunction with sterile, biocompatible and medically-acceptable cleaning fluids such as water, polyethylene glycol containing solutions (e.g. GoLYTELY) and physiological saline. The pressurized cleaning fluid may be brought to the distal head unit by means of a variety of pumping devices (e.g. simple water pumps, centrifugal, and peristaltic pumps) , as are well known to the skilled artisan in this field.

Methods of use:

In another aspect, the present invention is also directed to a method for cleaning a body lumen (such as the colonic lumen) in a mammalian (preferably human) subject, wherein said method comprises the steps of:

a) fitting a distal head device of the present invention, as disclosed and described hereinabove, onto the distal end of a colonoscope) or other endoscope; b) introducing the colonoscope with attached distal head into the colon (or other body passage) of said subject; c) providing a pressurized supply of cleaning fluid to the spray nozzles on said distal head device, such that the cleaning fluid is sprayed out of said nozzles into the body cavity to be treated; and d) providing negative suction pressure to tubing connected to the aspiration apertures present in said distal head device, such that fecal debris and/or other particulate matter present with in the body- lumen is removed therefrom,

wherein steps (c) and (d) may be performed sequentially or simultaneously.

In another embodiment of the above-disclosed method a distal head device of the type described hereinabove in relation to the third main embodiment is introduced into the working channel of a colonoscope, instead of being assembled around the distal end thereof.

The present invention also provides a method for cleaning a body lumen in a mammalian subject, wherein said method comprises the steps of:

a) introducing the colonoscope (or other endoscope) into the colon (or other body passage) of said subject; b) fitting a distal head device of the present invention, as disclosed and described hereinabove, onto the proximal end of a colonoscope (or other endoscope) ; c) sliding said distal head device along said colonoscope in a distal direction until it becomes positioned close to the distal end of said colonoscope; d) providing a pressurized supply of cleaning fluid to the spray nozzles on said distal head device, such that the cleaning fluid is sprayed out of said nozzles into the body cavity to be treated; and e) providing negative suction pressure to tubing connected to the aspiration apertures present in said distal head device, such that fecal debris and/or other particulate matter present with in the body lumen is removed therefrom,

wherein steps (d) and (e) may be performed sequentially or simultaneously.

In order to implement step (c) of this alternative version of the method, modified, open-ring versions of the various embodiments of the device may be used. Thus, Fig. 7 depicts alternative versions of the first, second and fifth embodiments of the device. As may be seen in this figure, each of said embodiments differs from those described above, in that the generally circular cross-sectional from thereof is incomplete, thereby leaving an aperture or gap in the various components from which the device is constructed. These incomplete-ring devices may then be readily fitted around the circumference in the proximal region of the colonoscope, by applying manual pressure to said devices, such that the aperture enlarges sufficiently to enable the device to encompass the colonoscope.

Following placement of the incomplete-ring device around the proximal part of the colonoscope circumference, said device may be advanced towards the distal part of the colonoscope in one of various ways. In one embodiment, pushing forces are exerted through semi-rigid tubes or guides, using inwardly facing water/air jets to enable hovering of the device on the colonoscope with reduced friction, and backward-facing jets to push the device forward. One advantage of this embodiment is that the colon may be cleaned during advancement of the device from its proximal assembly position to its distal working position. In an alternative embodiment, pulling forces may be applied to the device by means of a wire or cord connected to the distal part of the colonoscope. In this embodiment, a protective sheath may be used to reduce friction and damage to the colon tissue while introducing the device between the sheath and colonoscope. Once the device is in the desired location on the colonoscope it can be used as described in the other embodiments. The same advancement procedure may then be used after the colonoscope has been navigated to another location within the colon.

The embodiment of the method of the invention described immediately above (together with the incomplete-ring versions of the device needed for its implementation) is particularly useful for assessing the need for a cleaning device after a colonoscopic procedure has already begun, without the need for first removing the colonoscope from the body.

