US20050075581A1

Movatterモバイル変換

Info

Publication number: US20050075581A1
Application number: US10/420,197
Authority: US
Inventors: Jeffrey Schwindt
Original assignee: Individual
Current assignee: Tissue Extraction Devices LLC
Priority date: 2002-04-23
Filing date: 2003-04-22
Publication date: 2005-04-07
Also published as: US7749172B2; US20030199787A1; US20110092851A1

Abstract

A pneumatic circuit and other components are provided for the operation of a medical device. The pneumatic circuit provides controlled pressurized air to a medical device for use during a medical procedure.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Ser. No. 60/374,952 filed Apr. 23, 2002.

BACKGROUND OF THE INVENTION

The present invention relates to a pneumatic circuit, and particularly to a pneumatic circuit for use in the operation of an at least partially air-powered tool. More particularly, the present invention relates to a pneumatic circuit useful in the pneumatic operation of a medical device.

SUMMARY OF THE INVENTION

The present invention relates to one or more of the following features, elements or combinations thereof. A pneumatic control system is provided for use with a medical device, illustratively a suction biopsy device. The suction biopsy device has a cannula for insertion into a body to a point adjacent to a mass to be examined, and a rotating cutter device is housed within. The cannula has an orifice, and a pneumatic cylinder is coupled to the cutter for moving the cutter relative to the orifice.

A rinse or illustratively saline solution is provided for assisting in the removal of the mass to be examined. A suction is provided for assisting in the removal of the mass to be examined. The control system has an absence of electrical circuitry configured to control the operation of the suction biopsy device. Electrical power is illustratively provided only for the compressor and the vacuum.

The cannula defines an axis and the cutter is illustratively aligned coaxially with the cannula for rotation about the axis. A pneumatic motor actuates the rotational movement of the cutter. The pneumatic cylinder causes the cutter to move axially relative to the cannula.

A method of removing a tissue mass from a body is also provided. The method comprises the steps of inserting a hollow cannula having an aperture into the body such that the aperture is positioned adjacent to the tissue mass. Suction is provided to the cannula such that a portion of the tissue mass is pulled inside the cannula through the aperture. The cutter is pneumatically caused to move relative to the aperture so that the cutter cuts the portion of tissue mass from the remainder of the tissue mass. The cut portion of tissue mass is then transported through the cannula with the provided suction. The pneumatic movement of the cutter is controlled by a pneumatic circuit comprising a pressure sensor.

The control system drives a cutter blade connected to the biopsy device. The cutter blade moves from a recessed position to an extended position. The control system cycles the cutter between the recessed position and the extended position at a predetermined cycle rate, responding to user commands when determining whether to continue to cycle.

A pneumatically driven motor rotates the cutter. A pneumatically driven piston moves the cutter between the recessed position and the extended position. Pressurized gas is delivered to the pneumatic motor, and a saline supply is delivered to the cannula.

Suction assists in removing the mass from the body during a surgical procedure. The control system is configured to run continually but have cyclical elements responding to the continual operation.

Additional features of the disclosure will become apparent to those skilled in the art upon consideration of the following detailed description of preferred embodiments exemplifying the best mode of carrying out the invention as presently perceived.

BRIEF DESCRIPTION OF THE DRAWINGS

The detailed description particularly refers to the accompanying figures in which:

FIG. 1 is a top perspective partial view of a Breast Biopsy System having a hand wand, the Biopsy System including a pneumatic circuit internally, the circuit configured to operate the Biopsy System and hand wand;

FIG. 2 is a perspective view of the system shown inFIG. 1;

FIG. 3A is a view of the cannula of the hand wand inserted into a patient's breast adjacent a tissue mass, the cannula having an aperture positioned adjacent the mass;

FIG. 3B is a view similar to that ofFIG. 3A, showing a cylindrical cutter that has moved inside the cannula, thereby cutting away a portion of the tissue mass;

FIG. 4 is a view of an air compressor shown upside down with tie-down rails and springs attached;

FIG. 5 is a view of the compressor ofFIG. 4, showing the compressor right side up with additional fittings;

FIG. 6 is a view of a vacuum pump showing the tie-down rail and springs;

FIG. 7 is a view of the compressor ofFIGS. 4-5 and the vacuum pump ofFIG. 6 both installed in a console;

FIG. 8 is a view of a console mounting panel showing manifold subassemblies, a filter subassembly, and a terminal block subassembly mounted on the mounting panel;

FIG. 9 is a view of the console showing the mounting panel mounted in the console, and showing the cavity in the lower portion which houses the compressor and vacuum;

FIG. 10 is a view from the top of the console ofFIG. 8;

FIG. 11 is a view from the front of the open console similar to that ofFIG. 9, showing the compressor and vacuum pump mounted in the lower portion of the console and showing other components of the pneumatic circuit mounted in the upper portion of the console;

FIGS.12A-B are views of two embodiments of a water evaporation subassembly;

FIGS.13A-B show, respectively, the foot switch prior to attachment of tubing, and the foot switch partially assembled after the attachment of tubing;

FIG. 14 is a view of the terminal block subassembly;

FIGS.15A-B are perspective views of the two manifolds configured to route the pneumatic tubing within the console;

FIGS.16A-B are schematic representations of the pneumatic circuit elements;

FIG. 17 is a schematic representation of an evaporation valve portion of the pneumatic circuit;

FIG. 18 is another schematic representation of a portion of the pneumatic circuit;

FIGS.19A-D show specification drawings for the console;

FIG. 20A shows the configuration of the control panel;

FIG. 20B shows the configuration of the manifolds with relation to the filters and connection points;

FIGS.21A-D show diagrammatic representations of the manifolds depicting the ports and internal passageways associated with the manifolds;

FIG. 22A shows a top view of a pinch valve configured to control the flow of saline;

FIG. 22B is a front elevation view of the pinch valve shown inFIG. 22A, showing the tube positioned in the pinch valve, and showing the movement of the plunger between a flow position and a non-flow position;

FIGS.23A-D show specification drawings for the gasket;

FIGS.24A-B show a top view and a front elevation view, respectively, of a canister bracket;

FIGS.25A-D show front and side views of a pair of hose wrap pins;

FIGS.26A-B show a foot switch holder;

FIG. 27 shows a valve bracket;

FIGS.28A-B show an embodiment of tie-down rails;

FIGS. 29-33 show the test equipment used in testing certain elements in the pneumatic circuit in various stages of the test; and

FIGS.34A-C show parts listings of the various parts used in the construction of the Breast Biopsy System.

DETAILED DESCRIPTION OF THE DRAWINGS

One embodiment of the present disclosure is shown inFIGS. 1 and 2 in the form of aBreast Biopsy System2 having ahand wand4.Biopsy System2 illustratively includes aconsole6 having anaccess door8 and acontrol panel9 positioned toward the top of theconsole6.Biopsy System2 includes an internal pneumatic circuit10 (shown inFIGS. 8-12 and schematically inFIGS. 16-18) that is configured to operate amedical device70,illustratively hand wand4, as will be discussed in more detail below. It should be understood that as used herein,medical device70 can be any medical device that is powered at least in part by pneumatic pressure. The illustrativemedical device70 comprises ahand wand4, and such terms are used interchangeably throughout.

Biopsy System

2, and particularlyhand wand4, illustratively function in the following manner. A patient having a mass142 to be removed receives a local anesthetic and the mass is identified and located in the patient. Location methods may include ultrasound, magnetic resonance imaging (MRI), X-Ray, or any other method known in the medical industry. As can be seen inFIGS. 1 and 3A-B,hand wand4 illustratively includes a hollowed needle orcannula130 extending therefrom, thecannula130 having a sharpdistal end136 for facilitating piercing into the patient's body, and thecannula130 further having acutter134 positioned therein for rotational and axial movement relative to thecannula130.Cutter134 is illustratively a cylindrical blade, but other configurations are within the scope of the disclosure.Distal end136 is illustratively a frusto-conical stainless steel tip press-fitted on the end ofcannula130, the tip having a plastic cutting board (not shown) housed within for receivingcutter134 whencutter134 is at its full stroke position.