The above-defined methods of cleaning a body lumen or body cavity may also be used to introduce a fluid spray into said lumen or cavity, wherein the fluid to be sprayed may be inter alia an irrigation fluid or cleansing fluid (such as saline) , solutions or suspensions of therapeutic agents (such as chemotherapy agents; for example Xeloda, Oxaliplatin and CPT and biologic ' solutions such as Erbitux and Avastin) , and solutions or suspensions of diagnostic agents (such as iodine or barium-containing substances). In the case of methods aimed at introducing such a fluid spray into a body passage, said methods may either include the aspiration step defined hereinabove in the earlier-disclosed methods, or may omit such a step.

It should be noted that whenever the above description refers to a colonoscope, said description may equally be applied to other sorts of endoscope, including (but not limited to) bronchoscopes, sigmoidoscopes, duodenoscopes, and so on.

For the sake of completeness it should be noted that the terms "nozzle" and "aperture" (when referring to the first set of spray apertures) are used interchangeably in this disclosure .

While specific embodiments of the invention have been described for the purpose of illustration, it will be understood that the invention may be carried out in practice by skilled persons with many modifications, variations and adaptations, without departing from its spirit or exceeding the scope of claims.

Claims

1. A jet spray head unit suitable for being assembled circumferentially around an elongate medical instrument, comprising a ring-shaped element that is fitted with at least a first set of distally-directed apertures that extend from the distal face to the proximal face of said element, wherein each of said apertures is adapted such that the proximal end thereof may be connected to a source of pressurized irrigation fluid.

2. The spray head unit according to claim 1, wherein said unit further comprises a second set of distally-directed apertures which are adapted such that the proximal end of each said aperture may be connected to a suction line.

3. The spray head unit according to claim 2, wherein the distal opening of each of the second set apertures is larger than the distal opening of each of the first set apertures.

4. The spray head unit according to claim 3, further comprising a plurality of apertures located on the external circumferential surface of said unit.

5. The spray head unit according to claim 1, wherein said unit comprises a proximal ring, a distal ring and a separating ring that intervenes between said proximal and distal rings.

6. The spray head unit according to claim 1, wherein the apertures are arranged around the distal face of said unit in an eccentric manner with respect to the imaginary longitudinal (axis passing through the center of said unit, such that the width of the distal face of said unit is non^¬ uniform.

7. The spray head unit according to claim 6, wherein the distal face of said unit is crescent-shaped.

8. The spray head unit according to claim 1, wherein said unit comprises three or more concentric rings or tubes, such that the distally-directed apertures are provided in the form of annular passages between adjacent rings or tubes.

9. The spray head unit according to claim 8, wherein the inner diameter of the inner ring or tube is less than the external diameter of the elongate medical device, and wherein said inner ring or tube is constructed from an elastic material that permits radial expansion thereof.

10. The spray head unit according to claim 8, wherein one or more of the annular passages is provided with one or more deflectors at the distal opening thereof, wherein said deflectors are capable of altering exit angle of fluid flowing distally through said passage (s).

11. The spray head unit according to any one of the preceding claims, wherein said unit is suitable for being assembled around an endoscope.

12. The spray head unit according to claim 11, wherein the endoscope is selected from the group consisting of colonoscope, sigmoidoscope, duodenoscope and bronchoscope.

13. A jet spray head unit comprising at least a first set of distally-directed apertures that extend from the distal face of an endoscope, wherein said distal end has been adapted to accommodate said apertures, and wherein each of said apertures is adapted such that the proximal end thereof may be connected to a source of pressurized irrigation fluid.

14. The spray head unit according to claim 13, wherein the apertures are disposed around the distal face of the endoscope in an essentially annular distribution.

15. The spray head unit according to claim 13, wherein the distal region of the endoscope has a greater diameter than the body of said endoscope in order to accommodate the distally-directed apertures.

16. The spray head unit according to claim 13, wherein the distal region is capable of being inflated as a result of the internal fluid pressure of washing fluid introduced therethrough.

17. The spray head unit according to any one of claims 13 to 16, wherein the endoscope is a colonoscope.

18. A jet spray head unit suitable for passage through the working channel of an endoscope, wherein said head unit has a narrow proximal part suitable for connecting said unit with one or more conduits and a broader distal part, the external surface of which is pierced by one or more of the following sets of apertures: a) Forward-pointing jets; b) Jet nozzles directed at an angle other than 90 degrees to the distal face of the device; c) Radially outward-pointing jets; d) A rotatable ring that is capable propel liquids introduced into said head unit radially; e) Backward-pointing jets.