Anaperture132 is illustratively formed in the cylindrical wall ofcannula130 at its distal end. During operation, as shown in FIGS.3A-B, a physician insertscannula130 into the patient (i.e. the cannula is inserted into a woman's breast) such thataperture132 is positioned proximal to amass142 to be removed. While the cannula is being inserted into the patient's body, thecylindrical cutter134 is positioned insidecannula130 such thatcutter134 substantially closes offaperture132.Pneumatic circuit10 directs compressed air topneumatic cylinder26 in order to positioncutter134 at its full stroke position.

Aftercannula130 is in position in the patient's body,pneumatic circuit10 directs the retracting and advancing movement ofcutter134 relative to thecannula130 in response to signals from afoot switch16, aremote push button18, or apanel push button18A (seeFIG. 16B) operated by a medical technician or surgeon. Once the operator signals for the cutting to begin,pneumatic circuit10 directs vacuum pressure tohand wand4, and pneumatic circuit releases the compressed air from pneumatic cylinder26 (which is illustratively housed in hand wand4). Once compressed air is released frompneumatic cylinder26, a spring urges the plunger inpneumatic cylinder26 toward the retracted position, thereby causingcutter134 to move to the retracted position, consequently openingaperture132. Vacuum pressure is also applied bypneumatic circuit10 to the inside ofcannula130, causing a portion of themass142 to be drawn insidecannula130. While the portion of themass142 is drawn insidecannula130,pneumatic circuit10 sends compressed air tocylinder26, thereby movingcutter134 relative toaperture132 toward the extended, full-stroke position. At substantially the same time,pneumatic circuit10 further directs compressed air toward apneumatic motor138 housed inhand wand4.Pneumatic motor138 is coupled tocutter134 and causescutter134 to rotate about its axis insidecannula130. As a result of the rotational and axial movement ofcannula130,cutter134 cuts the portion of themass142 that extends inside thecannula130 as cutter moves towarddistal end136 ofcannula130.

Oncecutter134 has completed such a cycle and has returned to the position whereinaperture132 is closed,pneumatic circuit10 confirms whether further cutting will be necessary. Such confirmation is received fromfoot switch16 orremote push button18/panel push button18A, described further herein. In the illustrated embodiment, a short pause of approximately a half second prior to confirmation allows sufficient time for an operator to determine whether additional cutting will be necessary.

If additional cutting is not deemed to be required and themass142 is considered removed, the operator removescannula130 from the patient's body. If instead confirmation is made that additional cutting is required,pneumatic cylinder26 causescutter134 to again move to the retracted position, thereby opening theaperture132, and saline is directed through thehand wand4 and betweencannula130 andcutter134. Saline passing over the cuttingend140 ofcutter134 is suctioned into the central portion of thecannula130 with urging from the aforementioned applied vacuum pressure. Suctioning saline through the central portion ofcannula130 serves to flush the cut portion of the mass through the cannula toward awaste canister28, described further herein. Additionally, the saline serves as a lubricant between thecannula130 and thecutter134. In the illustrative embodiment,pneumatic motor138 is not actuated whilecutter134 is moved toward the retracted position, thereforecutter134 does not rotate relative tocannula130 during this retraction phase. Such operation is desirable so that tissue does not wrap aroundcutter134 ascutter134 retracts.

Pneumatic circuit

10 directs the continuous above-described cycling ofcutter134 as long asfoot switch16 orremote push button18 orpanel push button18A is depressed. Illustratively, ultrasound, magnetic resonance imaging (MRI), or other mass-locating methods known in the art may be used during the procedure in order to monitor the progress of the removal of themass142. It is advantageous thatBreast Biopsy System2, in one embodiment, can be used in conjunction with an MRI device because of the majority of its components being pneumatic and non-magnetic.

The components comprisingpneumatic circuit10, and their associated functions in the control ofhand wand4, are described below.FIGS. 4 and 5 show views of anair compressor11 having tie-downrails13 and springs15 attached thereto.Fittings17 are coupled to the top ofair compressor11 as shown inFIG. 5, andair compressor11 is illustratively mounted in the rear of theconsole6 as shown inFIG. 7.

Avacuum pump19 is shown inFIG. 6, the vacuum pump having a tie-down rail21 and springs23.FIG. 7 shows the relative placement ofvacuum pump19 andair compressor11 in the lower portion ofconsole6. Soundproofingmaterial37 is also placed in the proximity ofvacuum pump19 andair compressor11 in order to muffle the sound ofair compressor11 andvacuum pump19 during operation.

FIG. 8 is a view of aconsole mounting panel25

showing manifold subassemblies

27,29, anevaporation subassembly31, and aterminal block subassembly33 mounted on the mountingpanel25.FIGS. 9 and 10 show theconsole mounting panel25 mounted in theconsole6.Compressor11 andvacuum pump19 are not installed in the illustrativeFIGS. 9 and 10.

Console

6 is shown inFIG. 11 to havecompressor11 andvacuum pump19 mounted in theconsole6 while other components ofpneumatic circuit10 includingconsole mounting panel25 are mounted in the upper portion ofconsole6.Shelf35 is mounted to divideconsole mounting panel25 fromcompressor11 andvacuum pump19. As noted above, soundproofingmaterial37 is positioned to surroundcompressor11 andvacuum pump19.

FIG. 12A showswater evaporation subassembly31 prior to installation inpneumatic circuit10.Water evaporation subassembly31 includes afilter41,relief regulator43, and gas-permeable absorber45.Filter41 is configured to direct condensation toward gas-permeable absorber45, which in turn dissipates the condensation into the atmosphere. The schematic representation ofwater evaporation subassembly31 can be seen inFIG. 17.

FIG. 12B is analternative embodiment31′ of thewater evaporation subassembly31 ofFIG. 12A. Inalternative embodiment31′, conduits and fitting ofsubassembly31 are replaced with

manifolds

34,36.

Manifolds

34,36 act as conduits and as fitting receivers for components such asfilter41,relief regulator43, and gas-permeable absorber45.

FIGS. 13A and 13B show the assembly offoot switch16 prior to and after the attachment of tubing.FIG. 14 is a view of theterminal block subassembly33 prior to installation on theconsole mounting panel25, shown inFIG. 8. Theterminal block subassembly33 functions to distribute electrical power to thecompressor11,vacuum pump19, and dump valves.

Custom designed

manifolds

47,49 can be seen in perspective view in FIGS.15A-

B. Manifolds

47,49 are configured to route the pneumatic tubing (not shown in FIGS.15A-B, but viewable inFIG. 8) within the console. Schematics for

manifolds

47,49 can be seen in FIGS.20B and21A-D.

FIGS.16A-B illustrate the schematic of the illustrativepneumatic circuit10.Pneumatic circuit10 includes a first sequence loop12 (approximated as the elements within the broken lines) and a second sequence loop14 (outside the broken lines).First sequence loop12 is initiated with either afoot switch16, aremote pushbutton18, or apanel pushbutton18A.Foot switch16 is the illustrated embodiment in the drawings, however, any of theabove foot switch16, aremote pushbutton18, or apanel pushbutton18A, including combinations thereof, are within the scope of the disclosure.

Sensor20 (shown inFIG. 16B) senses pressurization and permits passage of pressurized gas through path22 whenfoot switch16,pushbutton18, orpushbutton18A is actuated, or any combination thereof. The pressurized gas shifts the vacuum valve48 (FIG. 16A), creating vacuum incollection canister28.Vacuum sensor30 passes a signal to thevacuum indicator150 when the vacuum level reaches 20″ Hg vacuum. Pressurized signals fromcomponents30,22 pass through the “and” gate50 (FIG. 16A) and latchrelay24, which in turnsignals cutter cylinder26 to retract to a non-extended position. Whencutter cylinder26 is retracted into the non-extended position, pressurized gas is delivered tomedical device70, illustratively to operatepneumatic motor138. However, it should be understood that pressurized gas may be utilized for any number of functions in a medical device, and is not restricted to the illustrative functions shown inhand wand4.