19. A method for cleaning a body cavity in a mammalian subject, wherein said method comprises the steps of: a) fitting a distal head device according to any one of claims 1-10 onto the distal end of an endoscope;

b) introducing the endoscope with attached distal head into the body cavity of said subject;

c) providing a pressurized supply of cleaning fluid to the spray nozzles on said distal head device, such that the cleaning fluid is sprayed out of said nozzles into the body cavity to be treated; and

d) providing negative suction pressure to tubing connected to a second set of apertures present in said distal head device, such that debris and/or other particulate matter present within the body lumen is removed therefrom,

wherein steps (c) and (d) may be performed sequentially or simultaneously.

20. A method for cleaning a body cavity in a mammalian subject, wherein said method comprises the steps of: a) introducing an endoscope into the body cavity of said subject;

b) fitting a distal head device according to any one of claims 1-10 onto the proximal end of said endoscope;

c) sliding said distal head device along said endoscope in a distal direction until it becomes positioned close to the distal end of said endoscope;

d) providing a pressurized supply of cleaning fluid to the spray nozzles on said distal head device, such that the cleaning fluid is sprayed out of said nozzles into the body cavity to be treated; and

e) providing negative suction pressure to tubing connected to a second set of apertures present in said distal head device, such that debris and/or other particulate matter present within the body lumen is removed therefrom,

wherein steps (d) and (e) may be performed sequentially or simultaneously.

21. A method for introducing a fluid spray into a body cavity in a mammalian subject, wherein said method comprises the steps of: a) fitting a distal head device according to any one of claims 1-10 onto the distal end of an endoscope;

b) introducing the endoscope with attached distal head into the body cavity of said subject; and

c) providing a pressurized supply of the fluid to be sprayed to the spray nozzles on said distal head device, such that said fluid is sprayed out of said nozzles into the body cavity to be treated;

22. A method for introducing a fluid spray into a body cavity in a mammalian subject, wherein said method comprises the steps of: a) introducing an endoscope into the body cavity of said subject;

b) fitting a distal head device according to any one of claims 1-10 onto the proximal end of said endoscope; c) sliding said distal head device along said endoscope in a distal direction until it becomes positioned close to the distal end of said endoscope; and

d) providing a pressurized supply of the fluid to be sprayed to the spray nozzles on said distal head device, such that said fluid is sprayed out of said nozzles into the body cavity to be treated;

23. The method according either claim 21 or 22, wherein the fluid to be sprayed is selected from a solution containing a therapeutic solution or suspension, an irrigation fluid or a diagnostic solution or suspension.

24. The method according to any one of claims 19 to 22, wherein the endoscope is selected from the group consisting of colonoscope, sigmoidoscope, duodenoscope and bronchoscope.

25. The method according to any one of claims 19 to 22, wherein the mammalian subject is a human subject.

26. A system for spraying fluid into a body cavity comprising:

a) a jet spray head unit suitable for being assembled circumferentially around an elongate medical instrument, as defined in any one of claims 1 to 10;

b) a reservoir containing the fluid to be sprayed;

c) a pumping device connected to said reservoir

d) one or more conduits for transporting said fluid to a first set of apertures or nozzles on said jet spray head unit; and optionally further comprising: e) one or more conduits connected at their proximal ends to a negative pressure source and at their distal ends to a second set of apertures on said jet spray head unit; and

f) a control unit for controlling the distally-directed flow of fluid to be sprayed through said first set of apertures or nozzles and/or the proximally-directed flow of fluid aspirated through said second set of apertures.

27. The system according to claim 26, wherein the control unit is capable of separately controlling the distally- directed flow of fluid to some or all of the first set apertures or nozzles.

28. The system according to claim 26, further comprising an endoscope upon which is assembled the jet spray head unit.

29. The system according to any one of claims 26-28, wherein the fluid to be sprayed is selected from the group consisting of irrigation fluid, cleansing fluid, solutions or suspensions of therapeutic agents and solutions or suspensions of diagnostic agents.