A saline supply152 (FIG. 16B) is also illustratively provided tomedical device70, thesaline supply152 fostering the flow of biological material removed by themedical device70 tocollection canister28. Pinchvalve72, which includes pneumatically actuated stopper88 (FIG. 16B), controls the flow ofsaline supply152 in a manner described further herein.

Collection canister

28 collects biological material from themedical device70 during the medical procedure using vacuum pressure. In addition to the biological material being collected, saline is collected in this manner. If the vacuum pressure fails, such failure is sensed byvacuum switch30, and the cycle stops. Otherwise, pressurized gas continues to be delivered for a period of time determined by timingcircuit148.

Timing circuit

148 incorporates a restricted orifice that fillsvolume chamber144 with gas and eventually signalsvalve146 to turn on the pressurized gas tomedical device70. Pressurized gas causescutter cylinder26 to advance at a rate controlled by timingcircuit38 until it reaches the extended position (also the position held during insertion of the cannula of the illustrative medical device, described above). Such pressurized gas continues to build up inmedical device70 untilpressure sensor52 senses a predetermined gas pressure incutter cylinder26 and illustratively trips at approximately 24 psi, indicating the end of the stroke. At such a point, signalingdevice54 causes a momentary audible signal, and also latchrelay24 resets, turning offdevice70. If signal22 is still present, therelay24 will not reset and the process will automatically repeat. If the process repeats the audible tone has a shorter duration than if it resets.

It is also possible thatcutter cylinder26 does not fully advance to the extended position beforepressure sensor52 trips. In such an instance,cutter cylinder26 may encounter difficulties cutting through themass142, and pressure will build up incutter cylinder26 even though the end of the stroke has not been reached. When the cylinder pressure reaches the predetermined amount of 24 psi,sensor52 trips, regardless of the position of cutter cylinder26 (and the attached cutter134).

Setup switch44 (FIG. 16B), which is controlled byknob154 on control panel9 (FIG. 1) allows an operator to load the saline tube into thepinch valve72 and primes the medical device by actuating, in parallel, the retraction ofcutter cylinder26, the opening ofsaline pinch valve72, and the opening ofvacuum valve48. During this setup mode, signals from22 are ignored, thereby inhibiting a cycle start condition. Aspiration switch40 (FIG. 16B), which is controlled byknob156 on control panel9 (FIG. 1) inhibits a cycle start condition and causescylinder26 to retract, if a signal delivered via path22 is present thevacuum valve48 shifts creating vacuum in the canister and the medical device.

Referring to FIGS.16A-B,pneumatic circuit10 operates in substantially the following fashion.Air compressor11 is turned on and creates air pressure and flow. The compression process creates heat and condenses the humidity in the air. At such a point, condensed water is in gaseous state. The hot moist air is then passed through a fan-driven air-to-air heat exchanger158 cooling the air and changing the water to a liquid state. The cooled air is then passed into a coalescingfilter41 where the water is captured in the filter media and drips into the bottom of the filter bowl. The filtered air then continues out to feed the control circuit.

The compressor runs continuously. If pressure is sensed by the relief regulator of greater than the set point of 70 psi, it will continuously vent the excess pressure. If the system is on and not in cycle, 99% of the compressor flow rate will vent out of the relief regulator. While the system is cycling the medical device, approximately 40% of the system capability will continuously flow through the relief regulator.

The water that is collected in the bottom of the filter bowl is dissipated withwater evaporation subassembly39. Water passes from thefilter41 through therelief regulator43 and into the base of thepermeable exhaust member45. Theexhaust member45 acts as a wick, drawing the fluid up the media. The flow rate through theexhaust member45 and the large “wick” surface area cause the liquid water to evaporate into a gas state. The flow rate through the enclosure caused by the heat exchanger fans removes the water vapor from the cabinet, thus eliminating the need to collect water and drain it from the system. Illustratively, a filter “muffler” is used as apermeable exhaust member45, the muffler being available from Allied Witan Company, of Cleveland, Ohio, as part number F02.

The pneumatic circuit components are mounted to

custom aluminum manifolds

47,49 minimizing the use of fittings and keeping the system compact. The components are “sub-base” style versions of the component allowing for ease of replacement. Each component that needs adjusted is bench tested and set to the specified level using certified fixtures. Diagrammatic representations of the manifolds can be seen in FIGS.21A-D.

Console

6 is designed to isolate the noise and heat created bycompressor11 andvacuum pump19. Design specifications forconsole6 can be seen in FIGS.19A-D. Shelf35 divides the cabinet into two sections. The lower section contains the spring-mounted

pumps

11,19, soundproofingmaterial37, and fans to isolate vibration, heat, and noise, as can be seen inFIG. 7.

As shown in various views in FIGS.22A-B,pinch valve72 includes a retainer comprised of acentral catch74 and opposing

catches

76,78. When pulled taut,silicone tubing80 assumes a substantially straight configuration and is disposed under cantileveredportion82 ofcentral catch74, and cantilevered

portions

84,86 of opposing

catches

76,78 respectively, as shown inFIG. 22A. Such a configuration secures thesilicone tubing80 and prevents accidental removal ofsilicone tubing80 frompinch valve72.

Pneumatically actuatedstopper88, shown diagrammatically inFIG. 22B, moves apiston90 between a stopped position (shown in broken lines) and a flow position. The default position is the stopped position, stopping the flow of fluid through thesilicone tubing80.

FIGS.25A-D show a pair of hose wrap pins that is used to wrap the foot switch tube set and the power cord when the system is not in use. FIGS.26A-B show a foot switch holder.FIG. 27 shows a valve bracket. And FIGS.28A-B show an embodiment of tie-down rails.

Thetest module92 for testing Airtrol electric pressure switch120 (as shown inFIGS. 11 and 16A), model number F-4200-60-MM, can be seen inFIGS. 29-33. Theswitch120 is placed ontest module92 and clamped in place, as seen inFIG. 29. Ared jumper94 is connected to the normally open (N.O.)terminal98 ofswitch120.Black jumper96 is connected toCOM terminal100. A plugged union fitting102 is connected to an end of naturalcolored tube104. With an air supply to testmodule92 turned on, 2-position detented button122 is pulled out and pressure observed. It is further observed when green indicator light106 turns on. If green indicator light106 does not turn on at 20 psi+/−0.5 psi, thenbutton122 should be pushed back in and adjustments made to switch120, and testing done again. After the proper target pressure is obtained, agreen dot sticker108 is placed over the adjustment screw. Pneumatic vacuum switch VP-701-30-MM is tested in a similar fashion, with a targeted setting of 20″ Hg vacuum.

Another test procedure fortest module92 is shown inFIGS. 30 and 31. In such a procedure, Airtrolpneumatic pressure switch120′ (model number PP-701-30-MM) is tested.Red tube109 is connected tooutput port110.Natural tube104 is connected to inputport112. With an air supply to testmodule92 turned on,button122 is pulled out and pressure at which largegreen light114 comes on is observed. If largegreen light114 does not turn on at 24 psi+/−0.5 psi, thenbutton122 should be pushed back in and adjustments made to switch120′, and testing done again. After the proper target pressure is obtained, agreen dot sticker108 is placed over the adjustment screw.

Yet anothertest module92′ for testing various regulators is shown inFIGS. 32 and 33. Thistest module92′ is illustratively used for the cutter cylinder regulator124 (model R4, R01-10 w/60 psi gauge), the air motor regulator126 (model R2, R01-12 w/60 psi gauge), and the main regulator128 (model R1, R01-12 w/160 psi gauge). The regulators are illustrated schematically in FIGS.16A-B, and on diagrammatic views of the manifolds in FIGS.20B and21A-B. During testing, the tested

regulator

124,126,128 should be set for the appropriate target pressure (60 psi, 60 psi, and 160 psi, respectively). Next, two O-rings116 (seen inFIG. 32) should be installed in the bottom of the tested regulator. The

regulator

124,126,128 is then placed on thetest module92′ aligning the locating pin and locating hole found on the test module and regulator.

Regulator

124,126,128 is then clamped in place.

Target pressures during testing of

regulators

124,126,128 varies depending on the regulator. Model R4 is targeted for 30 psi, rising. Model R2 is targeted for 40 psi, rising. Model R1 is targeted for 60 psi, rising. Once pressure is dialed in to the appropriate target, the regulator nut is tightened to prevent knob movement and a permanent marker is used to mark the cannula position of the regulator gauge. Finally, a green dot is placed in the center of the gauge face.

Illustrative parts used in the production of the above-described embodiment can be found in FIGS.34A-C. It should be understood, however, that other parts and constructions are within the scope of the disclosure.

While the disclosure is susceptible to various modifications and alternative forms, specific exemplary embodiments thereof have been shown by way of example in the drawings and have herein been described in detail. It should be understood, however, that there is no intent to limit the disclosure to the particular forms disclosed, but on the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the disclosure as defined by the appended claims.

A plurality of advantages arises from the various features of the present disclosure. It will be noted that alternative embodiments of various components of the disclosure may not include all of the features described yet still benefit from at least some of the advantages of such features. Those of ordinary skill in the art may readily devise their own implementations of a pneumatic circuit that incorporate one or more of the features of the present disclosure and fall within the spirit and scope of the disclosure.

Claims

1. A medical device comprising:

a biopsy device comprising

a cannula with an orifice, the cannula being configured for insertion into a body to a point such that the orifice is adjacent to a tissue mass to be biopsied,

a cutter housed within the cannula and configured to move relative to the orifice to selectively cut tissue from the mass, and

a pneumatic cylinder coupled to the cutter for moving the cutter relative to the orifice; and

a pneumatic circuit coupled to the biopsy device for controlling the pneumatic cylinder, the pneumatic circuit comprising a sensor configured to sense back pressure in the pneumatic cylinder.

2. The medical device ofclaim 1, wherein the cannula defines an axis and the cutter is aligned coaxially with the cannula.

3. The medical device ofclaim 2, wherein the cutter rotates about the axis.

4. The medical device ofclaim 2, further comprising a pneumatic motor controlled by the pneumatic circuit, the pneumatic motor actuating rotational movement of the cutter.

5. The medical device ofclaim 2, wherein the pneumatic circuit selectively causes the cutter to rotate relative to the cannula as the cutter approaches and closes the orifice and the pneumatic circuit further selectively causes the cutter to retract to a retracted position without rotating.

6. The medical device ofclaim 5, wherein the pneumatic circuit provides a signal to the operator when the cutter has completed one cycle of moving between the closed-orifice position and the retracted position and back.

7. The medical device ofclaim 2, wherein the pneumatic cylinder causes the cutter to move axially relative to the cannula.

8. The medical device ofclaim 1, wherein the pneumatic circuit directs the retraction of the cutter relative to the orifice when a predetermined back pressure is sensed in the pneumatic cylinder.

9. The medical device ofclaim 7, wherein the predetermined back pressure is approximately 24 pounds per square inch.

10. The medical device ofclaim 1, further comprising a pneumatic switch configured to permit an operator to selectively operate the cutter by actuating the pneumatic switch.

11. The medical device ofclaim 1, wherein the biopsy device is substantially free of magnetically sensitive objects such that it can be operated in conjunction with a Magnetic Resonance Imaging device.

12. The medical device ofclaim 1, further comprising a saline supply coupled to the biopsy device, the saline supply dispensing saline in a manner controlled by the pneumatic circuit.

13. The medical device ofclaim 12, wherein the saline is directed between the cutter and the cannula.

14. The medical device ofclaim 12, further comprising a vacuum coupled to the biopsy device for creating a suction and drawing the saline through the cannula.

15. A medical device comprising:

a cutter configured to selectively cut tissue from a body;

a pneumatic cylinder coupled to the cutter for moving the cutter relative to the body; and

a pneumatic circuit coupled to the pneumatic cylinder for controlling the pneumatic cylinder, the pneumatic circuit sensing the back pressure in the pneumatic cylinder and responsively controlling the pneumatic cylinder.

16. The medical device ofclaim 15, further comprising a pneumatic motor, wherein the cutter defines an axis and the pneumatic motor causes the cutter to rotate about its axis as the cutter is cutting tissue from the body.

17. The medical device ofclaim 15, wherein the pneumatic circuit provides a signal to the operator when the cutter has completed one cycle of cutting tissue from the body.

18. The medical device ofclaim 15, wherein the pneumatic circuit directs the retraction of the cutter relative to the body when a predetermined back pressure is sensed in the pneumatic cylinder.

19. The medical device ofclaim 18, wherein the predetermined back pressure is approximately 24 pounds per square inch.

20. The medical device ofclaim 15, further comprising a pneumatic switch coupled to the cutter for selectively operating the cutter.

21. The medical device ofclaim 20, wherein the pneumatic switch is foot pedal operated.

22. The medical device ofclaim 20, wherein the pneumatic circuit uses the pneumatic switch as an indication of whether to initiate another cutting cycle.

23. The medical device ofclaim 15, further comprising a saline supply for dispensing saline in a manner controlled by the pneumatic circuit.

24. The medical device ofclaim 23, wherein the saline is directed to flow around the cutter, providing lubrication to the cutter and providing a flush for tissue cut from the body by the cutter.

25. The medical device ofclaim 15, further comprising a vacuum coupled to the biopsy device, the vacuum being controlled by the pneumatic circuit.

26. The medical device ofclaim 25, wherein the vacuum is used to facilitate the removal of tissue after the tissue has been cut from the body.

27. The medical device ofclaim 15, wherein the tissue is breast tissue.

28. A method of removing a tissue mass from a body, the method comprising the steps of:

inserting a hollow cannula having an aperture into the body such that the aperture is positioned adjacent to the tissue mass, the hollow cannula housing a cutter therein;

providing suction to the cannula such that a portion of the tissue mass is pulled inside the cannula through the aperture;

pneumatically moving the cutter relative to the aperture so that the cutter cuts the portion of tissue mass from the remainder of the tissue mass; and

transporting the cut portion of tissue mass through the cannula with the provided suction, wherein the pneumatic movement of the cutter is controlled by a pneumatic circuit comprising a pressure sensor.

29. The method ofclaim 28, wherein the step of moving the cutter across the aperture is repeated such that additional portions of the tissue mass are removed.

30. The method ofclaim 28, wherein the cutter is rotating as it cuts the portion of tissue mass.

31. The method ofclaim 30, wherein the rotation of the cutter is pneumatically actuated by a pneumatic motor.

32. The method ofclaim 28, wherein the movement of the cutter is pneumatically actuated by a pneumatic cylinder.

33. The method ofclaim 28, wherein the pneumatic circuit controls the provision of suction and controls the movement of the cutter.

34. A biopsy device comprising

a cannula with an orifice, the cannula being configured for insertion into a body to a point such that the orifice is adjacent to a tissue mass to be biopsied;

a cutter housed within the cannula and configured to move relative to the orifice to selectively cut tissue from the mass;

a pneumatic cylinder coupled to the cutter for moving the cutter relative to the orifice, the pneumatic cylinder being controlled by a controller responsive to back pressure in the cylinder; and

a pneumatic motor coupled to the cutter for rotating the cutter relative to the orifice.

35. The biopsy device ofclaim 34, wherein the pneumatic motor comprises six pneumatic vanes.

36. The biopsy device ofclaim 34, wherein the controller is a pneumatic circuit.

37. The biopsy device ofclaim 34, wherein the controller responds to a back pressure of approximately 24 pounds per square inch.

38. The biopsy device ofclaim 34, wherein the controller directs the cutter to retract relative to the cannula when a predetermined back pressure is sensed in the pneumatic cylinder.

39. The biopsy device ofclaim 38, wherein the predetermined back pressure is approximately 24 pounds per square inch.